P37

SECOND WORLD CONGRESS OF STROKE, 1992

P3S

S25

C"'l:r,tia after first stroke: 3-;:ars survivalanelvsis.

3.D. Arcf,ovich, I.A. treves, N.M. Bornstein,A.C-. Yorc:yn

Althouh aulti-Inf'arct ~e!ler,th (MIDl is a ~ell

recegr.i:e-d and conc'n nosologic e:ltity. ttr. Isctcrsresponsible Ior the d~velcl~~-ent of d~!t~itia

f"Howing strokes are not well known. Tj find H.erate at whict. desentia develops following troles.100 consecutive patients who had stroke in 19;8(but ~ere not demente-d at that time) fer developmentof dementia, to 3 years after tbe ceretrcvesculerevent. Kaphn-Meyer survival analysis was perforaeden the total p(,pul.ticn and several sutgroups. 1n; ofthe patients developed deaentia within 1 year, and24' within 3 years. V:mer.ti. occurred acrefrequently in older subjects 132 vs 14X) and in thosewith lower education. N,) association was foundtetseen deaentia and sex, t,Te ,jf stroke, arterialterritory, CT fin,Hr,gs, hypertensic,n, Ischealc heartdisease, atrial fit-rillatien and sE"king.Cc-rdusior.s: A significar,t noster c,f patients aredooaed to develop desentta Iollcving a first-everstroke. Tt:e rate at which desentia develcps f:·llc~ing

strokes can te used to evaluate factors c"ntrit,utingto the developaent of derentra as well as the successof tberaFY.

P39

Extracranial carotid artery disease amongststroke patients in Singapore.

M.C.Wong, A.Tan, H.M.Chang, S.H.Khoo, K.P.Tan.(Singapore),

The pattern of cerebrovascular disease amongst Asiansis said to be different from that of White Americans.Specifically, that Asians have a higher incidence ofintracranial cerebrovascular disease than WhiteAmericans, who commonly have disease affecting thecarotid bifurcation.All patients with an acute stroke admitted to SingaporeGeneral Hospital over a 3 week period were assessedclinically and by CT (Computerized Tomography).Patientswith cerebral hemmorhage were excluded. Fortythree of fifty four patients with the diagnosis of ischemicstroke were studied by carotid duplex ultrasound whichrevealed: Normal examination 24 patients, Mild « 25%)stenosis 8 patients, moderate (25-75%) stenosis 8patients, severe (>75%) stenosis 3 patients. Weconclude that extracranial carotid artery disease occursin a significant proportion of patients with stroke in theAsian population of Singapore.

PREVALENCE OF STROKE IN ELDERLY IN TAIWAN

TK. LEE, ZS. HUANG, SK. NG, The GeriatricStudy Group of R.O.C. Department of InternalMedicine, College of Medicine, National TaiwanUniversity, Taipei, R.O.C.

Since the proportion and population of theelderly are rapidly increasing in Taiwan, anationwide survey of prevalence and outcome ofcerebrovascular disease in the elderly aged 65and over has been carried out. Taipei, Tai­chung, Kaohsiung and Hua1ien were selected forthis survey. About 27.5% of the elderly inTaiwan, i.e. 270,000, stayed in these fourareas and 1% of them were examined. Among theexaminees, 155 cases of CVA, including 91males and 64 females were found. The ageadjusted prevalence of CVA was 6290/100,000,and the prevalence was significantly higher inmale than in female. Cererebra1 hemorrhage(CH) and cerebral infarction (CI) were diag­nosed by brain CT while those cases withoutCT of the brain were grouped as unclassified.Of the 155 cases of CVA, 13.5% were CH, 74.3%were CI.and 12.3% were unclassified. By Bar­thel index and modified Rankin's criteria,47.1% to 56.1% of the post-stroke elderlyneeded varying degree of assistance in theirADL. On the other hand only 14.6% of thenon-stroke elderly required some assistance intheir ADL. Using Hasegawa's test, 24.4% ofpatients were at least mildly demented. In thenon-stroke elderly of this age group, only 8%were either mildly demented or demented.

P40

COLOR FLOW IMAGING OF HIGH-GRADE CAROTIDARTERY STENOSIS

K.Niederkorn, S.Horner, M.Duft; Austria

Duplex scanning and color flow imaging of thecarotid arteries was performed in 56 patients(33 men, 23 women, mean age 69 years) with high­grade ICA stenoses (ultrasound system: VingmedCFM 700, Horten, Norway; B. mode frequency 7.5MHz, Color Doppler frequency 6 MHz).In 7 cases (12.5 %) color flow imaging addedsignificant information to the Duplex result.Two of these patients had confirming angio­graphy. 4 stenoses were "Low-f'Low" stenoses,with'norma1 or reduced flow velocities due tothe severity of the lesion.These results indicate that color flow imagingis a clinically valuable diagnostic tool,increasing the accuracy of Duplex scanning inthe diagnosis of subtotal ICA stenosis.

S26

P41

SECOND WORLD CONGRESS OF STROKE, 1992

P42

Reopening Phenomenon in Cardioembolic Stroke Observed byDuplex Carotid Ultrasonography.

T. Omae, T. Tsuchiya, M. Yasaka, T. Yamaguchi, T.Omae.Cerebrovascular Division, Department of Medicine, NationalCardiovascular Center, Osaka, Japan

An attempt was made to detect a reopening of occluded arteryin cases with acute cardioembolic stroke by duplex carotidultrasonography (DCU). The timing of reopening related tohemorrhagic transformation was also subjected to the study.

For assessing the reopening phenomenon, 10 patients withocclusion of carotid axis were studied. Quantitative measurementof flow velocity in bilateral common carotid artery was repeated.Ratio of the end-diastolic flow velocity (ED-ratio;unaffected/affected) was related to angiographic or autopsyfindings. A significant decrease in ED-ratio was observed in 6cases, in whom the repeated angiography demonstrated reopeningof the artery. In the remaining four patients not showing thesignificant change, only one patient was found to have reopening(diagnostic accuracy; 90%). -

In addition to the above 10 cases, 7 patients who underwentrepeated DCU. but not repeated angiography, were enrolled in thestudy, in which the timing of reopening was related to theoccurrence of hemorrhagic transformation. Spolty hyperdensitylimited to the cortex was not defined as hemorrhagic infarction.Reopening was detected in 12 of 17 cases. The timing was 2.5hours after onset in one, Day 2 • 5 in 6, after Day 6 in 5.Hemorrhagic infarction was found in cases whose reopeningoccurred between 2 and 5 days after onset (5 of 6 patients).

DCU was useful to detect the timing of reopening in patientswith acute cardioembolic stroke. Hemorrhagic transformation inthe basal ganglia tend to develop in patients with reopeningoccurring between Day 2 and Day 5.

P43

A FOLLOW-UP STUDY OF ASYMPTOMATIC CAROTID STENOSIS

Leonard Y.Lo,Yun-On Luk,Wen-Jang Wong,Han-Hwa Huand Fu-Li Chu

Taipei,Taiwan,Republic of China

Eighty-eight subjects,66 male with mean age of72±6.9 years old,22 female with mean age of 67±7.4years old were selected from 1912 subjects withouttransient ischemic attack nor stroke between 1981and 1989.All 88 subjects were confirmed to haveinternal carotid artery stenosis greater than 50%by 5MHz contInucu s-wave Dopp ler and 7. 5MHz B-modeim<ging ultrasound on the first follow-up date. Theywere followed up each six months by attendingneuro Jogists and ultrasonic examination simultaneous-ly from January 1989 to June 1991.

During 30 months follow-up,the risk of internalcarotid stenosis progression was 7/10(70%) of thoseinternal carotid stenosis greater than 75% incomparison with 27/78(35%) of those stenosis between50% and 75%.The risk of ischemic stroke was 3/l0(30%) in those internal carotid stenosis greaterthan 75% comparing to 2/78(2.5%) in those stenosis­between 50% and 75%.

We cone lJded that those internal carotidartery stenosis greater than 75% were criticalstenosis for asymptomatic subjects.

Acoustic Encephalography: The Pilot Results

A.V. Alexandrov, O.H. Pranjavichus, J.W. Norris,Institute of Neurology, Moscow, Russia; Kaunas MedicalAcademy, Lithuania; University of Toronto, Canada.

Ultrasound wave velocity (UWV) in brain tissuedepends on its rheological properties and reflectstranscapillary fluid exchange. The present method is basedon our findings in comparing UWV changes duringtranscranial passage with commonly usedinvasive CSF andintracranial pressure measurements and SPECT and TCD.

Monitoring with acoustic encephalograph in 45 patientsrevealed several patterns of autoregulatory reactions:abnormal patterns were demonstrated in 10 hypertensives,12 carotid artery disease, 14 hydrocephalus and 4vasospasm in SAH, compared to 41 normal controls.Simultaneous recording of UWV changes duringtranscranial passage with invasive CSF pressuremeasurement has shown qualitative assessment ofintraparenchymal pressure dynamics.

Acoustic encephalography combined with SPECT andTCD is informative for the evaluation of brain edemadevelopment, metabolic changes and state of braincirculation in acute stroke and head injury.

P44

Vasoreactivity in Patients with UnilateralCarotid Disease Studied with TCD and SPECT

Dahl A, Russell 0, Nyberg-Hansen R, Rootwelt K.Rikshospitalet, University of Oslo, Norway

The aim of this study was to compare transcranialDoppler ultrasound (TCD) and rCBF measurementswhen assessing cerebral vasoreactivity in patientswith unilateral carotid occlusive disease.

In 52 patients with unilateral internal carotidartery stenosis (n=2l) or occlusion (n=3l) bloodflow velocities (BV) in both middle cerebralarteries (MCAS) and rCBF (using SPECT and IllXenoninhalation) in the perfusion territory of the MCA(rCBF~) were measured before and 20 mins afterthe i.v. administration of 1 g acetazolamide.BV increased in the ipsilateral MCA from 50.4 to62.9 em/sec (23.8%) and from 62.4 to 89.4 em/sec(44.0%) on the contralateral side. rCBF~ increasedfrom 53.0 to 63.1 ml/lOOg/min (22.0%) and from 56.4to 74.4 ml/lOOg/min (32.7%) in the corresponding MCAperfusion territories. Asymmetry in % BV increasewas 20.2 % which was significantly different(p<0.005) from that for the rCBF~ increase (10.7%).There was a significant positive correlation(r= 0.63; p<O.OOOl) between the % BV and absoluterCBF~ increase.

This study strongly suggests thatthere is a significant relationship between TCD andrCBF findings following a potent vasodilatorystimulus and that the TCD method may now be usedin the clinical situation to assess cerebralvasoreactivity.