Ataxia, chorea, seizures, and dementia. Pathologic features of a newly defined familial disorder.
Five generations of a family exhibit a unique autosomal dominant neurologic disorder characterized by the development (usually between 15 and 30 years of age) of ataxia, seizures, choreiform movements, progressive dementia, and death after 15 to 25 years of illness. Neuropathologic findings in two deceased family members revealed remarkably similar findings, including marked neuronal loss of the dentate nucleus, microcalcification of the globus pallidus, neuroaxonal dystrophy of the nucleus gracilis, and demyelination of the centrum semiovale. The clinical and pathologic findings are closely correlated. Ataxia and chorea are related to severe neuronal loss in the dentate nucleus with calcification in the globus pallidus. Dementia occurs with progressive demyelination of the centrum semiovale, and loss of posterior column function occurs with neuroaxonal dystrophy of the nucleus gracilis and nucleus cuneatus.