Ninety-Day Outcome Rates of a Prospective Cohort of Consecutive Patients With Mild Ischemic Stroke

Abstract

Background and Purpose— Prior studies have shown that patients with mild ischemic stroke have substantial disability rates at hospital discharge. We sought to determine disability rates at 90 days among patients not treated with thrombolytic therapy and explore the role of early neurological worsening. Methods— We reviewed a prospective cohort of 136 consecutive patients with mild deficits (National Institutes of Health Stroke Scale score ≤5) presenting within 24 hours of onset and no baseline disability. Baseline MRIs were performed on all subjects. Five-day MRIs were performed on a prespecified subcohort. Results— Among 136 patients, 40 (29%; 95% CI, 22%–38%) had poor outcomes (modified Rankin Scale score 2–6) at 90 days. Early worsening (4-point National Institutes of Health Stroke Scale increase; 25% versus 1%, P <0.001) and acute infarct growth (>10% on MRI–diffusion-weighted imaging; 79% versus 53%, P =0.02) from baseline to 5 days were more common among those with poor outcome. Conclusions— Patients with mild ischemic stroke have substantial rates (29%) of disability at 90 days.