Hemispheric Differences in Malignant Middle Cerebral Artery Stroke (P2.288)

Background: We recently reported an analysis of ischemic stroke laterality in which we found that with left versus right hemisphere cerebral infarctions patients more frequently have worse outcomes. In addition, the scores on the NIHSS are weighted towards left hemisphere lesions. However our clinical experience led us to suspect that the incidence of malignant middle cerebral artery (MMCA) was higher in the right compared to the left hemispheric strokes. Objective: To determine whether laterality in MMCA stroke is an important determinant of stroke sequelae Methods: A systematic search was performed for publications in PubMed from 1966-2014 using terms such as “malignant middle cerebral artery stroke,” as well as “malignant middle cerebral artery and infarction”. A total of 298 articles were obtained from which 73 relevant studies were identified and abstracted. Results: MMCA laterality data were available for 2673 patients, with 1687 (63[percnt]) right and 986 (37[percnt]) left hemispheric involvement, thus the right being more commonly associated with MMCA (binomial test, p<0.05). Further analysis showed similar sex ratios between the hemispheres. While mortality rates were similar, right hemispheric MMCA (n= 271) had mortality of 31[percnt] (n= 85) whereas left hemispheric MMCA (n= 144) had mortality of 36[percnt] (n= 53) (p=0.2751, RR of 0.85 with 95[percnt]CI of 0.73-0.98, NNT= -18.38), morbidity rates were worse on the right. 72[percnt] (n= 127) with right side involvement had unfavorable outcomes compared to the left where 62[percnt] (n= 46) had an unfavorable outcome (p=0.138, RR of 1.15 with 95[percnt]CI of 0.79-1.68, NNT of 10.43) Conclusion MMCA stroke appears to be more common on the right, and this laterality is also associated with significantly higher morbidity. Further prospective studies are needed to more completely understand the nature of this laterality and localization as well as test possible new treatments to reduce mortality and morbidity associated with MMCA. Disclosure: Dr. Stead has nothing to disclose. Dr. Rastogi has nothing to disclose. Dr. Penumudi has nothing to disclose. Dr. Lamb has nothing to disclose. Dr. Williamson has nothing to disclose. Dr. Hedna has nothing to disclose.