Certain methods of augmenting the senses have previously been shown to improve ‘postural sway’ (stability of stance) and gait in patients with poor balance due to ageing, vestibular disorders, Parkinson’s disease or progressive supranuclear palsy. It remains unclear, however, whether augmented sensory information could help patients with disorders relating to the cerebellum; a central part of the brain which is responsible for processing sensory information in order to control posture. One such disorder of the cerebellum is degenerative cerebellar ataxia.

A group of researchers from Germany and Italy hypothesised that people with cerebellar degeneration could benefit from audio-biofeedback (ABF). During their study they tested a wearable ABF system. This consisted of two main components: 1. a series of sensors which captured the movements of the torso and; 2. a smartphone app which received the information from the sensors via Bluetooth and delivered audio feedback via headphones. The audio feedback was delivered in the form of a continuous tone which fluctuated with the degree of postural sway. The volume and frequency of the tone was altered when the subjects moved outside of a stable reference region due to their ataxia.

The study, published in March 2019, tested the effect of the ABF device on 23 people with degenerative cerebellar ataxia. They were asked to perform tasks (standing and undertaking a fitness game) while under the influence of ABF and had their stability measured with eyes open and eyes closed prior to ABF, under ABF, and post ABF. 17 additional subjects were included as a control group who performed the same tasks as the ABF group but did not receive ABF in any of the conditions.

The researchers found that stability was significantly improved under ABF when participants had their eyes closed. Patients with the worst stability also improved when their eyes were open. No changes were observed in the no-ABF control group. These findings provide evidence that patients with cerebellar degeneration are able to use auditory cues to facilitate improvements in stability. Lead researcher Matthis Synofzik says: ‘This research suggests that in the future, this information could be used to inform rehabilitation treatments for people with cerebellar ataxia.’

The full paper can be viewed here