Assessing executive function following the early stage of mild Ischemic stroke with three brief screening tests.

Objective: Executive dysfunction following stroke is well documented, but less is known about whether it occurs in mild stroke patients. The purpose of the study was to investigate executive impairment in this population and explore the correlation between executive function tests and cognitive tests of other domains.

Methods: Cross-sectional study was undertaken to compare 139 mild ischemic stroke patients (National Institute of Health Stroke Scale (NIHSS) ≤ 7) aged 40-80 with 131 normal controls matched age, gender and levels of education. All participants were administered a neuropsychological test battery including three measures of executive functioning: Clock Drawing Test (CDT), Trial Making Test-A and B (TMT-A and B), and Stroop Color Word Test (SCWT). The CDT was evaluated using three quantitative scoring rubrics, with a total score of 3,10,18, respectively and a qualitative scoring method with six types of errors. Spearman's correlations were made to analyze the correlation between executive function tests and other neuropsychological tests.

Results: Control group performed better than stroke group on most executive function tests at a statistical significance. Qualitative CDT showed that errors of "graphic difficulties", "conceptual deficits" and "spatial and/or planning deficits" occurred frequently in the early stage of mild stroke. Correlation data clarified that among the executive function tests, time for TMT-B correlated with global cognition most.

Conclusion: Executive dysfunction is common following even mild strokes, and that relatively brief measures such as CDT, TMT and SCWT can be employed for it before discharge as part of rehabilitation planning.