title: Dementia after stroke: the Framingham Study.
abstract: OBJECTIVE
  Identification of risk factors for dementia after stroke is best performed in comparison with stroke-free controls, because older subjects at high risk for stroke also have a substantial risk of dementia in the absence of stroke. Previous case-control studies were hospital-based. We used a nested case-control design to prospectively evaluate these risk factors in the community-based Framingham Study cohort.
  
  
  METHODS
  We compared 212 subjects who were free of dementia in January 1982 and sustained a first stroke after this date, with 1060 age- and sex-matched, stroke- and dementia-free controls. We calculated 10-year risks of dementia (by Diagnostic and Statistical Manual of Mental Disorders, Volume IV criteria) developing in cases and controls and also estimated the hazard ratios within subgroups defined by exposure to various demographic factors (age, gender, education), stroke-related features (right or left hemisphere, stroke type, second stroke), stroke risk factors (hypertension, diabetes, atrial fibrillation, smoking) and apolipoprotein E genotype.
  
  
  RESULTS
  Dementia developed in 19.3% of cases and 11.0% of controls. Baseline stroke doubled the risk of dementia (hazard ratio [HR]: 2.0; 95% confidence interval [CI]: 1.5 to 3.1) and adjustment for age, sex, education, and exposure to individual stroke risk factors did not diminish the risk (HR: 2.4; 95% CI: 1.6 to 3.7). The HR was higher in younger subjects (age younger than 80 years [HR: 2.6; 95% CI: 1.5 to 4.5]), apolipoprotein E 3/3 homozygotes (HR: 3.4; 95% CI: 2.0 to 5.8), and high school graduates (HR: 2.4; 95% CI: 1.5 to 3.9).
  
  
  CONCLUSIONS
  Stroke increases a subject's risk of dementia as compared with age- and sex-matched controls. Primary and secondary prevention of stroke should significantly decrease the risk of all dementia.
authors.affiliation: Department of Neurology, Boston University School of Medicine, Boston, Mass 02118-2526, USA.
authors.forename: Cristina S
authors.initials: CS
authors.lastname: Ivan
authors.forename: Sudha
authors.initials: S
authors.lastname: Seshadri
authors.forename: Alexa
authors.initials: A
authors.lastname: Beiser
authors.forename: Rhoda
authors.initials: R
authors.lastname: Au
authors.forename: Carlos S
authors.initials: CS
authors.lastname: Kase
authors.forename: Margaret
authors.initials: M
authors.lastname: Kelly-Hayes
authors.forename: Philip A
authors.initials: PA
authors.lastname: Wolf
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D020521:Stroke / Q000150:complications*