Incidence and risk factors of cognitive impairment 3 months after first-ever stroke: a cross-sectional study of 5 geographic areas of China.

This study examined the incidence, neuropsychological characteristics and risk factors of cognitive impairment 3 months after stroke in China. Five regions that differed in geography and economy in China were selected. Patients from the hospitals located in the five regions were prescreened at admission, and the demographic data, vascular risk factors and clinical characteristics of stroke were obtained. A battery of cognitive-specific domain tests was performed in the patients who failed to pass cognitive screening 3 months post stroke. Patients were diagnosed as having post-stroke cognitive impairment (PSCI) or no cognitive impairment (NCI) based on the results of the neuropsychological tests. Univariate analysis was performed for suspect risk factors, and significant variables were entered in multivariable logistic regression analysis. Our results showed that a total of 633 patients were recruited 3 months after stroke; complete cognitive tests were performed in 577 of the stroke patients. The incidence of PSCI in these Chinese patients was 30.7%. There were 129 (22.4%) patients with visuospatial impairment, 67 (11.6%) with executive impairment, 60 (10.4%) with memory impairment and 18 (3.1%) with attention impairment. The risk factors associated with PSCI were older age (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.20-2.58), low education level (OR 2.45, 95% CI 1.65-3.64), depressive symptom (OR 1.69, 95% CI 1.09-2.61), obesity (OR 2.57, 95% CI 1.41-4.71), stroke severity 3 months post stroke (OR 1.62, 95%CI 1.10-2.37) and cortex lesion (OR 1.55, 95% CI 1.04-2.31). It was concluded that PSCI occurs commonly 3 months after first-ever stroke in Chinese patients. Visuospatial ability may be the most frequently impaired cognitive domain for the patients with stroke. The critical risk factors of PSCI are older age, low education level, depressive symptom, obesity, stroke severity 3 months post stroke and cortex lesion.