The peripheral nerve involvement in spinocerebellar degenerations

We studies peripheral nerves electrophysiologically in 15 cases of spinocerebellar degenerations (SCD). Three patients showed abnormalities in 40% or more of the 13 items examined in this study. Two patients showed abnormalities in 20--40% of the items. Ten patients showed abnormalities in 20% or less of the items; six of them showed no abnormalities in any of the items. The incidence of abnormalities was slightly higher in the sensory nerve than in the motor nerve and was slightly higher in the peripheral areas than in the proximal areas in both the motor and sensory nerves. A high incidence of abnormalities was observed in cases of olivo-ponto-cerebellar atrophy (OPCA), the longer the history of the disease, the higher the incidence of abnormalities. This finding supports the idea that OPCA, not being only a single system, will develop into multiple system atrophy in a broad sense through rigidity and peripheral nerve disorders during a long course of the disease. Two patients with talipes cavus with muscular atrophy had peripheral nerve disorders.