Study of a family with progressive ataxia, tremor and severe distal amyotrophy.

We have studied a large family of which seven members suffer from a progressive disease with onset in the first decade. The first symptoms were gait ataxia and clumsiness in all cases, followed by progressive development of severe distal amyotrophy reminiscent of Charcot-Marie-Tooth disease. In four patients a postural tremor which was relieved by pharmacological agents was also evident in the limbs or head. Cerebellar atrophy was confirmed on CT scan. Motor nerve conduction velocities were in the low normal range, while sensory nerve conduction was markedly decreased. All patients had impaired proprioception and vibration sense. The laboratory investigation revealed a normal CSF protein level and elevated serum bilirubin. The patients reported in this study apparently suffer from an original recessive form of spinal and olivocerebellar degeneration associated with a neuronal form of Charcot-Marie-Tooth disease.