Prior transient ischemic attack and dementia after subsequent ischemic stroke.

Although functional recovery and survival after ischemic stroke seem to improve in patients with prior transient ischemic attack (TIA), little is known about the effect of prior TIA on poststroke cognition. To evaluate the impact of prior TIA on dementia, 1697 nonaphasic patients who survived the first month after their first-ever ischemic stroke were identified from the population-based registry of Dijon, France, from 1985 to 2007 and divided into 3 groups according to the time interval between prior TIA and stroke (<4 wk, ≥4 wk, no TIA). Outcome was dementia diagnosed by neurologists using Diagnostic and Statistical Manual of mental disorders-III or IV criteria over the first month after stroke. Multivariate analyses were performed using logistic regression models. The prevalence of dementia after stroke was 20.6% [95% confidence interval (CI), 18.5-22.7], 26.8% (95% CI, 13.3-40.4), and 33.1% (95% CI, 27.3-38.9) among patients without TIA, with a prestroke TIA≥4 weeks, and with a prestroke TIA<4 weeks, respectively. Patients with prestroke TIA<4 weeks (adjusted odds ratio: 1.83; 95% CI, 1.32-2.52; P=0.0003) had a higher risk of dementia than those without TIA.