Cerebellar disease leads to problems in controlling movement. The most common
difficulties are dysmetria and instability when standing.
Recent understanding of cerebellar function has expanded to include non -motor
aspects such as emotional, cognitive and sensory processing. Deficits in the
acquisition and processing of sensory information are one explanation for the
movement problems observed in cerebellar ataxia. Sensory deficits result in an
inability to make predictions about future events; a primary function of the
cerebellum. A question therefore, is whether augmenting or replacing sensory
information can improve motor performance in cerebellar disease. This question is
tested in this thesis by augmenting sensory information through the provision of an
auditory movement guide.A variable described in motor control theory (tau) was used to develop auditory
guides that were continuous and dynamic. A reaching experiment using healthy
individuals showed that the timing of peak velocity, audiomotor coordination
accuracy, and velocity of approach, could be altered in line with the movement
parameters embedded in the auditory guides. The thesis then investigated the use of
these sonic guides in a clinical population with cerebellar disease. Performance on
neurorehabilitation exercises for balance control was tested in twenty people with
cerebellar atrophy, with and without auditory guides. Results suggested that
continuous, predictive, dynamic auditory guidance is an effective way of improving
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movement smoothness in ataxia (as measured by jerk). In addition, generating and
swaying with imaginary auditory guides was also found to increase movement
smoothness in cerebellar disease.Following the tests of instantaneous effects, the thesis then investigated the longterm consequences on motor behaviour of following a two -month exercise with
auditory guide programme. Seven people with cerebellar atrophy were assessed pre - and post -intervention using two measures, weight -shifting and walking. The results
of the weight -shifting test indicated that the sonic -guide exercise programme does
not initiate long -term changes in motor behaviour. Whilst there were minor,
improvements in walking, because of the weight -shifting results, these could not be
attributed to the sonic guides. This finding confirms the difficulties of motor
rehabilitation in people with cerebellar disease.This thesis contributes original findings to the field of neurorehabilitation by first
showing that on -going and predictive stimuli are an appropriate tool for improving
motor behaviour. In addition, the thesis is the first of its kind to apply externally
presented guides that convey continuous meaningful information within a clinical
population. Finally, findings show that sensory augmentation using the auditory
domain is an effective way of improving motor coordination in some forms of
cerebellar disease
