rO-B49

SECOND WORLD CONGRESS OF STROKE, 1992

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S79

Monitoring for stroke during carotidsurgery.

Claeys L.,Rtenidis R., Horsch S •.Federal Republic of Germany

We examined somato-evoked potentials andtranscranial dopplersonography as monitor­ing methods for intraoperative stroke.292 pat. undergoing 332 carotid operationswer~ <;t-110 i..,,~. 'l'r n ;>.~d SF:P we r e registeredprior to clamping,during clamping and afterdeclamping. We considered SEP reductionsof 50% and more or a loss of SEP as signs f.critical cerebral ischaemia or stroke.The incidence of TCD changes and flO\;reduction was compared to the critical SEP­changes.During 22% of the clampings we ob­served TCD reductions to 70% and more.In66,5% of these the SEP's were pathologic.In all cases of pathologic SEP's there wasalso a TCD reduction of 70 %.Therefore ifthe mean blood flow velocity of the middlecerebral artery is reduced " to 70% or moreduring clamping,there is an inadequatecerebral perfusion with a high risk ofstroke.We conclude that a loss of SEP or a redu~

tion to 50% or a reduction of the flow­velocity in the middle cerebral arteryindicates a critical cerebral ischaemia.

PO-BS1

ACUlE EEFFEcrs OF COCAINE ON CEREBRALHEMODYNAMICS ANDCARDIOYASCULAR SYSTEM: ASTUDY IN HUMANS

Pierre B. Fayad, Lawrence H. Price, Christopher J. McDougle,Frank J. Pavalkis, Lawrence M. Brass. (U.S.A.)

The cardiovascular and cerebral complications of cocaine canbe severe and life-threatening. Cocaine appears to have avasoconstricting effect on the coronary arteries, while its effectson the cerebral aneries are unclear. To assess the acutehemodynamic effects on the cardiovascular and cerebralsystems, we continuously monitored cerebral blood velocities(CaY) with transcranial Doppler (TCD), systolic (SBP) anddiastolic (DBP) blood pressure, and hean rate (HR) in 12volunteers, before, during, and up to 45 minutes followingintranasal cocaine administration (2mg/kg). Ten men and 2women, mean age 31(21-40), were pan of a research protocolevaluating the neurobiology of cocaine administration andwithdrawal.

There were: a 35% increase in HR, a 15% rise in SBP andDBP, and pulsatility index (PI) (1.07±0.16 at baseline, to1.23±0.19). Systolic CBYs also increased by 8% from96.9±18 .1 cm/s at baseline, to 105.1±18.1 cm/s. AU changesoccurred between 10 and 25 minutes after administration andwere all statistically significant (p<o.OI;2-tail paired t-test).Multiple stepwise regression analysis of percentage change ofSBP, DBP, and HR, were not predictive of the change in PI andsystolic CBY. Two patients had 6-7% decrease in systolic CBY.

Acute CBY changes and cardiovascular effects reach amaximum between 10 and 25 minutes after cocaine inhalation.The increase in systolic CBV and PI appear independent fromhematocrit or systemic BP and HR changes. The acute effects ofcocaine are more prominent on the carrliovascular system thanthe cerebral vessels, with some individual variability.

Cerebral Va~oreaclivity after Acetazolamide:Dose and T~oral Profile of lhe Response

Dahl A, Russell 0, Nyberg-Han~en R, Rootwelt K.Riksho~pitalet, University of Oslo, Norway

Blood flow velocities (BV) in both mi dd l e cerebralarteries were continuously mea s ur ed in 32 healthysubjects before and follOWing the i.v. injection of1 g acetazolamide (ACz) using permanently fixedprobes and transcranial Doppler ultrasound (TCD).In20 subjects rCBF was also measured before and20 mins after the Acz administration using SPECT and133-Xenon inhalation . The dose in mg/ kg wascalculated and the serumconcentration of Ac% wasmeasured in 15 subjects 5 mins after the admini­stration ..

BV increased by 43.3 ±2.7% (SEM) reaching a plateauphase after B mins which then lasted for 20 mins.After 45 mins (11 subjects) BV decreased to 67% ofthe maximal respon~e. The relationship between doseand serum concentration was good (r=0.84; p<O.OOl).The \ increase in BV was related to the dose andserum concentration of Ac% and the do se responsecurve de monstrated no fut her velocity increase inSUbjects receiving doses greater than 15 mg/kg. Norelationship was observed between the rCBF increaseand Acz dose or serum concentration.

In conclusion this study has shown that theassessment of vasoreactivity using Ac% should becarried out 10 to 30 minutes following the injectionof a 15 mg/kg dose.

rO-BS2

Vascular Dementia: Longitudinal Study with TranscranialDoppler Ultrasound

Linda A. Hershey, Geoff S. Hamill, Karen O. Burch, BJ.McClary-Graham, Waiter A. Olszewski, Buffalo, New York,USA.

To study the pathophysiology and natural history ofvasculardementia, we examined 13 patients within 21 days of anacute ischemic stroke using transcranial doppler ultrasound(TCD). We repeated TCD and the clinical examinationevery three months for at least 9 months. Six of these 13patients met DSM III criteria for dementia, scored 7 ormore on the Hachinski scale and were not demented priorto their original stroke. At the time of enrollment, therewas a significantly (p= 0.05) lower mean basilar artery flowvelocity in vascular dementia patients (16.6cm/sec),compared to nondemented stroke controls (38.3cm/sec).This difference did not persist over time. Five of the 6vro patients improved their cognitive scores by at least10% (3 pts/3D total) within the first 6 months of the stroke,while only 1 of the 7 nondemented controls improved to thesame extent. Vascular dementia is a condition that is atleast partially reversible' over time and may be morecommon in patients with ischemia in the posteriorcirculation. Funded by AHA NYS affiliate.

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PO-B53

SECOND WORLD CONGRESS OF STROKE, 1992

PO-B54

Establishment of a Tentative Criterion for The Diagnosis ofIntracranial Occlusive Lesions by Transcranial DopplerUltrasonographyTaiji Itoh, Masayasu Matsumoto, Nobuo Handa, Hiroaki Maeda,Hidetaka Hougaku, Takenobu Kamada. The First Department ofInternal Medicine, Osaka University Medical School, Osaka, Japan

In order to assess the usefulness of transcranial Dopplerultrasonography (fCD) in ischemic cerebrovascular disease, wetried to establish a tentative criterion for the diagnosis of theocclusive lesions in the middle cerebral artery or the internalcarotid artery.

In 18 healthy volunteers, a 95 percent confidence intervalof the velocity of middle cerebral artery was defined as a normalrange and based on this, we determined following four abnormalflow velocity criteria; a) the peak flow velocity of middle cerebralartery (MCAPF) z 127cm/sec, b) MCAPF ~ 53cm/sec, c)Turbulent flow, and d) MCAPF ratio between both MCAs z 1.34.

By using these signs, we investigated the diagnosticaccuracy of TCD for detecting occlusive lesions of the middlecerebral artery or internal carotid artery in 61 patients with bothTCD and angiographic examinations. The diagnostic accuracy for17 patients with occlusion or severe stenosis of unilateral internalcarotid artery was 84% by using the criterion [ b) and d) ], andthat for 9 patients with stenosis of unilateral middle cerebral arterywas 90% by using the criterion [ a) or c) ].

In conclusion, by using a tentatively established abnormalflow velocity criterion TCD proved to be a quite useful andaccurate method for the diagnosis of the occlusive middle cerebralartery or internal carotid artery lesions.

PO-B55

Positional Changes in Vertebral Artery Blood Flow

Alan E. Ottenstein and Giovanna I. Ruiz-Bonilla,Lawrenceville, New Jersey, USA

This retrospective study analyses significant hemodynamicchanges evoked in 32 intracranial vertebral arteries in 26 patientsby head rotation during in vivo monitoring. These patients hadinsonation of the basilar artery and both intracranial vertebralarteries in the usual position, and then had head rotation to eachside performed while blood flow velocities were continouslymonitored by transcranial Doppler ultrasound (TCD). Eachpatient reported here had an increase of 100% or a decrement of50% in the peak or thc mean blood flow velocity, as measuredby TCD. These changes may have clinical significance, andmerit further study.

USEFULNESS OF TRANSCRANIAL DOPPLER (TCD) INTHE CAROTID-CAVERNOUS SINUS FISTULAS (CCSF).

PREITI N.,BUONCRISTIANI P.,FLORIDI P.,CIORBA E.,ORVIETO P.,NASONI G., ANDCASOTTO A.,SIGNORINI E., GALLAI v.. PERUGIA, ITALY.

The CCSF syndrome is characterized by ethiopathogenic,haemodinamic and clinical features,which are relevantto the therapeutical approach.Haemodinamic aspects arecarefully evaluable by TCD;this not-invasive and reli­able method is feasible for pre-,intra-,and post-ope­rative studies (l).The AA. report their 4 cases experlence on the basis of an illustrative case in which waspossible to obtain a complete TCD study.This confirmedfrom the haemodinamic point of view the peculiarclinlcal features of the CCSF in our case:post-traumaticbut with incomplete ocular signs due to relative lowflow and to controlateral venous drainage.Correlationsof TCD and angiographic data pre and post operativel~

resulted in a better knowledge of the shunt mechanis~

During surgery TCD monitoring of the left superiorophtalmic vein flow indicated the precise time to stopthe introduction of fibrin glue into the cavernous slnus,obtaining complete obliteration of the fistula andavoiding compression to the carotid artery (2).REFERENCES:1) Aaslid R.:Transcranial doppler sonogaphy.Springer-Verlag Wien New York, 1986.2) Casotto A.,Castioto C:,Buoncristiani P.: F.C.C.post-traumatiche.Riv.Neurochirurgica 1:45-52.1987.

PO-B56

EFFECTS OF VALVULAR HEART DISEASE ONCEREBRAL BLOOD FLOW VELOCITIES

Frank J. Pavalkis PA, Michael Dewar MD, Pierre B. FayadMD, Lawrence M. Brass MD.Yale University School of Medicine, New Haven, CT, U.S.A.

Severe valvular heart disease and impaired cardiac outputhave been associated with ishemic cerebal infarctions andcognitive impairment. The mechanism for these changes havebeen attributed to hemodynamic impairment or microembolism.To investigate the potential effect of valvular disease on cerebralhemodynamic impairment, we did a pilot sutdy on patients withmitral regurgitation (MR) and aortic stenosis (AS) withtranscranial Doppler (TCD) within 24 hours pre-, and 48 hourspost-valve replacement.

Eight patients were studied with MR (5) and AS (3). Whenall patients were analyzed together no significant differences werefound in peak (Vs), end-diastolic (Vd), mean (Vm) velocities, orpulsatility index (PI) before and after surgery. When patientswith 1\1R were analyzed alone, similar non-significant differenceswere found. In patients with AS, there was a significant increasein Vs (p<.05), and a trend to higher Vm.

Despite a small number of patients studied we were able todetect some differential effects from valvular replacement oncerebral blood velocities between patients with AS and MR. Ourfindings justify the need for the investigation of patients withcardiac valvular disease with TCD. A larger number of patientsand a long-term follow-up may provide better understanding ofthe effect of valvular impairment on cerebral hemodynamics, andthe pathophysiology of its ischemic complications.

PO-B57

SECOND WORLD CONGRESS OF STlWKE, 1992

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S81

DUPLEX SCANNER WITH COLOR FLOW IMAGINGAS A NEW TECHNIQUE FOR THE STUDY OFINTRACRANIAL CIRCLE.Gibellini R., Ferrari Bardile A., -Zarnbelli M.Fondazione Clinica del Lavoro I.R.C.C.S. - CentroMedico di Montescano - Italia

The transcranial Doppler (TCD) can directlyprovide important emodynamic and diagnosticinformations about the intracranial circle.Its limits are represented by the selection ofinsonation depth and the certain identificationof intracranial vessels, in particular whenmalformative pathologies or anatomicalvariations are present.Aim of our study is to purpose a new technique, asDuplex Scanner with Color - Flow Imaging.certainly identifyng intracranial vascularstructures with a direct visualization and amore correct positioning of PW - Doppler samplevolume.This non invasive method is able to visualizelarge brain arteries with' a transtemporal andtransoccipital approaches, and to describeernodvnarnlc phenomenon of cerebral flow.

PO-B59

Transcranial Doppler During Contrast Echocardlographyin Stroke Patients With Patent Foramen Ovale1\1. Di Thllio, N. Venketasubramanian, D. Sherman, R. L.Sacco, A. Massaro, M. Holfmann, J.P. Mohr, S. Hornma,Columbia University, New York, JI.'Y

Paradoxical embolization (PE) through a patentforamen ovale (PFO) is regarded as a mechanism forstroke. A PFO is usually detected by contrastechocardiography (CE), which, however, docs not provideevidence of embolization to the brain. 'Ye used transcranialDoppler (TCD) to determine the delivery ofmicrocavltatlons to the cerebral vessels in stroke patientswith PFO. Flfty-five patients with acute ischemic stroke(301M, 21F, mean age 61.0±15.5 years) underwent TCD ofthe right middle cerebral artery during CE with aeratedsaline injection. A PFO was detected in 9 patients (16.4%)by CE and in 12 (21.8%) by TCD. Agreement between thetwo tests is showm

TCD (+) TCD (.)CE (+) 9 0CE (.) 3 43

Overall agreement was therefore 901.6% (52 of 55 patients).The 3 patients not Identified by CE had poor test imagequality. Conclusions: 1)During CE, stroke patients withPFO have microcavltatlons delivered to the brain,supporting the possible role of paradoxical embolism as acause of stroke 2) TCD is a valid alternative In case of CEpoor image quality.

Transcranial Doppler evaluation of in­operable AVM of brain treated by he­lium beam Bragg peak therapy

Nagbhushan S. Rao, Chitra Chari,Ade Adeshoye

A 27 year old man with an inoperablearteriovenous malformation (AVM) had trans­cranial Doppler (TCD) study which showedmean flow velocity of 136-148 em/sec.in left middle cerebral artery (MCA),86 em/sec. in right anterior cerebralartery (ACA) and 72 em/sec. in left poste­rior cerebral artery (PCA), consistentwith feeder arteries. C02 reactivityin these vessels was abnormal i.e. 0.63%change in velocity per mm Hg pC02 change,compared to 3-4% response of the oppo­site (normal) MCA. These "feeder" vesselsalso showed abnormal response to increasedperfusion. The patient received heliumbeam Bragg peak therapy to the AVM. Twen­ty two months post therapy repeat studyshowed almost normal flow velocity in allthe feeder vessels. C02 reactivity improv­ed to 2% from 0.63% and the r esponse to in­creased perfusion was same as opposite MCA .Magnetic resonance imaging revealed markedreduction in the size of AVM. In conclus­ion TCD can effectively. assess progressivetherapeutic outcome of AVM following Braggpeak therapy.

PO-B60

TRANSCRANIAL DOPPLER IN ELDERLY STROKEPATIENTS

Aldo E. Tammaro. Roberto Prlna, AntoninoFrustaglia. Celia Albanese (Milan. Italy)

Transcranial Doppler is a recently introduced.non-invasive technique for the study of intracranialcirculation . Its feasibility and diagnostic value in theelderly are still to be satisfactorily documented.

The aims of the study were 1. to assess the in­tracranial circulatory pattern in elderly subjects [Ss land 2. to ascertain the possible differences with el ­derly stroke patients (pts l ,

The study was carried out with EME TC 2-6lJ so­nograph on 11 pts with previous stroke (age range71 to 82 yr-s , Group 1) and on 11 Ss matched forage and sex. without clinical evidence of cerebrova­scular disease (Group 2). All participants were pre­viously subjected to a cranial CT -scan.

The mean blood velocity in the mean cerebral ar­tery (MVMCA) resulted 32.9.:!:2.36 em/sec in Group 1and 29.5.:!:2.lJ8, em/sec in Group 2 (P=ns)' However.our values were markedly lower than those reportedby previous Authors who studied young Ss [Aaslld,1982: 62.:!:12; Prati.1986 : 51.3.:!:12.9 cm/secl.

In conclusion. a reduction in MVMCA seems totake place with increasing age without significantdifferences between stroke pts and healthy Ss ,

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SECOND WORLD CONGRESS OF STROKE, 1992

PO-B62

Contrast Enhanced Transcranial and Pre­cerebral Doppler Studies

D. Russell, R. Brucher, A. Dahl, J. Jakobsen,Norway

The aim of this study was to assessthe effect of an ultrasound contrastagent (Albunex; Nycomed, Oslo) on theDoppler signal from the precerebral caro­carotid artery and middle cerebral artery.

Albunex consists of 4 x 108

microbubbles per ml and these have anaverage diameter of 3-5 ~m.Ten healthysubjects took part in the stUdy nnd eachreceived two intravenous injections ofAlbunex in doses of 0.08 ml/kg and 0.22ml/kg. Continuous Doppler monitoring of theright precerebral carotid and middlecerebral artery was carried out throughoutthe stUdy.

Transpulmonary passage of Albunexoccurred and the intensity of the Dopplersignal from the carotid and middle cerebralarteries increased by at least 15 dB. In 5cases the intensity increase was 50 greatthat,overloading of the Doppler instrumen­tation occurred.

These results strongly suggest thati.v. ultrasound contrast may lead to asignificant improvement in the quality oftranscranial and extracranial Dopplerexaminations.

PO-B63

Effect of Air Contrast Dose on the EchocardiographicDetection of Patent Foramen OvaleDavid Sherman, Marco Di Tulllo, Charles Marboe, N.Venketasubramanian, Ralph 1.. Sacco, J. P. Mohr, ShunichiHomma, Columbia University, NewYork, NY.

Transthoracic echocardiography (TI) with agltatedsaline injection is used to detect a patent foramen ovale(PFO) in paticnts presenting with a cerebrovascularaccidcnt (CVA). It has never been determined whetherinjecting different amounts of air might affect the detectionof a PFO. We therefore studied the effect of two differentcontrast preparations on 75 consecutive patientspresenting with a CVA(33 male, 42 female, mean age 65.6 ±14.4 years) undcrgoing IT. Preparation A (PA) consisted of0.2 ml of air mixed with 9 ml of saline by two syrlngesmounted on a three way stopcock; preparation B (PB) had1 ml of air mixcd with 9 ml of saline. Injections wereperformed at rest and during Valsalva maneuver. The sizeof the cavitations were similar in both preparations (range:30·110 microns). However, PB resulted in more numerouscavitations than PA (152 ± 79/mm3 vs. 3~ ± 9/mni3) . Nodifference was noted in PFO detection using either PA orPB. A PFO was detected in 9.3% of patients (7 of 75) withboth PA and PB. No side effects were observed.Conclusions: 1. PFO detection by IT is not affected by theamount of air mixed ~ith the saline. 2. Injection of largeamounts of air is therefore unnecessary.

SUDDEN NEUROLOGICAL EVENTS AND EEG IN MITRALVALVE PROLAPSER. Mai, D.Facchetti, S.Harangoni, M. PoloniFondazione Clinica del Lavoro,

- Gussago (BS) - Italy. "

We studied 22 consecutive unselectedpatients (pts) with clinical andechocardiographic diagnosis of mitral valveprolapse, either asymptomatic andsymptomatic. All pts underwent a completebattery test including clinical examinationand history, ECG, echocardiography, HoI terECG, spectral analysis of R-R intervals,EEG, and psychological evaluation in orderto better understand the correlation betweenheart and brain functioning. The pts were 19females and 3 males with a mean age of 35years (15-69). Seven (31.8 %) pts (allfemales) presented almost one sudden loss ofconsciousness (syncope) and 12 (54.5 %)presented pre-syncopal symptoms. Fiftheen(68.2 %) had paroxysmal tachycardia and 3(13.6 %) had panic at tacks. EEG recordsshowed mild focal epileptiform activity in 6(27.3 %) pts (5 of them with syncope), andbrief diffuse slowing in hyperpnea in 2 pts.The preliminary evaluation of EEG resultssuggest a relationship between EEG anomaliesand occurrence of syncope in mitral valveprolapse.

PO-B64

CARDIAC AND VASCULAR SOURCES OF CEREBRALISCHEMIC STROKE. A COMBINED TRANSESOPHAGEALAND VASCULARULTRASONOGRAPHIC STUDYR.Tramarin, R.Gibellini, C.Pistarini, M.Franchini, G.Forni,A.Torbicki, L.Tavazzi. Fondazione Clinica del Lavoro, Care andResearch Institute, Montescano, Pavia, Italy.

Transesophageal echocardiography (TEE) is useful for thedetection of sources of cerebral embolism, however the relativerole of cardiac versus coexistent vascular sources of embolism inthe pathogenesis of cerebral ischemic events has not been so farfully clarified. To assess the relation between cardioembolicsources and significant carotid lesions (>40% diameter stenosis;ulcerated plaques), 124consecutive patients with recent CT provenischemic stroke were prospectively studied by TEE and high­resolution duplex ultrasonography(HRDU) of carotid arteries.Results: Among 89 (72%) patients with negative (52 pts) or low­risk «40% diameter stenosis; non-ulcerated plaques) (37 pts)HRDU, potential cardiac sources of emboli (CSE) could beidentified with TEE in 36 cases (70%): mitral valve prolaps in 11(12%), left atrial or appendage thrombi in 9 (10%), left atrial orappendage spontaneous echo in 13 (15%), interatrial septumaneurysm in 15 (17%) and patency of the foramen ovale in 30(34%). In 35 (28%) pts with significant carotid lesions in side­appropriate arteries, coexisting potential CSE were found in 10cases (29%). The prevalence of potential CSE was similar in ptswith low-risk and normal HRDU (70 vs 69%, ns). CombiningTEE and HRDU results, potential thromboembolic sources werefound in 97 of 124 pts (78%). Only 16 (13%) pts had neithercarotid artery lesions nor potential CSE at TEE; 11 (9.8%) ptswithout CSE had low-risk carotid lesions.Conclusions:These results confum that cardioembolic mechanismis involved in most cases of ischemic stroke without significantcarotid lesions. CSE and coexistent carotid lesions may occur insome pts. Combined TEE and HRDU may be useful in thecomprehensive non-invasive evaluation of the patogenesis ofcerebral ischemic stroke.