Prospective follow-up study between 3 and 15 months after stroke: improvements and decline in cognitive function among dementia-free stroke survivors >75 years of age

Abstract

Background and purpose: Poststroke cognitive impairment is frequent. There are, however, few longitudinal studies examining delayed changes in poststroke cognition.

Methods: As part of a longitudinal study of incident dementia after stroke, 115 older stroke survivors (>75 years of age) without dementia were evaluated at 3 and 15 months with a detailed neuropsychological evaluation (including memory, attention, executive performance, and language).

Results: we found that 9% of older stroke patients developed incident dementia, with significant deterioration in global cognition, memory, and attention. Only the severity of expressive language performance at 3 months was associated with dementia at follow-up. Conversely, 57 patients (50%) experienced some improvement in global cognition. None of the criteria for early cognitive impairment identified people at increased risk for dementia.

Conclusions: Delayed dementia is frequent in older stoke patients, but current criteria for early cognitive impairment are not useful as predictors of cognitive deterioration. Improvement in cognition occurred in most patients.