Biologiccrt Psychology 24 (1987) 23-37 North-Holland 23 zyxwvutsrq EVOKED POTENTIAL CHANGES AND NEUROPSYCHOLOGICAL PERFORMANCE IN PARKINSON’S DISEASE Brian F. O’DONNELL and Nancy K. SQUIRES * P~ych#~o~ department, State Un~~e~sj~ of New York, Stony Brook, NY I1 790, U.S.A. Merrill J. MARTZ, Jia-Rhon CHEN and Andrew J. PHAY ** Brooklyn Veierans Administration Medical Center Accepted for publication 4 September 1986 Auditory brainstem responses (ABRs) and long latency exogenous and endogenous auditory evoked potentials (EPs) were investigated in 16 patients with Parkinson’s disease and 11 control subjects. Parkinson’s disease patients were impaired on mental status testing. While ABRs and the Nl component of the auditory EP were of normal latency in Parkinson patients, the endogenous components, N2 and P3, were prolonged. Prolongation of P3 latency in Parkinson’s disease correlated with mental status decline, but not with severity of motoric disturbance. Thirteen PD patients also received neuropsychological evaluation. P3 latency was correlated with tests requir- ing learning or mental manipulation of information, but not with measures of verbal performance, immediate memory, or depression. P3 latency prolongation appears to have a selective relation- ship to intellectual changes in PD, and may be most sensitive to deficits requiring significant cognitive effort. 1. Introduction Parkinson’s disease (PD) has traditionally been conceptualized as a motor disorder related to degeneration of the nigrostriatal system. Investigations over the past decade have placed increasing scrutiny on the cognitive and sensory changes which frequently accompany the disorder. Neurobehavioral studies have shown that intellectual functions are mildly to severely disturbed in PD * Brian F. O’Donnell is currently at the University of Massachusetts Medical Center, U.S.A. Address request for reprints to: Brian F. O’Donnell, Department of Neurology, University of Massachusetts Medical Center, 55 Lake Avenue North, Worcester, MA 01605, U.S.A. Portions of this paper were presented at the 14th Annual Meeting of the International Neuropsycho- logical Society, Denver, 1986. ** The investigators would like to thank Drs. John NeaJe and David Emmerich for their criticisms and helpful advice provided during the completion of the dissertation which formed the basis for this study. We would also like to thank Ms. Linda Cumin, who assisted in the preparation of this manuscript. 0301-0511/87/$3.50 0 1987, Elsevier Science Publishers B.V. (North-Holland)