Hereditary ataxia, photomyoclonus, skeletal deformities and lipoma.

An account is given of a form of hereditary, cerebellar ataxia and photomyoclonus. Eight cases from 5 generations were affected. The disease seemed to be transmitted as an autosomal dominant trait. The age at onset usually varied between 35 to 40 years. The symptoms and signs consisted of a cerebellar ataxia, dysarthria and intention tremor. There was no nystagmus. All patients exhibited photomyoclonus and were extremely sensitive to photic stimuli. Other signs were dementia, kyphosis, pes cavus and lipoma localized in the nape of the neck, shoulders and back. Two patients had a partial syndrome with photonyoclonus and skeletal deformities. None of the patients suffered from epilepsy, In one case, histopathological examination revealed atrophy within the cerebellar cortex, dentate nucleus and the posterior columns of the spinal cord. It is concluded that this syndrome belongs to a groups of hereditary ataxias and myoclonus, and differs from myoclonic cerebellar dyssynergia (Ramsay Hunt) and alos from a variety of familial myoclonus and ataxia (Gilbert et al. 1963);