Predictors of life-threatening brain edema in middle cerebral artery infarction

Background: We performed a systematic review to identify predictors of the development of life-threatening brain edema in patients with middle cerebral artery infarction. Methods: We searched Medline from January 1966 and Embase from January 1974 to April 2007 for cohort and case-control studies on predictors of life-threatening edema in patients with middle cerebral artery infarction. Crude data were used to calculate risk ratios, odds ratios, or weighted mean differences. Results: Infarct size was the major determinant of the development of life-threatening edema. Other associated determinants were early mass effect, involvement of other vascular territories, higher body temperature, internal carotid artery occlusion, and need for mechanical ventilation. However, predictive values were only moderate. Conclusions: The size of the ischemic area is the major determinant. Single predictors lack sufficient predictive value to select candidates for surgical decompression before the onset of clinical signs of herniation.