Differential effects of cognitive task demands on gait performance and cognitive-motor interference in chronic stroke.

BACKGROUND

Stroke survivors often struggle with dual tasks, which involve simultaneous motor and cognitive activities essential for daily life, but few studies have systematically compared how distinct cognitive domains affect gait and cognitive performance after stroke.

AIM: This study aimed to 1) quantify dual-task costs (DTCs) in gait and cognition across seven cognitive task types; 2) identify cognitive domains producing the greatest interference during walking; 3) explore associations between dual-task performance and clinical measures of motor, balance, and cognition; and 4) determine the most sensitive dual-task paradigms for identifying susceptibility to cognitive-motor interference in individuals with chronic stroke.

DESIGN

An analytical cross-sectional, laboratory-based within-subject design.

SETTING

Neurorehabilitation laboratory.

POPULATION: Fifty-three individuals with chronic stroke.

METHODS

Participants performed the Stand and Walk for a 20 m Round Trip (SWR) test under single- and dual-task conditions involving seven cognitive or motor tasks targeting executive, attention, working memory, verbal fluency, and visuospatial domains. Gait parameters were recorded using a wearable motion system, and cognitive performance was measured as correct responses per second. DTCs were calculated for both gait and cognitive speeds.

RESULTS

Dual-task walking significantly reduced gait speed across all conditions (P<0.001), with the greatest decrements observed during Word Association (-19.00±12.93%) and Serial Subtraction (-15.59±12.61%). These were accompanied by the greatest corresponding declines in cognitive speed (-12.48±17.31% and -17.50±20.80%, P<0.001). The Attention Number and Visual Fixation tasks elicited smaller gait costs (-5.65±12.46%, and -8.47±9.79%, respectively) but demonstrated high diagnostic specificity (86%). Dual-task performance correlated strongly with motor (r=0.565-0.646) and balance functions (r=0.534-0.611), and moderately with cognition.

CONCLUSIONS

Dual-task walking significantly compromises gait and cognition after stroke, particularly during executive and working memory tasks. Better motor, balance, and cognitive functions were associated with superior dual-task performance. Although attention and visuospatial tasks imposed lower interference, their high diagnostic specificity indicates potential value as practical tools for identifying susceptibility to cognitive-motor interference.

CLINICAL REHABILITATION IMPACT: Integrating dual-task protocols into stroke rehabilitation may enhance concurrent motor and cognitive recovery while providing sensitive tools for assessing mobility safety risks.