The investigators studied laboratory measurements and previously identified risk factors to identify factors predictors of early deterioration following stroke. A prospective observational study of 196 patients with first-time acute ischemic stroke was performed. Following multivariate analysis, only a Bun/Cr >15 was independent predictor of SIE. These patients were 3.41-fold more likely to have SIE (P=0.008). The elevated Bun/Cr ratio indicates relative dehydration of the patients. An immediate intervention for such patients should be the maintenance of proper hydration.