Cognitive Recovery After Stroke: A Meta-analysis and Metaregression of Intervention and Cohort Studies

Background Cognition affects poststroke recovery, but meta-analyses of cognition have not yet provided a comparison of observational and intervention evidence. Objective To describe the trajectory of poststroke cognition and the factors that moderate it across intervention and observational cohorts. Methods Six databases were searched up to January 2020. Studies describing quantitative changes in cognition in adults poststroke were included. Interventions were classified into pharmacological, therapist-led, nonroutine/alternative, and usual care. Summary estimates were compared via hierarchical mixed-effects models. Age, recovery stage, stroke etiology, cognitive domain targeted in studies, and intervention types were investigated as moderators of cognition. Recovery stage and intervention were further analyzed in a multiplicative metaregression model. Results A total of 43 intervention trials and 79 observation cohorts involving 28 222 stroke participants were included. Heterogeneity was significant (τ2 = 0.09; CI = 0.01-0.21, P < .001) with no evidence of publication bias. Cognitive recovery was greater in intervention trials (g = 0.47; CI = 0.37-0.58) than observational cohorts (g = 0.28; CI = 0.20-0.36) across all moderators analyzed. Nonroutine/alternative and pharmacological trials achieved the best overall results (g = 0.57, CI = 0.42-0.73, and g = 0.52, CI = 0.30-0.74, respectively), followed by therapist-led (g = 0.46; CI = 0.17-0.74), and usual care (g = 0.28; CI = 0.11-0.45) interventions. Medium recovery effects (ie, g ≥ 0.5) were observed in examining first-ever stroke, executive function, visuo-perceptual, consciousness, and psychomotor skills, 61 to 180 days poststroke, in participants aged 65 to 70 years. Conclusion Cognitive recovery is possible using different controlled interventions in all recovery stages, with smaller benefits ≥2 years poststroke. Longer-term studies are needed to determine the role of nonroutine/alternative therapies and the association between cognitive recovery and performance in everyday activities.