Influence of Preexisting Cognitive Impairment on Clinical Severity of Ischemic Stroke: The Dijon Stroke Registry

BACKGROUND AND PURPOSE—The ongoing ageing population is associated with an increasing number of patients with stroke who have preexisting cognitive impairment. This study aimed to evaluate clinical severity in patients with ischemic stroke according to prestroke cognitive status. METHODS—Patients with ischemic stroke were prospectively identified among residents of Dijon, France using a population-based registry (2013–2017). Prestroke cognitive status (no impairment, mild cognitive impairment [MCI], or dementia) was recorded, and severity at stroke onset was measured using the National Institutes of Health Stroke Scale (NIHSS) score. Association between prestroke cognitive status and severity was evaluated using ordinal regression analysis models in which the NIHSS score was considered as a categorical variable. RESULTS—Among the 1048 patients (mean age, 76.3±15.2 years; 54.0% women), a greater severity was observed in those with MCI (n=132; median NIHSS6; interquartile range, 2–15), and those with dementia (n=164; median NIHSS7; interquartile range, 3–16), than in patients without cognitive impairment (n=752; median NIHSS3; interquartile range, 1–9). MCI (odds ratio [OR], 1.70 [95% CI, 1.21–2.38]; P=0.002) and dementia (OR, 2.24 [95% CI, 1.65–3.04]; P