Electrophysiological and pathological studies in spinocerebellar degenerations.

Electrophysiological and pathological studies have been performed on the peripheral nerves of patients with spinocerebellar degenerations. In Friedreich's ataxia there is impairment of sensory conduction and mild slowing of motor conduction which may be correlated with loss of large diameter fibres in the sural nerve. The abnormalities in Friedreich's ataxia are present early, in the first decade. In hereditary spastic paraparesis the nerve conduction studies and sural nerve biopsy are normal. In the other spinocerebellar degeneration and a mild loss of myelinated fibres in the sural nerve. However the abnormalities differ from those seen in Friedreich's ataxia.