Dual-task exercise reduces cognitive-motor interference in walking and falls after stroke : a randomized controlled study

Abstract

Background and Purpose-Functional community ambulation requires the ability to perform mobility and cognitive task simultaneously (dual-tasking). This single-blinded randomized controlled study aimed to examine the effects of dual-task exercise in chronic stroke patients. Methods-Eighty-four chronic stroke patients (24 women; age, 61.2±6.4 years; time since stroke onset, 75.3±64.9 months) with mild to moderate motor impairment (Chedoke-McMaster leg motor score: median, 5; interquartile range, 4-6) were randomly allocated to the dual-task balance/mobility training group, single-task balance/mobility group, or upperlimb exercise (control) group. Each group exercised for three 60-minute sessions per week for 8 weeks. The dual-task interference effect was measured for the time to completion of 3 mobility tests (forward walking, timed-up-and-go, and obstacle crossing) and for the correct response rate during serial-3-subtractions and verbal fluency task. Secondary outcomes included the Activities-specific Balance Confidence Scale, Frenchay Activities Index, and Stroke-specific Quality of Life Scale. The above outcomes were measured at baseline, immediately after, and 8 weeks after training. Fall incidence was recorded for a 6-month period posttraining. Results-Only the dual-task group exhibited reduced dual-task interference in walking time posttraining (forward walking combined with verbal fluency [9.5%, P=0.014], forward walking with serial-3-subtractions [9.6%, P=0.035], and the timed-up-and-go with verbal fluency [16.8%, P=0.001]). The improvements in dual-task walking were largely maintained at the 8-week follow-up. The dual-task cognitive performance showed no significant changes. The dual-task program reduced the risk of falls and injurious falls by 25.0% (95% CI, 3.1%-46.9%; P=0.037) and 22.2% (95% CI, 4.0%-38.4%; P=0.023), respectively, during the 6-month follow-up period compared with controls. There was no significant effect on other secondary outcomes (P>0.05). Conclusions-The dual-task program was effective in improving dual-task mobility, reducing falls and fall-related injuries in ambulatory chronic stroke patients with intact cognition. It had no significant effect on activity participation or quality of life.