Working memory and mental practice outcomes after stroke

Abstract

Objective: To examine the relationship between working memory and motor improvement obtained after a single training session combining mental and physical practice.

Design: Before-after trial.

Setting: Laboratory of a university-affiliated research rehabilitation center.

Participants: A sample of 12 patients with stroke and 14 age- and gender-matched healthy subjects.

Intervention: In a single session, patients were trained with combined mental and physical practice to increase the loading on the affected leg while standing up and sitting down.

Main outcome measures: Motor improvement as measured by the percentage change in limb loading on the affected limb after training and 24 hours later (follow-up), and the relationship between working memory and percentage motor improvement.

Results: The loading on the affected leg was improved after training (P< .01) and at follow-up (P< .05), and working memory scores at follow-up correlated significantly (P< .004 to P< .007) with the level of improvement. The visuospatial domain yielded the strongest correlation (r= .83), followed by the verbal (r= .62) and kinesthetic (r= .59) domains.

Conclusions: These results suggest that the outcome (improved limb loading) of mental rehearsal with motor imagery depends on the ability to maintain and manipulate information in working memory.