P067	DIAGNOSIS OF STENOSES OF THE PROXIMAL VERTEBRAL ARTERY USING 2-D- AND 3-D-COLOR-CODED-DUPLEXSONOGRAPHY Lammers G1 , Poerwowidjojo S1 , Mull M2 , Klötzsch C1 , Depts. of Neurology1 and Neuroradiology2 ; RWTH Aachen, Germany Background: Vessel tortuosity of the proximal vertebral artery is the main reason for insufficient visualization of stenoses using 2D-color coded duplexsonography. In addition the differentiation between a stenosis and a compensatory elevated flow in the vertebral artery caused by a severe stenosis in the carotid circulation may be difficult. The aim of the present study was to determine the clinical value of 3D- duplexsonography of the proximal vertebral artery relative to 2D- duplexsonography in patients with normal vessel findings and in patients with vertebral artery stenoses. Methods: We included 25 patients with normal color-coded 2D-sonography findings of the proximal vertebral artery (Group A; mean age 35 years; range: 19 to 47 years) and 13 patients with proximal vertebral artery stenosis (Group B; mean age: 67 years; range: 58 to 74 years). All patients underwent additional 3D-sonography of the proximal vertebral artery and the subclavian artery. The degree of stenosis using 2D-sonography was determined according to hemodynamic criteria while for 3D-sonography it was calculated using the intra-stenotic diameter in relation to the post-stenotic diameter (NASCET criteria). Five patients of group A underwent additional digital subtraction angiography (DSA). Results: Sufficient visualization of the proximal 1-2 cm of the vertebral artery at the origin from the subclavian artery were possible in 15 patients of group A using 2D-sonography (60%) and in 21 patients using 3D-sonography (84%). 2D-sonography enabled a visualization of the suspected pathological area in 7 patients of group B (54%) while 3D-sonography lead to a suitable demonstration of the stenosis in 11 cases (85%). In one of the five patients DSA failed to demonstrate a low grade stenosis which was detected with 2D- and 3D-duplexsonography. Conclusions: 3D-sonography can be used as an additional tool for the detection of proximal vertebral artery stenosis. In comparison to conventional 2D-sonography it is easier to differentiate between extracranial stenosis, vessel tortuosity and compensatory elevated flow of the vertebral artery.
P068	CAROTID AND FEMORAL INTIMA-MEDIA THICKNESS IN ADULT PATIENTS SUCCESSFULLY OPERATED FOR AORTIC COARCTATION Eric de Groot, Joris Vriend, John Kastelein, Barbara Mulder. Departments of Cardiology and Vascular Medicine, AMC, Amsterdam, Netherlands Background Despite succesful aortic coarctation surgery, cardiovascular mortality and morbidity, notably premature coronary artery disease and cerebrovascular accidents, are greatly increased in middle aged adult post-coarctectomy patients. This may be due to increased blood pressure in pre-coarctatial arterial conduits. Methods B-mode ultrasound imaging can describe status and changes in intima-media complex thickness (IMCT) of carotid and femoral arterial walls. IMTC was investigated in 26 normotensive (SBP≤140mmHg) adult post-coarctectomy patients (31.7(SD9.1)yrs) and age and sex matched controls (33.9(9.9)yrs). Per subject IMTC was defined as average of three right and three left carotid, and two left and two right femoral arterial wall segments. In comparisons of carotid and femoral IMTC per subject averages of arterial conduits were used. Unpaired t-tests were used. Results Post-coarctectomy patient IMTC was increased (0.65(0.17) vs 0.59(0.11)mm: D IMT= 0.06mm, p=0.002). Carotid IMTC was increased increased in patients (0.70(0.10) vs. 0.60(0.09)mm: D IMT=0.14mm, p<0.0001). Femoral IMTC’s were similar: (0.56(0.10)mm vs. 0.57(0.07)mm: D IMT=0.01mm, p=0.64). Conclusions Normotensive post-coarctectomy patients presented with increased carotid IMTC where femoral IMTC is similar to controls. Vascular arterial wall change in post-coarctectomy patients is more appearent in the vascular bed proximal to the former aortic coarctation. This finding reflects increased risk for cardiovascular and cerebro-vascular events in patients. Moreover, the results illustrate the need to investigate multiple vascular beds according to a standardized protocol in order to describe mechanism of disease and improve disease prevention in those at vascular risk.
P069	IN-VIVO DUPLEX ULTRASOUND OF CAROTID STENOSIS COMPARED WITH PLANIMETRIC MEASUREMENTS OF THE CORRESPONDING POSTMORTEM SPECIMENS G. Schulte-Altedorneburg, D.W. Droste, S. Felszeghy, L. Csiba, V. Popa, L. Módis, E.B. Ringelstein Departments of Neurology and Anatomy, University of Debrecen, Hungary Department of Neurology, University of Münster, Germany Background: The correct detection and quantification of carotid artery disease is of decisive impact for the patient´s prognosis and his adequate treatment. In this study, we evaluated the ability of ultrasonography to detect and to grade carotid artery stenosis by means of a comparison of the in-vivo ultrasound findings with the planimetric analysis of the corresponding postmortem specimens. Methods: Shortly before their death, fifty-nine critically ill neurological patients (mean age 70 years) were prospectively examined by extra- and intracranial Doppler sonography, as well as colour-coded duplex ultrasound. Carotid stenosis was classified by haemodynamical and morphological ultrasound criteria. Carotid specimens were removed in toto during autopsy. Under standardised conditions, specimens were redistended, sectioned and histologically processed. Computerised planimetric measurements of the arteries were carried out and were compared with the ultrasound findings. Results: Correlation of the ultrasound and postmortem planimetric findings was available in 93 carotid bifurcations. By means of both techniques 46 carotid arteries were found to be normal. Stenoocclusive carotid lesions ranged from 8.5 % to 100% lumen reduction. The overall r was 0.96, and adjusted R^2 was 0.90, respectively. For the stenoocclusive carotid lesions, the r value was 0.91. Conclusion: Extra- and intracranial Doppler and colour-coded duplex ultrasound permit a reliable detection and quantification of carotid artery stenoses and occlusions even under difficult examination conditions in critically ill patients.
P070	COLOUR DUPLEX SCANNING IN INVESTIGATION OF CHILDREN WITH PATHOLOGICAL KINKING OF INTERNAL CAROTID ARTERIES J.V. Smirnova, K.V. Smirnov, M.V. Sidor Altai Diagnostic Center, Barnaul, Russia Background: Previous work shows that the kinking of internal carotid arteries (ICA) in adults is a common pathology. But the prevalence of this anomaly in children is unknown. The purpose of study was to investigate the prevalence and influence of pathology kinking (PK) of ICA upon brain circulation in children by using Color Duplex Scanning (CDS). Methods: 2520 children aged from 1 month to 15 years old were investigated. All examined children were divided into four groups: 36 children aged from 1month to 12 months (5,5± 1,2); 32 children aged from 1 to 3 years old (1,9± 0,7); 102 - aged from 3 to 7 years old (5,8± 1,2) and 508 - aged from 7 to 15 years old (10,5± 1,9). CDS of neck vessles were performed by using ultrasound scaner "Spectra Masters" (Diasonics, USA). Results: It was established that the prevalence of PK of ICA was the same in all groups. PK of ICA was found out in 26,9 % of children. This anomaly occured more frequently in the boys (69 %). PK of ICA more often had the S-shape. The loop was found out in 7,7 % of children. The C-shape of PK of ICA did not meet. It has been established that PK of ICA in children was characterized by a marked turbulence of blood flow at the sites of curves. Belateral PK of ICA was marked at 51 % of the patients. Unilateral PK of ICA was scanned more often on the right side (60% of cases). In 58 % of cases unilateral PK of ICA was combined with hemodinamical nonsignify elongation of opposite ICA. At half of patients the PK of ICA was combined with a different anomaly of vertebral arteries (VA) such as: elongation and kinking of V2 and V1, asymmetry of diameters and blood velocities of VA, high entrance of VA in bone channel and hypoplasia of VA. In children with PK of ICA the symptoms of chronic cerebrovascular insufficiency were dominated. In 19,5 % of cases the epilepsies syndroms were established. The transitor ishemic attack were reveled in 4,4 %. 72 children with PK of ICA were examined several times during 6 years. It is necessary to note that the shape of kinking and hemodinamical desorders did not change with age. Conclusion: Thus, the PK of ICA is a common pathology in children. The PK of ICA may be cause of brain circulation disorders and epilepcy in children. The shape and hemodinamical infringements in children with PK of ICA have no any positive dynamic changes with age. The results received by using CDS of neck vessels in children testify that this anomaly has inherent character.
P071	A parental history of early stroke is independently and specifically associated with early carotid bulb arteriosclerosis Sitzer M, Jerrard-Dunne P*, Steckel DA, Buehler A, von Kegler S, Markus HS*. Dept. Neurology, J.W. Goethe-University Frankfurt/Main, Germany; *Div. Clin. Neurosciences, St. Georges Hospital. Medical. School, London, UK Background: Carotid artery intima-media-thickness (IMT) is an intermediate-phenotype for studies of candidate stroke genes. However, genes may predispose either to stroke risk itself, or merely to conventional risk-factors. We hypothesised that a measure of "unexplained" IMT might be a useful way of identifying individuals with a specific genetic predisposition to carotid atherosclerosis, independent of conventional risk factors. Methods: Using IMT measurements and regression modelling we determined the proportion of IMT that remains unexplained after controlling for vascular risk-factors ("IMT residuals"). In a middle-aged community population (n=5460), we determined whether parental history of stroke is associated more strongly with this measure of unexplained atherosclerosis than with unadjusted IMT values and whether these associations differed at specific sites in the carotid arterial tree. Results: A parental history of stroke £ 60 years was strongly associated with increased carotid BULB IMT residuals- odds-ratio (OR) for BULB IMT residuals in the upper quartile 2.14(1.59-2.89), p<0.001. The association with common carotid artery (CCA) IMT residuals was much weaker - OR 1.21(0.87-1.70), p=0.262. In contrast there was no relationship between a parental history of young myocardial infarction and BULB IMT residuals, but a highly significant association with CCA IMT residuals- OR 2.18(1.75-2.71) p<0.001. All associations were much weakened when unadjusted IMT values were used. Conclusions: Internal carotid BULB IMT is more strongly associated with familial stroke risk than CCA IMT. Future candidate gene studies may be more successful if they determine associations with carotid BULB IMT, as opposed to CCA IMT. Our measure of "unexplained" IMT identifies individuals with a particularly strong genetic component, which is independent of conventional risk-factors.
P072	Internal Carotid Artery Angle of Origin – A Novel Risk Factor for Early Carotid Atherosclerosis Sitzer M, Puac D, Buehler A, Steckel DA, von Kegler S, Markus HS*. Dept. Neurology, J.W. Goethe-University Frankfurt/Main, Germany; *Div. Clin. Neurosciences, St. Georges Hospital. Medical. School, London, UK Background: Established ‘systemic‘ vascular risk factors do not fully explain the occurrence of atherosclerosis at the carotid bifurcation. Local anatomical and hemodynamic factors may also influence the initiation of the atherosclerotic process. We determined whether the angle of internal carotid artery (ICA) origin is a risk factor for early atherosclerosis. Methods: In 1300 normal population individuals aged 40-70 years, we measured both carotid intimal-media thickness (IMT) at three arterial sites (common carotid artery, CCA; bifurcation, BIF; internal carotid bulb, BULB), and the presence of any atherosclerotic plaque within the BULB on both sides by means of high-resolution ultrasound. A standardised transverse insonation was used to determine the angle of ICA origin, expressed as the angle of rotation relative to the external carotid artery. Results: This angle was positively associated with BULB-IMT but not with IMT at other sites. After controlling for age, gender and other cardiovascular risk factors each 15° increase in the ICA angle of origin conferred an odds ratio (OR) for having an IMT in the highest quartile of 1.25 (95% CI, 1.12-1.40) on the left and 1.22 (1.11-1.35) on the right, both p<0.001. A similar relationship was found for plaque. On multivariate analysis these odds ratios were 1.38 (1.10-1.72) on the left and 1.33 (1.10-1.60) on the right side, both p<0.025. Conclusion: This study provides the first evidence that the angle of ICA origin is an independent risk factor for early atherosclerotic changes at the ICA bulb.
P073	Evaluation of a Screening Protocol for Carotid IMT using a hand-held Ultrasonography Instrument U. Schminke, R. Tang, J.H. Burkart, M.G. Bond Wake Forest University School of Medicine, Winston-Salem, USA and Ernst Moritz Arndt University Greifswald, Germany Background: Although it has been proposed to include carotid artery IMT ultrasound measurement as a part of screening procedures for cardiovascular risk assessment, this method is still regarded as a research tool because of high instrument costs, and complex scanning and reading protocols that are performed exclusively in specialized ultrasound reading centers. However, IMT measurements would become more feasible if simple screening methods were available to measure carotid IMT during clinical practice. Methods: Three different IMT measurement protocols were applied to 41 patients with end-stage renal disease receiving hemodialysis treatment. (1) Standard scanning and reading protocols using a duplex sonography instrument (AU 5, Biosound Esaote, Italy); (2) the same standard protocol using a hand-held, lightweight (2.4 kg) ultrasonography device (SonoSite 180, Bothel, WA, USA); and (3) an abbreviated screening protocol, in which IMT measurements were performed by the sonographer on frozen digital images during the exam. For each exam, the average time cost was approximately 60 minutes using the standardized research protocol and 10 minutes using the screening protocol, respectively. Results: The average absolute difference of the mean carotid IMT (MMax) using standard research protocols and comparing the two instruments was 0.1 mm (correlation: r = 0.84). Comparing the research with the screening protocol, the absolute MMax IMT differences were 0.3 mm, regardless of combination of instruments used (correlation r = 0.47 and 0.56, respectively). Conclusions: The present study demonstrates the feasibility of using a screening protocol for assessment of carotid IMT, even if applied in a worst case scenario involving patients with advanced atherosclerosis. Using a portable hand-held instrument that can be hand carried allows carotid IMT screening independently of expensive stationary laboratories.
P074	THROMBUS IN THE INTERNAL CAROTID ARTERY COMPLICATING AN « UNSTABLE » ATHEROMATOUS PLAQUE F. Perren, L. Urbano, A. Rossetti, L. Von Segesser, P.-A. Despland, J. Bogousslavsky, G. Devuyst, CHUV, University of Lausanne, Switzerland Background: To report and illustrate with 4 dynamic B-mode high-resolution and Duplex imaging cineloops, the importance of arterial wall imaging in acute cerebrovascular disease. Method/Results: A 64-year-old healthy man, under treatment of pravastatin was admitted to our stroke unit following brief clumsiness of the left hand associated to ipsilateral numbness one week before. Neurological examination disclosed a left-sided sensory deficit. MRI of the brain revealed a subacute infarction of the right fronto-parietal region suggesting a "borderzone infarct". Extracranial ultrasound examination showed a non-stenotic, heterogenous plaque with an interrupted "fibrous cap" (FC) situated at the origin of the right internal carotid artery (ICA). The patient treated under anticoagulants could be rapidly discharged; unfortunately he had to be readmitted 10 days later after recurrence of left sensitive symptoms. An extracranial ultrasound was again performed and revealed the presence of an isoechoic pulsating mass attached to the plaque previously seen in the right ICA. This finding strongly evoked a floating thrombus, which was confirmed by MRA. The patient underwent emergency ICA thrombendarterectomy which allowed to remove the suboccluding fresh thrombus from the above mentioned plaque. Conclusions: This case illustrates well the new concept of unstable atherosclerotic plaques described by the cardiologists and probably applicable to the ICA. We consider that at least some ischemic stroke could be the consequence of the rupture of a lipid-laden coronary plaque covered by a thin FC from a carotid atheromatous plaque. We want here to highlight the importance of ultrasound as a useful diagnostic tool to explore the emergence of a fresh thrombus on an "unstable plaque".
P075	ULTRASONIC ASPECTS OF COMMON CAROTID ARTERY THROMBUS. J.M. de BRAY ^1, G. DEVUYST ^2, J BOULLIAT, J.O. FORTRAT ^3, F. DUBAS ^1, A. ROSSETTI ^2, J. BOGOUSSLAVSKY ^2. 1 – Département de Neurologie-Larrey – CHU - 49033 ANGERS cedex 01 2 – Département de Neurologie – CHU Vaudois – LAUSANNE 3 – Laboratoire d’Explorations Fonctionnelles Vasculaires – CHU – 49033 ANGERS cedex 01 Carotid artery thrombi are uncommon (Buchan , Caplan, Akins, Devuyst) but they cause strokes and could be misdiagnosed by ultrasonic methods .Our aim is to analyse the color Doppler flow imaging finding, in 6 cases of ³ 70 % common carotid thrombus without identifiable carotid disease by this investigation . POPULATION. 3 females and 3 males, mean age 53 ± 11 years, have been admitted for a stroke in 5 cases and for transient ischemic attacks in 1 case. All were studied by Duplex scanning then by intra arterial angiography or MR angiography. RESULTS. The thrombus was always hypoechoic with a regular linear surface. It was located 1 to 2 cm before the carotid bifurcation and respected the intima media layer. This fact allowed to exclude a dissection and did not seem in favor of an atheroma disease. This lesion could be a soft thrombus since it was compressible by the probe and gave no increase of blood flow velocities within the residual lumen. This aspect was assessed by angiography and by pathological studies in 3 cases, all the patients were treated by intravenous Heparin. Two thrombi were resolutive, 4 were operated, followed by a stroke in 1 case. The main causes of this series were an atheroma, a presumed paroxystic arythmia. an essential thrombocythemia and a Sneddon Syndrom DISCUSSION. These thrombi seem exceptional but have characteristic ultrasonic aspects. They could be misidentified if the Duplex scanning examination was late or incomplete on this site. An hypercoagulable status with local turbulences could favor this soft thrombus, but a minimal atheroma ulceration unrecognized by ultrasound was present in 3 cases .
P076	ACCELERATION OF THROMBOLYSIS IN ACUTE STROKE PATIENTS BY TCCS MONITORING – CASE REPORTS D.Skoloudik, M.Bar, P.Hradile, M.Häringova Faculty Hospital Ostrava-Poruba Some in vitro and in vivo experiments indicate that ultrasound can accelerate thrombolysis. We started to use TCCS monitoring in acute stroke patients. We report results of our first four patients. Methods: In January and February 2002 we admitted to Dept. of Neurology four patients with acute stroke in MCA territory and with TCCS finging of MCA occlusion (main stem or branches occlusion). We performed 60-minutes TCCS monitoring with maximum energy. It started 60-150 minutes after stroke onset (median 118 minutes). One patient was treated with IV rtPA. Results: Mean NIHSS score at admission was 13.8 (8-18), at 1 hour after start of TCCS monitoring NIHSS score was 3.8 (0-6) and at 24 hour it was 1.8 (0-4). In all cases we detected recanalization of occluded artery between 18 and 27 minutes after beginning (mean 24 minutes). In 3 patients was detected complete recanalization within 1 hour, in the last patient it was at 24 hours. Mean Rankin score at day 7 was 1 (0-2). Discussion: Acceleration of thrombolysis by ultrasound could be a perspective method of acute stroke treatment. It could improve outcome of patients treated by rtPA (Alexandrov 2000) and without thrombolytic treatment too (Cintas 2002). Conclusion: TCCS monitoring could improve outcome of acute stroke patients but it must be properly investigatedfurther.
P077	Cag-A positive Helicobacter pylori strains and IMT in different stroke subtypes: a possible role in progression of atherosclerotic process. M. Diomedi, B. Rizzato, L.M. Cupini, A. Pietroiusti*, F. Ferrante, M. Silvestrini** Neurological Clinic and * Medical Semiology and Methodology, University of Rome Tor Vergata;**Neurological Clinic, University of Ancona: Italy Background: Several studies have discussed about the possibility of an involvement of chronic bacterial infections in atherosclerotic process and in predisposing to an increased risk of cardiovascular and cerebrovascular diseases. The aim of this study was to evaluate the possibility of a relationship between virulent H. pylori (HP) strains infection, the evolution of atherosclerotic process and the occurrence of different stroke subtypes. Method: 145 consecutive patients with acute first ever ischemic stroke were included in the study. According to TOAST criteria on the basis of neurological manifestations, neuroimaging and clinical history, ischemic events were classified in 1) large artery stroke (55); 2) lacunar stroke (42); 3) cardio-embolic stroke (48). 143 controls were recruited among the relatives of patients and were matched for age and sex. Serum titres of IgG antibodies against H. pylori, seropositivity and IgG antibodies to cytotoxin-associated gene-A (CagA) protein, a strong virulence factor, were determined by enzyme linked immunoadsorbent assays. In stroke patients, inflammatory markers (C-reactive protein, withe blood cell count, SER, fibrinogen, a 1 antitrypsin, a 1 acid glycoprotein) were also evaluated. All subjects performed a complete ultrasonographic study of extracranial vessels to evaluate plaque status and intima-media thickness (IMT) on the common carotid arteries, along » 1.5 cm proximal to the flow divider. Results: The titre of HP antibodies, CagA seroprevalence, and mean IMT were significantly higer in patients than in controls. Among stroke subgroups, the seroprevalence of CagA positive strains was significantly higher in large artery stroke in comparison to lacunar stroke and cardio-embolic stroke, whereas IMT was significantly higher in patients with large artery stroke in comparison to patients with lacunar stroke. Differently from the other stroke subtypes, in lacunar patients there was a significative correlation between IMT and serum titre of antibodies to HP. Plaque status was not correlated with HP infection or with the presence of Cag-A positive strains. Conclusions: The evolution of the atherosclerotic process, as showed by a thickening of vessel wall, seems to be influenced by a significantly higher immune response towards a chronic infection and by the presence of virulent H. pylori strains. An increased IMT in lacunar stroke might help to identify a subgroup of patients at risk for the subsequent development of large artery stroke.
P078	CAROTID INTIMA-MEDIA THICKNESS IN HEALTHY KOREANS: IS IT ALSO USEFUL IN CEREBROVASCULAR RISK ASSESSMENT IN INTRACRANIAL DISEASE PRONE POPULATION? Kim YJ^1, Park KD^1, Choi KG^1, Han SR^2, Kho SB^2, Cho HG^1, Heo GB^3 EWHA Womans Univeristy^1, Catholic University of Korea^2, Yonsei University^3, SEOUL, KOREA Background: Carotid intima-media thickness (IMT) measurements are being applied widely as a measure of atherosclerosis. There is a growing belief that changes in carotid IMT is associated with atherosclerosis elsewhere in the arterial system. However, evidence of an association between carotid IMT and intracranial atherostenosis is sparse. Data on IMT has been available mostly from studies of whites. Unlike whites, atherostenosis arising within the intracranial arteries, especially of medium-sized branches, is common in Asian people. We investigated the hypothesis that extracranial carotid IMT is also useful in stroke risk assessment in Korean individuals, whose major stroke subtype is intracranial atherosclerosis. Methods: Noninvasive measurements of the IMT of the common carotid artery were made with high-resolution B-mode ultrasonography in 1,230 healthy subjects, living in the district of Hwagock in Seoul, Korea. Detailed information about number of parameters, including classical risk factors of stroke, was gathered. Results: IMT was significantly correlated with age and systolic blood pressure (p<0.05). However history of smoking and fasting sugar were correlated weakly with IMT without stastical significance. Alcohol intake was not related to IMT. Though it made a room for further analysis, this preliminary data showed that carotid IMT might be an useful tool in stroke risk assessment also in intracranial disease-prone group.
P079	THE OXFORDSHIRE COMMUNITY STROKE PROJECT CLASSIFICATION PREDICTS FOR SYMPTOMATIC OCCLUSIVE EXTRACRANIAL CAROTID DISEASE RU Esagunde, CLHP Chen, HM Chang Singapore General Hospital, Singapore Background: The Oxfordshire Community Stroke Project (OCSP) classification may be useful in predicting stroke aetiologies, such as symptomatic severe extracranial carotid disease (SSECD), and hence may have a role in selecting appropriate investigations. Methods: Patients were identified from the Singapore General Hospital Brain Centre Stroke Database which prospectively classified patients using the OCSP criteria and documented the presence or absence of SSECD ( 70-100%) by Doppler and duplex studies. Results: Over a 2-year period from January 1999 to December 2001 , 2585 stroke patients were admitted. 111 with intracerebral hemorrhage, 735 without Doppler studies and 197 POCI were excluded. 1542 patients were included in the analysis. 56% were male and the mean age was 65.3 years. 81.6% were Chinese, 10.1% Malays, 5.9% Indians and 2.4% other races. OCSP classification was 5.6% TACI, 15.7% PACI, 66.1% LACI and 12.6% TIA . SSECD was found in 6.7% of patients. Univariate analysis showed that SSECD was more common in male patients (p<0.01), and in patients with TACI (16.2 %), PACI (11.9 %) or TIA (10.2 %) compared to LACI (3.9 %). Patients with SSECD were also significantly older. Logistic regression analysis showed that age, gender and OCSP classification independently predicted for SSECD. Conclusions: SSECD is more common in patients with TACI, PACI and TIA. It is also present in a small percentage of LACI strokes. As carotid endarterectomy is beneficial in non-disabling strokes, our results suggest that all TIA and PACI strokes should be screened. The cost benefit of screening LACI is yet to be determined.
P080	b -Fibrinogen Gene Polymorphism (-455G/A) Is Mediated Inflammation Degree and Is Associated With Asymptomatic Carotid Artery Atherosclerosis E Ben-Assayag¹, I Bova², D Zeltser³, S Berliner³,T Nissel², S Lorenz M Levkovski², I Shapira³, N Bornstein² ¹Dpt. of Human Genetics and Molecular Medicine, Sackler Faculty of Medicine, Tel-Aviv Universisty, Dpt. of ²Neurology and ³Internal "D", Tel-Aviv Sourasky Medical Center, Israel Background: The -455G/A polymorphism at the promoter region of the b -fibrinogen gene has been related to plasma fibrinogen concentration and to the severity of coronary artery disease, the progression of atheroma, thrombosis risk and was associated with stroke in Japanese. Since fibrinogen is an acute-phase protein, an increased plasma fibrinogen level may reflect the inflammatory state of the vascular wall. Inflammatory processes may facilitate the transition of clinically stable to unstable atherosclerotic plaques. Methods: We investigated the relation of this polymorphism with carotid atherosclerosis and inflammation in 162 neurologically asymptomatic individuals. Atherosclerosis was quantified as intima-media thickness (IMT) measured in the common carotid artery and degree of stenosis measured in the internal and external carotid arteries by high-resolution ultrasonography. Inflammation examined using common inflammatory markers and erythrocyte aggregation test by a simple slide technique and image analysis. Results: The b -fibrinogen -455G/A polymorphism was significantly associated with elevated inflammatory degree and atherosclerosis: elevated plasma fibrinogen level (p=0.033), high-sensitive CRP (p=0.011), WBC (p=0.004), erythrocyte sedimentation rate (ESR), plasma interleukin-6 and increased degree of stenosis in the right carotid artery and slightly increase in mean IMT in the right common carotid artery. Individuals homozygous for the A allele had very high correlation between plasma fibrinogen and ESR (r=0.91, p=0.001) versus individuals homozygous to the G allele (r=0.62, p=0.000). The homozygous AA individuals presented also very high correlation between their other inflammatory markers, erythrocyte aggregation and with their IMT. Conclusions: These data suggest that the A^-455 allele of the b -fibrinogen promoter is associated with elevated inflammation and increased susceptibility for atherosclerosis in the carotid artery. The data suggest that their fibrinogen is more adhesive, and therefore they have such high correlation between their fibrinogen and ESR. Due to their baseline inflammatory degree, individuals homozygous for the fibrinogen –455A allele may be at particular risk for thrombotic event following an acute phase stimulus. Once identified, they may benefit from risk factor reduction and early therapy with statins or anti-inflammatory agents.
P081	DIFFERENCES IN CEREBRAL HAEMODYNAMICS IN FEMALES WITH MIGRAINE. TCD STUDY. Lutfiyya Khalilova MD., Yunus Efendiev MD. Institute of Physiology, Academy of Science, Baku, Azerbaijan Background: In the study we have evaluated cerebrovascular reactivity to hypercapnia that occurs in women suffering from migraine, before and after menopause. Methods: 23 premenopausal (mean ± SD age 34 ± 7) and 21 postmenopausal (48 ± 6) females were studied during headache-free periods as well as during migraine attacks. Cerebral reactivity was evaluated with the breath holding index (BHI). Bilateral TCD measurements of mean flow velocity (MFV) in the MCA and ACA before and after breath holding have been used to evaluate possible side asymmetries. The same measurements were recorded in two control groups of women of the same age, who had no symptoms of classic migraine. The examination was performed with "Angiodin" TCD unit (BIOSS, Russia). Results: In the younger group of women with migraine, BHI was much lower (0.78 ± 0.4) than in the older group (1.49 ± 0.4). These results are comparable with those of the premenopausal (0.70 ± 0.5) and postmenopausal (1.63 ± 0.7) control groups. BHI values during the period of migraine attack was reduced in 70% of the migraine patients and was similar both in the headaches presenting and headaches free head sides in all arteries During the headache-free period, there was no detectable BHI differences between the all groups. Marked MCA MFV asymmetry was found in 29% of the patients with migraine and only in 9 % of the "healthy" patients group. At all the tests, the variability of MFV was significantly higher in the migraineurs than in the control group of women. Conclusions: TCD cerebrovascular reactivity tests proved to be diagnostically insufficient for examining the patients with migraine. BHI in postmenopausal females could be considered as a factor influenced by hormonal disturbances, and age. Failure of cerebrovascular regulation occurs during migraine attacks.
P082	THE TRANSESOPHAGEAL ECHOCARDIOGRAPHY AND ISCHEMIC STROKE Tavciovski D, Raicevic R*,Markovic Lj**, T.Lepic*, M.Cvejic*. Department of Neurology*, Department of Cardiology, Department of Radiology**. Military Medical Academy, Belgrade, Yougoslavia. Introduction. Ischemic stroke (IS) represents unique clinical entity with various ethiological factors. Embolic mechanisms of development with thrombotic material of cardiac origin is the cause in 20-50% of the cases.The aim of the study was to determine the significance and sensitivity of TEE in detection of cardiac abnormalities which are considered to be the small risc source in patients with IS in which the embolic mechanism of disease development was suspected. Methods and results: We examined 80 patients with acute acute IS, proved according to clinical and radiological criteria, of probably cardioembolic development mechanism and by transthoracal(TTE) and TEE peformed by two examiners in order to exclude bias.Significance of diferences in detection of cardiac abnormalities was determined by statistical calculations.In patients group examined by TEE mitral valve prolaps was detected in 24 patients(was detected in 13 cases when TTE was used). Atrial septal aneurism was detected in 11 patients by TEE and with only 2 positive finding when TTE was used. Spontaneous echo contrast was seen in 7 cases only by TEE method. Conclusions: According to our results,we can conclude that TEE is significantly more sensitive diagnostic method for detection of small risk cardioembolic sources in development of IS which is specially related to younger patients.
P083	EFFECT OF ANTIHYPERTENSIVE TREATMENT ON CO2 REACTIVITY OF CEREBRAL ARTERIOLES DURING PHYSICAL EXERCISE T. Magyar, A. Valikovics,* I. Czuriga, L. Csiba. Departments of Neurology and * Cardiology, University of Debrecen, H-4012 Debrecen, Hungary Background: Previously, 30 untreated hypertensive patients (mean age 42.4 + 5.4 years) were investigated by transcranial Doppler monitoring during physical exercise, and changes of hemodynamic parameters were compared with those of age-matched healthy subjects. The aim of this study was to investigate the effect of 3-year antihypertensive treatment on cerebral hemodynamics in hypertesives during ergometer cycling. Methods: Until now, 12 out of 30, previously untreated hypertensive patients were investigated after 3-year antihypertensive treatment. The examination will be continued. Blood pressure, heart rate, end-tidal CO2 (Capnogard capnograph), and MCA mean blood flow velocity (Multidop X DWL) were continously monitored during ergometer cycling according to the WHO protocol. Our preliminary results: Loading time of the 1^st and the 2^nd examination didn't differ significantly (mean + SD: 4.58 + 1.92 and 4.41 + 1.67 min). Systolic blood pressure decreased after 3-year treatment (mean + SD: 176.16 + 11.35 mmHg and 162.66 + 21.81 mmHg) (p< 0,05). Unfortunately, out of 12 patients 3 hypertensives didn't take any antihypertensive drugs. In one of them, maximal CO2-reactivity during exercise decreased from 1.82 cm/s/mmHg (1^st) to 1.54 cm/s/mmHg (2^nd examination) after 3 years. Otherwise, in one of 3-year regularly treated patient maximal CO2-reactivity increased from 1,38 cm/s/mmHg (1^st) to 2 cm/s/mmHg (2^nd examination). Conclusions: TCD combined with ergometer cycling might be useful for evaluation of therapeutic efficacy.
P084	Impaired dynamic cerebral autoregulation in eclampsia? E. Oehm, M. Reinhard, J. Spreer^1, C. Keck^2, T. Els, and A. Hetzel Department of Neurology and Clinical Neurophysiology, University of Freiburg, Germany ^1 Section of Neuroradiology, University of Freiburg, Germany ^2 Department of Gynaecology and Obstetrics, University of Freiburg, Germany Background: Eclampsia accounts for 24-47% of ischemic stroke during pregnancy or the puerperium. It causes cerebral arteriopathy, leading frequently to dilation of arteriolar vessels and arterial vasospasms, resulting in cerebral edema or infarction. We analysed the vasodilatory response by CO2-reactivity testing and dynamic cerebral autoregulation (DCA) by transfer function phase between spontaneous oscillations of arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) in an eclamptic woman. Case Report: A 28 year old primaparous woman with normal pregnancy presented 3 days after delivery with preeclampsia. On the fifth day postpartum sudden manifestation of reduced consciousness, bilateral cortical blindness and generalized seizures occured. T2-weighted MRI revealed cortical and subcortical, as well as deep white matter lesions, most pronounced in the occipital and parietal lobes. Venous and arterial MRA showed normal findings. Control MRI two months later documented a complete resolution of the lesions. CSF analysis, vasculitis and hemostasis screening, HSV 1+2 and VCV PCR were normal. TCD demonstrated increased CBFV in both MCA and ACA. CO2-reactivity of right MCA was reduced to 1,2%/mmHg (normal range: 1,5-4%/mmHg). Cross-spectral analysis revealed significant coherency values between ABP and CBFV (right MCA) at 0.1 Hz. Phase shift was substantially reduced to +5° (normal range: +60± 30°). Neurological symptoms resolved within 5 days. Conclusions: To our knowledge, we present the first case of impaired DCA, as documented by decreased transfer function phase, in eclampsia. The vasodilatatory response was only slightly reduced compared to severely altered DCA, suggesting dissociated vasoparalysis, a condition described as diffuse loss of cerebral autoregulation with widely preserved vasomotor reactivity.
P085	THE EFFECTS OF ACUTE SMOKE ON THE CEREBRO-VASCULAR SYSTEM ARE DIFFERENT IN QUOTIDIAN VERSUS OCCASIONALLY SMOKERS V. Bohotin, C Bohotin, D Baltag, CD Popescu University of Medicine and Pharmacy Iasi Romania Background : The acute systemic haemodynamic effects of the cigarette smoking are well known, but there are no studies dealing with the possible smoke-related changes of cerebral circulation. Objective : In the present study we evaluated the acute effects of cigarette smoking on blood flow velocity of the internal carotid artery by use of extracranial Doppler ultrasound in people who smoke at least 15 cigarettes/day (quotidian smoker CS)and in people who smoke occasionally less then 5 cigarette/month (occasionally smoker OS). Methods : Twenty five normal volunteers (15 CS and 10 OS with a mean age of 24 ± 3 years) were asked to smoke one cigarette with a total known nicotine content (1.1 mg) during a five minutes period. Using extracranoial Doppler we measure the systolic, diastolic and mean flow velocity and resistivity index in right internal carotid artery before and immediately after a cigarette smoke. Results : No significant difference was found in the baseline condition between the two groups. The resistance index increase after cigarette smoke. The increase is more evident in OS group but is also present in CS group. (IR 0.56 ± 0.09 before and 0.85 ± 0.05 after in OS group before 0.58 ± 0.08 and after 0.79 ± 0.06 CS group). The systolic and diastolic flow velocity increase was not significant. There is an increase of the heart rate from 65 ± 8 to 76 ± 11.and of the blood pressure from 120/75 mmHg to 155/90 mmHg which is not different in the two groups. Conclusion : The cigarette smoke induce an sudden vasoconstriction of the cerebral vascular bed more pronounced in the occasional smoker reflected by an increase of the resistance index which could induce a decrease of the blood supply to the cerebral tissue.
P086	CEREBRAL AUTOREGULATION IN PATIENTS WITH MIGRAINE AND TENSION HEADACHE Z. Kazibutowska, A. Gołba, A. Bal, A. Warsz-Wianecka, J. Machowski Neurological Clinic SLAM Katowice, Poland Background. Headache etiology is heterogeneous and still unknown. The most recent findings delineate three mechanisms: autonomic, vascular and neuronal (n. trigeminal). The increased arterial reactivity and serotonin metabolism disturbances are postulated. The data imply that vascular abnormalities observed in migraine may be secondary to a primary abnormalities in neuronal function in the brainstem. Vascular mechanism in migraine is based on changes in cerebral flow as follows: angiospasm causing visual deficit (aura), next vasodilatation causing pain and oedema. The studies examining cerebral blood flow try to characterize vasomotor sensitivity and explain whether cerebral autoregulation is intact or impaired in patients with migraine end tension headache. The aim of this study was to evaluate the mean velocity blood flow (mVBF) and pulsatility index (PI) in middle cerebral artery (MCA) during normocapnia, hypocapnia and relative hypercapnia in patients with migraine and tension headache. Methods. Transcranial Doppler sonography was performed in 20 patients diagnosed with migraine, 20 with tension headache and 20 control subjects matched in age and sex to the patient group. There were mVBF and PI measured in right middle cerebral artery at rest, next after 30-sec hyperventilation test and after 5% CO2 + 95% air rebreathing for 3 min. The time of return these parameters to baseline values was measured. Results. The mean velocity flow in MCA at rest is higher in patient with migraine in comparison with patients with tension headache and control group. The decrease of mean velocity flow in MCA after HV test was greater and faster in patients with migraine. PI increased 2-fold more during HV test in patients with migraine vs patients with tension headache. The return mVBF in MCA and PI after HV test and rebreathing CO2 + air to baseline values was faster in patients with migraine in comparison with patients with tension headache. Conclusions. Approximately 2-fold more cerebral vasoreactivity in patients with migraine vs patients with tension headache can be associated with small vessels diameter changes dependent on autonomic mechanism.
P087	ESTROGENE-PROGESTERONE THERAPY INFLUENCE ON CEREBRAL BLOOD FLOW DISORDERS IN TRANSCRANIAL COLOR DOPPLER MEASUREMENTS. E.Kudybka-Glownia;J.Siejka-Jurenczyk Neurology d.,Municipal Hospital Katowice-Murcki,Poland A group of 40 women at the age 25-55y.o.,during or after finishing hormone therapy /supplementary or contraceptive h.th./ had been examined.Patients suffered from headaches,dizziness,transient or fixed speech abnormalities and weakness of the limbs-in 55% of the right side.Neurological examination showed senso-motorial aphasia/30%/,pyramid symptoms /75%-on the right side/ and cerebellar symptoms/20%/. Transcranial Color Doppler/TCD/ examination performed invariably showed cerebral blood flow/CBF/ disorders /Vmax decrease,turbulances,no echo in the cerebral arteries/ concerning the left brain hemisphere in 95% of patients;bilateral abnormalities concerned 5%group of elderly patients.EEG rutine procedure showed vascular record in 80% of patients. Blood examination showed high coagulability /INR 0,9-1,1/ in 60% of cases;lipids level increase occured in 40% of elderly patients.Anticlot treatment,finishing hormone therapy /supervised by gyneacologist/ and motorial rehabilitation gave improvement of neurological state. Taking into consideration majority of disorders in the left brain hemisphere,we suggest that because of anatomical difference between precerebral vessels of the left and right side , left hemisphere is more exposed to pharmacodynamic consequences od drugs activity /e.g.influence of h.th.on blood thickness/.
P088	CHANGES IN BASILAR ARTERY BLOOD FLOW IN PATIENTS WITH SYNCOPE OF UNKNOWN ORIGIN Z. Kazibutowska, A. Gołba, A. Bal, A. Warsz-Wianecka, J. Machowski Neurological Clinic SLAM Katowice, Poland Background: Differential diagnosis of syncope frequently imposes a major problem in clinical practice.Previous work shows that cerebral blood flow changes alone , in the absence of systemic hypotension , may result in syncope. We use Transcranial Doppler Ultrasonography to asses basilar cerebral artery mean flow velocity (Vmean) and pulsatility index (PI) during orthostatic challenge and CO2 reactivity testing. Methods: Twenty five patients with history of cerebral syncope and twenty healthy controls were examined .Basilar cerebral artery V mean and PI and end –tidal pressure of carbon dioxide were measured in patients et rest during normocapnia , after 30 –second hyperventilation and during hypercapnia. The same parametres were assesed under postural stress. Results: Et rest basilar cerebral artery V mean was significant lower in patients with syncope during normo- hypo- et hypercapnia .They have also higher values of PI but it was nonsignificant.Under postural stress in patients with syncope a significant increase in V mean and decrease of PI can be observed. Conclusions: TCD measurements may represent e new approach to the work-up of patients with syncope of unknown origin.In those patients myogenic mechanism of cerebral blood flow autoregulation may an important role in derangement of cerebral autoregulation with resultant cerebral hypoxia.
P089	INNOVATIVE NONINVASIVE TECHNOLOGY FOR LONG - TERM CEREBROVASCULAR AUTOREGULATION MONITORING A.Ragauskas^1, G.Daubaris^1, V. Ragaisis^2 ^1Kaunas University of Technology and ^2Kaunas Medical University Neurosurgical Clinic, Kaunas, Lithuania Background: The ultrasonic "time-of-flight" monitoring technique (Vittamed) was investigated in our previous works (1-3). This technique can be used for up to 120h of patients‘ continuous cerebrovascular autoregulation (CA) monitoring because it‘s brain insonation energy is 180 times less comparing with the standard TCD technique. The objectives of this study are to show the similarity between invasively recorded ICP slow B waves and simultanesouly noninvasively recorded intracranial blood volume slow waves and also to prove the reliability of the "time-of-flight" long-term CA noninvasive monitoring technology under ICU conditions. Methods: A new noninvasive "time-of-flight" monitor (Vittamed) has been used at first time in ICU for clinical study of CA simultaneously with invasive ICP and ABP slow wave monitoring techniques. One hour CA monitoring sessions have been repeatedly performed on 12 patients with traumatic brain injuries (10 M, 2 F, age average 26 years). Data were collected from 83 one hour sessions of simultaneous invasive and noninvasive intracranial slow B wave monitoring and from 55 one hour sessions of invasive and noninvasive CA monitoring. Bland & Altman plots were used to assess the agreement between invasive and noninvasive slow wave and CA monitoring data. Results: It has been shown experimentally that the reliable long-term continuous noninvasive CA monitoring (Vittamed) can be used interchangeably with invasive CA monitoring under ICU conditions. The statistically estimated (Bland & Altman) difference between invasively and noninvasively recorded intracranial slow B waves (standard deviation SD=0.089, p=4.5x10^-7) and the difference between invasively and noninvasively recorded CA indexes (SD=0.05, p=1.1x10^-6) are small enough and such differences are not clinically important. Conclusions: In this clinical study it is shown at the first time that ultrasonic "time-of-flight" technique (Vittamed) provides reliable information about cerebrovascular autoregulation state during long-term continuous noninvasive monitoring. 1. Cerebrovasc Dis 1999;9 (suppl.2):31, 46; 2. Cerebrovasc Dis 2000;10 (suppl.1):34; 3. Cerebrovasc Dis 2001;11 (suppl.3):44 This work is supported by US DAMD Award 17-00-2-0065
P090	CEREBROVASCULAR REACTIVITY TO VISUAL STIMULI ^1Zaletel M, ^1Žvan B, ^2Štrucl M, ^1Pogačnik T ^1University Clinical Center, Dept. of Neurology, ^2School of Medicine, Institute of Physiology, Ljubljana, Slovenia Cerebrovascular reactivity (CVR) to complex visual stimuli is higher compared to simple-white stimuli. It is not clear, whether CVR to red light stimuli is different compared to simple–white stimuli and complex stimuli. Methods: 19 healthy volunteers (mean age 29± 6.7 years) participated in our study. Visually evoked flow responses (VEFRs) were measured in the posterior and middle cerebral arteries by 2 MHz probe using TCD monitoring system. Mean arterial pressure was continuously measured by Tonometer, End-tidal (Et-CO2) was monitored by infrared capnograph. Stimulus was applied by computer screen with adjustable intensity of light. Three different intensity of white, simple stimulus was used: 21.4 cd/m^2, 10.5 cd/m^2 and 2 cd/m^2. Than we performed different type of stimuli with different intensity: white-simple stimulus (WSS) (21.4cd/m^2), red stimulus (RS) (3.9cd/m^2) and complex-checkerboard stimulus (CCS) (10.5cd/m^2). The amplitudes of VEFR were further statistically evaluated by ANOVA for repeated measures and paired t-test. Results: The results of repeated measures ANOVA for different intensities of WSS did not show significant differences between measurements (p=0.56). The ANOVA of repeated measures for different type of stimuli showed significant differences between measurements (p=0.001). Paired t-test showed significant differences between WSS and CCS (p=0.002 ), WSS and RS (p=0.010) as well as red and CCS (p=0.044). MAP and Et-CO2 did not change significantly during stimulation. Conclusions: We concluded that CVR to red stimuli is higher compared to simple-white stimuli, however, it is lower compared to complex stimuli.
P091	Effects of nitrous oxide on cerebral autoregulation during Sevoflurane anaesthesia. A transcranial Doppler Study Iacopino DG, Conti A, Battaglia C, Santamaria L, Tomasello F. Neurosurgical Clinic and Anesthesiological Service. University of Messina. Italy. Background. Cerebral autoregulation is a homeostatic mechanisms that minimizes deviations in cerebral blood flow when cerebral perfusion pressure changes. It acts through vasomotor effectors that control cerebrovascular resistance (CVR). A number of studies have demonstrated an adverse effect of N2O on cerebro-vascular hemodynamics, in both humans and animals. Increased intracranial pressure, cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2) and reduced autoregulation indexes have been reported, but their magnitude is still debated. Objectives. Our study was designed to evaluate the effect of N2O on CBF and autoregulatory indexes during N2O/Sevoflurane anesthesia in a large prospective randomized controlled series of patients. Methods. Patients were randomly divided in two groups of twenty on the base of the use of N2O in the gas mixture, creating a study group (O2-N2O-SEVOFLURANE) and a control group (O2-NITROGEN-SEVOFLURANE). The Transient Hyperemic Response Test, using transcranial Doppler techniques, was used to assess cerebral autoregulation. Results. The systolic flow velocity, considered as an index of actual CBF, demonstrated a statistical significant difference between the two groups (p= 0.0011) with an increase after introduction of N2O. The hyperaemic response, considered as the index of autoregulatory potential, decreased significantly in the study group after the introduction of N2O, compared with the control group (p< 0.001). Conclusions. The increase of cerebral blood flow and the reduction of autoregulatory indices suggests caution in using N2O during Sevofluorane anesthesia, especially in patients with reduced autoregulatory reserve, and during neurosurgical interventions.
P092	L-ARGININE IMPROVES DIMINISHED CEREBRAL CO2 REACTIVITY IN PATIENTS C. Zimmermann, R.Haberl Krankenhaus München-Harlaching, Department of Neurology, Munich, Germany Background There is experimental evidence that L-arginine restores diminished CO2 reactivity after mild traumatic brain injury in rats. This effect is believed to be mediated by L-arginine derived nitric oxide being a permissive substrate for CO2 reactivity. To verify these findings and underline a possible beneficial effect of L-arginine in clinical situations we have tested the influence of L-arginine on CO2 reactivity of the cerebral vessels in human subjects. Methods 42 patients with mild signs of arteriosclerosis without having extra- or intracranial stenoses were examined by bilateral transcranial Dopplersonography of the right and left middle cerebral artery. Vasomotor reserve (VMR) was tested by 1min hyperventilation followed by a 3min inhalation of 5%CO2. Examination was performed twice, once before and once after infusion of 30g L-arginine over 30 min and results were compared before and after administration of L-arginine. Results There was no difference of right and left side vasoreactivity, initial mean vasomotor reactivity (VMR) of 42 patients was 51 ± 14%. In patients with reduced VMR (< 50%) in the first examination (42 ± 8%, n=22) vasoreactivity was significantly increased after infusion of L-arginine (52 ± 14%, p=0.005). In patients with normal CO2 reactivity (> 50%, n=20) values did not change after infusion of L-arginine (59 ± 8% before versus 59 ± 13% after L-arginine). Conclusions Our data supports the hypothesis that L-arginine is able to improve impaired cerebral CO2 reactivity also in patients when they have slight disturbances of vasomotor reactivity.
P093	CEREBRAL VASOMOTOR INSTABILITY CAUSED BY THE DECREASE OF VESSELS WALL’S TONE G.Baltgaile , T.Timofejeva Latvian Medical Academy, Riga, Latvia Autonomic regulation of haemodynamic involves the regulation of vessels wall’s tone and is examined as a clinical routine tests and dopplerographical tests for autoregulation. Sonologically detected vasomotor instability manifested as an abnormal blood flow velocity’s distribution in cerebral arteries without certain signs of arterial wall pathology is often defined in young people with symptoms of autonomic nervous system dysfunction. To define the role of vessel wall’s tone in such processes 25 healthy subjects and 73 patients (19-38 y.o.) with autonomic nervous system dysfunction had been examined clinically and sonologically. Carotidal arterial wall dilatation in diastole-systole had been measured used M-mode (cardiac regime) as well as routine distance measurement by linear probes 7-12Mhz and 4-7Mhz (HDI-5000, ATL). Other pre- and cerebral vessels have been examined usual way. The most characteristic ultrasonological feature in patients with autonomic nervous system dysfunction was decrease of precerebral and cerebral vessels wall’s tone detected as: 1) the increase of carotid artery’s wall dilatation during diastole (mean on 0,07+-0,03 cm) with the increase of pulsative index (mean 1,96+=0,67); 2) the flow acceleration in normal sized or dilated middle cerebral arteries (Vmax +=s/d 136+=15,6 cm/sec) with the presence of vascular noises in cerebral arteries (in 38% of cases on arterial branching); 3) the dilatation of vertebral and basal veins (in 24% of patients) with the venous flow’s acceleration in a varying degree ( in 68% of patients).
P094	TCD FINDING OF BASILAR OCCLUSION IN PATIENTS AFFECTED BY MILD ASPECIFIC SYMPTOMS WITHOUT STROKE. D.Bosone , S. Marcheselli, A. Cavallini, G.Giardini, G. Micieli. Neurovascular Unit, "C.Mondino" Foundation, University of Pavia. Italy Background: Basilar artery occlusion (BAO) is known as a cause of dramatic ischemic stroke presenting with well described clinical syndromes (1) and characterised by a very poor outcome and no effective treatment. The introduction of early intra-arterial fibrinolysis has provide a stimulus to develop non invasive diagnostic tools like Transcranial Doppler. The chance to investigate non invasively and within few minutes a large number of patients is now disclosing new correlation between clinical symptoms and vascular status. In particular there are few data concerning premonitory symptoms of BAO, not associated with stroke (2). We describe two cases in which BAO Doppler finding was surprisingly associated with mild and non-specific clinical symptoms. Case1: A men (50 years old) was admitted at the end of 2001 to our hospital for a 10 minutes lasting episode of vertigo and headache in orthostatic position. He was a smoker, affected by arterial hypertension. CT scan was normal. A routine TCD examination disclosed a suspect of BAO, confirmed with MRA. The patient received anticoagulant therapy. Two months later TCD still confirmed occlusion of basilar artery. The patients up to date is still alive and free of symptoms. Case2: A woman (60 years old) was admitted in 2000 for two year-lasting vertigo and more recent transient episodes of ocular flashes and palpebral ptosis. Personal history was positive for arterial hypertension. CT scan was normal. A routine TCD suggested BAO, confirmed by arterial angiography. This patient received anticoagulant therapy too. One year later the basilar artery was still occluded but the patient was alive and free of symptoms. Conclusions: TCD helped to discover BAO and to prevent very probable serious stroke in patients with underestimated premonitory symptoms.
P095	INVESTIGATION OF CEREBROVASCULAR REACTIVITY IN MIGRAINE WITH AURA AND WITHOUT AURA J. Petrova, E. Vassileva, P. Shotekov University Hospital "Alexandrovska", Sofia, Bulgaria Background: Migraine pain is usualy ascribed to changes of blood flow of transcranial arteries. In this study we have investigated cerebrovascular reactivity in migraine patients with aura (MWA) and without aura (MWOA). Methods: By using transcranial Doppler ultrasonography we studied the changes of flow velocity after Valsalva, dynamic orthostatic tests and Nytroglicerine test. 15 patients with MWA and 15 with MWOA. Inclusion criteria were: 1) Age >18 years, 2) Migraine patients out of attacks, 3) Adequate transtemporal visualization of the MCA, 4) Non-smokers. Results: The group with aura had higher baseline systolic velocity and lower distolic velocity than the group without aura. The response to Valsalva and Nitroglicerine tests had significantly higher values at patients with aura than the group without aura. The group with aura had significantly lower diastolic velocity at Valsalva, Orthostatic and Nitroglicerin tests than this without aura. Conclusions: These data shows that the cerebrovascular failures are of different type in migraine patients with aura and without aura.
P096	Cerebral Autoregulation in Patients with Intracranial Aneurysms after Anesthesia Induction V.B. Semenyutin, V.A. Aliev, V.V. Alexeev, G.A. Assaturyan, S.K. Sergienko Russian Polenov Neurosurgical Institute, St. Petersburg, Russia Background: An effect of different types of anesthesia on cerebral autoregulation (CA) has been described in volunteers and patients, subject to orthopedic operations. However, these data do not permit to give reliable assessment of anesthesia induction (AI) and its effect on CA in patients with intracranial aneurysms (IA). Methods: We examined 25 patients, who underwent surgical interventions for IA. They were divided into two groups. The 1^st group included 13 patients, operated in a "cold" period of SAH; the 2^nd group comprised 12 cases, operated in its acute period (grade ll-lll, WFNS scale). A combination of arduan, propophol and clophelin was used for AI. CA was assessed with the help of a cuff test. Systemic blood pressure (SAP) in a radial artery was registered continuously by the M-34 Mingograph (Siemens). Blood flow velocity (BFV) in both middle cerebral arteries was recorded, using the Multi-Dop X (DWL) system. Results: Before AI patients of the 1^st group had SBP equal to 96.7+7.2 mm Hg; a rate of regulation (RoR) on the right and left was 20.9+2.0%/s and 20.5+1.7%/s respectively. These data correspond to normal values, determined earlier. SBP in the 2^nd group was 97.1+9.2 mm Hg; RoR on the left and right 13.1+2.3%/s and 13.5+2.1%/s respectively. These indices were considerably smaller (p<0.001) and reflected CA disorders. AI was followed by decrease both SBP and BFV up to 31.9+8.5% and 38.7+10.1% respectively in 10 patients of the 1^st group and 8 patients of the 2^nd group (there was no reliable difference in changes of BFV and RoR on the left and right; thus, all the values presented below, are referred to the side of their maximum decrease). At the same time SBP in 3 patients of the 1^st group and 4 patients of the 2^nd group fell to 18.4+4.1% after AI; BFV decreased up to 20.9+7.8.%. After AI and during normal ventilation ROR of all patients of the 1^st group was 13.7+1.2%/s, it was equal to 9.5+1.3%/s in all patients of the 2^nd group. As for hyperventilation, there was a significant increase of ROR (p<0.001) both in patients of the 1^st (17.5+1.9%/s) and 2^nd groups (13.5+3.4%/s). Conclusion: Anesthesia induction in ICA causes decrease of RoR in patients, operated in "cold" and acute periods of SAH.
P097	STUDY THE EFFECT OF CARBON DIOXIDE PNEUMOPERITONEUM ON THE CEREBRAL BLOOD FLOW VELOCITY USING TRANS－CRANIAL DOPPLER DURING LAPAROSCOPIC SURGERY Chunfeng Liu, Hong Xie, Hao-rong Wu, et al. Department of Neurology,Second Affiliated Hospital of Suzhou University,Suzhou,China Background:Recently laparoscopic surgery has been widely used in the clinic particuly in elderly patients,but it is not reported that carbon dioxide pneumoperitoneum effects on the cerebral circulation during operation. Methods: Use the TCD of biprobe(EME 2020) to monitor dynamically the MCA’s mean cerebral blood flow velocity and pulsatility indexes through the temporal windons,also measurements of blood pressure in 19 patients with cholelithiasis underwent laparoscopic surgery. Results: The mean cerebral blood flow velocity of MCA has no change,even though the pulsatility indexes decreases and blood pressure increases after carbon dioxide inflation of the peritoneum,during the laparoscopic operative procedure.When the operation was over,the pulsatility index and blood pressure soon became normal,especially the diastolic pressure became stable. Conclusions: carbon dioxide pneumoperitoneum will not do any harm to the cerebral blood flow while operation clone with laparoscopiy.
P098	CHANGES IN CEREBROVASCULAR RESISTANCE AFTER HEAD-UP TILT IN COMPENSATED AND DECOMPENSATED ORTHOSTATIC HYPOTENSION PATIENTS H.Y. Hsu, H.H. Hu, Y.C. Chen, P.Y. Wang Section of Neurology, Taichung Veterans General Hospital, Taiwan Background: Patients with decompensated orthostatic hypotension(OH) had decreased cerebral blood flow on head-up tilt (HUT). Patients with compensated OH had normal cerebral blood flow despite postural hypotension. Loss of cerebrovascular reserve might result in the difference. We tried to investigate the pathogenesis of decompensated cerebral flow change. Methods: Totally, 36 subjects were study. There were 12 subjects in each group (control, compensated & decompensated OH). Radial blood pressure(ABP) (tonometer, Colin 7000) and middle cerebral artery flow velocity (CBFV) (transcranial doppler, Nicolet, EME TC4040) were recorded continuously. Both signals were digitalized and stored into an IMB compatible PC. Critical closing pressure (CrCP) and resisatnce-area product (RAP) were calculated from 2 stable segments (before and after HUT respectively) of CBFV and ABP signals using beat-to-beat linear regression method. Non-parametric Kruskal-Wallis test and Mann-Whitney test were used to compare the change in CrCP and percentage change of RAP among groups. Results: The reduction of ABP was similar between compensated OH and decompensated OH groups. The decompensated OH group had significant reduction in mCBFV( 12.6±2.6 cm/sec,p<0.001). The change in CrCP was not different among 3 groups (p=0.597). The percentage reduction of RAP after HUT was significantly larger in the compensated group (35.4±4.9%, p=0.007). However, the percentage change of RAP was not significant different between control (14.3±7.9%)and decompensated group (24.1±7.1%). Conclusions: The limited cerebrovascular reserve was insufficient to cope with marked ABP change on HUT in patients with decompensated OH. RAP was a useful parameter in assessing cerebrovascular reactivity.
P099	SMALL VS LARGE-VESSEL STROKE: IS CEREBRAL VASOMOTOR REACTIVITY DIFFERENT? ISRAELI-TURKISH COLLABORATIVE STUDY A.Y. Gur,¹ D. Gücüyener,² N. Üzüner,² G. Özdemir,² A.D. Korczyn,¹ N.M. Bornstein¹, Departments of Neurology, Tel Aviv University, Tel Aviv, Israel,¹ Osmangazi University, Eskisehir, Turkey Background: Both small- and large-vessel strokes are well-known types of cerebrovascular ischemic events. The cerebral hemodynamic features of patients after different types of stroke are still poorly defined. Our study aimed to assess and compare cerebral vasomotor reactivity (VMR) in patients with small- (SV) and large-vessel (LV) strokes. Methods: We assessed VMR using transcranial Doppler and the Diamox test (1 g acetazolamide i.v.) in 20 post-stroke patients. The percent difference between blood flow velocities in the middle cerebral arteries before and after the Diamox test was defined as VMR%. All patients underwent carotid duplex to exclude severe carotid occlusive disease as a factor which might affect VMR. Lacunar or single large artery infarcts were confirmed by CT and/or MRI in all patients. The patients were divided into those with SV (group 1) and LV (group 2) strokes; their VMR% values were compared using the ANOVA test. Results: Group 1 (n=10, 7 men, mean age 64.2±19.5 years) and group 2 (n=10, 5 men, mean age 68.2±18.5) were well matched for common vascular risk factors and timing after stroke (3-36 months). The mean VMR% was 43.7±29.5% for group 1 and 40.8±24.8% for group 2. There was no statistically significant difference between the VMR% of the two groups (P=0.2). Conclusions: Our data suggest a similar VMR in patients with SV and LV types of ischemic stroke. While they are clearly different in terms of etiology, clinical features and prognosis, both types have comparable hemodynamic patterns.
P100	KINETICS OF CBF AUTOREGULATION WITH AGEING A Pavy-Le Traon, M C Costes-Salon, G.Geraud, V Larrue *Neurology department, Rangueil Hospital, 1 Avenue Jean Poulhes, 31 054 TOULOUSE CEDEX, France Background and objectives Cerebral autoregulation can be defined as the homeostatic mechanism that minimises changes in cerebral blood flow (CBF) in response to changing cerebral perfusion pressure. Ageing is associated with cardio-vascular changes including more frequent orthostatic hypotension but the effects of normal ageing on cerebral autoregulation capacity are not well known. The objectives of our study were to assess changes in kinetics of CBF autoregulation with age.3. Methods Continuous monitoring of middle cerebral artery (MCA) blood flow velocity (BFV) by TCD and beat-to-beat blood pressure (BP) by Finapres was performed during the sharp physiological decrease in blood pressure induced by standing up rapidly after two minutes in squatting position in three groups of male and female healthy volunteers (14/group) of different ages (Group 1: 30+/-6 y ; Group 2: 44+/-3y ; Group 3: 63+/-6 y). To assess the effects of BP decrease on CBFV, an index (CR) was calculated by dividing mean BP by mean MCA BFV. Rate of regulation was determined as normalised changes in CR per second during the blood pressure drop. Results In squatting position, mean BP was significantly higher in Group 3; mean MCA BFV did not differ in the three groups. The mean decrease in MBP induced by standing up tended to be greater in group 3 (-40%) than in group 1 (-31%) (P=0.06) as well as the mean decrease in mean BFV (-34% vs -23%) (P=0.04).In response to the larger drop in BP, the rate of autoregulation was larger in group 3. The time to obtain maximum vasodilation (in sec) did not differ with age (group 1 : 11.3+/-2.5 ; group 3: 12.7+/-4.8). Conclusion This study suggests that the kinetics of cerebral autoregulation is maintained with normal ageing.
P101	FRACTAL ANALYSIS OF MCA FLOW VELOCITY FLUCTUATIONS IN PATIENTS WITH VASOMOTORIC DISTURBANCES M.Glaubic-Latka*, M.Latka**, D.Latka*, B. J. West*** *Dept.of Neurology, Dept.of Neurosurgery, Opole, POLAND **Physics Department, University of Technology, Wroclaw, POLAND ***Mathematic Division, Army Research Office, NC, USA Background: Many physiological signals fluctuate in apparently irregular and complex manner. However, the fractal analysis of these fluctuations often reveal the existence of long-range correlations in healthy subjects. The breakdown of these correlations may be caused by disease or aging. In the same way, the authors decided to establish how the normal cerebral blood flow autoregulation in healthy subjects is reflected in the fractal properties of MCA flow velocity fluctuations and whether these properties may be altered in pathological states. Method: We studied the MCA flow velocity (MCAfv) in human using TCD (DWL Multi-Dop T). The 2-MHz Doppler probes were placed over the temporal windows and fixed at a constant angle and position. The measurements were taken continuously for approximately 2 hours at supine rest. The study comprised the healthy individuals and the subjects with presumed vasomotoric disturbances. The fractal analysis of the time series of the axial flow velocity fluctuations averaged over a cardiac beat interval was performed. The Hurst exponent which determines the monofractal properties as well as the singularity spectrum which characterizes the multifractal properties were calculated. Results: The time series of the axial flow velocity averaged over a cardiac beat interval exhibit clear multifractal properties for healthy subjects. We observe a loss of multifractality for some subjects with vasomotoric disturbances. Conclusion: The fractal analysis of MCA blood velocity may be useful in diagnostics of vasomotoric disturbances. We are currently investigating the fractal properties of the MCAfv time series in migraineurs.
P102	THE POSSIBLE MECHANISMS OF THE CEREBRAL BLOOD FLOW CHANGES IN HYPOKINESIA CONDITION A.H. Manukyan Yerevan State Medical University, Yerevan, Republic of Armenia Background: To determine the possible mechanisms of the changes of the local cerebral blood flow (lCBF) in early (15 day) hypokinesia (HK) condition and to establish the possible ways of a correction of these changes. Previous works show that a decrease of lCBF may be mediated by the different factors such as the vascular sensitivity increase to the endogenous vasoconstrictor substances, the changes in aggregation and metabolic intensity. Methods: lCBF was measured by laser Doppler flowmetry in rats being in early HK condition. The isotonic contractions of the isolated grafts of the thoracic aorta of rats were registered with the help of the apparatus "Isotoche Messeinrichtung" (Germany) on the apparatus of registration "Hitachi" (Japan). The thrombocyte aggregation was investigated by classic nephelometric method on aggregometer "Payton" (USA). Results: In early HK the intensification of the lipid peroxidation processes are observed. Some products of lipid degradation have a vasoconstrictor activity. One of these substances is malonic dialdehyde (MDA). It results in the decrease in lCBF in early HK. The reason of lCBF decrease may be the vascular sensitivity increase to the vasoconstrictor substances that is manifested by the increase of the isolated graft contractility to MDA. The decrease of lCBF may be also mediated by the strengthening of thrombocyte aggregation caused by MDA. In early HK both atropine and a -tocopherol acetate diminish the drop of lCBF. Besides GABA-ergic remedies render a positive influence on the lCBF changes that is possibly explained by the antioxidant action of GABA-mimetics as well as the antagonism with MDA in regard to GABA receptors. Conclusion: The worsening of cerebral blood flow in HK may be the result of an influence of some products of lipid degradation, accumulation of which is observed in an intensification of the lipid peroxidation processes, on the cerebral vessels and an aggregating ability of thrombocytes. In HK condition the substances with the antioxidant and antiaggregating activities as well as the compounds with GABA-ergic and M-cholinolytic properties can compensate the infringements of the cerebral blood flow.
P103	CEREBROVASCULAR RESISTANCE DURING ACUTE OSMOTIC BLOOD-BRAIN BARRIER DISRUPTION JM McGregor, ME Miner, S Bell The Ohio State University, Columbus, Ohio, USA BACKGROUND: Cerebral hemodynamics and resistance during osmotic blood brain barrier disruption (BBBD) remain to be fully elucidated. The effects of this method of drug delivery on Transcranial Doppler velocity parameters were studied in our patient population undergoing disruption. METHODS: Continuous TCD monitoring was performed on patients undergoing BBBD for delivery of chemotherapy in the treatment of their brain tumor (glioblastoma, anaplastic astocytoma, CNS lymphoma). Anterior circulation disruptions were studied. Per protocol, each patient was anestheized, intubated, and stabilized for BP, HR, and end-tidal CO2 immediately prior to disruption. Continuous TCD monitoring of the ipsilateral MCA was performed (depth 56-48cm) and recordings of mean velocity(Vm), systolic velocity(Vs), diastolic velocity(Vd), pulsatility index(PI), and resistance index(RI) were made. Values from infusion of mannitol to completion of chemotherapy (15-20min) were compared to pre-disruption baselines. CT scans post disruption classified the degree of disruption and were compared to changes in TCD parameters. RESULTS: At BBBD onset, velocity measures increased by over 150%. Average time to maximum velocities was 2.2 – 2.9 minutes; Average times back to baseline was 15-17 minutes. Three resistance patterns were noted: a decrease in resistance that slowly returned to baseline, a bi-phasic pattern of a drop then elevation of resistance, and a pattern of prolonged elevation. CONCLUSIONS: Multiple physiologic alterations are at work during osmotic BBBD, and the effects on vascular resistance are somewhat variable. The BBBD that show patterns of decreased resistance are associated with CT scans showing greater degree of disruption.
P104	THREE DIMENSIONAL ULTRASOUND OF THE VERTEBROBASILAR SYSTEM Zavoreo I, Kesic MJ, Lovrencic-Huzjan A, Roje Bedekovic M, Demarin V Neurology Depr University Hospital "Sestre milosrdnice", Zagreb, Croatia Background: Transcranial color-coded sonography (TCCS) is used for evaluation of the vertebrobasilar (VB) system. In most indviduals the origin of the basilar artery (BA) can not be visualised due to unfavourable angle of the vertebral arteries (VA) junction or unfavourable angle of insonation. All three vessels can be rearly visualised at the same time. Three-dimensional ultrasound (3D US) enables reconstruction from transcranial power Doppler (PD) imaging of the VB system. Methods: We tried to display the 3D images of the intracranial parts of the VA and BA. Interactive 3D imaging software was integrated into an ultrasound platform (Aloka Prosound 5500). Data aquisition was performed using 2,5 MHz sector transducer, freehanded in a fixed length of time (10 seconds), allowing PD sonography. The images were postprocessed (TomTec imaging system). 12 patients were investigated in order to visualise all three vessels at the time, and to calculate the angle between each pair of vessels, according to the direction of the blood vessels. Results: In TCCS was not possible to obtain all three vessels at the time in niether patient while in PD mode we were able to obtain all three vessels at the time in 2/12 patients. 3D PD enabled visualization of all three vessels at the time in 9/12 patients (1 VA was occluded-diagnose was suspected by 3D PD and confirmed by angiography, in 2 cases suboptimal suboccipital window ). The angle between VA could be obtained in 9/12 patients. In 2 patients the the angle between VA and BA origin couldn’t be adequately visualised, but mathematical reconstruction according to the direction of the blood vessels was possible. Conclusions: 3D US enabled visualization of the VB junction, and in the cases of inadequate visualisation of the BA origin mathematically reconstruction was possible.
P105	GLOBAL CEREBRAL CIRCULATION TIME (CCT) MEASURED BY EXTRACRANIAL DOPPLER IN PATIENTS WITH DEMENTIA S. Schreiber, F. Doepp, E. Spruth, J.M. Valdueza Dept. of Neurology, University Hospital Charité, Berlin, Germany Background: Differentiation of vascular dementia (VD) from non vascular dementia (NVD) is a difficult clinical task. Microangiopathy as one of the main causes for VD leads to vessel rarification and a subsequent prolongation of CCT. Assessment of a global CCT might allow a clear differenttiation between VD and NVD. Methods: Global CCT was assessed as the extracranial time delay of an echocontrast bolus arrival (Levovist ®) between the distal internal carotid artery and the internal jugular vein. 27 VD patients, 9 NVD patients and 28 healthy age matched controls were studied. Results: Median CCT was 8.8 sec in the VD group (mean± SD: 9.0 ± 2.4 sec), 8.0 sec in the NVD group (8.2± 1.8 sec) and 6.6 sec in controls (6.9± 1.1 sec). Statistical analysis revealed a significant difference among the group medians (Nonparametric ANOVA, p=0.001, KW=13.9). Post test analysis showed a significant difference between controls and VD only (Dunn, p<0.05) but not between VD and NVD. Discussion: VD patients show a significantly prolonged global CCT when compared to healthy controls, supporting the hypothesis of increased blood flow resistancy in microvasculopathy. In contrast to previous reports also the NVD patients seem to have an altered cerebral circulation time which reduces the power of the test for the differentiation between patients with VD and NVD. Further inclusion of patients should allow to perform sensitivity and specificity analysis for the proposed test.
P106	COMPARISON OF PLATELET FUNCTION ANALYSIS; PLATELET AGGREGATION TESTS AND MICROEMBOLUS DETECTION BY TRANSCRANIAL DOPPLER ULTRASOUND IN IDENTIFICATION OF ASA-NONRESPONDER S.Guhr, T.Blaser, K.Hofmann, G.Lutze, M.Goertler Department of Neurology, Otto-von-Guericke-University Magdeburg, Germany Background: Conventional platelet aggregation tests have failed to detect patients who are at increased risk for a recurrent stroke even under secondary prevention with ASA (ASA-nonresponder). Laboratory testing by the Platelet Function Analyser (PFA) 100 might be an alternative. In contrast, cessation of embolic signals after antithrombotic prevention in patients with arterio-embolic stroke was associated with a reduced risk of stroke recurrence. Methods: Twenty patients (12 men, mean age 63.5 years) with a recently (<30 days) symptomatic stenosis of the internal carotid or middle cerebral artery underwent collagen induced platelet aggregation test as well as PFA 100 testing just before and 11 days (mean) after start of a secondary prevention with ASA. Eleven patients additionally underwent transcranial Doppler (TCD) for the detection of embolic signals. Results: After ASA, 19 patients showed pathologic aggregation test (maximal aggregation <82%) as well as increased PFA values (> 165 s). Of the 11 patients who underwent TCD, 5 initially were signals positive ( mean 23/h; range 1 to 37), who all demonstrated laboratory response to ASA by both, platelet aggregation and PFA 100 test. Conclusion: ASA response at PFA 100 testing is not related to cessation of embolic signals. As the latter has shown to be related to stroke recurrence, PFA 100 tsting might not predict clinically relevant ASA response.
P107	Reduced risk of recurrent arterio-embolic TIA and stroke is related to cessation of embolic signals after antithrombotic prevention M. goertler, T. Blaser, S. Krueger, K. Hofmann, S. Guhr, CW. Wallesch Department of Neurology, Otto-von-Guericke University Magdeburg, Germany Background: We aimed to determine the predictive value of decreased embolic signals on the risk of early stroke recurrence after the initiation of an antithrombotic secondary prevention in patients with recent arterio-embolic stroke. Methods: Eighty six consecutive patients with a non-disabling arterio-embolic ischemic event within the last 30 days and a medium- or high-grade stenosis of the ipsilateral carotid or middle cerebral artery underwent one-hour transcranial Doppler monitoring at admission. Then antithrombotic secondary prevention was started. Patients who had embolic signals underwent a second monitoring within 4 days. All patients were followed up within the next 6 weeks. Results: Embolic signals were detected at admission, 5.4 days (mean) after the initial event in 44 patients, 25 were positive for embolic signals also at the second monitoring, in 19 signals had ceased. 42 patients, without embolic signals already at admission, served as controls. During follow-up, 6 ischemic events occurred in 25 patients with persisting embolic signals but none in 19 patients in whom signals had ceased by the second monitoring. One patient of the control group suffered a TIA. Persistence of embolic signals was an independent predictor of a recurrent ischemia (adjusted odds ratio: 37.0; 95% CI: 3.5-333; p<0.003). Cessation and decrease of embolic signals was associated with the administration of antiplatelet agents but not with anticoagulation with intravenous heparin (p<0.001). Conclusions: Rapid cessation of embolic signals detected in patients with recently symptomatic arterial stenosis decreases elevated risk of an early ischemic recurrence. Effect of antithrombotic agents on embolic signals might serve as a marker for their efficacy on preventing stroke recurrence.
P108	Cerebral microembolism in antiphospholipid syndrome: An indicator for recent arterial ischemic events Buchkremer M, Rademacher J*, Kahles T, Sitzer M. Dept. Neurology, JW Goethe-University Frankfurt/Main, *Inst. of Medicine, Forschungszentrum Juelich, Germany Background: Antiphospholipid syndrome (APS) is associated with an approximately 10fold increased risk of venous thromboembolism. Furthermore, in a subgroup of APS patients arterial thromboembolic complications mainly in the cerebral circulation can also occur. We were interested whether the detection of silent cerebral microembolic signals (MES) by means of transcranial Doppler (TCD) can identify this subgroup of APS patients. Methods: To detect MES, we performed long-term TCD recording of the middle cerebral artery in 44 patients (mean age± SD, 39,8± 14yrs; 90% female) with proven diagnosis of APS according to standard criteria (Arthritis Rheum 1999;42:1309-11). Furthermore, a detailed medical history was taken concerning any arterial thromboembolic event within the past 12 months. Results: 19 patients (43%) were MES-positive on TCD recording with a mean number (± SD) of 5.7± 3.6 MES per hour (range, 1-17/hr). Additionally, 19 patients (43%) have had suffered from a recent (£ 12 months) arterial thromboembolic event (n=17 cerebral, n=1 peripheral, n=1 myocardial). Of these 19 recently symptomatic patients, 18 were MES positive (95%), but only 1 of the remaining 25 patients showed MES with 4 embolic signals per hour (Pearson’s r=0.91; P<0.001). By this, a positive MES recording is 95% predictive for a history of a recent arterial thromboembolic event in APS patients. Conclusions: A substantial proportion of APS patients show silent cerebral microembolism on long-term TCD monitoring. The occurrence of MES is highly associated with a history of recent arterial thromboembolic ischemic events. At this moment, antiphospholipid antibody pattern can not differentiate between those patients with a high venous or arterial thromboembolic risk. Therefore, prospective studies should validate the yield of MES detection as a paraclinical marker of increased risk of arterial thromboembolic complications in APS.
P109	Micro-embolic signals and carotid plaque morphology: a study of 71 patients with moderate or high grade stenosis I. Mayor, MD, C. Fossati, E. P. Burkhard, R. Sztajzel, MD Background: Micro-embolic signals (MES) have been reported in patients presenting increasing degrees of carotid artery stenosis. Several studies, moreover, tend to demonstrate that MES may be a surrogate marker for the risk of stroke. Only a few observations have considered a possible relationship between MES and carotid plaque morphology.Low plaque echogenicity has also been associated with an increased risk of stroke and we therefore sought to determine whether particular carotid plaque features on ultrasound are more likely to produce MES. Methods: We have reviewed 71 patients (94 carotid stenosis) with a degree of stenosis varying from 30 to 99%. Plaque appearance was classified according to 5 subtypes considering different ultrasonic plaque features. Transcranial monitoring of the right and left middle cerebral arteries was performed on each patient during 30 minutes. Results: MES were more frequently encountered in patients with anechogenic/ hypoechogenic plaques compared to isoechogenic/ hyperechogenic lesions (p<0.01). MES+ patients presented also more frequently an irregular surface of the plaque and more severe stenosis, however the differences did not reach significance. When considering the different above mentioned variables by using a logistic regression model analysis, only plaque morphology appeared to be a risk factor for the presence of MES. Conclusion: Patients with MES presented a significantly increased frequency of anechogenic/ hypoechogenic plaques. Since MES may be a marker of increased risk of stroke, the clinical significance of this particular association should be further investigated.
P110	TCD: IS A REDUCED FLOW VELOCITY IN THE MCA INDUCING CHRONIC ISCHEMIA OF THE WATERSHED REGION? Minkner K.(1), Sztajzel R.(2), Wetzel S.(1), Dfouni N.(1), Rüfenacht D.(1), Departement de radiologie (1), Departement de neurologie (2), Hôpital cantonal et universitaire de Genève Purpose: To investigate, if there is interest in measuring middle cerebral artery flow velocity by TCD to assess the risk for producing lesions that are compatible with chronic ischemia in the anterior watershed area of the brain such as visualised on MRI. Materials and methods: Retrospective evaluation of imaging and flow data was performed for a group of thirty patients which presented with signs of chronic cerebrovascular impairment. All underwent MRI, TCD and investigations of the internal carotic artery bifurcation, either by angiography or by ultrasound. In TCD the velocities of the MCA were measured on both sides. MRI was used to evaluate signs of low flow chronic ischemia in the white matter of the watershed areas of each hemisphere. For this, lesion with hyperintense signal on FLAIR or T2 weighted sequences were considered. Lesions located closer than within 5 mm distance from the ventricular surface or cortical grey matter were not considered to be chronic ischemic due to low flow. Flow speed of MCA in the TCD was correlated for each hemisphere with the presence of hyperintesities in the MRI of presumed low flow chronic ischemia. Results: The mean flow speed in the MCA of hemispheres with chronic ischemic lesions was 42 cm/s. The mean flow speed in the MCA of hemispheres without chronic ischemic lesions on MRI was 50 cm/s. Conclusions: Loss of flow velocity in the MCA was seen in presence of chronic ischemic lesions in the anterior watershed areas. Low flow as detected on TCD may be an indicator of chronic brain ischemia.
P111	CLUSTER HEADACHE AND RIGHT-TO-LEFT SHUNT ON TRANCRANIAL DOPPLER Del Sette M, Finocchi C, Angeli S, Sugo AL, Rizzi D, Gandolfo C Department of Neurological Sciences and Vision - University of Genova, Italy Objective: The prevalence of right-to-left shunt (RLS), usually due to patent foramen ovale, is significantly higher in subjects with migraine with aura than in normal controls. Aim of our study was to evaluate the prevalence of RLS in patients with cluster headache. Materials and methods: We evaluated 40 patients (32 males, 8 females, mean age 42.9 + 13.3) suffering from cluster headache, and compared them with 40 controls (21 males and 19 females, mean age 39.6 + 5.8), asymptomatic for cerebrovascular disease, and without a history of headache. All the subjects underwent bilateral transcranial Doppler with injection of contrast medium (9 ml saline plus 1 ml of air) in an antecubital vein. The test was performed during normal ventilation and during Valsalva manouvre, recording both the middle cerebral arteries. Results: Seventeen out of 40 patients with cluster headache (42.5%) showed RLS, as opposed to 7 of 40 controls (17.5%) (p= 0.028). Discussion: The prevalence of RLS in patients with cluster headache is significantly higher than in normal controls and is similar to the prevalence previously reported in young patients with stroke and with migraine with aura. Conclusion: These findings could be helpful in understanding the relationship between cluster headache and migraine. It remains to be clarified if cluster headache patients may have a risk of ischemic stroke higher than normal young subjects.
P112	PATIENTS WITH PROSTHETIC HEART VALVES MAY HAVE BOTH SOLID OR GASEOUS MICROEMBOLI DEPENDING ON THE NUMBER OF MICROEMBOLI G.A. Darbellay^1, P. Ruchat^2, V. Kemeny^3, T. Karapanayiotides^3, J.-M. Vesin^1, C.Lucchesi^4, J. Bogousslavsky^3, P.A. Despland^3, G. Devuyst^3 ^1EPFL, Lausanne , Switzerland;^2Department of Vascular Surgery, CHUV, Lausanne, Switzerland; ^3Department of Neurology, CHUV, Lausanne , Switzerland; ^4Institute of Applied Physics, UNIL, Lausanne, Switzerland Background: The nature (solid or gaseous) of TCD detected microembolic signals (MES) in patients with prosthetic heart valves (PHV) remains debated. Nitrogen bubbles produced by the cavitation phenomenon may substantially contribute to MES generation. We investigated the nature of MES in PHV carriers by applying a new automated system.. Patients and Methods: 58 patients, 17 with biological (BV) and 41 with mechanical valves (MV) were monitored over both middle cerebral arteries during 60 minutes using a Multi-Dop T2 ultrasound device (DWL, Germany). MES were identified according to standard criteria and analyzed by an off-line automated system to predict their nature. This system is based on the wavelet transform of MES combined with bigated TCD. All patients were sufficiently anticoagulated at the time of the TCD monitoring. Results : All but one BV patients had a strong majority of solid emboli [mean number of emboli/10 minutes of recording (M/10)= 1.7]. Only one BV patient had predominantly gaseous emboli. MV patients had a two-fold M/10 (3.42). In 6 (15%) MV patients more than 2/3 of emboli were gaseous; in 4 (10%) MV patients almost50% of emboli were gaseous; and 31(75%) patients had predominantly (>65%) solid emboli. In MV patients with M/10 >3 the odds for detecting gaseous emboli were almost 50%. Conclusions : Our findings suggest that a threshold of 3 MES/10 minutes exists, beyond which the chances of detecting gaseous or solid emboli are almost equal. As the number of emboli per unit of time increases the probability of detecting gaseous emboli rises as well. In contrast, MES in patients with biological valves are almost exclusively due to formed material.
P113	Limits of uncertainty on measured values of embolus-to-blood ratio due to Doppler sample volume shape and location E.L. Angell, D.H. Evans, A.R. Naylor University Hospitals of Leicester NHS Trust, Leicester, UK Background: Measurements of the relative Doppler power scattered by an embolus and its surrounding blood pool are widely used to infer the composition of the embolus. For a given embolus, the measured value of embolus-to-blood ratio (MEBR) will depend on the shape of the Doppler sample volume (SV), the geometrical relationship between the blood vessel and the SV, and the trajectory that the embolus follows in the blood vessel. This study was designed to quantify the likely magnitude of such effects on MEBR. Method: The shape of the Doppler sample volume of a transcranial Doppler system was characterised by combining ultrasound field intensity measurements made with a point hydrophone in an acoustic tank, with axial Doppler sensitivity measurements made with a string phantom. Four samples of human temporal bone were obtained at post-mortem, and the above method repeated with each bone sample coupled to the transducer. A numerical model that allows the calculation of theoretical values of MEBR as a function of the geometrical relationship between a blood vessel and a defined SV, and embolic trajectory was constructed. Numerical simulations were carried out to determine the range of MEBRs that would be measured for identical emboli, given the likely ranges of insonation angle, beam misalignment, and embolus trajectory that will occur in practice. Results: The distortion of the Doppler sample volume by bone had a significant effect on MEBR, however all bone samples produced similar changes so that the modal values of MEBR for all bone samples (0° insonation angle, zero offset) were all within 1-2 dB. The range of MEBRs due to embolus trajectory for this configuration was ~3 dB. As insonation angle increased, MEBR values increased (~3-4 dB at 30°). Offset, due to beam misalignment, had little effect on maximum and modal values of MEBR, but produced a significant tail of lower MEBR values (~10-12 dB for offsets that reduced the Doppler signal from blood to 80% of its maximum value). Overall, the effects of embolus trajectory, likely insonation angles, and small-scale vessel misalignments introduced uncertainties in MEBR values of ~10-12 dB for a given vessel size. Conclusions: Individual values of MEBR are affected by embolus trajectory, anatomical and geometrical considerations, and measurement technique. In practice the only operator-controlled factor is the degree of vessel misalignment, but relatively large degrees of misalignment produce relatively small changes in the Doppler signal power from blood (which is used to optimise alignment), and can significantly affect MEBR.
P114	EVALUATION OF AUTOMATIC CLASSIFICATION OF HITS BASED ON FUNDAMENTAL TONE ANALYSIS A.D. van Dijk, R.B.P. de Wilde, R.A.E. van der Rijken,E.F. Bruggemans Leiden University Medical Center, Leiden, The Netherlands Background: Since long, the ‘golden standard’ for classification of HITS into MES or artefact has been expert classification. In large patient studies and in clinical practice, however, this method is very time-consuming. In search for objective and powerful criteria for classification of HITS, we developed an automatic classification system that has strong parallels to human sound perception. Methods: As part of a larger study, 30-min TCD recordings of the middle cerebral artery blood flow of 12 patients with an aortic mechanical heart valve were analysed by an expert panel (RW, RR, EB) and by a Matlab-based computer program. Besides extracting standard event features, like power and width, this program performed Fundamental Tone (FT) analysis: FT power, frequency, and purity. Classification criteria were optimized in the learning set. The validity of these criteria was tested in a validation set consisting of 12 other patient recordings which were also subjected to computer analysis and expert classification. Results: Comparison of classification by computer and by expert panel produced the following results: # MES by computer # false positives # false negatives Learning set 252 25 9 Validation set 403 36 26 In conclusion: Parameters from fundamental tone analysis offer strong criteria for classification of HITS.
P115	ASYMPTOMATIC CAROTID EMBOLI STUDY - (ACES) Marisa Cullinane & Hugh Markus for the ACES Investigators. Division of Clinical Neuroscience, St. George's Hospital Medical School London, UK Background: Operating on all patients with asymptomatic carotid artery stenosis has poor cost benefit and risk benefit ratios. Techniques are required that allow identification of patients who are at highest risk of stroke. One such technique is the detection of embolic signals (ES) using transcranial Doppler ultrasound (TCD). Small studies suggest that ES predict stroke risk in patients with carotid stenosis. Aim: This is a multi-centre prospective study to determine whether asymptomatic cerebral embolic signals detected in the ipsilateral middle cerebral artery with TCD can predict stroke and TIA risk in patients with ≥70% asymptomatic carotid stenosis. 600 patients will be recruited. Methods: Patients are included if they have a 70-99% carotid stenosis that has been asymptomatic for ≥3 years. Subjects are followed up every 6 months for a period of two years with TCD recordings performed twice at entry and once on each follow-up visit except the last one. Carotid duplex is performed at entry and at one year. Primary end points are ipsilateral stroke and transient ischaemic attack. All TCD analysis is performed at the co-ordinating centre with analysis blinded to patient identity. To Date: 21 centres are recruiting patients in to the study. 152 patients had been recruited by the end of January 2002. There have been 4 ischaemic events, 3 of which were in the study artery territory.
P116	ON-LINE AUTOMATED DETECTION OF CEREBRAL EMBOLIC SIGNALS FROM A VARIETY OF EMBOLIC SOURCES. S Reihill, Z Kaposzta, M Cullinane, H S Markus St George’s Hospital Medical School, London, UK Background: A major limitation of embolic signal (ES) detection by transcranial Doppler is the lack of a reliable automated system. Characteristics of ES, particularly intensity, vary with different embolic sources. The performance of a new system needs to be evaluated separately for each different embolic source on consecutively acquired typical clinical recordings. Method: We evaluated a new on-line frequency filtering approach in a total of 565 hours of data containing 925 ES from patients with symptomatic and asymptomatic carotid stenosis, atrial fibrillation and immediately post-carotid endarterectomy. Results: The following sensitivities and specificities were achieved: symptomatic carotid stenosis: sensitivity 88.6%, specificity 98.4%. Asymptomatic carotid stenosis: sensitivity 85.7%, specificity 13.0%. Post-carotid endarterectomy: sensitivity 88.2%, specificity 96.2%. Atrial fibrillation: sensitivity 54.8%, specificity 7.0%. The low number of ES in patients with atrial fibrillation and asymptomatic carotid stenosis contributed to the lower specificity. Conclusion: This is the first on-line automated system with a performance similar to that of the human expert for ES detection post-carotid endarterectomy and in symptomatic carotid stenosis. Further work is required to improve its sensitivity and specificity in atrial fibrillation. We have shown the importance of evaluating any new system on consecutive routine clinical data from different possible embolic sources.
P117	CEREBRAL MICROEMBOLIC SIGNALS PREDICTING SYMPTOMS IN SEVERE ASYMPTOMATIC CAROTID STENOSIS G.Orlandi,S.Fanucchi,A.Gelli,C.Sonnoli,S.Gallerini,F.Sartucci Department of Neuroscience, Clinic of Neurology, University of Pisa, Italy Background: Ultrasonographic evaluation of carotid plaque morphology may fail to identify unstable plaques able to determine cerebral ischemic events. Transcranial Doppler (TCD) microembolic signals (MES) detection might be an useful tool to predict symptoms occurrence in such cases. Method: Twenty-one patients (13 males and 8 females, mean age 75.2 years) with asymptomatic >70% carotid stenosis documented by selective angiography were submitted to TCD monitoring prolonged for 60 minutes to detect MES in middle cerebral arteries. Monitoring was repeated after 6, 12, 18 and 24 months and clinical follow-up aimed to identify onset of symptoms (amaurosis fugax, transient ischemic attack, stroke) related to carotid stenosis was performed during such period. Results: Six of 21 (28.6%) patients showed MES in the middle cerebral artery on the same side as carotid stenosis during at least one of monitoring times and 5 of these 6 (83.3%) patients became symptomatic (transient ischemic attack in 2 cases and stroke in 3 cases). MES occurrence was intermittent at different monitoring times but always preceded symptoms onset. All the patients without MES remained asymptomatic during follow-up. Conclusions: These data suggest that MES detection may reflect fluctuations of carotid plaque embolic activity predicting symptoms occurrence.
P118	EMBOLIC AND HEMODYNAMIC MECHANISMS OF CEREBRAL ISCHEMIC EVENTS IN THE PATIENTS WITH CAROTID ARTERY DISEASE A. Kuznetsov, Yu. Kolbin, A. Erofeev, M. Odinak, Yu. Shevchenko, I. Voznyuk Military Medical Academy, St.-Petersburg, Russia Background: Embolism and hemodynamic disturbances can cause cerebral ischemic events (CIE) in the patients with carotid artery disease. The purpose of this study was estimation of relative significance of these mechanisms. Methods: We studied 65 special selected patients with carotid artery disease. We used transcranial Doppler sonography with 60-minute monitoring of middle cerebral artery and detection of microembolic signals (MES) in on-line/off-line regimes automatically and by experienced observer on the device "Sonomed-300" ("Spectromed", Russia), and colour-coded duplex sonography of carotid arteries on the device "Acuson 128XP" ("Acuson", USA). 37 patients had MES in the middle cerebral artery following ipsilateral carotid artery compression or percussion (evoked microembolism). They had unstable atherosclerotic plaques in the appropriate carotid artery without thrombosis. We did not register appearing of neurological symptoms following carotid artery compression (percussion). Other 28 patients had carotid stenosis without ipsilateral evoked or spontaneos microembolism. The degree of stenosis was 15%-100%. Results: We detected spontaneous MES during 60-minute transcranial Doppler sonography monitoring only in 16.2% of the patients with evoked microembolism. All of them had ulcerated carotid plaques. 45.9% of the patients with evoked embolism had the history of CIE: in 94.1% of cases - ipsilateral to MES, only in 5.9% - contralateral. There was a correlation between CIE and MES (r=0.44 Spearman, p<0.001). But there was no correlation between CIE and degree of stenosis. CIE developed even in conditions of low degree of stenosis. In 28 patients with carotid artery stenosis without microembolism correlation between CIE and occurring of stenosis was not detected, but there was a correlation between CIE and degree of stenosis (r=0.49 Spearman, p<0.001). Conclusions: Artery-to-artery cerebral embolism is main mechanism of cerebral ischemic events in the patients with carotid artery disease, independent from a degree of stenosis. Carotid artery stenosis without microembolism can cause cerebral ischemic events only in conditions of high degree of stenosis (hemodynamic mechanism).
P119	HETEROGENEITY OF EMBOLIC MATERIAL IN THE PATIENTS WITH CARDIAC SOURCES OF CEREBRAL EMBOLISM A. Kuznetsov, A. Lupeev, A. Prokofiev, V. Piriev, M. Odinak, Yu. Shevchenko Military Medical Academy, St.-Petersburg, Russia Background: Estimation of embolic material content is necessary for choice of adequate regime of preventive antithrombotic therapy. It seems that Doppler detection of cerebral microembolism can be useful in it. The purpose of this study was estimation of embolic material content in the patients with different types of cardiac sources of cerebral embolism. Methods: We studied 49 patients with mechanical prosthetic heart valves (MPHV) in aortic and mitral position, 13 patients with non-valvular atrial fibrillation (NVAF), 21 patients with infectious endocarditis (IE). We used transcranial Doppler sonography with monitoring of middle cerebral artery and detection of microembolic signals (MES) in on-line/off-line regimes automatically and by experienced observer on the device "Sonomed-300" ("Spectromed", Russia), and transthoracic echocardiography on the device "Acuson 128XP" ("Acuson", USA). Results: The most of cerebral ischemic events in the patients with MPHV and NVAF were happened in conditions of inadequate oral anticoagulation (66.7% and 100%, accordingly). There was no correlation between oral anticoagulation intensity as well as blood coagulability parameters and MES incidence as well as MES number. MES in the patients with NVAF were not detected. There was the correlation between MES incidence (and MES number) and MPHV dysfunction (r=0.79 Spearman, p<0.001). MES in the patients with IE were detected only in first two months of disease in conditions of active inflammation and friable valve vegetations. Additional antiplatelet therapy in the patients with MPHV and MES resulted in elimination or reduction microembolism in most cases (75%). The MES number was not reduced in 25%. There were no the history of cerebral ischemic events in these patients.
P120	CEREBRAL MICROEMBOLISM DURING HEART SURGERY WITH CARDIOPULMONARY BYPASS AND MEMBRANE OXYGENATION A. Kuznetsov, A. Erofeev, M. Odinak, Yu. Shevchenko, A. Mikhailenko Military Medical Academy, St.-Petersburg, Russia Background: Heart surgery with cardiopulmonary bypass (CPB) is accompanied by constant cerebral microembolism. The authors reported about absence of microembolism during the period of full CPB with membrane oxygenation. The purpose of this study was estimation of microembolism during different periods of heart surgery with CPB and membrane oxygenation. Methods: We studied 20 patients during heart valve replacement (HVR, n=10) and coronary artery bypass graft surgery (CABG, n=10). Moderate hypothermia (28-29 degrees С) and cold cardioplegia were used in HVR. Normothermia and warm cardioplegia were used in CABG. There were membrane oxygenation, non-pulsatile perfusion, 40-micron arterial line filter, and alpha-stat regime in HVR and CABG. We used transcranial Doppler sonography with monitoring of middle cerebral artery and detection of microembolic signals (MES) in on-line/off-line regimes automatically and by experienced observer on the device "Sonomed-300" ("Spectromed", Russia). Results: We have detected MES during heart surgery in all patients (100%). There were about 10 MES following aortic cannulation in all patients (100%). The incidence of MES during full CPB was also 100%. The number of MES was no more than 100 in most cases (70%). MES had tendency to appearing in the beginning of full CPB. 30% of the patients had the MES number more than 100. In the most of these cases we found out a very small leakage of junction of CPB lines. The removal of leakage resulted in elimination of microembolism. There was the constant microembolism during restoring heart activity after open-heart surgery within 30-40 minutes (MES number was about 100). In some cases intensive microembolism was registered during removal CPB venous lines. Conclusions: Microembolism is often event in the period of full CPB with membrane oxygenation. It can be caused by violation of tightness perfusion lines with injection of an air. The same mechanism of microembolism can be during removal CPB venous lines.
P121	DETECTION AND CHARACTERIZATION OF EMBOLIC SIGNALS BY PARAMETRIC MODELING. D.Kouamé, J.M. Girault, M. Biard and F. Patat. LUSSI FRE 2448 CNRS, University of Tours, France Background: Classical detection and characterization of embolic signals are based on an energetic analyze such as the Fourier spectrogram. Recently, we have proposed a new detection technique^1 based on a parametric Autoregressive (AR) modeling. This method has shown to be better than conventional energetic methods by using synthetic and some in-vitro Doppler signals. Methods: Concerning embolic signals detection, a deeper investigation is performed by using in vitro data and AR modeling. This data consists of acrylic particulates with different sizes. The existing characterization techniques^2 are revisited and extended to AR modeling. Results: Embolic signals Detection by AR Modeling is better than conventional energetic methods as far as probability of non detection is concerned. Concerning the characterization, experimental results of existing methods verified the theoretical predictions. Conclusion: It seems that AR modeling is a promising way to characterize and detect embolic signals. 1. J.M Girault, D. Kouamé, A. Ouahabi and F. Patat. "Micro-emboli detection : an ultrasound doppler signal processing viewpoint". IEEE Transactions on Biomedical Engineering 2000, vol (47) pp 1431-1439. 2. Moehring et al. "Sizing emboli in blood using pulse doppler ultrasound I : verification of the EBR model". IEEE Transactions on Biomedical Engineering 1996, vol (43) pp 572-580.
P122	IN VITRO BLOOD FLOW AND CROSS-SECTION INDEXES MEASURED USING TRANSCRANIAL DOPPLER ULTRASOUND D. Russell, R. Brucher. University of Oslo, Norway and Ulm University of Applied Sciences, Germany Background: The aim of this study was to assess the accuracy of blood flow and cross-section indexes measured with transcranial Doppler (TCD) in vitro. Methods: The study was carried out using a closed-loop system with a roller pump Windkessel function to flatten small ripples in the flow. This contained heparinized whole blood with an hematocrit value of approx. 30%. Measurements were made by insonating silicone tubes of 2, 3 and 4 mm diameters and a wall thickness of 1 mm. Flow was changed in these tubes as follows: 320, 240, 150 and 320 ml/min. The tubes were insonated at an angle of 45^oC with TCD instrumentation (DWL) using a 2 MHZ probe, 10 mm sample volume, 59 mm depth and peak repetition frequency of 6 KHZ. Frequency-weighted first moment calculations of Doppler power were made using specially designed software (BR02) and these arbitrary values were calibrated off-set for 0 flow. Cross-section area indexes were calculated by dividing the flow indexes by the maximum velocities. Reference flow index values were measured to ensure that back-scattering from the circulating blood remained constant throughout the studies. This was carried out by insonating a rectangular plexiglass tube (10x5x1 mm) throughout the studies with a fixed 2MHZ probe and constant settings. Results: The relative flow index values showed a very good correlation with changes of the known flow values using the three different tube diameters: tube diameter 2 mm (correlation coefficient, r) = 0.994, p<0.01; 2 mm, r = 0.999, p<0.01; 4 mm, r = 0.999, p = 0.001). The calculated cross-section index values for the 4 flow measurements varied for 2 mm diameter by a SD value of 0.85% for 3 mm diameter: 2.08%, and for 4 mm diameter: 2.53%. Conclusion: This in vitro study has shown that relative flow and cross-section indexes may be measured using TCD instrumentation. Methods to overcome beam distortion due to the temporal bone should now be developed so that this method may be adapted for in vivo transcranial use.
P123	ULTRASOUND DIAGNOSIS OF PREVALENCE ASIMPTOMATIC CAROTID DISEASE Djajić V, Vujković Z, Kovačević M, Žikić M, Arbutina M, Preradović LJ, Miljković S, Račić D Background: A lot of strokes are caused by pathologic proceses on carotid arteries. Their early recognition and mainteince of therapeutic measures is very important specially in patients with no associated neurologic symptoms. Ultrasonographic doppler sonography is method of choice for diagnosis of asimptomatic carotid disease, wich is uninvasive way to determine morphology of blood vesels and the quality of blood flow. Metods: We analised 360 patients with no associated neurological symptoms. Their carotid arteries were examinated by auscultation and by color doppler ultrasonography. Results: We have found pathological changes in 6,5 % of patients. They were more prominent in patients with risc factors for cerebrovascular disease and in eldery patients (one third of patients of 70 years and eldery had pathological changes). Among them only 22,05 % patients had murmor detectable by auscultation of carotid arteries so we concluded that is nesessary to performe color doppler ultrasonography examination.
P124	TRANCRANIAL COLOR CODED DUPLEX SONOGRAPHY IN DIAGNOSIS OF STENOSIS/OCCLUSIO INTRACRANIAL ARTERIES Vujković Z, Djajić V, Žikić M, Arbutina M, Miljković S, Račić D Background: Transcranial color coded duplex sonography exam is method of choice in diagnosis of cerebral occlusive disease. Metods: We examinated 128 patients with occlusive disease of endocranial arteries. All patients were examinated with transcranial color coded duplex sonography and computed tomography. Some of patients were examinated with magnetangiography. Results: We had 72 male (56%) and 56 female (44%). Midlage were 60,05. 20 patients were examinated with magnetangiography (15,62%) . 59,38% patients had stenosis/occlusio of midle cerebral artery. 79% patients with stenosis/occlusio middle cerebral atery had infarct in temporal and/or parietal part of cerebrum. CONCLUSIONS: The most common place of stenosis were middle cerebral artery. The most common place of cerebral infarct was at the part of vascularisation by pathology changed blood vessels (Transcranial color coded duplex sonography verify stenosis/occlusio).
P125	THE DEGREE OF CEREBRAL ATHEROSCLEROSIS(CA) AND CHANGES IN HEMOSTATIC SYSTEM IN PATIENTS WITH ACUTE ISCHEMIC STROKE(AIS) Raicevic R, Mandic-Radic S*, Lepic T, Pesic V**, Markovic Lj**, Tavciovski D***. Dpt. of Neurology, Dpt. of Biochemistry*, Dpt. of Radiology**, Dpt. of Cardiology*** Military Medical Academy, Belgrade, Yougoslavia Introduction. Blood coagulation and fibrinolytic process are involved in thrombotic vessel obstruction.It is accepted that are association among dysfunction of vascular endothelium and changes of coagulation proteins. Considering these facts, it was established the hypothesis that in patients with AIS existed changes in hemostatic system, which were were in positive correlation with the degree of CA. Methods and results. The study was performed in 99 patients (74 males and 24 females), average 66 years (range 44-82) with AIS confirmed by standard clinical and radiological criteriaa. The citrate blood was taken within 24-72 hours after acute event.The activities of protein C(PC),antithrombin III (ATIII),protein S(PS),a 2 antiplasmin(AP),and plasminogen activator inhibitor(PAI1) and D-dimer were measured by commercial reagents (Behring,Marburg and Instrumentation Labaratory,Milan).The results were compared with the values of 41 matched (31 males and 10 females) nonvascular neurological patients and compared.to the degree of CA (ultrasonographically). There was positive correlation of degree of CA cervical arteries and PAI 1 concentrations (p<0,05). For D-dimer it had boreder-line value (p=0,064). Significant negative correlation existed between ultrasonographic findings CA and antithrombin III and platelet aggregation (p<0,05). Conclusion. It is concluded that essential anticoagulants and inhibitors are important in regulation of hemostasis in patients with AIS, and.there is a significant increase in concentration of procoagulant factors in patients with AIS, which is in positive correlation with degree of CA.
P126	THE CORELATION OF PROTEINURIA, ISCHEMIC BRAIN DISEASE (IBD) AND CAROTID ATHEROSCLEROSIS R.Raicevic, S.Mandic-Radic*, T.Lepic, L.Markovic**, D.Tavciovski***, N.Vukotic.Dpt. Of Neurology, Dpt of Biochemistry*, Dpt. Of Radiology**, Dpt. Of Cardiology***. Military Medical Academy, Belgrade, Yougoslavia. Introduction. In about 80% of the cases of vascular brain diseases it is ischemic brain disease (IBD). In recent years it was reported for the first time of the association of atherosclerosis and/or its complications and proteinuria. Assuming that there exists the significant association between the degree of proteinuria, clinical parameters of IBD and degree carotid atherosclerosis. The aim of this study was to investigate the frequency and patterns of the association of proteinuria and clinical IBD parameters and with degree of carotid atherosclerosis -CA (ultrasonographically). Methods and results. The study was performed in 80 patients with IBD of atherothrombotic origin and 60 patients with the disease of non-vascular origin, as the control group. In all patients quantitative determination of proteinuria was performed and in the patients with IBD was determined the degree of IBD and afterwards the degree of functional and neurological impairment prior to and at the end of treatment in acute phase using standardised scales (Canadian¢ s neurological scale and Bartel¢ s index) The results were compared with degree of CA (ultrasonographically). There was positive correlation of degree of CA cervical arteries and proteinuria (p<0,05). The results of the study revealed the existence of significant frequency of proteinuria in patients with IBD, as well as the significant association between the degree of proteinuria and severity of IBD. Conclusion. It was concluded that proteinuria in patients with IBD was probably associated with the atherogenic processes and physopathologic processes of IBD, respectively, which could have predictive value fot the outcome of the disease in the early stage.
P127	A concept for a Fuzzy pattern-based network for Medical decision support system in Early Treatment of Stroke R.P. Hofmann ^1, S. Bocklisch ^2, A. Türk ^2, B. Schmidt ^1, J.J. Schwarze ^1, J. Klingelhöfer ^1 ^1 Dept. of Neurology, Chemnitz Medical Centre, Chemnitz, Germany ^2 Dept. of Systems Theory, Technical University, Chemnitz, Germany Stroke is a complex disease which requires detailed historical data and extended diagnostic tests within a limited time period after the event. A central computerised decision support system might be useful in order to recommend therapeutic procedures in acute stroke. A method called Fuzzy Pattern Classification was previously developed at the Technical University of Chemnitz and used for process analysis and control in mostly industrial applications. However, this method was also successfully used to estimate cerebral compliance by analysis of ICP pulse waves. Moreover, its benefit for the non-invasive assessment of ICP has been presently proved and is subject of ongoing investigations. Fuzzy-Pattern-Classification method allows a simultaneous processing of exact (metric) data and intuitive information. In the present study a decision support system in early treatment of stroke is being developed. Decision rules are derived from patients reference data or from explicit expert knowledge. The system is structured as a network of linked local Fuzzy-Pattern-Classification knots, each of them representing a well-defined state in the patient’s treatment process and each of them being concerned with a state-related task of decision finding. The system’s network structure is chosen in order to correspond to the human process of decision finding. The splitting into local decision knots reduces complexity, increases transparency and facilitates testing of the system. Furthermore the modular structure simplifies possible extensions of the system. In view of the complex stroke treatment, we are developing a prototype model using data of 10 representative stroke patients to demonstrate the decision finding strategies in principle.
P128	Aortic Dissection Presenting as an Acute Ischemic Stroke K. Uchino, Z. Garami, S. Calleja, A. Estrera, A.V. Alexandrov University of Texas-Houston, Houston, Texas, United States of America Background: Thrombolysis for treatment of acute ischemic stroke requires careful selection of patients. Aortic dissection carries high mortality and is accompanied by cerebral infarction in approximately 6% of cases. We report a case of aortic dissection presenting with acute ischemic stroke for which emergent ultrasonographic evaluation was performed. Methods and Results: A 56 year-old woman with history of hypertension was found on the floor at home. She presented to our emergency center 45 minutes after last seen normal. She had left hemiplegia, dysarthria, and neglect with the total NIH Stroke Scale score of 16 points. She also complained of midsternal chest and bilateral ear pain. On examination, her blood pressure was 108/56 with heart rate of 51. Her heart sounds were regular without any murmur and peripheral arterial pulses were symmetric. A non-contrast CT scan of head was normal. ECG showed sinus bradycardia without any changes suspicious of myocardial infarction. Her laboratory studies, including platelet count and creatinine kinase, were normal. Chest X-ray was normal without any mediastinal widening. Emergent transthoracic echocardiogram revealed no wall motion abnormalities, pericardial effusion, or tamponade. She qualified for the standard intravenous tPA therapy, and the bolus dose of 5 mg was given. Transcranial Doppler showed right middle cerebral artery occlusion and carotid duplex examination revealed a proximal right common carotid occlusion with a thrombus. Based on this information, tPA was stopped and she underwent urgent chest CT angiography, which revealed type A thoracic aortic dissection. She underwent surgical repair of the dissection with hypothermic arrest and retrograde perfusion of the brain. Her stroke symptoms did not improve significantly and at 3 months after the dissection and stroke she had modified Rankin score of 4 and Glasgow Outcome Scale of 3. Conclusions: Careful vascular diagnostic work-up of patients who are candidates for thrombolysis is necessary. An experienced sonographer with skills to perform rapid intra- and extra-cranial examinations may help to change treatment plan for acute stroke patients.
P129	SPONTANEUS MCA RECANALIZATION: TRANSCRANIAL DOPPLER FINDINGS IN PATIENTS WITH ACUTE STROKE IN CAROTID TERRITORY J. Salevic Obradovic, G. Obradovic, P. Nikic, S. Jotic, D. Arsic Medical center Krusevac, Yugoslavia Background: In the patients with ischemic stroke in carotid artery territory Transcranial Doppler (TCD) with low MHz frequency had a high sensivity and specificity to determine occlusion and spontaneus recanalization of the middle cerebral artery (MCA) compared with angiography studies. In those patients we applied TCD to investigate a frequency and site (proximal vs. distal) of ipsilateral MCA occlusion and to establish the rate of spontaneus MCA recanalization. Methods: A standard TCD examination was performed with a MultiDop unit between 3 to 6 hours of onset to identify the MCA occlusion site in consecutive 100 patients with acute ischemic stroke in carotid artery territory Repeated TCD (after 48 hours and 7 days) was used to identify spontaneus MCA occlusion according to previously published diagnostic criteria. Results: In the patients with acute ischemic stroke in carotid artery territory ipsilateral MCA occlusion was identified in 27 patients (27%). Proximal MCA was occluded in 8 (29,6%) and distal in 19 patients (70,4%). On TCD, 48 hours after stroke onset evidence for spontaneus recanalization was found in 4 (50%) with proximal and in 12 patients (63,2%) with distal MCA occlusion. After 7 days, spontaneus recanalization on TCD was found in 1 (12,5%) with proximal MCA occlusion and in 1 patient (5,3%) with distal MCA occlusion. Conclusions: TCD findings 48 hours and 7 days after stroke onset confirmed a great rate of spontaneus ACM recanalization, more often in patients with distal -13 of 19 (68,4%) than in patients with proximal MCA occlusion - 5 of 8 (62,5%). The rate of spontaneus MCA recanalization was greater seen over first 48 hours -16 of 18 patients (88,8%). It was neccessary to determine assotiation between recanalization of MCA ocllusion and clinical recovery of stroke patients.
P130	Cerebrovascular Haemodynamic Mapping Using Colour Duplex Ultrasound In Subjects With Internal Carotid Artery Stenosis S.M. Byrd, A. Zambanini, A.D. Hughes, S.A. McG Thom. Department of Clinical Pharmacology, NHLI at St. Mary’s Hospital, London, UK Background: Clinical trials indicate patients with higher degrees of ICA stenosis are at increased risk of stroke.The pathogenesis of stroke may be embolic, but the haemodynamics of the cerebral circulation were not evaluated in these trials. Cerebrovascular haemodynamic mapping (CHM) combines carotid duplex and transcranial colour-flow imaging to produce a detailed velocity map of the extra- and intracranial vasculature. The aim was to evaluate the effects of increasing degrees of ICA stenosis on the haemodynamics of the cerebral circulation. Methods: Normal subjects and subjects with ICA stenosis were evaluated with CHM using an ATL 3000 scanner. Severity of ICA disease was categorised by established Doppler criteria (Strandness/Moneta) into mild, moderate, and severe/occlusion. Using velocity and flow directional information from CHM, the presence of collateral flow was defined as reversed flow in the ACA, or an elevated velocity in the PCoA on the side of the stenosis. Pulsatility index (PI-Gosling) was also measured in the ipsilateral MCA. Results: 104 subjects (83 M, mean 64 yrs) with ICA stenosis, and 13 normals (9 M, mean 57 yrs) were studied. Eighty-six subjects had bilateral ICA stenoses, and 18 had unilateral stenosis. Data summarised in table (below). Data: mean (± 95% CI);*p < 0.05 compared to normals Conclusion: This study suggests that even with the presence of intracranial collateral flow, subjects with severe ICA stenosis/occlusion have a significant decrease in MCA flow velocity/ PI, and may be at increased risk of stroke. Cerebrovascular haemodynamic mapping is a novel technique which can identify alterations in cerebral haemodynamics, and may provide further insight into the haemodynamic mechanism of stroke.
P131	Influence of the detection time on the relation between persisting embolic signals after secondary prevention and stroke recurrence T. Blaser, S. Guhr, K. hofmann, S. Krueger, M. Goertler Department of Neurology, Otto-von-Guericke University Magdeburg, Germany Background: A one hour recording has been proven of clinical relevance to predict stroke recurrence by persistence of embolic signals (ES) after initiation of antithrombotic secondary prevention. However, this time period might not be tolerated by restless patients and limit usefullness of the examination in an akute stroke setting. Methods: Based on the results of 2 one hour monitorings in 86 patients with recent arterioembolic stroke before and after the initiation of an antithrombotic therapy, we calculated the relationship between cessation/persistence of embolic signals and stroke recurrence at shorter recording times. We thereby shortened the detection time in steps of 5-10 minutes from 60 minutes to 10 minutes. Results: In 44 patients ES were detected during an 1 hour–recording at admission before antithrombotic therapy and in most of them all ES were recorded during the first 10 min (40 patients). 25 of this 44 patients had embolus signals during the 1 hour monitoring after antithrombotic therapy. In this second recording all ES were detected in most of the patients within 45 min recording (24 patients). 6 patients with persistent ES suffered a re-ischaemia. Persistence of ES detected within recording time of 30 min at admission and 40 min at second monitoring was an independent predictor of a recurrent ischemia (adjusted odds ratio: 18,9; 95% CI 1.0-347; p=0,048) Conclusions: A 30 min-recording time may be sufficient to determined the persistence of ES and the assessment of the risk for recurrent ischemia.
P132	CORRELATION BETWEEN TISSUE OXYGENATION INDEX (TOI) AND CBV: A TOOL TO EXPLORE CBF. D.Bosone , D. Canova°, S. Roatta °, S.Marcheselli, M.Passatore°, G.Micieli. Neurovascular Unit, "C. Mondino" Foundation, University of Pavia, Italy ° Dept. of Human Physiology, University of Turin, Italy Background: Different studies have evidenced that the relationship between CBV, as monitored by transcranial Doppler sonography, and cerebral tissue oxygenation parameters, as measured by near infrared spectroscopy (NIRS), may change in response to different hemodynamic stimuli. Since both TOI and CBV can in principle reflect changes in cerebral blood flow (CBF), we sought to specifically analyse their correlation under different hemodynamic challenges. Methods: Ten healthy subjects underwent a random sequence including the following tests: hyperventilation (HV), rebreathing, head-down tilt (HDT), Valsalva maneuver (VM), head-up tilt (HUT), handgrip (HG), sublingual nitroglycerine (NTG). Each subject remained in a supine position during the whole sequence, a resting period of 5-10 min being allowed between tests. CBV was monitored from the left MCA along with NIRS parameters (TOI, D totHb, D oxyHb, D deoxyHb, CytOx), cutaneous blood flow (laser Doppler) and arterial blood pressure (Finapres). Results: Correlation between TOI and CBV was not observed in all conditions. They both decreased in HV and VM and increased in rebreathing. Little effects were observed in HG while unrelated effects were observed in HDT, HUT and NTG. Conclusion: Assuming unchanged brain metabolism, TOI theoretically increases with increasing blood flow and viceversa, thereby correlating with CBV provided MCA diameter remains constant. Absence of correlation as observed in NTG has to be attributed to MCA dilatation while in HUT and HDT it probably reflects an artero-venous imbalance in the NIRS sampled volume. For instance HDT, by inducing an increase in the venous pressure, is likely to cause venous dilatation thereby increasing the venous/arterial volume ratio and reduce TOI without implying a change in CBF or brain metabolism.
P133	DIAGONOSTIC ACCURACY OF TRANSCRANIAL DOPPLER IN HYPERACUTE STROKE COMPARED TO URGENT ANGIOGRAPHY Yong-Seok Lee & Andrei V. Alexandrov^* Seoul Municipal Boramae Hospitlal, Seoul National University, South Korea & University of Texas Houston Medical School^*,U.S.A. Background: Arterial occlusion in acute stroke may be in a dynamic process of thrombus propagation, spontaneous recanalization, and reocclusion. Transcranial Doppler (TCD) can be used to diagnose the presence of arterial occlusion, its location, and to monitor recanalization. Previous studies showed significant yield of urgent TCD, however, there were substantial time delays between TCD and angiography. Subjects and Methods: Consecutive patients with acute symptoms of cerebral ischemia were included if TCD was performed within 6 hours from symptom onset and subsequent digital subtraction (DSA) or computerized tomographic angiography (CTA) was also performed urgently. Previously published TCD criteria for occlusion were applied. TCD and angiography results were independently interpreted by neurologisits and neuroradiologists not involved in this study. Results: Thirty-four patients (M:F=19:15, mean age: 65± 17, 32-88 years, median NIHSS 14 points) met these inclusion criteria (32 DSA and 2 CTA). Median time from onset to TCD examination was 125 minutes (mean 155± 79 minutes), and from TCD examination to angiography was 120 minutes (mean 177± 197 minutes). There were 25 true positive, 3 false positive, 0 false negative, and 6 true negative TCD studies for occlusion presence. Sensitivity, specificity, positive predictive value and negative predictive value were 100%, 67%, 89%, and 100% with overall accuracy of 91%. False positive TCD results of distal middle cerebral artery (MCA) and basilar artery occlusion were obtained in patients with NIHSS score 3, 13 and 4 points. True-positive occlusions were located in the MCA (14), terminal internal carotid (5), proximal internal carotid (3), basilar (1) and terminal vertebral artery (2). TCD monitoring until angiography was employed in 12 patients. Seven had persistent occlusion, four had complete recanalization and one showed reocclusion. In all of these patients, final TCD interpretation was confirmed at angiography. Conclusion: Emergent TCD can sensitively and reliably detect arterial occlusion in hyperacute stroke patients. TCD findings suggestive of distal branch occlusion in patients with low NIHSS should be interpreted with caution. Repeated TCD examinations or continuous monitoring are recommended to enhance the diagnostic accuracy.
P134	Cerebral vasospasm – more frequent following endovascular aneurysm coiling? R.Stendel, A.Schilling, T. Picht, A. Derdilopoulos, C. DaSilva, J. Heidenreich, T. Pietilä, M. Brock Dept. of Neurosurgery, UKBF, Free University of Berlin, Germany Background: Cerebral vasospasm is the most common cause of morbidity and mortality in patients with subarachnoid hemorrhage. The early removal of subarachnoid blood and irrigation of the basal cisterns during surgery has been reported to reduce the incidence of vasospasm. In contrasst to aneurysm clipping, endovascular treatment does not allow removal of subarachnoid blood. The present study compares the incidence and severity of symptomatic cerebral vasospasm following endovascular treatment and aneurysm surgery in patients with subarachnoid hemorrhage due to aneurysm rupture. Methods: A total of 52 patients with subaracnoid hemorhage classified as Hunt and Hess grdaes I to III were included. From these, 25 patients underwent aneurysm clipping and 27 endovascular aneurysm coiling. The amount of blood on computerized tomography was classified by means of Fisher´s scale. Hypertensive, hypervolemic, hemodilution therapy was used to treat vasospasm. Results: Vasospasm occurred in 8 (35%) patients following clipping, and in 11 (41%) following endovascular treatment. The eman duration of vasospasm was 17.5 days in the coiling group as compared to 10.7 days in the clipping group (p<0.05). The mean blood flow velocity in the middle cerebral artery during the first 21 days following subarachnoid hemorrhage was 117.4 cm per second in the coiling group and 94.9 cm per second in the clipping group. Conclusions: The incidence of cerebral vasospasm after aneurysmatic subarachnoid hemorrhage seems to be higher in patients following endovascular aneurysm coiling as compared to patients following clipping.