Cognitive function and risk of stroke in elderly men

Abstract

Vascular risk factors are associated with ischemic changes in the cerebral white matter. We studied the predictive value of cognitive test performance especially related to subcortico-frontal pathways, together with a cognitive screening test, for later incidence of fatal or nonfatal stroke or TIAs and stroke subtypes. A sample of 930 70-year-old men without previous stroke/TIA from the community-based Uppsala Longitudinal Study of Adult Men was investigated at baseline using Trail Making Tests (TMT) A and B and the Mini-Mental State Examination (MMSE). During up to 13 years of follow-up, 166 men developed a stroke or TIA; 105 participants had a brain infarction. In Cox proportional hazards analyses adjusting for education, social group, and traditional cardiovascular risk factors, a 1-SD increase in TMT-B time was associated with a higher risk for brain infarction (hazard ratio 1.48, 95% confidence interval 1.11-1.97). The risk of brain infarction was more than threefold higher in the highest (TMT-B = 146-240 s) compared to the lowest (TMT-B = 43-84 s) TMT-B quartile. TMT-A and MMSE results were not consistently related to stroke outcomes. Impaired performance in elderly men measured by Trail Making Test B, a cognitive test especially reflecting subcortico-frontal activities, was an independent predictor of subsequent brain infarction in this community-based sample of elderly men. Our results extend previous findings of cognitive decline as an independent predictor of stroke and indicate that the risk of brain infarction is increased already in the subclinical phase of cognitive deficit.