DISTRIBUTION OF THE BRAIN STEM LESIONS IN POSTENCEPHALITIC PARKINSONISM

Abstract

The distribution of the brain stem lesions is described in 3 cases of Parkinsonism in which microscopical examination showed neurofibrillary tangles in the brain stem neurons. Two of the cases were clearly postencephalitic. In the 3rd there was no history of an overt encephalitis but the presence of oculogyric crises suggests a postencephalitic genesis also in this case. Serial sections of the entire brain stem were examined in 2 cases. Nerve cells with neurofibrillary tangles were found in the substantia nigra, locus coeruleus, substantia innominata, hypothalamus, and in widespread areas of the reticular formation and the mesencephalic periaqueduclal grey. It is pointed out that the nerve cell loss from such diffuse lesions is difficult to appreciate and that the full extent of the lesions can be determined only in cases where degenerating neurons can be identified.