Lewy bodies in progressive supranuclear palsy.

Lewy bodies (LBs), whose major component is alpha-synuclein, are a pathological hallmark of Parkinson's disease (PD) but have rarely been reported in progressive supranuclear palsy (PSP). Whether LBs in PSP represent the aging process or the coexistence of PD remains unclear. We found LBs in 5 of 16 patients with PSP. In 4 patients LBs were distributed widely throughout the brain stem and cerebrum in a pattern similar to that in PD. In the remaining patient one LB was found in the pontine reticular formation. Semiquantitative analysis showed that neuronal loss in the locus coeruleus and the dorsal vagal nucleus was more severe in patients with LBs than in patients without LBs. Double-labeling immunohistochemical studies showed co-localization of alpha-synuclein and tau in some neurons. Our study suggests that patients who have PSP with LBs constitute a subset of patients with PSP in whom Lewy body disease is also present.