Cognitive impairment after stroke: clinical determinants and its associations with long-term stroke outcomes.
OBJECTIVE
To identify factors that were associated with cognitive impairment 3 months after stroke, and to examine the associations of cognitive impairment with stroke outcomes up to 4 years after stroke.


METHODS
Observational study.


METHODS
Population-based stroke register.


METHODS
Six hundred forty-five subjects with first-ever stroke, identified from the register.


METHODS
Subjects were assessed for cognition using the Mini-Mental State Examination (MMSE) 3 months after stroke. Cognitively impaired subjects (MMSE <24, n = 248 (38%)) were compared with cognitively intact subjects (MMSE 24-30, n = 397) in terms of demographic details, stroke risk factors, laterality of stroke, and initial poststroke impairments. Outcome data collected at 1, 3, and 4 years poststroke included disability assessed by the Barthel Index (BI) and the Frenchay Activity Index, case fatality, and institutionalization.


RESULTS
Two hundred forty-eight (38%) of 645 subjects were cognitively impaired 3 months after stroke. Using multivariate analyses, cognitive impairment was associated with age of 75 and older (odds ratio (OR) = 2.5, 95% confidence interval (CI) = 1.5-4.2), ethnicity (Caribbean/African (OR = 1.9, 95% CI = 1.2-3.2) and Asian (OR = 3.4, 95% CI = 1.1-10.2), lower socioeconomic class (OR = 2.1, 95% CI = 1.3-3.3), left hemispheric lesion (OR = 1.6, 95% CI = 1.01-2.4), visual field defect (OR = 2.0, 95% CI = 1.2-3.2), and urinary incontinence (OR = 4.8, 95% CI = 3.1-7.3). Using multivariate analyses, cognitive impairment was associated with death or disability (BI <15) at 4 years after stroke (OR = 2.2, 95% CI = 1.1-4.5). In univariate analyses, it was also associated with higher institutionalization 4 years after stroke (P =.001).


CONCLUSIONS
Cognitive impairment is common 3 months after stroke and is independently associated with older age, ethnicity, lower social class, left hemispheric stroke, visual field defect, and urinary incontinence. It is associated with poor long-term outcomes, including survival and disability, up to 4 years after stroke. Because physical and cognitive impairments after stroke have independent prognostic implications, measures that evaluate both functions should be used in future studies of stroke outcome and in care of stroke patients.
Patel
Mehool D
MD
Department of Public Health Medicine, Guy's, Kings, & St. Thomas' School of Medicine, King's College, London, England. mehoolpatel@aol.com
Coshall
Catherine
C
Rudd
Anthony G
AG
Wolfe
Charles D A
CD
D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D012042:Registries; D012307:Risk Factors; D012720:Severity of Illness Index; D012923:Social Class; D020521:Stroke / Q000145:classification / Q000150:complications* / Q000401:mortality; D013997:Time Factors