Temporal Evolution of Poststroke Cognitive Impairment Using the Montreal Cognitive Assessment.

BACKGROUND AND PURPOSE The Montreal Cognitive Assessment (MoCA) is nowadays recommended for the screening of poststroke cognitive impairment. However, little is known about the temporal evolution of MoCA-assessed cognition after stroke. The objective of this study was to examine the temporal pattern of overall and domain-specific cognition at 2 and 6 months after stroke using the MoCA and to identify patient groups at risk for cognitive impairment at 6 months after stroke. METHODS Prospective cohort study in which 324 patients were administered the MoCA at 2 and 6 months post stroke. Cognitive impairment was defined as MoCA<26. Differences in cognitive impairment rates between 2 and 6 months post stroke were analyzed in different subgroups. Patients with MoCA score <26 at 2 months, who improved by ≥2 points by 6 months, were defined as reverters. Logistic regression analyses were used to identify determinants of (1) cognitive impairment at 6 months post stroke and (2) reverter status. RESULTS Between 2 and 6 months post stroke, mean MoCA score improved from 23.7 (3.9) to 24.7 (3.5), P<0.001. Prevalence of cognitive impairment at 2 months was 66.4%, compared with 51.9% at 6 months (P<0.001). More comorbidity and presence of cognitive impairment at 2 months were significant independent predictors of cognitive impairment 6 months post stroke. No significant determinants of reverter status were identified. CONCLUSIONS Although cognitive improvement is seen ≤6 months post stroke, long-term cognitive deficits are prevalent. Identifying patients at risk of cognitive impairment is, therefore, important as well as targeting interventions to this group.