Vestibular rehabilitation by auditory feedback in otolith disorders

Rehabilitation strategies have been applied successfully over the last few decades to initiate central compensation of the tonus imbalance and to facilitate substitution in different types of peripheral vestibular dysfunction. However, these vestibular rehabilitation strategies are often not successful in patients with isolated otolith disorders. The aim of the present study was therefore to evaluate a specific rehabilitation strategy for patients with an isolated otolith disorder by using an auditory feedback system. Thirteen patients, which suffered from different types of otolith disorders, but no other vestibular pathology and 13 normal controls were included in this study. Vestibular rehabilitation exercises were performed daily over a 2-week period (weekends excluded). During all exercises the patients of the test group (n=13) obtained an acoustic feedback signal when their trunk angle velocity exceeded a preset level while the patients of the control group (n=13) performed the same exercises without auditory feedback. The most effective exercise in the test group was "walking eight tandem steps on a foam support surface". Approximately 85% of the patients showed a significant decrease of trunk sway in this condition. In contrast to these results, patients of the control group showed no significant improvement of postural control after the training. The results indicate that an auditory feedback rehabilitation program with exercises related to the specific neurotological disease could significantly improve the postural control in patients with otolith disorders.