Abstract T P145: Incidence and Determinants of Clinical Dementia after Ischemic Stroke: a Population-based Study in Rochester, MN

Abstract

Introduction: Studies have suggested a high incidence of dementia after stroke; however data regarding risk factors are conflicting and few studies are population-based. The aims of this population-based study are to determine the frequency of diagnosis and predictors of clinical dementia after ischemic stroke. Methods: The Rochester Epidemiology Project medical records linkage system was used to ascertain all first ischemic strokes (IS) occurring among Rochester, MN residents between 1990 -1994. Comprehensive medical records were reviewed. Patient and stroke characteristics, medical comorbidities, and the development of clinical dementia any time after IS were recorded. Dementia was defined as any reflection in the chart by a clinician of memory loss resulting in functional impairment. Patients with a pre-stroke diagnosis of dementia were excluded. Associations between new dementia after the index IS and other variables of interest were analyzed using univariate logistic regression. Results: First IS was detected in 490 people, 82 of whom had a prior history of dementia, and 119 (29%) of whom developed dementia during a mean follow-up of 6.5 years (range 0-23.8). The mean age at index stroke was 76.6 years (SD 12.9). Those who developed dementia were a mean 4 years older at the time of IS (p = 0.003). The odds of developing dementia were 1.7 higher in those who had at least one recurrent stroke. There was no effect of sex, stroke location (cortical, subcortical, brainstem), stroke mechanism, or premorbid stroke risk factors (coronary artery disease, atrial fibrillation/flutter, hypertension, diabetes mellitus, left-sided valvular disease) on the occurrence of dementia. Conclusions: Dementia is commonly diagnosed following ischemic stroke. While stroke risk factors did not impact the risk of diagnosis of dementia, recurrent stroke increased this risk. Stroke risk factors may indirectly increase the risk of dementia by increasing the risk of recurrent IS. This suggests that aggressive secondary stroke prevention measures may significantly decrease the risk of being diagnosed with dementia following IS.