HYPERTROPHY OF THE INFERIOR OLIVARY NUCLEUS IN PATIENTS WITH PROGRESSIVE SUPRANUCLEAR PALSY

Hypertrophic changes in the inferior olivary nuclei have been occasion ally described in patients with progressive supranuclear palsy (PSP). To elucidate the incidence of olivary hypertrophy, we investigated mor phologically the olives and their associated pathways in 20 autopsied cases: 11 cases of PSP, 3 cases of Machado-Joseph disease and 6 cases of dentatorubropallidoluysian atrophy (DRPLA) as control diseases that usually exhibited lesions of the cerebellofugal pathway. Olivary hype rtrophy was observed in 5 of 11 PSP cases, but not in the other diseas es, except for 1 case of DRPLA with an old infarct in the dentate nucl eus. In the olivopetal pathway, grumose degeneration of the dentate nu cleus and mild neuronal loss in the red nucleus were observed in all p atients with PSP and in the control subjects. Atrophy and fibrillary g liosis of the tegmentum of the pens, including that of the bilateral c entral tegmental tracts, were observed in all patients with PSP, more severe in the cases with hypertrophic neurons in the olives. We specul ate that a lesion that involves the central tegmental tracts may play a major role in inducing hypertrophy of the olives in patients with PS P.