Parkinsonism and neurofibrillary tangle pathology in pigmented nuclei.

Four parkinsonian patients had neurofibrillary tangles, neuronal loss, and gliosis restricted to the substantia nigra and locus ceruleus. No Lewy body inclusions or other neuropathological changes accounting for parkinsonism were found in any of these patients. Their clinical features were characterized by an early age of onset, absence of dementia, absence of other neurological abnormalities, good response to drug therapy, and a long, slowly progressive course of illness. None of the patients had any history of encephalitis. These patients either represent a forme fruste of postencephalitic parkinsonism or a new entity thus far not described.