Objectives: To determine whether patients with Alzheimer's disease (AD) and coexisting cerebral infarction (CI) that satisfy the National Institute for Neurological Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) neuroimaging criteria for vascular dementia (VaD) progress faster than those who do not satisfy the neuroimaging criteria.
Design: Retrospective cohort study.
Setting: Multidisciplinary memory clinic in a tertiary hospital.
Participants: One hundred thirty consecutive patients with AD, with or without CI, followed up regularly for more than 1 year.
Measurements: The patients were classified according to the distribution and severity of CI as defined according to the NINDS-AIREN neuroimaging criteria into those with AD and no CI (AD-N), those with AD and CI not fulfilling neuroimaging criteria (AD-I), and those with AD and CI fulfilling neuroimaging criteria (AD-V), and their differences in dementia progression were tested. The loss of independence, indicated by institution admission or a clinical dementia rating (CDR) score of 3, was defined as the endpoint for a poor outcome.
Results: The mean age was 75.8, and 68.5% were women. The initial Mini-Mental State Examination (MMSE) score was 15.3+/-0.4, and the average duration of follow up was 30.4 months. Fifty-four patients had reached study endpoint at the time of analysis. AD-V (hazard ratio (HR)=3.1, 95% confidence interval (CI)=1.2-8.2), use of psychotropic drugs (HR=2.7, 95% CI=1.1-6.4), and initial MMSE score (HR=0.9, 95% CI=0.8-1.0) were independent predictors of poor outcome in the Cox regression model.
Conclusion: In AD, co-occurrence of CI with distribution and severity as defined in the NINDS-AIREN neuroimaging criteria for VaD is associated with faster dementia progression.