Increased wave P 300 latency in progressive supranuclear palsy.

The visually evoked P 300 wave and related reaction times (RTs) were studied in 25 patients with progressive supranuclear palsy (PSP). Both the P 300 wave latency and the RTs were significantly increased compared with 14 control subjects, and were correlated with an intellectual deterioration index calculated from neuropsychological scores. It is suggested that the study of wave P 300 may contribute to the diagnosis of cognitive disorders in PSP.