Dynamic trajectory of long-term cognitive improvement up to 10 years in young community-dwelling stroke survivors: A cohort study

Abstract

Background and objective: The trajectories of long-term and domain-specific cognitive alterations over a decade after stroke are largely unknown. This study aims to investigate the dynamic alterations of domain-specific cognitive performance among young stroke survivors over 10 years after their first stroke. Methods: A prospective cohort study was carried out on 38 young stroke survivors (aged 18-65 at stroke onset) living in the community at 10 years after their first stroke. The cognitive outcomes were assessed repeatedly at 1 week, 7 months, and 10 years after their first stroke on the sub-domains: process speed (Symbol search and Coding from WAIS, TMT-A), visual attention (Bells test), visuospatial function (Block design from WAIS, RCFT), executive function (TMT-B, verbal fluency), verbal function [Letter fluency (FAS) from D-KEFS and CD], working memory (Digit Span from WAIS), immediate memory (RCFT and CD), and delayed memory (RCFT and CD). Global cognition was evaluated with Mini mental state examination at the two later time-points. Results: We found a delayed significant improvement of working memory with total recovery 10 years after participants' stroke. Visuospatial function recovered already at 7 months and remained stable at 10-year follow-up. Process speed demonstrated a significant decrease at 10 years compared to 7 months after stroke onset, a decrease which could be compensated by enhancements of other cognitive domains. No further deterioration was found in verbal function, immediate-, and delayed memory, and executive function during 10-year follow-up. Global cognition improved by on average two points between 7 months and 10 years. Education level and fatigue showed low to moderate positive correlations with cognitive improvements. Conclusions: The concordance of cognitive improvements between domain-specific and global cognitions strongly suggest that some young stroke survivors do improve their cognitive outcome over a 10-year period following their first stroke. This finding fills a gap of knowledge with respect to the dynamic trajectory of post-stroke cognition, with important implications in clinical practice.