Post-Stroke Cognitive Impairment: High Prevalence and Determining Factors in a Cohort of Mild Stroke

Background: Because of the aging population and a rise in the number of stroke survivors, the prevalence of post-stroke cognitive impairment (PSCI) is increasing. Objective: To identify the factors associated with 3-month PSCI. Methods: All consecutive stroke patients without pre-stroke dementia, mild cognitive disorders, or severe aphasia hospitalized in the Neurology Department of Dijon, University Hospital, France (November 2010 - February 2012) were included in this prospective cohort study. Demographics, vascular risk factors, and stroke data were collected. A first cognitive evaluation was performed during the hospitalization using the Mini-Mental State Exam (MMSE) and the Montreal Cognitive Assessment (MOCA). Patients assessable at 3 months were categorized as cognitively impaired if the MMSE score was <= 26/30 and MOCA <26/30 or if the neuropsychological battery confirmed PSCI when the MMSE and MOCA were discordant. Multivariable logistic models were used to determine factors associated with 3-month PSCI. Results: Among the 280 patients included, 220 were assessable at 3 months. The overall frequency of 3-month PSCI was 47.3%, whereas that of dementia was 7.7%. In multivariable analyses, 3-month PSCI was associated with age, low education level, a history of diabetes mellitus, acute confusion, silent infarcts, and functional handicap at discharge. MMSE and MOCA scores during hospitalization were associated with 3-month PSCI (OR = 0.63; 95% CI: 0.54-0.74; p < 0.0001 and OR = 0.67; 95% CI: 0.59-0.76; p < 0.0001, respectively). Conclusion: Our study underlines the high frequency of PSCI in a cohort of mild stroke. The early cognitive diagnosis of stroke patients could be useful by helping physicians to identify those at a high risk of developing PSCI.