Cognitive impairment predicts poststroke death in long-term follow-up

Abstract

Background: Poststroke global cognitive decline and dementia have been related to poor long-term survival. Whether deficits in specific cognitive domains are associated with long-term survival in patients with ischaemic stroke is not known in detail.

Methods: Patients with acute stroke subjected to comprehensive neuropsychological evaluation were included in the study (n = 409) and followed up for up to 12 years.

Results: In Kaplan-Meier analysis, impairments in following cognitive domains predicted poor poststroke survival (estimated years): executive functions (48.2%) (5.8 vs 10.1 years, p<0.0001), memory (59.9%) (6.8 vs 9.3 years, p = 0.009), language (28.9%) (5.3 vs 8.6 years, p = 0.004) and visuospatial/constructional abilities (55.2%) (5.6 vs 10.1 years, p<0.0001). Low Mini Mental Status Examination (MMSE) <or=25 (30.5%) (4.4 vs 9.3 years, p<0.0001), low education (<6 years) (31.8%) (6.4 vs 8.2 years, p = 0.003) and poor modified Rankin score (39.9%) (3.9 vs 9.7 years, p<0.0001) were also related to poor survival. In Cox regression proportional hazards analyses including age, sex and years of education as covariates, deficits in executive functions (hazard ratio (HR) 1.59, p<0.0001), memory (HR 1.31, p = 0.042), language (HR 1.33, p = 0.036) and visuospatial/constructional abilities (HR 1.82, p<0.0001) were significant predictors of poor poststroke survival. Of these, executive functions (HR 1.33, p = 0.040) as well as visuospatial/constructional abilities (HR 1.53, p = 0.004) remained as significant predictors after addition of MMSE<or=25 and poor modified Rankin score as covariates. Furthermore, cognitive impairment no dementia (CIND) was also an independent predictor of poor poststroke survival (HR 1.63, p = 0.0123).

Conclusions: In patients with ischaemic stroke, cognitive impairment, particularly in executive functions, and visuospatial/constructional abilities relate to poor survival.