What Is a Minor Stroke?

TLDR

The term “minor stroke” is frequently used, yet no consensus definition exists. The study aimed to evaluate six proposed definitions of minor stroke and assess their validity across patient subgroups. A cohort of 760 acute ischemic stroke patients was classified by six criteria (A–F); short‑term outcome was discharge home, medium‑term outcome was a modified Rankin Scale ≤2 at 3 months, and analyses were stratified by sex, age, stroke location, and admission timing. Definitions A (NIHSS ≤ 1 with normal consciousness) and F (NIHSS ≤ 3) yielded the highest short‑term (74%/71%) and medium‑term (90%/90%) outcomes, making them the most appropriate for defining a minor stroke.

Abstract

Background and Purpose— The term “minor stroke” is often used; however a consensus definition is lacking. We explored the relationship of 6 “minor stroke” definitions and outcome and tested their validity in subgroups of patients. Methods— A total of 760 consecutive patients with acute ischemic strokes were classified according to the following definitions: A, score ≤1 on every National Institutes of Health Stroke Scale (NIHSS) item and normal consciousness; B, lacunar-like syndrome; C, motor deficits with or without sensory deficits; D, NIHSS ≤9 excluding those with aphasia, neglect, or decreased consciousness; E, NIHSS ≤9; and F, NIHSS ≤3. Short-term outcome was considered favorable when patients were discharged home, and favorable medium-term outcome was defined as a modified Rankin Scale score of ≤2 at 3 months. The following subgroup analyses were performed by definition: sex, age, anterior versus posterior and right versus left hemispheric stroke, and early (0 to 6 hours) versus late admission (6 to 24 hours) to the hospital. Results— Short-term and medium-term outcomes were most favorable in patients with definition A (74% and 90%, respectively) and F (71% and 90%, respectively). Patients with definition C and anterior circulation strokes were more likely to be discharged home than patients with posterior circulation strokes ( P =0.021). The medium-term outcome of older patients with definition E was less favorable compared with the outcome of younger ones ( P =0.001), whereas patients with definition A, D, and F did not show different outcomes in any subgroup. Conclusions— Patients fulfilling definition A and F had best short-term and medium-term outcomes. They would be best suited to the definition of “minor stroke.”