Habituation of event-related potentials in patients with Parkinson's disease

Auditory event-related potential (ERP) was studied in idiopathic Parkinson' s disease (PD) using our new procedures. We examined 12 non-demented patien ts with PD, and 9 age-matched control subjects. Ninety responses induced by rare stimulation were continuously recorded from Fz. Ct, Pz referred to li nked earlobe electrode (A1A2), and were divided into nine blocks (one block = 10 responses) for statistical analysis. We assessed the habituation of a uditory ERP to detect delicate changes related to the information processin g in PD. N100 and P300 latencies were significantly longer in PD than in co ntrol subjects (p < 0.05). P300 latency gradually increased with progressio n of recording blocks in both PD and control subjects, whereas N100 latency increased only in PD. Three way analysis of variance for P300 amplitude re vealed significant effects of subject group, recording electrode site, and trial block. P300 amplitude was smaller in PD than in control subjects. Sig nificant negative correlation between P300 amplitudes and block numbers wer e observed at Ct and Pt in PD, and at Fz in the control group. Previous rep orts as well as present results suggest that prolongation of N100 latency m ight be related to frontal lobe dysfunction, and abnormality of P300 to dys function in both the frontal lobe and hippocampus in PD. (C) 2000 Elsevier Science Inc. All rights reserved.