Predictors of Outcome in Patients Presenting with Acute Ischemic Stroke and Mild Stroke Scale Scores

Abstract

Although National Institutes of Health Stroke Scale (NIHSS) is a known predictor of outcome in acute ischemic stroke, there are other factors like age, ambulatory status, and ability to swallow that may be predictors of outcome but are not assessed by the traditional NIHSS. The aim of this retrospective review was to identify predictors of outcome in mild ischemic stroke. Discharge outcomes from patients who presented to our large academic stroke center with acute ischemic stroke from 2005 to 2013 were retrospectively reviewed. Of 7189 patients reviewed, 2597 had initial NIHSS less than 5. Outcome measures were modified Rankin Scale (MRS) score 0-1 and discharge to home. In all, 65% of patients with NIHSS 0-4 were discharged directly home independent of treatment. Of those patients discharged to home, 74% were able to ambulate independently and 98% passed their dysphagia screen. Of patients not discharged directly home, 66% were unable to ambulate independently and 21% did not pass their dysphagia screen. Multivariate logistic regression analysis revealed a significant effect of dysphagia screen (P = .001), ability to ambulate independently (P = .002), age (P = .016), and NIHSS (P = .005) on discharge to home but not MRS of 0-1 (P = .564). In patients with mild stroke scale scores defined as NIHSS 0-4, several factors including age, NIHSS, ambulatory status, and ability to swallow may be independent predictors of functional outcome and discharge home. These data support the development of a modified grading system for assessing functional outcome in mild stroke that considers these factors.