Early sensory information processes are enhanced on visual oddball and S1-S2 tasks in Parkinson's disease: a visual event-related potentials study.

To observe sensory and cognitive information processing in Parkinson's disease (PD), 34 PD patients and 26 controls were investigated. A visual oddball paradigm and an S1-S2 paradigm were employed to record the early (P1, N1, P2) and late (N2, P3) event-related potentials (ERPs) at Cz, Pz and Oz. Results showed: (1) enlarged P1 amplitude at all electrode locations on both tasks, (2) shortened N1 latency and enlarged P2 amplitude at Oz on both tasks, (3) enlarged N1 amplitude at Cz during an oddball paradigm, (4) delayed N2 latency and decreased N2, P3 amplitude on both tasks, and (5) delayed P3 latency and reaction time during the S1-S2 paradigm. Abnormal ERP changes were correlated with worsened scores on Wechsler Adult Intelligence Scale-Revised and motor dysfunction scales in PD. We surmise overactive aspects or failed inhibitory modulation of sensory information processing in the early ERP stage and deficient cognitive information processing during the late ERP stage in PD.