Virtual Reality and Field Training to Enhance Community Walking After Stroke

While stroke survivors discharged from rehabilitation present with some recovery in mobility, their ability to ambulate in the community remains limited. The investigators propose to test a novel, low-cost, intensive and individually tailored intervention that combines virtual reality (VR) and field training to enhance community ambulation and participation in stroke survivors discharged from rehabilitation.

The aims are to: (1) Assess feasibility, acceptability, safety and adherence of the intervention in stroke survivors; and (2) Examine the extent to which post-intervention changes in functional walking and participation to community walking vary according to walking, cognitive and visual-perceptual abilities.

The investigators will use a virtual environment prototype simulating a shopping mall and surrounding streets, in which participants will interact using VR goggles and game controllers. Scenarios of increasing levels of complexity will be introduced. This intervention study involves a single group, multiple pre- multiple post- study design where chronic stroke participants will engage in a 4-week training program. The program will include VR training sessions performed in the clinical setting (3/week) and practice of community ambulation skills while supervised by family/caregivers (2/week). Participants will be assessed on measures of functional walking, balance \& mobility and participation to community walking. Adherence, safety and acceptability will be documented. This study will generate foundation knowledge on the response to the intervention based on individual capacities.

Ambulating in community environments requires the skills to cope with multiple, simultaneous dimensions such as walking speed and distance, etc. Such skills remain compromised in the majority of stroke survivors due to insufficient or lack of targeted practice. The investigators propose to test a new, individually-tailored intervention, developed by the research team, grounded in best evidence in community ambulation, principles of motor learning and participatory action research. This unique intervention will combine virtual reality (VR) and field training practice to optimize learning that can be generalized to daily walking activities.

Participants will engage in the 4-week, individually-tailored intervention that comprises of supervised VR training sessions (3 times/week) performed in the clinical setting. VR sessions will be completed by field training assignments. Subjects will be assessed twice prior to the intervention, immediately after the intervention and at follow up.

Generalized estimating equations will be used to compare changes in main and secondary outcomes across time points, with each personal factor of interest (e.g. walking capacity, visual-perceptual function, and cognitive function) analyzed individually while adjusting for age. Outcomes on adherence, safety and acceptability will be analyzed with descriptive statistics.

Required sample size was estimated based on Green's rule (effect size=0.5, power=80%, α=0.05) with a variance inflation factor assuming moderate within-subject correlations for 3 post-baseline measurement time points. This yields a sample size of 30. Assuming a worst-case scenario of 30% attrition rate, a total of 40 stroke subjects (20/site) will be recruited.

Eligibility Criteria:
Inclusion Criteria:

People with chronic stroke and persistent deficits in walking / visual-perceptual / cognitive capacities. They can be male or female, aged from 40 to 74 years, with normal/corrected visual and auditory acuity, and present with:

* First-ever supratentorial unilateral stroke 9-24 months ago (such chronicity will ensure steady-state mobility without long-term disuse-related changes
* Mild-to-moderate hemiparesis (Chedoke McMaster Stoke Assessment stages 4/7-6/7 on postural control, leg \& foot)
* Ability to walk independently with/without walking aids for at least 1 min at 0.4-0.9 m/s (such a speed range indicates mobility not sufficient for functional community ambulation: shopping \~1.1m/s, street crossing \~1.2 m/s)
* Intact or mildly affected cognitive function (Montreal Cognitive Assessment scores ≥ 22/30)
* Intact to moderately affected visual-perceptual function (positive scores on a maximum of 3/6 tasks on the Behavioural Inattention Test)

Exclusion Criteria:

* Subjects with comorbidities interfering with walking
* Subjects with comorbidities interfering with visual perception
* Subjects without medical clearance for exercise