Relationship between poststroke cognition, baseline factors, and functional outcome: data from "efficacy of nitric oxide in stroke" trial

Abstract

Background: Poststroke cognitive impairment is common and identification of prognostic factors associated with it and its relationship with other functional outcomes may help in developing preventative strategies.

Methods: Previously independent patients with acute stroke, enrolled into the ongoing "Efficacy of Nitric Oxide in Stroke" trial, were assessed by telephone on day 90 for cognitive impairment using modified versions of "Mini Mental State Examination" (MMSE-M) and "Telephone Instrument for Cognitive Status" (TICS-M) scales and category fluency. The relationship of cognitive impairment with baseline prognostic factors and other functional outcomes at day 90 were studied.

Results: The analysis included 1572 patients, mean age 69 years (standard deviation, 12), and female 40%. By 90 days, 246 patients had died, and cognitive impairment was present in 38%. Increasing age, stroke severity, heart rate, and presence of cerebral atrophy on baseline neuroimaging were associated with cognitive impairment (all P < .001). Hypertension and atrial fibrillation were also associated with category fluency and MMSE-M, respectively. Cognition was significantly related to other functional outcomes, TICS-M with dependency (modified Rankin Scale, rs = -.562, P < .001); disability (Barthel Index, rs = .577, P < .001); mood (Zung Depression Score, rs = -.542, P < .001); and quality of life (Euro Quality of life-5 Descriptor, rs = .519, P < .001).

Conclusions: In previously independent individuals, cognitive impairment was common 3 months after stroke and related to increasing age, stroke severity, hypertension, atrial fibrillation, and cerebral atrophy on brain scanning. Cognition was related to dependency, disability, low mood, and quality of life. Hence, treatment directed toward reducing dependency might also reduce cognitive impairment.

Keywords: ENOS; Poststroke cognitive impairment; dementia; functional outcome; randomized controlled trial; stroke.