Shivji S, et al. Neuropathol Appl Neurobiol 2020.
Hexanucleotide repeat expansions of C9orf72 usually present clinically with amyotrophic lateral sclerosis (ALS) and/or behavioural-variant frontotemporal dementia (bvFTD). Parkinsonism is an unusual clinical manifestation of C9orf72 and the limited neuropathological descriptions of this phenomenon implicate co-existing Lewy body pathology. Herein we describe the neuropathology from a patient with C9orf72 repeat expansion with Parkinsonism and we suggest that C9orf72 pathology itself, not Lewy
bodies, may underlie the observed striatopallidonigral degeneration.