Sporadic case resembling autosomal-dominant motor system degeneration (Azorean disease complex).

We describe a case of an adult-onset progressive dystonia with external ophthalmoplegia, occurring in a black man without a family history of neurologic disorders. Neuropathologic examination demonstrated neuronal loss and gliosis in the anterior horn and Clarke's column in the spinal cord, nuclei of cranial nerves III, VI, X, and XII, vestibular complex, lateral cuneate nucleus, lower pontine tegmentum, red nucleus, substantia nigra, and dentate nucleus. The cerebral cortex, corpus striatum, basis pontis, inferior olives, and cerebellum were spared. The clinical and pathologic findings closely resemble autosomal-dominant motor system degeneration or "Azorean disease," without, however, demonstrable familial transmission. In addition to the absence of a family history, unique features of the case include the presence of Alzheimer type II glial cells in the red nucleus and an unexplained persistent elevated concentration of serum amylase.