Progressive Supranuclear Palsy: A Review of Co-existing Neurodegeneration

Abstract

The neuropathological findings of 32 progressive supranuclear palsy (PSP) cases over a period of 17 years were reviewed. Of the 26 cases with adequate clinical data, 20 patients either presented with cognitive dysfunction or developed a cognitive impairment subsequently during the course of the disease. Co-existing changes of argyrophilic grains and corticobasal degeneration (CBD) were found in 28% and 32% of the cases respectively. Alzheimer-related pathology was found in 69% of cases but only 18.75% of cases fulfilled the consortium to establish a registry for Alzheimer's disease (CERAD) criteria for either definite or probable Alzheimer's disease. Lewy bodies were noted in four cases (12.5%), all in the subcortical regions. Only seven cases of PSP showed no pathological evidence of other co-existing neurodegenerative diseases. The severity of the cerebrovascular pathology in this cohort was insufficient to explain any clinical symptomatology. As in previous studies, this study has demonstrated the frequent co-existence of pathological changes usually noted in other neurodegenerative diseases in PSP. Whether these co-existing pathological changes contribute to the cognitive impairment in PSP remains uncertain.