LARGE INFARCTS IN THE MIDDLE CEREBRAL-ARTERY TERRITORY - ETIOLOGY ANDOUTCOME PATTERNS

Large supratentorial infarctions play an important role in early morta lity and severe disability from stroke. However, data concerning these types of infarction are scarce. Using data from the Lausanne Stroke R egistry, we studied patients with a CT-proven infarction of the middle cerebral artery (MCA) territory that covered at least two of three MC A subterritories (deep, superficial anterior [superior] and posterior [inferior] territory). We compared these patients with patients presen ting more limited infarction in the MCA territory. Our study group of large MCA (laMCA) infarction contained 208 patients, corresponding to 7.6% of all ischemic infarctions in the Lausanne Stroke Registry. Seve nty-two patients had complete infarction in the whole MCA territory (c oMCA). Internal carotid artery (ICA) occlusion (41%) and ICA dissectio n (12%) were more common than in limited superficial MCA (lsMCA) infar ct and anterior circulation infarct (p < 0.001). Among the patients wi thout ICA occlusion, atrial fibrillation (33%; p < 0.002) and cardioge nic embolism in general (54%; p < 0.001) were more frequent in laMCA t han in lsMCA infarct. Severe neurologic deficit (hemiplegia and hemise nsory loss in the face, arm and leg, hemianopia, global aphasia, reduc ed consciousness) was more common than in other types of infarct. A co mbination of these symptoms had a positive predictive value for laMCA infarction of 0.73 (sensitivity for left side laMCA infarcts, 0.56). M ortality (17%) and severe disability (50%) were higher with laMCA than for other infarcts (p < 0.001). Sixteen of the 35 deaths could be att ributed to brain edema. Reduced consciousness, hemianopia, and coMCA i nfarction were independent predictors of death or severe disability; f or death only, coma was an independent predictor. Patients who died be cause of brain edema were younger than patients whose death was due to other causes (mean age, 57 versus 73 years; p < 0.001); they also die d sooner (mean time of death after stroke, 5 versus 37 days; p < 0.001 ). Furthermore, patients who developed coma on the day of admission we re more likely to die because of brain death (p < 0.001). Large middle cerebral artery infarction is associated with cardiogenic embolism, I CA occlusion, and ICA dissection. It is a major predictor of death and severe disability, although a lower frequency of malignant brain infa rction was found than previously reported.