Poster Abstracts Thursday, November 10, 2005 $405

also interpreted CT scans. CT was repeated at 24 hours and outcome evaluated at average 4 weeks (range 3 to 12 weeks) using NIHSS and modified Rankin Scale (mRS). Results: We treated 8 patients (6 men, 2 women) with henfispheric infarction/ischemia with mean age of 51 years (range 32-57). Average time to arrival from onset was 67 minutes (range 21 to 150 minutes), time to CT after arrival 40 rain (range 15 to 120 minutes), door to needle time 70 minutes (range 45 to 120 minutes) and time to treatment after stroke onset 117 minutes (range 60 to 170 minutes). Average pretreatment NIHSS 17. Five patients had EIC on CT less than 1/3 of the MCA. Outcome on the mRS was, 2/8 had no or minimal symptoms, mRS 3-4, 3/8 moderate disability (able to walk n - 2, unable to walk n - 1), mRS 5-6, 3/8 severe disability (n -- 2) or death (n - 1). Average post treatment NIHSS 8 (range 0-24). There were 3 hemorrhages, two symptomatic parenchymal hematomas (1 expired, 1 craniotonly) and one asymptomatic hemorrhagic transfomlation. Adnfinistration of antihypertensive medication and initial CT hypo- density were associated with unfavorable outcome (mRS 4-6). Of the untreated group (resolving deficit n - 8, unknown time of onset or > 3 hours n - 11, CT changes > 1/3 of M C A n -- 7, non ischemic stroke n - 5, patient/family refusal n - 2), four patients had more than one contraindications. The mortality in the untreated group was 5/24 (ischemic strokes). Hemorrhagic transformation was seen in 4/26 patients and none developed a parenchymal hematoma. Radiologist misinterpreted 8/37 CT scans (missed EIC on 4, tumor called a stroke) and failed to ment ion the amount of M C A territory involved. Conclusion. Thrombolysis of acute stroke is effective in our clinical setting. In spite of no protocol violations there were hemorrhagic complications. The number of patients is small to draw any conclusion about the safety in our population. There is a need for education of the radiology and emergency room staff.

1194 Isehenlic Stroke mechanisms in a metropolitan city of South India: (Hyderabad Stroke Registry)

Kanna, Meena A 1, Kaul, Subhash 1, Suvarna, Alladi 1. 2Nizam's Institute Of Medical Sciences, Andhra Pradesh, India

Background: Limited data exists on the mechanisms of ischemic stroke from the Indian subcontinent. The present study was aimed to investigate the frequency, spectrmn and risk factors of various subtypes of ischemic stroke in a major south Indian University Hospital and referral centre. Method: The study was conducted on consecutive patients of ischemic stroke, fully investigated to determine the underlying mechanism, enrolled in the stroke registry of Nizam's Institute of Medical Sciences, Hyde rabad , I nd i a , between 1 ~t February 2000 to 31 ~t January, 2003. The subtyping was done as per the TOAST criteria. Reslflts: Of the 605 patients with ischemic s t roke , there were 422 men and 183 women. (mean age 54 years ; range 2-97 years).Of all ischemic stroke patients, 255 patients (42%) had large-artery atherosclerosis (1207 intracranial and 48 extracranial ). Other major subtypes included lacmmr strokes in 105 (18%), cardio-embolic strokes in 73 (12%), strokes due to other etiologies in 13 (2%) and strokes due to unknown etiology in 159 (26%) patients. Hypertension, diabetes and smoking were the common risk factors among all subtypes. Coronary artery disease and rheumatic heart disease were responsible for most of the cardioembolic strokes. Conclusions: All major stroke mechanisms contribute to ischenlic stroke in India. The most notable difference of this registry from western registries is the predominance of intracranial rather than extracranial location of the large artery atherosclerosis.

1195 Aspirin resistance and Aspirin overdosing in patients atter First-Ever Isehenlic Stroke

Karepov, V ~, Tolpina, G ~, Klaiuman, E s. 1Medical Center "Meteor", Tel-Aviv, Haifa, Israel.." 2 Gefen'" - Cardiac Health Center, Givatayim, Tel Aviv University and Ariel Academic College, Israel

Background: Aspirin (ASA) fails quite frequently to prevent recurrent ischemic events. Platelet aggregation test is useful for identification of the optimal ASA dosage needed for more effective secondary stroke prevention. Objective: To assess platelet function in the patients using ASA after first-ever ischemic stroke (FIS) for further optimization of their treatment. Malerial and Melhods: We recruited 224 consecutive patients with documented FIS who took ASA (aged 69±7 years, 139 males). Whole blood samples were studied using the platelet function analyzer (PFA- 100). ASA resistance was defined if the duration of epinephrine test was less then 170 see., and/or if adenosine-diphosphate (ADP) test was less then 70 sec. ASA-overdosing was diagnosed in the patients with A D P tests prolonged more then 114 sec. Results: Sixty-seven of the 224 patients (29.9%) were resistant to ASA treatment. Forty-six of all studied patients (20.5%) had ASA- overdosing. The optimal laboratory response to ASA was demon- strated only in the ha l f of the studied patients (113/224-50.4"/o). Conclusions: ASA-resistance was found in a third of the ASA-users after FIS, and their therapy needed to be changed. On the other hand, about 20¢/0 of the ASA-users had ASA overdosing with potential bleeding complications. Therefore, it is recommended that post-stroke ASA-users need to be tested by platelet function analysis for optimization of their anti-aggregation treatment.

1196 Aspirin resistance among Post-Stroke Patients with Coronary Syndxoines: I?om tile laboratory phenomenon to clinical success

Karepov, V 1, Tolpina, G 1, Klaniman, E 2. 2Medical Center "Meteor", Tel-Aviv, Haifa, Israel.." 2 Gefen'" - Cardiac Health Center, Givatayim, Tel Aviv University and Ariel Academic College, Israel

Background: Aspirin (ASA) resistance was demonstrated in 20-40% among ASA users, but it was not evaluated in clinical practice yet. Objective: To evaluate the results o f ASA resistance correction in the post-stroke patients with coronary syndromes using ASA in prospec- tive longitudinal study. Materials and Methods: Consecutive post-stroke ASA-users with coronary syndromes were included in the study. Citrate whole blood samples were studied using platelet functions analyzer. The patients were determined as ASA non-responders if their epinephrine test was less than 170 sec, and/or the duration of adenosine-5-diphosphate test was less than 70 sec. ASA resistance was corrected using increased ASA doses. The total number of the vascular events during two-years follow-up period was the end-point o f the study. An expected rate of the vascular events was 20%. The chi-square test was used for the comparison with the real rate of the vascular events in the study. Results: Blood samples were collected from 127 consecutive post- stroke patients with coronary syndromes using ASA. Thirty-nine (130.7%) of them were determined as ASA non-responders. Their impaired platelets functions were corrected using ASA increased doses. The total nmnber of the vascular events during two-years follow-up was 6 (4.7%, OR -- 5.04, p < 0.01). Two patients died from cardio- embolic stroke while used ASA combined with Coumadin. Conclusions: The platelet function evaluation could be helpful not only for laboratory diagnosis of ASA resistance, but it could significantly diminish the number of the candidates for the vascular events in the clinical reality.

1197 Nucleus ambiguus has a minhnal prognostic role in dysphagia associated with lateral medullary infarctio n