comparative efficacy of two different dual-task balance interventions

Conditions: Stroke; Healthy Older Adults

Summary: the objective of this study is to investigate the effects of two different dual-task balance interventions for stroke patients and older adults.

english synopsis i. title of study: comparative efficacy of two different dual-task balance interventions on balance, gait, and cognitive performance under single- and dual-task conditions in stroke patients and older adults ii. study objectives: the objective of this study is to investigate the effects of two different dual-task balance interventions for stroke patients and older adults. specifically, the investigators will compare the immediate and retention effects of motor and cognitive dual-task balance training \[mcdt\] and cognitive dual-task balance training \[cdt\]) on balance, gait, and cognition under single- and dual-task conditions in individuals with stroke (aim 1) and elderly people (aim 2). the third aim of this study is to elucidate the mechanisms underlying changes in balance, gait, and cognitive performance of stroke patients and older adults after mcdc and cdt (aim 3). iii. study design a prospective randomized control trial will be conducted at medical centers in this study. fifty stroke patients and 48 elderly people will be randomly allocated to either mcdt or cdt group. both groups will receive 12 hours of training over 4 weeks at progressively increasing task difficulty (60 minutes per session, three times a week, for four weeks). the cdt group will undertake dual-task balance training and concurrently perform only cognitive tasks with instruction of a variable priority. the mcdt group will train the same set of balance/gait activities as the cdt while simultaneously performing motor and cognitive tasks with instruction of a variable priority. during each session, all participants practice shifting attention between tasks by spending half of the training attention focus on the balance task, and half focus on the secondary cognitive or motor tasks. a blinded assessor will conduct three assessments at baseline, post intervention, and 1-month follow-up. at baseline, all participants will be examined balance, gait, and cognitive performance under single-task (standing, walking, cognitive tasks only) and dual-task conditions (standing/walking while performing cognitive tasks). six cognitive tasks (simple reaction time task, serial three subtractions task, stroop task, auditory stroop task, spatial memory task, and choice reaction time task) will be used to examine dual-task performance because these tasks represent different domains of cognitive function (information processing speed, working memory, and executive function). the primary outcome measure of balance, gait, and cognition will be the sway index, gait speed, and composite score of accuracy and reaction time under single- and dual-task conditions. secondary outcome measures will include: berg balance scale, timed up and go test under single- and dual-task conditions, functional gait assessment, activity-specific balance confidence scale, chair stand test, and patient global impression of change. repeated measure anova will be used to compare measurements at baseline, after training, and follow-up between the groups. number of planned patients: 50 stroke patients and 48 elderly people duration of the study: 2017/08/01～2020/07/31

Eligibility criteria:
inclusion criteria for stroke individuals: * first-ever stroke with onset duration more than 3 months * able to walk 10 m * no severe vision, hearing, and language problems inclusion criteria for healthy elderly: * more than 65 years old * able to walk 10 m * no neurological or musculoskeletal diagnosis * no severe vision, hearing, cognition, and language problems. exclusion criteria: * orthopedic and other neurological disorders that affect walking * other treatments that could influence the effects of the interventions (e.g., recent botulin toxin treatment of the lower extremity) * moderate or severe cognitive impairments (score \<21 on mini-mental state examination) * severe uncorrected visual deficits