A head-mounted Tilted Reality Device for the treatment of pusher syndrome: a usability study in healthy young and older adults

Pusher syndrome is a disorder of postural control after stroke. Patients show a mismatch in their perception of (almost preserved) visual and (pathologically tilted) postural verticality. In order to reduce this mismatch, we developed a novel head-mounted Tilted Reality Device (TRD). It presents patients visual footage of their actual surroundings but tilted to one side rather than upright. We investigated its usability and possible limitations in its use for the treatment of pusher patients in two samples of healthy participants with an average age of 26.4 years and 63.9 years respectively. Individuals from both age groups showed similar levels of tolerance to prolonged exposure to the tilted visual environment for an average of 40.4 min while walking around in the hospital. The TRD was found to be comfortable and not frustrating whilst wearing, but somewhat challenging in terms of technical handling, particularly for older participants. At the end of the maximally tolerated exposure time participants of both groups experienced some feelings of discomfort, like dizziness or increased stomach awareness, which disappeared rapidly after terminating TRD exposure. Our TRD appears to be a practical device especially for an older population, like pusher patients. While users must be aware of the possibility of side effects, these should be balanced against the benefits of future use for rehabilitation purposes.