Background:
This study aimed to show the contribution of cognitive impairment toward the development of behavioural disturbance following stroke.
Method:
Subjects in the Sydney Stroke Study comprised patients admitted to two university hospitals after an ischemic stroke and controls from the community who received extensive medical, psychiatric and neuropsychological assessments, with a subset receiving a magnetic resonance imaging scan. Patients were assessed 3–6 months after their stroke and again a year later. Controls were similarly assessed twice, 12 months apart. This sample comprised 123 stroke patients and 88 control subjects, with complete ratings on cognitive impairment at 15 months.
Results:
Of the 88 controls, 55.7% were classified as having no cognitive impairment, 30.7% had mild cognitive impairment and 2.3% had dementia at 15 months. Of the 123 patients, 42.3% had no cognitive impairment, 39.8% had VCI and 16.3% had dementia. The stroke group had significantly higher rates of dementia [odds ratio (OR): 8.35, 95% confidence interval (CI): 1.90–36.73] but not of cognitive impairment (OR: 1.71, 95% CI: 0.93–3.15). Using nonparametric correlation, total NPI score was correlated with cognitive impairment in the total sample (Spearman's ρ = 0.27, P = 0.001). Within the stroke group, dementia was significantly associated with NPI score at 15 months but not MMSE, stroke severity, IADL/ADL score, more than one stroke, total stroke volume, total atrophy or total white matter hyperintensities.
Conclusion:
Having a stroke does not necessarily lead to behavioural disturbance; however, it is associated with higher rates of cognitive impairment (in particular dementia), which in turn is associated with more disturbance.
