TYPES OF COGNITIVE TASK USED IN DUAL-TASK PARADIGM AND ITS EFFECTS ON GAIT IN STROKE

Abstract

Background: The Timed Up and Go Test (TUG) with serial subtraction was commonly used to assess cognitive dual-task performance while walking for fall prediction. Some people with stroke cannot perform number subtraction, thus, it was unclear on which cognitive tasks could be used to substitute for subtraction task in the TUG test.

Research Question: Which type of cognitive tasks produced the highest detrimental effects during TUG dual-task in stroke patients who were both capable and incapable to complete a subtraction task.

Methods: The participants in this study consisted of twenty-three people who had suffered strokes that were capable of completing subtraction (ST) and nineteen persons who had strokes and were unable perform subtraction (STP). Both groups had a similar age range (thirty-six to eighty-one years) and a stroke onset duration of 0.5 to 252 months. The participants performed TUG without a cognitive task (TUG-single) followed by a cognitive task when seated (cognitive-single). In addition, TUG with a cognitive task (TUG-dual) was performed, with the activity selected from four cognitive tasks, including alternate reciting, auditory working memory, a clock task, and phonologic fluency. The main outcome variables; including TUG duration and cognitive costs, were recorded using an OPAL accelerometer and analyzed using a repeated measure ANOVA.

Results: The TUG duration was significantly longer for all cognitive tasks compared with TUG single (p<0.0001) in the ST group. Whereas, TUG duration was significantly increased only during phonologic fluency task in the STP group (p<0.01). There was a significant difference in cognitive costs between the subtraction task and phonologic fluency task in ST (p<0.01), but no significant differences were identified between tasks in STP. The subtraction task let to the highest decline in both motor and cognitive performances in ST, whereas the phonologic fluency task caused the greatest detrimental effect in STP.

Significance: For stroke patients unable to perform subtraction, phonologic fluency is a suitable method for use in the TUG-cognitive assessment.

-