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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. |
|
P135 |
A NON-LINEAR MODEL FOR THE ESTIMATION
OF ICP from MCA flow velocity and arterial blood pressure B. Schmidt 1, S. Bocklisch 2, M. Päßler
2, M. Czosnyka 3, J. Schwarze 1, J.
Klingelhöfer 1 1 Dept. of Neurology, Chemnitz Medical Centre, Chemnitz, Germany 2 Dept. of Systems Theory, Technical University, Chemnitz, Germany 3 Academic Neurosurgical Unit, Addenbrooke's Hospital, Cambridge, UK Background and Purpose. A model previously introduced by the authors allowed a non-invasive estimation of intracranial pressure (nICP) by the installation of a linear relationship between certain hemodynamic parameters and the quotient of mean ICP and arterial blood pressure (ICP / ABP). Former results suggested that this relationship might vary with the patients disease and other parameters, e.g., the state of cerebral autoregulation. In this approach the former global linear relationship between hemodynamic parameters and the ICP / ABP ratio was split into pieces of local linear functions in order to adapt the model to a potentially non-linear relationship. Methods and Results. Simultaneous recordings of cerebral flow velocity (FV), ABP and ICP in 66 traumatic brain injured patients (mean age: 39, range:6-73 years) with impaired autoregulation were studied. Hemodynamic parameters, calculated at several time points from FV and ABP recordings, as well as the time corresponding ratios ICP / ABP were sampled and analysed. A method called Fuzzy Pattern Classification was used to identify substructures (classes) in the set of all parameter samples. On each of the classes a specific linear function which related hemodynamic parameters to the ICP/ABP ratio was defined. In the current basic model we defined constant functions (mean ICP/ABP ratio) in each class. Using this model ICP was estimated as follows: From FV and ABP the hemodynamic parameters were calculated and related to the matching class(es). ABP multiplied by the class specific estimator(s) of ICP/ABP yielded the estimated value of ICP. Median error between ICP and nICP was 6.9 mmHg. A-waves of ICP and nICP significantly agreed, and long-term trends of ICP could be assessed properly. Conclusion. The results encourage the
application of this model for nICP assess-ment. The class structure of the
method allows modular extensions of applicability in heterogeneous patient
groups without affecting the previous validity. This might enable the
inclusion of patients with irregularities like vasospasm or hyperemia. |
|
P136 |
Clinical and ultrasound findings after
percutaneous transluminal stent angioplasty of the internal carotid artery: a
mid-term follow up Becker U, Gahn G, Hallmeyer-Elgner S, Mueller A, Mucha D,
Reichmann H, von Kummer R Departement of Neurology and Neuroradiology,
University Hospital Dresden, Germany Objective: To assess complications after percutaneous
transluminal stent angioplasty (PTSA) in the proximal internal carotid artery
(ICA). Material and Methods: Since 1998, we consecutively and prospectively
investigated the clinical and sonographical course of 46 PTSA in the ICA of
43 patients (mean age 67.5+9.1, 9 women, 34 men). Indications for
intervention were symptomatic stenosis > 70% (38), asymptomatic progressive
stenosis > 90% (6) and symptomatic stenosis < 70% (2)
(NASCET). The mean grade of stenosis was 80.1+11.8%. We used
self-expanding stents in conjunction with angioplasty. All patients received
a combination of aspirin and clopidogrel for 4 weeks, thereafter aspirin
(30), clopidogrel (2), aspirin and clopidogrel (6) or warfarin (2).
Neurological examination and color-coded duplex sonography (CCDS) were
performed before and after the procedure. Fourty patients (93.0%) were
follwed by CCDS and clinical interview after 1, 4, 10, 22 and 34 months (mean
follow up 9.3+7.4 m). Results: During PTSA 3 patients (6.5%) had an ischemic
stroke. CCDS detected 7 residual stenoses (15.2%) directly after PTSA. Six of
them were due to narrowing of the stent, were not progressive and remained
asymptomatic. One of them was due to an acute symptomatic stent-thrombosis.
This stenosis was treated with rt-PA and recanalized completly within 1 week. During follow up 1 patient (2.2%) had a
recurrent stroke after 4 weeks, 3 patients (6.5%) died due to another reason
than stroke. CCDS detected 6 asymptomatic restenoses (13.0%). Diagnostic
angiography showed intimal hyperplasia. In one patient incomplete stent
expansion at the common carotid artery caused a double lumen. All restenoses
remained clinically asymptomatic. The ipsilateral external carotid artery was
in all cases patent. Conclusion: PTSA has an acceptable clinical risk in the
treatment of symptomatic or critical ICA stenoses. The risk of recurrent
strokes is low. CCDS appears to be a useful technique to detect restenoses. |
|
P137 |
MICROVASCULAR DOPPLER ULTRASONOGRAPHY
MONITORING IN NEUROSURGICAL PROCEDURES. Ghadirpour R, Farneti M, * Zoppellari R,* Guberti A and
Padovani R. Department of Neurosurgery, *Service of
Anesthesiology, St. Anna Hospital - University of Ferrara, Italy Background: Vascular injuries occurring during neurosurgical
operations can be responsible for high morbidity. Therefore, we consider of
help detecting in real time the location and the integrity of critical
vessels, the damage of which may cause a worse outcome. Methods: With the use of a 20 MHz microprobe, 2 mm in
size, all arteries located within 15 mm from the tip of the probe could be
rapidly and noninvasively revealed, without interfering with the operative
field. We present some illustrative cases of our experience on microvascular
doppler ultrasonography monitoring (MDUM) during transsphenoidal, aneurysms,
spinal dural arteriovenous fistulae (AVF), carotid endarterectomy (CEA) and
skull-base tumours surgery. Results: During transphenoidal surgery, the device is used
to identify the intracavernous portion of ICA embedded in the tumour mass or
in the presence of aberrant anatomic course. In aneurysms surgery the MDUM
let us control an inadvertent occlusion of an adjacent vessel by the aneurysm
clip or an incomplete aneurysm closure. In spinal AVF, detecting the
variation of the arterial spectrum on the perimedullary draining veins before
and after the interruption of the arteriovenous shunt, the monitoring is able
to confirm complete obliteration of the fistula. In CEA it is possible to
evaluate the anatomical extension of the stenosis, to verify the absence of
flow after clamping and to control the plaque removal. The skull-base
tumours, like meningiomas, can encase and displace the middle cerebral artery
or other branches of the circle of Willis; the 20 MHz microprobe can localize
these vessels inside the tumour, avoiding their direct mechanical injury
during the procedures of dissection and removal of the lesion. Conclusion: Microvascular doppler ultrasonography enhanced operative safety with technical simplicity and should be used routinely in neurosurgical procedures. |
|
P138 |
CEREBRAL AUTOREGULATION MONITORING BY
TRANSCRANIAL DOPPLER DURING LIVER TRANSPLANTATION A. Arrigo, G. Ardizzone*, G. Brusa, M.
Messina*, C. Siani*, G.A. Ottonello Neurofisiopatologia-Ospedale S. Martino,
*V SAR-Università, Genoa, Italy Background: Patients undergoing orthotopic liver
transplantations (OLTx) for end stage liver failure frequently have
hepatic encephalopathy, condition which is associated with impairment of
Cerebral Autoregulation (CA). During OLTx hemodynamic instability is
frequently encountered and the most dramatic hemodynamic imbalance is mainly
seen after reperfusion of the liver graft. Cerebral blood flow velocity (CBF-V) and
CA changes were studied, on line, during 24 OLTx by transcranial doppler. Method: CBF-V was continuously recorded by a fixed (helmet)
2 Mz probe through the transtemporal window on the MCA. CA was studied by
linear regression analysis between parallel CBF-V and MABP percentual changes
from baseline during slow phenilephrine infusion. We calculated the slope
"S" of the regression line in each patient. The line slope
"S" corresponds to cerebrovascular resistance (CVR) since it is the
ratio of the corresponding variations of CBF-V on MABP. When the slope
"S" tends to "0" CVR are fully preserved and CA is
maintained. On the contrary when the slope "S" is ≥ 1, CVR
are markedly reduced and CA is lost. Results: Wilcoxon’s test showed a significant slope
"S" increase between ANHEPATIC vs POST-REPERFUSION PHASE (first
hour after graft reperfusion) and a recovery in the NEOHEPATIC phase (end of
surgery). Conclusions: Our data show that in the first hour after graft
reperfusion there is a failure of CA coupled to a reduction of CVR. This
phoenomenon causes an increase of CBF-V and could expose the brain to
hyperperfusion when MABP rises and could not avoid the onset hypoperfusion
during systemic hypotension. In addition, transcranial doppler has been an usefulness tool for the cerebral hemodynamics changes monitoring in operatory room, having allowed to identify on line cerebral hemodynamics imbalances. |
|
P139 |
CEREBRAL AUTOREGULATION DURING
ANAESTHESIA IN CIRRHOTICS PATIENTS: A TRANSCRANIAL DOPPLER STUDY A. Arrigo, G. Ardizzone*, G. Brusa, E.
Riccò*, C. Siani*, G.A. Ottonello Neurofisiopatologia-Ospedale S. Martino,
*V SAR-Università, Genoa, Italy Background: Patients undergoing liver transplantation for end
stage liver failure frequently have hepatic encephalopathy, condition which
is associated with impairment of Cerebral Autoregulation (CA). The aim of
this study is to verify the influence of anesthetics (isoflurane and propofol
without N2O) on CA studied with TCD, in cirrhotics patients during
liver transplantation. Methods: 24 patients (17 males, 52 ± 5.4 y.rs) were studied. Anesthesia was carried on in the first hour with isoflurane at an end tidal concentration of 0,6% without N2O. During the second hour, after discontinued isoflurane, propofol was infused at the rate of 0.6 ± 0.2 mg/kg/h. Mean CBF velocity (CBF-V) was measured by transcranial doppler on the MCA. CA was studied by linear regression analysis between parallel CBF-V and MABP percentual changes from baseline during slow phenilephrine infusion. We calculated the slope "S" of the regression line in each patient. The line slope "S" corresponds to cerebrovascular resistance (CVR) since it is the ratio of the corresponding variations of CBF-V on MABP. When the slope "S" tends to "0" CVR are fully preserved and CA is maintained. On the contrary when the slope "S" is ≥ 1, CVR are markedly reduced and CA is lost. Differences were studied by nonparametric Wilcoxon's signed rank test. Results: Slope "S" resulted statistically higher
during isoflurane (0.9 ± 0.5) than propofol (0.55 ± 0.2) anesthesia (P<
0.01). No differences were found in MABP and CO2 between the two
stages. Conclusions: In our patients 0.5 MAC of isoflurane is sufficient to impair CA and to produce a CVR reduction. Propofol is able to perform better condition for CA. TCD monitoring has allowed to study the cerebral hemodinamic on line in operatory room and it has offered the possibility to find the anesthetic of choice in the patients with end stage liver failure. |
|
P140 |
EARLY DETECTION OF HYPERPERFUSION
SYNDROME (HS) BY DAILY TRANSCRANIAL DOPPLER INVESTIGATION (TCD) DURING DAY
0-4 AFTER CAROTID ENDARTERECTOMY (CEA) A.Schaafsma, L.vd.Veen and J.P.M.Vos, Martini Ziekenhuis
Groningen, the Netherlands. Methods: at our hospital all CEA patients with sufficient
temporal windows receive daily TCD-investigation of ipsi- and contralateral
middle cerebral artery (MCA) on postoperative days 0-4. This has enabled
pre-symptomatic detection of 2 cases of definite HS in nearly 150 consecutive
patients. Results: 1 patient showed abnormally high MCA flow
velocities (FV) straight after surgery. Based upon TCD measurements we
advised prolonged intensive care monitoring. On postoperative day 2 the
patient developed surges of hypertensive blood pressures up to 210 / 105.
Prompt administration of anti-hypertensive drugs probably prevented secondary
complications. A second patient developed abnormally high MCA FV on
postoperative day 3. We advised against discharge from hospital. On postoperative
day 4 the patient developed a focal status epilepticus contralateral to the
side of CEA together with surges of hypertensive blood pressures up to 210 /
120. Despite the prompt administration of anti-hypertensives and
anti-epileptics the patient suffered a worsening of pre-existent hemiplegia. Conclusion: daily TCD-monitoring after CEA may enable
presymptomatic detection of HS. Abnormal increases in MCA flow velocity seem
to develop prior to other symptoms of HS, such as malignant hypertension,
focal status epilepticus, focal neurological deficit and, ultimately, brain
hemorrhage and death. Ref.: Eur.J.Vasc.Endovasc.Surg. Vol 23(1) pp. 17-22. |
|
P141 |
MONITORING OF CEREBRAL BLOOD FLOW WITH
POWER MODE DOPPLER TCD DURING RETROGRADE CEREBRAL PERFUSION Z. Garami1, A. Estrera2, R. Sheinbaum3,
S. Calleja1, O. Chernyshev1, K. Uchino1, M.
Malkoff1,A. V. Alexandrov1, H. Safi2 1 Department of Neurology, 2 Dept of Cardiothoracic and
Vascular Surgery,3 Dept. Of Anesthesiology, University of Texas-Houston, USA Background: Retrograde cerebral perfusion (RCP) is used for
cerebral protection during repairs of the ascending and transverse aortic
arch with profound hypothermic circulatory arrest (PHCA). A single channel
transcranial Doppler (TCD) monitoring has been used previously with varying
success. The purpose of the study was to determine the effectiveness of a new
technology, Power Motion-mode Doppler (PMD or M-mode), in detection of
retrograde flow dynamics in the major intracranial arteries during RCP. Method: A prospective, observational study of patients
undergoing ascending and transverse aortic arch repairs was performed using
PMD and single gate spectral TCD combined in a TCD 100M unit, Spencer
Technologies. PMD simultaneously displays flow intensity and direction over 6
cm of intracranial space and makes it easier to select depth for spectral
waveform analysis. Data on pump-flow characteristics and patient recovery
were collected. Results: A total of 26 patients were studied (one patient
did not have temporal window). In 5 patients with suboptimal windows we
monitored ICA, vertebral arteries (2-2) and basilar artery (1). Mean RCP time
was 34.8 minutes, and mean RCP pump flow and RCP peak pressure for
identification of cerebral blood flow were 0.62 L/minute and 31.3 mmHg,
respectively. Retrograde cerebral blood flow during RCP was detected in 100%
of cases with a mean TCD flow velocity of 16.8 cm/sec. In the study group,
30-day mortality was 15.4% (4/26). The incidence of stroke and temporary
neurological deficits were 7.7% (2/26) and 26.9% (7/26), respectively. Conclusions: PMD-TCD monitoring can be used to effectively determine reversal of flow in the M2, M1 MCA, and vertebro-basilar segments in all patients undergoing RCP. Potential for PMD-TCD to identify patients at risk of perioperative events can be determined in an interventional study with stratified adjustment of pump-flow settings using intracranial reversed flow measurements. |
|
P142 |
Microembolusdetection in patients with
Fabry's disease - Further support for the primarily microangiopathic origin
of early cerebrovascular symptoms M. A. Ritter, R. Dittrich, D. W. Droste Department of Neurology,
Universitätsklinikum Münster, Germany Introduction: Fabry’s
disease is a sex-linked recessive storage disorder leading to cerebrovascular
symptoms in many cases. Fabry’s disease predominantly results in small vessel
disease, but also may affect large arteries. This is why the primary origin
of cerebrovascular symptoms is under debate. Microembolic signals indicative of an
active embolic source can be recorded by transcranial Doppler sonography
(TCD). We report on three patients with Fabry’s disease from one kindred in
whom we carried out microembolus detection recordings. Methods: Three patients of our department from one family
were examined clinically and by ultrasound. Fabry’s disease was diagnosed by
pathologically decreased a-galactosidase activity in lysomsomes of
lymphocytes. The right MCA was continuously insonated by TCD through the
temporal window for one hour in all patients. The Doppler signal
was recorded onto digital audio tape (DAT) and an experienced observer
analysed the tape off-line blinded to the patients’ diagnosis. Results: No microembolic signals were found in
one-hour-recordings in all patients. Conclusion: Our results support the thesis that early cerebrovascular symptoms in patients with Fabry’s disease arise from small vessel occlusion and not from embolic sources. MES-detection might proof useful to justify therapeutic means such as antiaggregation or anticoagulation in patients with Fabry’s disease who have had cerebrovascular symptoms. |
|
P143 |
B-MODE AND COLOR-CODED DUPLEX
SONOGRAPHY OF THE OPTIC NERVE AND OF THE CENTRAL RETINAL VESSELS IN OPTIC
NEURITIS U. Walter1, U. Kirchhoff2, V. Hingst3,
U.K. Zettl1, R. Guthoff2, R. Benecke1 University of Rostock, Germany, 1Department
of Neurology, 2Department of Ophthalmology, 3Institute
of Diagnostic and Interventional Radiology Background: To investigate the frequency and degree of
abnormalities detected by B-mode sonography (BS) and color-coded duplex
sonography (DS) in patients with acute unilateral optic neuritis. Method: 25 patients aged 38 ± 10 years with unilateral
optic neuritis were prospectively studied. BS was performed through the
abducted ocular bulbus imaging the transsectional area of the optic nerve
(ON). Diameters of the affected and the contralateral ON were measured. The
quotient of both diameters was calculated for each patient. If the quotient
exceeded 1,1 the affected ON was considered as swollen. MRI was performed to
objectively localize and measure the ON lesions. In 10 patients DS of the
ophthalmic arteries and the central retinal vessels was performed. Peak
systolic flow velocity, mean flow velocity, and resistance indices were
calculated for each vessel. Results: In 17 of the 25 patients the affected ON was
swollen. The mean diameter of the affected ON of all patients was 3,6 ± 1,0mm,
and of the contralateral ON 2,7 ± 0,4mm. The difference was statistically
significant (t test, p < 0,001). A significant difference was also
found in the resistance index in the central retinal artery between the
affected and unaffected eyes. Conclusion: In patients with acute unilateral optic neuritis abnormalities of ON morphology and of central retinal artery perfusion may be frequently detected by sonography. BS and DS appear to be sensitive tools which are of potential use for disease monitoring. |
|
P144 |
THE STUDY OF INTRACEREBRAL ANEURYSMS BY
USING TRANS-CRANIAL-COLOR-DOPPLER S. Sanguigni, C. Paci, T. Carboni, R. Gobbato, G. Malferrari1,
F. Accorsi2, G. Galletti3, G. Landini4, L.
Curatola Department of Neurology, San Benedetto del
Tronto, Italy Dept of Neurology, Reggio Emilia1,
Dept of Medicine, Bologna2, Dept of Neurology, Forlì3,
Dept of Medicine, Firenze4 – Italy Background: The probable presence of intracranial aneurysms
and their possibility rupture with conseguent subarachnoidal hemorrage can
cause very important problems in precocious diagnosis and screening.
Furthermore the incidence of aneurysms by autopsy is about 2%. At present,
angiography and angio-RMN represent the gold-standard methods for the
diagnosis of cerebral aneursyms. Nevertheless Trans-Cranial-Color-Doppler
(TCCD), occasionally associated with contrast agent (Levovist , SonoVue), can
be useful to dectect intracranial aneurysms. Methods: In the last year we observed 12
cases of patients with intracranial aneurysm. In our laboratories we used
ACUSON 128XP10 with sectorial probe at 128 channels. Results: We report some borderline cases which include
aneurysm of: a) middle cerebral artery- cm 1 x 0.5-; b)
sovraclinoideus syphon, partially thrombosed ; c) top of the basilar d) M2
segment . Conclusions: The possibility of dectecting both partially thrombosed aneurysms and small ones, emphasizes the importance of TCCD in the precocious diagnosis of cerebral aneurysms. |
|
P145 |
Microvascular Doppler Monitoring in
Surgery of Superficial Arteriovenous Malformations V.B. Semenyutin, P.I. Nikitin, B.B. Govorov Russian Polenov Neurosurgical Institute,
St. Petersburg, Russia Background: The study goal was to estimate potentialities of
microvascular dopplerography (MVD) in identifying afferent (feeding),
efferent (draining) and transit vessels and controlling totality of resection
of superficial arterivenous malformations (AVM), localized in eloquent areas
of the brain. Methods: We examined 14 patients with superficial cerebral
AVM, localized in eloquent areas. Blood flow velocity (BFV) in afferent,
efferent and transit vessels was recorded before and after AVM removal. It
was done with the help of microvascular Doppler using a 20 MHz probe (MDX
system, DWL, Germany). Results: Before AVM removal afferent vessels of 11 out of
14 cases were characterized by mean BFV of 33-95 cm/s (56.6+17.3) and
pulsatility index (PI) of 0.26-0.66 (0.40+0.12). Spectra of BFV in
draining vessels of all 14 patients had a marked arterial pattern. Transit
vessels were identified in 10 out of 14 cases. Values of BFV (13.2+3.9
cm/s) and PI (1.10+0.19) were normal. After AVM removal spectra of BFV
in afferent vessels of 9 patients were characterized by low-amplitude spike
signals, confirming absence of blood flow. Mean BFV and PI in efferent
vessels of all patients reduced up to 5.0+1.0 cm/s and 0.25+0.07
respectively. BFV reduction was accompanied by disappearance of an arterial
component in its spectrum. The observed pattern was typical of normal veins.
Disappearance of the arterial component in BFV spectrum of efferent vessels
was indicative of AVM total removal. Control angiographic examination,
carried out on discharge was indicative of AVM total exclusion from blood
circulation. Conclusions: MDV ensures dynamic estimation of BFV in afferent, efferent and transit arteries of superficial AVM, localized in eloquent brain areas and permits to control totality of AVM resection. Preservation of blood flow in transit arteries of superficial AVM, localized in these areas, helps to avoid additional disability of patients after radical operations. |
|
P146 |
A pilot study of preoperative
transcranial Doppler examinations to predict cerebral hyperperfusion
following carotidendarterectomies R.W.M. Keunen, H.W. Nijmeijer, D.L.J. Tavy, R.C. Edelenbos, E.B.
Muskens, C.M.S Bruijnincks, J.C. Sier, C.J. Stam Dept of Neurovascular Medicine Leyenburg
Hospital The Hague Background: The objective was to determine if pre-operative
transcranial Doppler (TCD) examinations have the
potential to predict post-operative cerebral hyperperfusion following
carotidendarterectomies (CEA). Methods: 55 patients (mean age 64.4 yrs/ ratio male/female
31/14) with symptomatic internal carotid artery stenosis were
included. TCD examinations included pre- operative measurements of
bloodflowvelocities (BFV) and pulsatility indices (PI) of the ipsilateral middle cerebral artery
(MCA). Patients were monitoried by TCD during the CEA procedure and upto 1 hour
post CEA. Normal pre-operative hemodynamics were
defined when the product of BFV*PI was > 36 cm/s; abnormal pre-operative cerebral hemodynamics were present as the BFV*PI < 36 cm/s. Cerebral
hyperperfusion was defined when the BFV pre and post- operative showed and increase of > 100
% in the MCA. Results: The range of changes between pre- and
postoperative BFV varied between -44.4 % and + 182.6 % (mean change 27.7
%). Cerebral hyperperfusion occurred in 9.9 %. Cerebral hyperperfusion was seen in 31 %
of the patients with abnormal pre-operative hemodynamics. None of the patients with
normal pre-operative hemodynamics experienced a post-operative cerebral
hyperperfusion. The post-operative stroke risk was in patients with abnormal
pre-operative hemodynamics ten-fold higher compared to patients with normal cerebral
hemodynamics. Conclusion: pre-operative TCD examinations can reliable identify patients who will not have a risk for cerebral
hyperperfusion following CEA. Poor pre-operative hemo- dynamics were associated with an increase
chance for cerebral hyperperfusion following CEA and an increased post CEA stroke risk.
Larger prospective studies are warranted to base firm evidence for the observationss of this pilot study. |
|
P147 |
Vestibular caloric stimulation causes
prevailing Activation of the right hemisphere M. Rosenkranz, U. Sonnemann*, D. Burkhardt, W. D. Niesen,
W. Zangemeister, C. Weiller, U. Sliwka. Depts. of Neurology and ENT*, University
Hospital Eppendorf, Hamburg, Germany Objective: To assess activation of the vestibular cortex
during vestibular caloric stimulation by means of functional TCD. Methods: Simultaneous TCD from both MCA was performed
during caloric irrigation (CI) of the external ear canal in 6 healthy
right-handed subjects. 5 cycles of CI were performed for either ear.
Computing the ratio of the right and left CBFV traces (MCAR/MCAL) separated
specific laterality of flow responses from global changes in CBF. Results: CI caused rotatory vertigo and horizontal
nystagmus in all subjects and induced complex bilateral alterations of CBFV,
probably attributed to multisensory, vestibular, and ocular motor functions.
However, 2.15± 1.19 sec after start of CI the averaged MCAR/MCAL
ratio increased rapidly (2.34±2.06%/sec), reached a peak (7.1±2.62%) 7.5±3.43
sec after start of CI, and declined back to baseline after CI ceased. No
significant differences between the MCAR/MCAL ratio of left and right CI was
observed. Conclusions: The CBF changes indicated by changes in CBFV reflect functional activation of the vestibular cortex. Unilateral stimulation of either horizontal semicircular canal being associated with prevailing right-hemispheric activation reflects right-hemispheric dominance of the vestibular cortex. |
|
P148 |
Cerebral Hemodynamics and Bioelectrical
Brain Activity in Patients after Uterine Extirpation with Adnexa. M. R. Bekouzarova, MD, PhD., T. A.
Adyrkhaev, V. V. Brodgenko Russian State Medical University,
Department of Neurology and Neurosurgery, Moscow Background: To analyze functional conditions of nervous
system, insufficiency of cerebral hemodynamics, bioelectrical brain activity
and hormonal status of women in age 35-50 years, after uterine extirpation
with adnexa, in connection with uterine mioma, before and after substitution
hormone therapy. To work out methods of complex therapy for this patients. Methods: Investigation of psychological status (Mini Menta
State, Folstein M.T., 1975), transcranial Doppler sonography,
electroencephalography, laboratory analysis of female hormones.
Investigations conducted at the Department of Neurology and Neurosurgery of
the Russian State Medical University, based at the 1-st City Clinic Hospital
(Moscow). Results: We analyzed 15 women in age of 35-50 years, after uterine extirpation with adnexa, in connection with uterine mioma. Medium age of this patients 40,5 years, they are women of reproduction age. In a year after uterine extirpation with adnexa, at the background of insufficiency of female hormones, developed an alarm-depression disturbances, vegetative-vascular syndrome (headache, dizziness, hypertension, climacteric cardiopathy, climacteric neurosis, disturbance of sleep, sweating, hot flushes of the upper half of the body, fatigability, enhanced emotional lability). To analyze cerebral hemodynamics, using transcranial Doppler sonography, in this patients determined the Vertebral-Basilar insufficiency (more causes) and in some causes our patients had insufficiency in carotid and medium cerebral artery system. All of this patients had a dysfunction of mese-diencephalon structures of brain (according to electroencephalography investigations). After the uterine extirpation with adnexa arise a disturbances of complicated neuro-endocrinology interactions in hypotalamus-hypophysis-adnexa-adrenalcortex-thyroid system. |
|
P149 |
FUNCTIONAL SIGNIFICANCE OF AFFERENT
VESSELS OF CEREBRAL ARTERIOVENOUS MALFORMATIONS: INTRAOPERATIVE ASSESSMENT V.B. Semenyutin, P.I. Nikitin, I.M.
Bukhaev, V.V. Alexeev, S.K. Sergienko Russian Polenov Neurosurgical Institute,
St. Petersburg, Russia Background: Modelling of cerebral hemodynamics in patients
with cerebral arteriovenous malformations (AVM) by Gao et al. (1997) showed
dependence of blood pressure (BP) in afferent vessels on a degree of shunting
(volumetric blood flow through AVM). Nornes et al. (1980) established
dependence of an afferent vessel diameter on volumetric blood flow through
it. Use of modern technologies of microsurgical engineering, in particular
microcatheters for embolization, allows to measure BP in afferent vessels; it
appears that its value may be used for estimation of functional significance
of AVM afferent vessels under the above conditions. Methods: 8 patients with cerebral AVM of grades 3-5
according to Spetzler, Martin (1986) were examined. They were subject to 9
superselective embolizations with the help of Magic STD 1.8F microcatheters
(Balt, France) and sedation-analgesia. The M-34 mingograph (Siemens-Elema,
Sweden) was used for direct measurement of systemic blood pressure (SBP) in a
femoral artery and BP in AVM afferent vessels. Wada test was performed before
every embolization with administration of 30-50 mg of thiopental sodium via a
microcatheter. Results: Wada test was negative in 9 cases. BP in afferent
vessels, whose diameter did not exceed 3 mm, varied from 15 up to 43 mmHg; it
made 21.4-48.6% from SBP. A value of BP was indicative of low functional
significance of afferent vessels in all 9 cases; it was in compliance with
computation data obtained on the aforesaid model. BP in afferent vessels,
whose diameter did not exceed 3 mm, was within the range of 56-72 mmHg in 3
cases with positive Wada test; it made 50.7-64.2% from SBP. According to
computation data and results of Wada test, these afferent vessels provided
partial blood supply of eloquent brain structures. AVM embolization through
these efferent vessels was not carried out. Conclusions: A value of BP in an AVM afferent vessel can serve the basis for assessment of its functional significance. The method is demonstrative and informative for AVM of various localization; it allows to achieve considerable reduction of a number of complications, increasing a risk of invalidism in performing superselective embolization through afferent vessels. |
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P150 |
CO-RELATION BETWEEN TRANSCRANIAL
DOPPLER SONOGRAPHY, CALORY TEST OF VESTIBULARIS AND ELECTRONISTAMOGRAPHY IN
CASE OF VERTEBRO BALISAR INSUFFICIENCY J.Đelilović, V. Demarin, H.
Lončarević, S. Žarković Neurology Clinic, U.K.C. Sarajevo, Sestre
Milosrdnice Clinic, Zagreb, Croatia Introduction Transcranial Doppler Sonography is
non-invasive, ultrasound diagnostic method, which provides insight into the
status of hemo dynamic of the frontal carotid and rear VB system, as well as
such method of selection in diagnosis of VB insufficiency. This method is in
use since 1982. For the purpose of confirmation of VB insufficiency diagnosis
are used test of calorie testing of vestibularis and electronystagmogryphy,
as additional method in some cases. Materials Subjects and Methods During the work were made analyses of
group of 50 individuals with symptoms of VB Insufficiency, age of 40 – 60
years, and control group of 50 healthy individuals of the same age. From all
individuals were taken history, neurology examination, laboratory results
(blood count, sugar in blood, lypidogram and blood pressure), ophthalmologic
examination, EKG and cardiology examination, RTG of neck spine, transcranial
Doppler (TCD), calorie test of vestibularis, test of electronystagmography,
EEG and CT of brain. Work results After examination by transcranial Doppler
using sonography, pathological (reduced) value of SBSK were found in
investigative group with 30% of individuals AV right, in control group only
12%, but AV left was found with 54% in investigative group and only 10% in
control group, in AB with 52% individuals in investigative group and with 8%
in control group. Calorie test of vestibularis was pathological in
investigative group with 78% of individuals, but in control group only with
14% of individuals: the majority findings were asymmetric and areflectic. 88% of individuals in investigative group
had pathological test of electronystamography, but in control group only 16%. Statistic is significant among groups in
all three mentioned groups. Conclusions:
|
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P151 |
Ultrasound Imaging of atlas loop of
vertebral artery M.V. Sidor, K.V. Smirnov, J.V. Smirnova Altai Diagnostic Center, Barnaul, Russia Background: Existing ways of ultrasound visualizations of V3
portion of vertebral artery (atlas loop or V3) do not allow to get imaging of
all its length. Consequently diagnostic of circulation desorders in V3 are
little efficient by using this ways. That is why were developed new way to
ultrasound visualizations of V3 by using different ultrasound mode: B-mode,
Color Doppler and Power Doppler (invention №2001114954 from
31.05.2001). Methods: The methods of ultrasound vizualisation B-mode,
Color Doppler and Power Doppler Imaging were performed in 20 voluntaries.
Investigation has been performed with ultrasound scanner (Spectra Masters
"Diasonics", USA) on claimed technique. Results: Distal and proximal part of V3 portion of
vertebral artery was successful vizualisated in all cases (100%) by using
Color and Power Doppler imaging. By using only B-mode it was possible to get
image of distal part of V3 portion in 80% (n=16) and proximal one in 55%
(n=11). Conclusion: It suggests that new way of atlas loop of vertebral artery vizualisation allows to examine over the whole length of the vessel. Vizualisation V3 segment of vertebral artery in Color and Power Doppler mode is more effective than in B-mode. |
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P152 |
UltrasonographIC Measurement of Global
Cerebral Blood Volume in Healthy Adults F. Doepp, S. Schreiber, J.M. Valdueza Department of Neurology, University
Hospital Charité, Berlin, Germany Background: Up to now values of cerebral blood volume could
only be assessed by MRI, SPECT or PET techniques. We present a new
ultrasonographic approach to determine the global cerebral blood volume
(CBV). Methods: 41 healthy subjects, age ranging from 20 to 79
years (mean± SD: 45± 19, median: 48) were studied. CBV was determined
as the product of global cerebral blood flow (CBF) and the global cerebral
circulation time (CCT). CBF was calculated as the sum of the flow volume in
both internal carotid arteries (ICA) and vertebral arteries using duplex
sonography. CCT was measured as the time delay of echocontrast bolus arrival
between the ICA and the contralateral internal jugular vein at the
submandibular level using 2-MHz-Doppler probes. In 5 subjects reproducibility
studies and measurements under controlled hyperventilation were performed. Results: Measurement was successful in all subjects. CBV
ranged from 45 to 108 ml (mean± SD: 77± 14 ml) and did not correlate with age, end tidal
CO2, heart rate or blood pressure. Mean difference after repeated
testing in 5 subjects was 16± 16 ml. Under hyperventilation, CCT increased from
5.7± 0.7 sec to 7.8± 0.8sec (p<0.05), CBF decreased from 765± 72 ml/min
to 518± 52 ml/min (p<0.05). However, CBV values did not show a significant
difference (71± 8 ml vs.68± 11 ml, p=0.4). Conclusions: Ultrasonographic measurement of global CBV is a reliable and easy method demonstrating values in good agreement with previously published data. Hyperventilation results in the expected CBF and CCT changes, supporting the robustness of our test. Interestingly, CBV did not seem to be significantly altered. |
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P153 |
CAN BE USEFUL
TRANS-CRANIAL-COLOR-DOPPLER TO CONFIRM A RARE CASE OF RIGHT SIDED TEMPORAL
LOBE VARIANT OF FRONTO-TEMPORAL DEMENTIA (FTD)? S. Sanguigni, C. Paci, T. Carboni, R. Gobbato, G. Malferrari*,
F. Accorsi ^, L. Curatola Department of Neurology, San Benedetto del
Tronto, Italy Dept. of Neurology, Reggio Emilia*, Dept
of Medicine, Bologna – Italy Background: Fronto-temporal dementia involves progressive
dysfunction of the anterior temporal frontal lobes. Despite the presence of
relatively uniform pathology, some patients display diffuse, bilateral
frontal and temporal degeneration, whereas others may suffer degeneration
primarily in the frontal or temporal lobe. The degeneration can be either symmetric
or highly asymmetric, affecting primarily on frontal or temporal region. Methods: We describe a 70 years old woman affected by a
right sided temporal lobe variant of FTD. Nine months ago the patient
presented impairment in her executive and attentional abilities while the
memory was minimally involved. She had difficulty to relate to others such as
her friends or family. She showed dishinibition, distractibility, sterotypes
and alterated speech output. All cognitive disorders were confirmed by a general
neuropsichological battery that evaluated attention, executive functions and
problem solving abilities, language, verbal and spatial memory, praxias and
visuo-spatial abilities. Brain MRI scan, SPECT and
Transcranial-Color-Coded-Duplex Sonography (TCCD) were obtained in our
patient. Results: MRI showed a right temporal lobe atrophy while
SPECT revealed severe hypoperfusion in right fronto-temporal lobe. The TCCD study was performed with the use
of Acuson 128 XP10 and showed an important reduction of cerebral blood flow
detected at the right middle cerebral artery compared with the controlateral
one. Conclusions: TCCD study represents an important diagnostic technique to confirm a rare case of right temporal lobe variant of FTD. |
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P154 |
IMPAIRED VISUALLY EVOKED RESPONSE IN
POSTERIOR CEREBRAL ARTERY IN PATIENTS WITH ADVANCED CAROTID STENOSIS OR
OCCLUSION Roje Bedeković M, Lovrencic-Huzjan
A, Bosnar Puretic M, Demarin V Neurology Depr University Hospital
"Sestre milosrdnice", Zagreb, Croatia Background: Up to now vasoreactivity testing was almost always
performed investigating middle cerebral artery or rearly anterior cerebral
artery, showing similar reactivity in both. Testing of posterior circulation
using visual stimuli was described only in few studies, mostly on healthy
individuals, although visual stimulation is noninvasive, and the most
powerful stimuli of metabolism in visual cortex. The aim of the study was to
investigate visual evoked response in posterior cerebral artery (PCA) in
patients with carotid disease. Methods: Mean blood flow velocities (MBFV) of the PCA were
investigated in patients with advanced carotid stenosis or occlusion by means
of transcranial Doppler (TCD), 2 MHz probe MultiDop X4 DWL. Velocities were
measured successively in the dark and during white light visual stimulation
three times. Mean reaction changes in MBFV compared to dark in all
stimulations were calculated. Mean reaction time (time to peak velocities)
was measured. The data were compared with 8 healthy controls. Results: We investigated 16 male patients: 8 with subtotal
internal carotid artery (ICA) stenosis (5 right, 3 left), 5 ICA occlusion (2
right, 3 left), and 3 patients with bilateral stenosis or occlusion. During
light stimulation mean MBFV increase was 46,56 +2,56% on the right and
44,13+3,01% on the left. In healthy controls right PCA MBFV increase
was 44,71+6,5%, and 42,67+6,65% on the left. Mean reaction time
in patients with carotid disease was 26,79+6,72 s in the right PCA,
and 27,06+7,6s in the left PCA. In healthy controls mean reaction time
was 15+3,3 s in the right and 15+3,3 s in the left PCA
(p<0.05). Conclusions: TCD testing using visual stimuli showed prolonged visual evoked response in patients with carotid disease, although MBFV changes didn’t differ compared to healthy controls. TCD testing using visual stimuli is an usefull method in the evaluation of vascular reserve capacity in patients with carotid disease. |
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P155 |
THREE DIMENSIONAL ULTRASOUND OF THE
PLAQUE ULCERATION Kesic MJ, Lovrencic-Huzjan A, Zavoreo Husta I, Demarin V Neurology Depr University Hospital
"Sestre milosrdnice", Zagreb, Croatia Background: Carotid plaque ulceration is associated with an
increased risk of cerebral embolism. Still controversy of the diagnostic
ability of conventional two-dimensional ultrasound and angiography to detect
plaque ulcers exists. Three-dimensional ultrasound (3D US) facilitates
visualisation of the luminal plaque surface. Methods: We tried to display 6 stenosed internal carotid
arteries (ICA) with plaque ulcers by mean of B mode, color Doppler flow
imaging (CDFI), power Doppler flow imaging (PDFI), 3D US and 3D PD. We
performed 3D US examination of 6 ICA plaques with an ulcerated surface. B
mode slices were obtained with 10 MHz linear array transducer. CDFI and PDFI
were done in a standardised manner. 3D data sets were obtained with the same
probe, free handed, in a defined period of time (10 seconds). The recorded
images were reconstructed (TomTec imaging system) and volumetry was done. Results: Plaque ulcers were good visualised by B mode in 2/6
ICA, by CDFI mode in 4/6, by PDFI mode in 5/6 ICA and by 3D US and 3D PDFI in
6/6 ICA. The diameter of the plaque ulcers couldn’t be measured by means of B
mode. Mean diameter of plaque ulcers was in CDFI 2,7±0,44mm, in PDFI
3,1±0,8mm, in 3D US 2,55±0,21mm and in 3D PDI 2,74±0,29mm. Surface area of
the ulcer wasn’t measurable in B mode. Mean plaque ulcer surface was in CDFI
4,83±0,75mm2, in PDFI 5,6±0,3mm2, in 3D US 7,56±0,4mm2,
and in 3D PDI 7,89±0,12mm2. Plaque volume couldn’t be measured by
mean of B mode. Mean plaque ulcer volume was in CDFI mode 12,9±1,3 mm3, in
PDFI mode 17,5±4,4 mm3, in 3D US 19,1±2,6mm3 and in 3D
PDFI 21±2,4mm3. Conclusions: 3D US accompanied by PD enabled good visualisation and measurement of the plaque ulcers diameter, surface and volume. |
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P156 |
Is ultrasound safe when applied
parallel with thrombolysis? G.Panczel, V.Kemeny*, P.Bönöczk,
Z.Nagy National Stroke Center Budapest, Hungary Ferenc Flór Hospital Kerepestarcsa,
Hungary Background: Fibrinolysis is associated with substantial risk
of hemorrhagic complication. Insonation with ultrasound (US) parallel with
systemic thrombolysis may increase efficacy, however, safety of US insonation
with special respect to heating effect should first be evaluated. Methods: A low-frequency, high-energy US transducer (100
kHz, 3 W energy intake) and a standard 2 MHz TCD transducer were applied at
maximal power output, for a 60- minute insonation of 10-10 cadaver brains
through temporal window and the temperature was monitored simultaneously at
1-2-and 3 cm depths from temporal bone in the brain parenchyma along the axis
of US propagation. Results: The baseline temperature of brain parenchyma was
an average of 22.2 ± 2.6, 21.9 ± 2.7, 21.5 ± 2.6° C, and 22.3 ± 3.0, 21.9 ± 3.1, 21.8 ± 3.0 ° C for 100KHz and 2 MHz insonations respectively at
1-2-and 3 cm depths, they did not differ significantly between the two
insonation groups. The temperature increased by 1.14± 0.35,
0,99 ± 0.31, 0.82 ± 0.24 ° C, and 0.16 ± 0.15, 0.18± 0.15, 0.17± 0.1 ° C during insonation with 100 KHz and 2 MHz
transducers respectively at the 3 different depths. Differences between the 2
groups at a given depth were significant (p<0.05 for all depths). Conclusions: The 100 KHz insonation exerted a mild heating with significant decrement with increasing depth while the 2 MHz insonation was practically not associated with temperature elevation. Temperature increase is presumably higher in cadavers than in living persons given the cooling effect of circulating blood. US insonation may be considered safe as heating side-effect is mild and can be overweighed by the benefit of its recanalyzing effect. |
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P157 |
ULTRASOUND AND tPA ENHANCED
THROMBOLYSIS: INFLUENCE OF ULTRASOUND FREQUENCY AND PULSE LENGTH A. Voie, D. Amory, J. Amory, M. Moehring, M. Spencer Spencer Technologies, Seattle WA, USA;
Institute of Applied Physiology & Medicine, Seattle WA, USA; University
of Washington, Seattle WA, USA Background. Studies indicate that ultrasound (US) may enhance
the thrombolytic properties of tPA. The aim of this study was to contrast the
enhancement of low-frequency (200 kHz) US with diagnostic (2 MHz) pulsed US,
using low intensity (50 mW/cm2) as might be experienced in
transcranial diagnostic evaluation. Additionally, the influence of cycles per
pulse (cpp) at each of the US frequencies was examined. Methods. 48 rabbits were used, divided into 6 groups of n =
8. In addition to the 4 US groups (3 & 8 cpp at 200 kHz, 8 & 30 cpp
at 2MHz) a control group received no therapy, and 1 group received tPA only.
In each experiment, a fresh autologous clot (66 μl) was injected into an
isolated segment of the abdominal aorta via a cannula in the left renal artery.
After flow meter confirmation that the embolic clot had caused a total
occlusion at a 40 % stenosis site on the aorta, therapy was initiated. Results. Mean clot weight (MCW) was 29.8 mg for the control
group. That of the tPA-only group was 4.6 mg, a significant reduction (p =
0.02). The MCW in groups receiving tPA and 2 MHz US (8 & 30 cpp) were 6.4
mg and 4.0 mg, respectively, which did not differ significantly from the
tPA-only group (p = 0.439 & 0.419). The MCW for the group receiving tPA
and 200 kHz US (3 cpp) was 7.2 mg, which also did not differ significantly
from the group receiving tPA only (p=0.221). However, the MCW for the group
receiving tPA and 200 kHz US (8 cpp) was 0.8 mg, which was significantly less
than the group receiving only tPA (p = 0.006). Conclusions. In this model, tPA caused significant clot lysis, but enhancement was not observed using 2 MHz US at 8 or 30 cpp, nor with 200 kHz US at 3 cpp. However, 200 kHz US at 8 cpp did significantly enhance the thrombolytic effect of tPA. |
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P158 |
CEREBRAL HEMODYNAMICS IN LEUCOARAIOSIS,
REDUNDANT INTERNAL CAROTID ARTERY AND NORMAL AGED A.Berchio, G.Ottone, C.Valenzano D.E.A. Osservazione Medicina – A.S.O. San
Giovanni Battista – Torino (Italy) Cronic ischaemia should be the most likely
mechanism of leucoaraiosis. The role of redundant (kinks, coils and loops)
internal carotid artery (ICA) as stroke risk factor is still controversial.
The aim of the paper was to relate the middle cerebral artery (MCA) flow
parameters in subjects affected by leucoaraiosis with the ones recorded in
ICA redundancy bringers. Methods: we studied 19 pz. with leuco-araiosis based on
head-CT and 25 pz. with ICA redudancy. The following MCA parameters were
examined: · peack systolic velocity ·
end-diastolic velocity · some derived parameters: 1) mean flow velocity 2)
PI (Gosling pulsatility index) 3) RI (Pourcelot resistence index).
Measurements were also made in a normal aged control group. ECST method >
30° ICA and > 50% MCA stenosis were excluded. Results: average ages were: leucoaraiosis group 77,2± 6,8 ;
redundancy bringers 67,9 ± 14,9; normal aged 74,3 ± 3,1.
Statistically increased relevant values were observed between: ¨
leucoaraiosis group vs. normal aged PI and RI: both p<0,000 and peack
systolic velocity: p< 0,002 ¨ redundancy bringers vs. normal aged PI and RI:
both p<0,000 and ¨ redundancy bringers vs. leucoaraiosis group
end-diastolic flow velocity and middle flow velocity: respectively p<0,004
and p<0,01. Discussion: the increased peack systolic flow, PI and RI in the leucoaraiosis group might be expression of poor collateral supply for white matter, atherosclerosis and narrowing of small vessel lumen. The P.I. and R.I. reduction in the redundancy bringers might be expression of the reduction of arterial vascular resistence due to the activation of a compensatory mechanism to flow reduction due to ICA tortuosity. Since there were no significative differences in flow parameters values between leucoraiosis and redundancy bringers, both groups might be considered at risk because of a vascular disesase on a haemodynamic basis. |
|
P159 |
USEFULNESS OF COLOR-CODED DUPLEX
SONOGRAPHY FOR AN ASSESSMENT OF INFANTILE HYDROCEPHALUS A. Cerniauskaite1, J. Valaikiene2, V. Basys1 Clinics of Neonatology1 and
Neurology2, University of Vilnius, Lithuania Background: In most cases only the anatomical data are
evaluated in an assessment of infantile hydrocephalus, however evaluating of
cerebral haemodynamics is extremely important. Our purpose of the study was
to determine cerebrovascular resistance index (RI) by transcranial
color-coded duplex sonography (TCCS) in infantile hydrocephalus and to assess
the relationship between RI and ventricular index (VI). Method: 60 infants (age range 36-80 weeks) were
examined by TCCS: for 12 infants with severe hydrocephalus confirmed by CT
were performed 32 examinations, comparing with 48 healthy infants group. The
aetiology of hydrocephalus was posthaemorrhagic in 9, was postmeningitic in 2
and of congenital origin in 1. Such haemodynamical parameters as systolic,
diastolic, mean velocities and RI of the anterior cerebral artery (ACA) were
obtained performing TCCS through the anterior fontanelle. On a frontal
section, through the head of the caudate nucleus were assessed VI by US
according formula: laterolateral diameter between the points of the frontal
horns/distance between the left and right internal table on that section. Results: RI and VI in infants with hydrocephalus was
statistically significant (p<.0001) higher comparing with healthy infants
group (0,93 +/- 0,06 v.s. 0,67+/-0,06 and 0,58+/- 0,07 v.s. 0,24+/- 0,045). Correlation analysis of the data
(Spearman’s test) showed a statisticaly significant positive correlation
between RI and VI (P<.0001) Conclusion: Our study indicates that TCCS is a reliable method for a noninvasive assessment of infantile hydrocephalus, evaluating such indices as RI and VI. |
|
P160 |
THE Changes in catecholamine metabolism
in the brain and heart tissues under the condition of hypokinesia V. P. Hakopyan, V. H. Karapetyan, O. P. Sotsky Yerevan State Medical University, Yerevan,
Republic of Armenia Background: Our previous studies have shown expressed the
morphological changes in the cerebral microcirculation in animals under the
condition of hypokinesia (HK). Taking into account the important role of
catecholamine in the cerebral blood flow regulation we have studied the
dynamic changes in the content of adrenaline (A) and noradrenaline (NA) in
the brain cortex and in myocardium of white rats under HK. Methods: The experiments were done on white male rats,
weighing 150-180 g. HK was achieved by placing the rats in the individual
small cages. The animals were decapitated on the 15th, 30th
and 45th days of HK. As a control were used the rats kept in
similar conditions in vivarium. Catecholamine were determined by fluorometric
methods by Euler&Lishajko. Results: The obtained results have shown that NA quantity
in brain cortex is decreased by 41,3% on the 15th day of HK, and
the quantity of A - by 56%. On the 30th day of HK the content of
NA in brain cortex is normalized, whereas the quantity of A is sharply
decreased. On the 45th day of HK the level of NA is sharply
decreased (by 66,5% as compared with control) and the quantity of A
approaches to normal one. Taking into account the different origin of NA in
the brain tissue and viscera we also studied the changes of catecholamine
quantity in the heart tissue at the same terms of HK. At the same time the
morphological studies of the heart and brain tissues were carried out. The
comparison of the tendency of the catecholamine shifts in both tissues has
shown that only on the 15th day the direction of the changes in A
and NA content coincides, whereas on the 30th day the A and NA
content in the heart is more than the control one, but less in the brain
tissue. On the 45th day the amount of NA in both tissue and A in
brain tissue is less than in the control ones, and the A content in the heart
tissue is the same as in animals on the 15th day of HK. Conclusion: The analysis of the dynamics of biogenic amine content in the different terms of HK proves that on the 15th day of HK unidirection of A and NA changes in both tissues is due to the same reason i.e. hypoxic-metabolic stress. And in the late terms, when the process of adaptation occurs, other mechanisms defining the specifity of this stress are involved |
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P161 |
Second Harmonic Imaging and Perfusion
Magnetic Resonance Imaging to Assess Perfusion of High-grade Gliomas 1Judith U. Harrer, MD, 2Walter Möller-Hartmann, MD, 1Christof
Klötzsch, MD. 1Dept. of Neurology, 2Dept. of Neuroradiology, University
Hospital Aachen, Germany Background and Purpose: To evaluate the potential of second harmonic
imaging (SHI) for the assessment of perfusion of high grade gliomas and to
compare this ultrasound technique with perfusion magnetic resonance imaging
(MRI). Methods: Eight patients with high-grade gliomas underwent a
transtemporal second harmonic imaging investigation and a perfusion-sensitive
MRI procedure (spin-echo EPI technique). After application of 2.5 g (400
mg/ml) of LevovistÒ , 62 time-triggered images (1 frame/s) were
recorded. Time-intensity curves of 2 different regions of interest (tumor
tissue (ROItt); brain tissue (ROIbt)) were calculated off-line and the
following parameters were compared between the two methodologies;
time-to-peak-intensity (TP [ s] ), the ratios of the peak intensities (PI-ratio)
and the ratios of the time-to-peak-intensities (TP-ratio) of tumor to healthy
tissue. P < .05 was considered statistically significant. Results: Sonographically focal abnormal echogenicity could
be detected in native B-mode in all patients. Administration of the contrast
agent lead to remarkable echo contrast enhancement in the tumor tissue,
corresponding to the calculated time-intensity curves. The analysis of SHI
and MRI data showed no significant differences of all examined parameters; TP
15,5 s vs. 22,2 s (p = 0.1); PI-ratios 2.63 vs.1.67 (p = 0.2); TP ratios 0.40
vs. 0.91(p = 0.1); Wilcoxon-signed-rank-test. Conclusions: SHI provides a new technique to assess brain tumor perfusion. Overall comparison of this methodology with perfusion MRI was encouraging. Having shown its feasibility to evaluate brain tumor perfusion, further SHI studies are needed to evaluate the clinical potential of SHI in brain tumors especially in view of tumor response to non-invasive treatment and tumor recurrence. |
|
P162 |
TRANSCRANIAL SONOGRAPHY OF THE
SUBSTANTIA NIGRA IN PATIENTS WITH PARKINSON`S DISEASE L. Niehaus, N. Savyer, R. Hertel, C.H. Nolte Department of Neurology, Charité, CVK,
Humboldt-University Berlin Background: Recently it has been shown that patients with
idiopathic Parkinson´s disease (IPD) exhibit an increased echogenicity of the
substantia nigra (SN) on transcranial sonography (TCS). TCS using
conventional B-mode imaging (CI) is limited by low contrast resolution.
Tissue harmonic imaging (THI), as a new diagnostic tool, promises a more
detailed visualization of parenchymal brain structures on TCS. The purpose of
the study was to investigate whether THI is also useful to delineate the SN
within the mesencephalic brainstem and to demonstrate abnormal echo pattern
in IPD. Methods: Mesencephalic brainstem was investigated by TCS
(Sonoline Elegra, Siemens) in 40 healthy volunteers and 45 patients with IPD.
TCS examination was performed with a 2.5 MHz phased-array probe using
conventional B-mode and tissue harmonic imaging. The SN was visually
identified by two investigators separately and the area-size of elevated
echogenicity was measured. Results: THI more frequently failed to show
SN than CI (22% vs. 12%) due to insufficient bone window.The mean area-size
of SN in healthy volunteers did not differ when measured by CI (13.6 ± 3.2 mm²)
and by THI (12.2 ± 4.2 mm2 ). In IPD patients the SN area
was significantly larger when both CI (19.4 ± 5.0 mm2,
p<0.01) and THI (19.2 ± 7.1 mm2, p<0.01) were applied. Conclusion: Transcranial ultrasonography may be applied to differentiate IPD patients from healthy subjects by assessing the area size of the SN. Using both CI and THI the present study demonstrates that the SN area is greater in IPD patients than in healthy subjects. The main advantage of THI is the improvement of visualization of the mesencephalon and SN. However, its usefulness is slightly more restricted by a higher frequency of insufficient bone windows in comparison to conventional TCS. |
|
P163 |
CONTRAST BURST DEPLETION IMAGING
(CODIM): A NEW METHOD FOR SEMI-QUANTITATIVE ULTRASONIC PERFUSION IMAGING J. Eyding, W. Wilkening, M. Reckhardt, G. Schmid, S. Meves,
H. Ermert, H. Przuntek, T. Postert Background Established methods of ultrasonic
perfusion imaging using a bolus application of echo contrast agent provide
only qualitative data due to various physical phenomena. This study was
intended to investigate if a new ultrasound perfusion imaging method called
"Contrast Burst Depletion Imaging (CODIM)" may provide
semi-quantitative measures of parenchymal perfusion independent of
examination depth and acoustic energy distribution. Methods and Results In a system of constant concentration of
contrast agent, analyzing the decrease in image intensity that occurs with
mircobubble-destructive imaging modes yields parameters that are considered
to be correlative to tissue perfusion. This method was evaluated in 17 human
volunteers using two different contrast agents with the main resulting
parameter "perfusion coefficient" (PC). Results were correlated
with perfusion weighted MRI examinations. PC did not show significant
differences in gray matter areas (ranging from 1.466·10-2s-1
to 1.641·10-2s-1) of the brain despite of different
insonation depths (e.g. ipsilateral and contralateral thalamus). In contrast,
white matter exhibited significantly lower perfusion values in both imaging
modes (PC: 0.604·10-2s-1-0.745·10-2s-1,
p<0.05). Conclusions CODIM is a promising new tool of imaging parenchymal (brain) perfusion in healthy individuals. The method provides semi-quantitative and depth-independent perfusion parameters and in this way overcomes the limitations of the perfusion methods using bolus kinetics. Further investigations have to be done to evaluate the potential of the method in patients with perfusion deficits. |
|
P164 |
Internal Jugular Valves Incompetence: A
Study Using Air-Contrast Ultrasonography on General Population N. Maalikjy Akkawi, C. Agosti, B. Borroni, L. Rozzini, M. Magoni,
M.L. Colleoni, L.A. Vignolo, A. Padovani Background: Internal jugular (IJ) valves are the only venous
valves between the heart and the brain. Conditions, such as cough and other
precipitating activities may result in retrograde cerebral venous flow due to
absence or presence of incompetence of IJ valves, allowing a brief
transmission of high venous pressure and resulting in brain disturbance. Methods: In this study, we apply air-contrast ultrasound
venography (ACUV) to a large sample of normal subjects (n=125) in order to
evaluate ultrasonographic aspects of IJ valves and their competence. Results: The valves were observed in 96.8% subjects, and
were present bilaterally in 85.6% and unilaterally in 11.2%. In four subjects
we did not detect the valves. Retrograde venous flow (RVF) was present in
38.4% of subjects. The frequency of IJ valve incompetence was significantly
higher on the right side (30.2%) than on the left (6.4%) (p<0.0001). RVF
due to incompetence of jugular valves was significantly more frequent in the
more advanced age (20% age<50 and 38.75% age ≥ 50; p<0.03). Conclusion: This study showed that ACUV is a non-invasive method to evaluate IJ valves and to identify RVF. These information may be useful in clinical and interventionalist care. |
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P165 |
Estimation of non-invasive Cerebral
Perfusion Pressure using Transcranial Doppler Ultrasonography during infusion
test Schmidt EA, Czosnyka M, Czosnyka Z,
Momjian S, Pickard JD Academic Neurosurgery, Addenbrooke’s
hospital, Cambridge, UK Background: The
estimation of Cerebral Perfusion Pressure (CPP) using Transcranial Doppler
(TCD) has been recently evaluated [1,2]. We investigated whether changes in
flow velocity (FV) and in estimation of the CPP during infusion study were
correlated with changes in cerebrovascular parameters. Methods: 35
patients presenting symptoms of hydrocephalus with enlarged ventricles
underwent a computerised infusion test. The intracranial pressure (ICP) was
measured intraventricularly, and steady baseline level was recorded. Then the
saline solution was infused with until an ICP plateau has been reached.
Simultaneously we recorded flow velocity by using transcranial Doppler, and
arterial blood pressure (ABP) with a Finapress finger cuff. Pulsatility index
(PI), CPP and a non-invasive CPP (eCPP) was also calculated as: eCPP = ( ABPmean * FVdiatolic
/ FVmean ) + 14 [2] Results: Between
baseline and plateau, the changes in FVsystolic, diastolic or mean were
not correlated with the changes in ICP, CPP nor ABP. However, changes in PI
and ratio FVdiatolic / FVmean were correlated with
changes in ICP (r2 =0.36, p=0.0001 and r2
=0.25, p=0.002), but not with changes in ABP nor CPP. The changes in
CPP were correlated with changes in both eCPP (r2 =0.69,
p=0.0001) and ABP (r2 =0.64, p=0.0001), but not with
ICP. Conclusion: During
infusion study change in CPP is flawed by a rise in ABP, which
compensates for increase in ICP. Change in ICP produces modification of cerebrovascular
haemodynamics which can be depicted by the change in PI and in ratio FVdiatolic
/ FVmean .The estimation of CPP, using the ratio FVdiatolic
/ FVmean, is able to express non-invasively changes in CPP related
to change in ICP. [1] Schmidt EA J Neurol Neurosurg Psychiatry 2001;70:198-204 [2] Czosnyka M J Neurosurg 1998;71:673-80 |
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P166 |
WEB-BASED INTERACTIVE DATABASE SYSTEM
FOR THE TRANSCRANIAL DOPPLER ULTRASOUND LABORATORY M. Gorman, B. Jacobs, S. Levine, K. Agee, R Carhuapoma, J.
Kraus, R. Madhavan, M. Castellanos, Wayne State University, Detroit and NYC,
USA Background: TCD is limited by a number of variables that are
inherent to the test modality such as the problem of angle correction, that
it is a blind insonation and the difficulty in penetrating the skull in many
patients. TCD is also limited by the lack of standardized protocols for
performance of the various types of examinations, criteria for localization
and confirmation of vessel identification, and interpretation of the tests varies
substantially between laboratories. Handling of the data in laboratories is
often inefficient. Methodology and Conclusions: A web-based interactive database system for the cerebrovascular u/s lab provides convenient solutions to several of these non-inherent problems. Publication of a laboratory’s protocols for test performance, vessel identification and interpretive paradigms via public-accessible web pages allows interested parties to understand the way the data is obtained and processed in that lab, improving communication between physicians and labs. In this particular system, a database of test and test-related information is created and the interpreting physician reviews the data while the study report is being generated (improving validity of the data). The completed patient reports are directly e-mailed to the referring physicians and are available in a secure manner over the web, allowing for rapid and flexible interpretation as well as access to patient care information for the treating physician. Normative data is dynamically compiled by the individual lab and is presented for comparison during report interpretation. Sharing this system provides the potential for linkage of u/s labs worldwide, encouraging acceptance of standardized test protocols and interpretive paradigms. This would encourage validity and applicability of cerebrovascular u/s research by standardizing procedures, by facilitating collection of research data and could serve to establish regional and national normative databases. A demonstration of the system and of other potential benefits will be presented. |
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P167 |
FUNCTIONAL TRANSCRANIAL DOPPLER (fTCD):
DEMONSTRATION OF ITS CLINICAL USE BY INTRODUCING A CONTROL SYSTEM APPROACH
FOR EVALUATION B.Rosengarten, A.Dost, M.Kaps Justus-Liebig University of Giessen,
Germany Background: With some exceptions functional Doppler tests did
not reveal a wide clinical relevance due to the high inter- and
intraindividual variability of the overshoot parameter, flawing statistical
comparisons. Assuming features of an underlying regulative principle behind
the activity-flow coupling we tested a control system approach for data
evaluation with respect to its clinical use. Method: A 40 s silent reading task which was validated
against a checkerboard stimulation paradigm was used to evoke a flow response
in the posterial cerebral artery. The averaged relative flow changes from 10
test cycles were used to specify parameters of a second order linear system
model which were time delay, gain, attenuation, natural frequency and rate
time. Results: Within- and intersession reproducibility of data
was high compared with that of the resting phase. Interindividual variability
was higher but less than that of the overshoot. Systolic- and enddiastolic
indices differed in their time course with a higher sensitivity of the
latter. The response due to stimulation as well as cessation of stimulation
can be described with the same model. States of endothelial dysfunction such
as migraine and diabetes mellitus can be quantified. Gene polymorphisms such
as angiotensin-converting-enzyme, aldosteron-synthase: C344T,
G-protein-ß3-subunit: C825T, angiotensin II receptor 1: A1166C,
angiotensinogen: M235T, endothelial NO-synthase (eNOS): G894T and
intron4-deletion/insertion potentially involved in pressure regulation showed
for the eNOSG894T an association with the attenuation parameter. Conclusions: The clinical use of the fTCD method might be increased if a more detailed analysis of dynamic features of the activity-flow coupling is undertaken. |
|
P168 |
ADBF technology for non-invasive
real-time ICA volume blood flow measurements D. Manor, O. Hornick, J. F. Soustiel Cardiosonix Hydrodynamic Laboratory, Hod
Hasharon, Israel, and Rambam Medical Center, Haifa, Israel Background: The ideal system for determining cerebral blood
flow was characterized by Doberstein and Martin (1996) as "portable,
have high spatial resolution, have the capacity for continuous or frequent
measurements, and be noninvasive and easy to perform". The
Angle-independent Doppler Blood Flow (ADBF) technology was designed to
address the above requirements, with a focus on global, rather then regional
blood flow. Method: The technique is based on the simultaneous
application of two PW beams with a known geometrical configuration, digital
Doppler, simultaneous spectral analysis of hundreds of sample volumes and a
special algorithm for real-time determination of vessel boundaries, angle of
insonation, blood flow velocity profile, and ultimately volume blood flow.
The technology was tested under various in vitro conditions and with healthy
volunteers vs. Duplex measurements and with EtCO2 modulation. Results: High correlation was found between ADBF and
electromagnetic and time-collected flow measurements in the in vitro setup.
Mean normative CCA and ICA flow volumes were 456 ± 39 and
277 ± 25 ml/min, respectively. Average ICA flow was significantly lower
during hyperventilation relative to hypoventilation. Conclusions: The method provides an opportunity to allow simple identification of global cerebral hyperemic and ischemic events. Further clinical evaluation of this technique should be carried out. |
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P169 |
ON THE VARIABILITY OF MICRO-EMBOLIC
SIGNAL FEATURES FOR REPEATED SAME-EMBOLUS MEASUREMENTS, AND ON BACKGROUND
SPECKLES VARIANCE. C.Lucchesi2,
G.Darbellay3, V.Kemény1, J.M.Vesin3,
G.Devuyst1 and G.Dietler2. 1 CHUV, Lausanne, Switzerland; 2 Lausanne University,
Lausanne, Switzerland; 3 EPFL, Lausanne, Switzerland. Background and aims: As academic research groups and R&D services
focus on finding ways of differentiating solid and gaseous emboli, and of
determining e.g. emboli sizes, it is of interest to analyze the variability
that may plague repeated measurements of one embolic particle, as well
as the variance of the background blood flow speckles. Methods: An invitro setup has been specifically developed
for allowing repeated signal acquisition on the same, re-circulating embolus
mimic. Such measurements have been performed for various artificial emboli,
as well as for biological particles dissected from ulcerated areas of human
atheromatous plaques. Background speckles above 4dB have also been measured
in vivo, and compared to invitro results. Results: We show (for the various materials listed above)
that for one repeatedly measured embolus mimic most signal features – such as
frequencies, envelope slope, etc – show a variability (defined as the
standard deviation over the mean) of 20-50%. Furthermore, the signal power
does not correlate with emboli sizes, therefore making size predictions based
on MES power questionable. The background speckles countings also show a high
variability, both invivo and invitro. Conclusions: The variability of MES features, e.g. of the signal power, can possibly be explained by effects such as the non-homogeneity of the sample volume insonation. In any case, such a variability should be taken into account when exploring ways of predicting emboli characteristics from MES signal processing. |
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P170 |
AMBULATORY TRANSCRANIAL DOPPLER
MONITORING A. D. Mackinnon R. Aaslid H. S. Markus St. George's Hospital Medical School,
University of London, England Background and Purpose: Transcranial Doppler (TCD) detection of
circulating asymptomatic emboli is currently limited to short recordings by
equipment size. Embolisation shows marked temporal variability and prolonged
recordings reduce this and improve sensitivity. We have evaluated a portable
TCD machine for continuous ambulatory recording of the middle cerebral artery
(MCA) Doppler signal and subsequent embolic signal detection. Methods: The system consists of a 18x11.5x3.2 cm battery
powered Doppler unit, connected to a 13mm diameter servo-controlled 2MHz
transducer probe mounted on spectacles (or headband). The MCA spectrum is
shown and the transducer position optimised by display on a laptop, which is
disconnected when the MCA was located. An autosearch algorithm restores the
vessel insonation during recording if signal quality falls. The quadrature
raw audio signal is stored on flash disk and simultaneously on digital
audiotape (DAT) for later analysis. Recordings (2-4 hours) were made on
normal volunteers (N=3) and ambulatory acute stroke patients (N=7) to
optimise transducer fixation. Consecutive ambulatory acute stroke patients
(N=15) then had recordings for >5 hours per patient. Results: Of the 15 ambulatory acute stroke patients 11 were
male, median age 74 (Range 42-88). Median set-up time was 15-30 minutes. The
maximum available capacity of the current size flash disk was 5 hours 25mins.
The median ambulatory time was 5.5 hours (R: 303-385min). Of the data
recorded onto flash disk the median time a MCA signal was achieved was 5
hours exactly (R: 134-326 min). Discussion: Ambulatory TCD is possible and patients tolerated recordings of 5 hours well. We are now applying this technique for emboli detection in patients to determine the additional yield from performing prolonged recordings. |
|
P171 |
particulate Microembolic signal
signature evaluated with a customized Radiofrequency based analysis W.H.Mess(1), J.M.Willigers(2), R.G.A.Ackerstaff(3),
A.P.G.Hoeks(2); University Hospital Maastricht (1). University Maastricht(2),
St.Antonius Hospital, Nieuwegein(3) Background: Particulate and gaseous microembolic signals (MES)
differ in their appearance when evaluated with conventional Doppler systems.
The detected trajectory of MES has even been used as a criterion for
differentiating between both groups since gaseous MES, compared to
particulate MES, can be observed over a longer depth range because of their
high reflectivity. The aim of the present study was to evaluate whether a
difference in MES signature could be observed when an RF based analysis
system with a high spatial resolution was employed. Methods: Four patients were monitored after carotid
endarterectomy with transcranial Dopplersonography (TCD) with a 2 MHz probe
fixed over the right temporal bone window. It was assumed that the MES
acquired were particulate. The MES were stored on a customized RF based
system, connected to the TCD device. The amplitude of the RF signals containing
an MES was median filtered and then color coded and plotted as a function of
time and depth. The spatial resolution achieved was on the order of 2 mm,
depending mainly on the length of the ultrasound burst emitted. Results: 52 particulate MES were available for analysis.
The particulate MES had a relatively low S/N ratio, which made the
determination of flow direction in 15 signals impossible. In the remainder,
the particulate MES appeared as straight lines as has been described for
gaseous MES. There was a limited depth range of occurrence and a rather
consistent length (5.1 mm +/- 2.1 mm [SD]), which was comparable to the data
of the gaseous MES (4.5 mm +/- 1.6 mm [SD]; n=122; observed in a separate
study with the same system applied; MES acquired during heart valve surgery).
The particulate MES did not exhibit a change of flow direction. Conclusions: In general, particulate and gaseous MES exhibit a comparable signature. There is a consistent depth range of appearance, while no significant velocity changes in the course of particulate MES could be observed. The detected length was comparable to that of gaseous MES, showing that the RF based system used is insensitive for absolute signal intensity in detecting the depth range of an MES. These results can be explained by the fact that the color coded amplitude display scales all amplitude values with respect to the maximal value. Still, the rather low S/N ratio of particulate MES did not allow for velocity analysis of about ¼ of MES. |
|
P172 |
ASSESSMENT OF TEMPORAL BONE BEAM
DISTORTION WHEN USING MULTIFREQUENCY DOPPLER TO DIFFERENTIATE CEREBRAL
MICROEMBOLI R. Brucher, D. Russell, R. Ulm University
of Applied Sciences, Germany, and the National Hospital, University of Oslo,
Norway Background: The aim of this study was to assess the influence
of temporal bone beam distortion when multifrequency Doppler is used to
differentiate between solid and gaseous cerebral microemboli. Methods: The beam characteristics of dual frequency transcranial
Doppler (TCD) probes were scanned in a water bath without and after passing
through human temporal bone ( depth = 5 mm). Scanning was carried out using a
calibrated hydrophone (0.2mm) at a depth range from 38mm to 65mm, for 2MHZ
and 2.5MHZ frequencies, with a spatial stepping resolution of
50µm. The trace in time of an Embolus-Blood-Ratio signal was calculated by
assessing a sample volume with an axial length of 10mm along the beam axis.
The blood background signal was calculated as the mean value of the spatial
beam intensity distributed in the assumed sample volume when insonating the
red blood cells of a theoretical artery. Several spatial paths for
microemboli corresponding to an intensity distribution along a line through
the sample volume were calculated as dB-time traces for the two frequencies. Results: The focal area of the transducer was moved
approximately 4mm closer to it when insonating through the temporal bone due
to the additional focusing effect of the bone layers on both the 2MHZ
and 2.5MHZ frequencies. The lateral extension of the focal area
for 2.5MHZ was 0.5mm smaller than that for 2.0MHZ. This
results in higher EBR maximum values when an embolus is travelling through
the beam axis for 2.5 compared to 2.0MHz. Within 6dB (25%) beam limits
characteristics for both frequencies showed a difference of less than 1.5 dB.
This can therefore lead to similar underestimations of EBR differences when
differentiating between solid and gaseous microemboli. Conclusion: In this study of EBR curves using temporal bone we found that for solid microemboli the difference between EBR values for 2.5 and 2.0MHZ (dEBR) were from -0.8 dB to 2.05 dB which is similar to in vitro findings. |
|
P173 |
RISK FACTORS OF PLAGUE WIDTH IN CAROTID
BIFURCATION. M.Bar,D.Skoloudik,O Skoda,D.Vaclavik, P.Hradilek,K.Simickova. Dept.Neurology, Faculty Hospital,Czech
Republic Dept.Neurology,BMA Hospital Ostrava ,
Czech Republic Dept.Neurology ,City Hospital Pelhrimov
Czech Republic Backgrounds: The aim of study was to find
correlation between risk factors and width of atherosclerotic plague in
carotid bifurcation at patients with hypercholesterolaemia. Materials and method: During 24 months ,
in three neurosonology laboratories we have screened patients with not know
and not treated hypercholesterolaemia who had atherosclerotic plagues in
carotid bifurcation over 2 mm of width. All patients with total cholesterol level
> 5mmol/l were included to the study. We found out : age, gender, BMI, history
of hypertension (HT),diabetes mellitus(DM),smoking(Sm),stroke and TIA(S/T)CHD
and laboratory data :level of total cholesterol (Ch),LDL-cholesterol
(L-Ch),HDL-cholesterol(H-Ch), and triglycerides(TG). Correlation between
plague width and risk factors or laboratory data we tested by Student´s
t-test(p),Pearson´s coefficient(P) and linear correlation. Results: 377 patients we enrolled to study
during 24 months, 237 male and 140 female. Mean age was 63,3 years (35-84),
mean plague width 3,05mm. 233 patients had HT(62%), 88DM(23%),
87Sm(23%), 184S/T(49%), 99CHD(26%). Plague width was dependent on male
gender(p=0,000009), hypertension (p=0,0007),stroke or TIA(p=0,04 for<50years
versus >70 years). Mean cholesterol level was 6,5mmol/l. No
correlation was found between plague width and Ch(P=0.07), L-Ch(P=-0.1),
H-Ch(P-0.14), TG(P=0,1) Conclusion: At patients with
hypercholesterolaemia , a width of atherosclerotic plague in carotid
bifurcation is dependent on age , male gender ,hypertension , a history of stroke or TIA and CHD. We are not found any correlation between plague width and level of cholesterol , LDL-cholesterol, HDL-cholesterol or triglycerides. Also plague width was not dependent on diabetes mellitus , BMI and smoking. |
|
P174 |
New Way of Visualizing
of the Blood Flow: B-flow Sonography of the Cervical Main Arteries
(comparative study) L.Németh MD.’ K..Hiramatsu MD."C. Mihara PhD." J.Nikl
MD’,T.Shima PhD." Coun |