Persistent cognitive impairment after transient ischemic attack

Abstract

Background and purpose: By definition, the symptoms of a transient ischemic attack (TIA) subside completely within 24 hours. Imaging studies show signs of persistent ischemic tissue damage in a substantial amount of patients with TIA. Cerebral infarction can cause permanent cognitive impairment. Whether permanent cognitive impairment occurs after TIA is unclear, as is its profile.

Methods: Patients with TIA aged 45 to 65 years without prior stroke or dementia underwent comprehensive neuropsychological testing within 3 months. Z scores per cognitive domain were obtained, based on the mean of a control group within the same age range. Cognitive impairment was defined as a domain z score <-1.65. Patients underwent either computed tomography or MRI brain imaging.

Results: One hundred seven patients with TIA (63% women, mean age, 56.6 years) were included and compared with 81 controls (56% women, mean age, 52.9 years). Patients performed worse on all cognitive domains except episodic memory. Working memory (25%), attention (22%), and information processing speed (16%) were most frequently impaired and more often than in the control group (age- and sex-adjusted odds ratios, respectively, 22.5 [95% confidence interval, 2.9-174.3], 6.8 [1.9-24.3], 7.1 [1.5-32.5]). More than 35% of patients with TIA had impairment of ≥1 cognitive domain. Presence of silent brain infarcts was related to worse executive functioning but did not explain the whole relationship between TIA and cognitive impairment.

Conclusions: More than a third of patients with TIA have impairment of ≥1 cognitive domain within 3 months after their TIA. The affected domains fit in the vascular cognitive impairment profile.

Keywords: cognition; ischemic attack, transient.