Effect of Right Insular Involvement on Death and Functional Outcome After Acute Ischemic Stroke in the IST-3 Trial (Third International Stroke Trial)

Strokes involving the insular cortex tend to be more severe. Preliminary evidence suggests that insular involvement is associated with poorer functional outcome after ischemic stroke regardless of infarct size, as well as with higher case fatality rates. However, these associations are controversial. The pathophysiological mechanisms explaining the apparent association of insular involvement with poor ischemic stroke outcome remain unknown. Differences in outcomes between left and right insular cortex strokes arise because of the laterality of autonomic representation in the brain, although there is disagreement whether the right or left insula is the one most associated with poor prognosis. We therefore examined the associations between insular involvement, its laterality, and outcome at 6 months after stroke in the large prospective data set provided by the IST-3 study (Third International Stroke Trial).