Clinical and pathological study of two patients with progressive supranuclear palsy and Alzheimer's changes. Antigenic determinants that distinguish cortical and subcortical neurofibrillary tangles.

Two cases with classical clinical manifestations of progressive supranuclear palsy (PSP) showed severe progressive dementia as an additional clinical feature. Neuropathological study demonstrated typical features of PSP in the brainstem. Additionally, histological criteria of Alzheimer's disease (AD) were observed. A topographic and immunohistological study (with neurofilament subunit and Tau and Ubiquitin antibodies) of the distribution of neurofibrillary tangles (NFTs) was performed in order to compare the characteristics of NFTs from cortex and brainstem. NFTs from cortex were positive with all antibodies used and were predominantly distributed in cortical layers III and V and affected medium size neurons. Brainstem NFTs were positive only for neurofilament subunits and Tau. Cortical and brainstem NFTs showed immunohistological differences. Cortical NFTs in our two cases had a similar distribution as in control AD cases. On the basis of our observations we believe (1) that cortical tangles in our PSP cases are related to Alzheimer's disease and (2) that the cortical NFTs of PSP and AD are morphologically and immunohistologically distinct. Mechanisms concerned with the production of cortical and brainstem NFTs in PSP and AD are discussed.