JUVENILE PARKINSONISM - A CASE WITH 1ST CLINICAL MANIFESTATION AT THE AGE OF 6 YEARS AND WITH NEUROPATHOLOGICAL FINDINGS SUGGESTING A NEW PATHOGENESIS

A clinico-pathological study of a 39-year-old female with Juvenile parkinsonism was carried out. Although the clinical manifestations were consistent with parkinsonism, the pathological findings were significantly different. Pathological examination showed the lesion to be localized to the substantia nigra, the number of neurons to be abnormally low, the proportion of melanin-containing cells to be reduced, and a large number of immature cells to be present. No neuronal degeneration associated with gliosis or release of melanin granules, such as seen in Parkinson's disease, was observed. Neuropathological studies, including cytometry and comparison against normal controls in the distribution of melanin granules, suggested hypoplasia and poor neuronal maturation of the substantia nigra. Since neuromelanin is thought to be the result of normal dopamine metabolism, reduction of melanin-containing cells in this case suggests inadequate or abnormal dopamine metabolism. Thus, the clinical manifestation of parkinsonism in this case seems to be related to the small number of melanin-containing cells which implies the dopamine deficiency state.