Pure akinesia as initial presentation of PSP: a clinicopathological study.

Pure akinesia (PA) is a rare neurodegenerative condition that may represent a limited expression of progressive supranuclear palsy (PSP). Only a few pathological studies have been reported and its classification remains unclear. We report the case of a 57-year-old Caucasian man who was initially clinically diagnosed with classical PA. After four years the patient developed additional symptoms and signs compatible with the diagnosis of clinically probable PSP. The diagnosis of PSP was confirmed by post-mortem examination. Genetic analysis of the MAPT gene revealed an A0/A0 genotype, which has been repeatedly associated with the PSP phenotype, and might discriminate between PA and other gait disorders. Our case strengthens the hypothesis that PA should be considered as initial manifestation of PSP.