Working memory and mental practice outcomes after stroke.

Abstract

To examine the relationship between working memory and motor improvement obtained after a single training session combining mental and physical practice. Before-after trial. Laboratory of a university-affiliated research rehabilitation center. A sample of 12 patients with stroke and 14 age- and gender-matched healthy subjects. 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. 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. 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. 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.