Auditory and visual event-related potentials and flash visual evoked potentials in Alzheimer's disease: correlations...

We investigated possible correlations among neurophysiological examinations [auditory and visual event-related potentials (A-ERPs, V-ERPs), and flash visual evoked potentials (F-VEPs)] and neuropsychological tests [Mini-Mental State Examination (MMSE) and Raven's Coloured Progressive Matrices (RCPM)] in 15 subjects with probable or possible Alzheimer's disease (AD) according to the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria. The P300 latency of A-ERPs was correlated with the scores of MMSE but not with those of RCPM. The P300 latency of V-ERPs was more significantly correlated with the scores of RCPM than with those of MMSE. The P2 latency of F-VEPs was more significantly correlated with the scores of RCPM than with those of MMSE. The P2 latency of F-VEPs was not correlated with the P300 latency of A-ERPs but was correlated with the P300 latency of V-ERPs. The close relationship among V-ERPs, F-VEPs and RCPM suggests that these examinations at least partly reflect the functions of visual association areas in AD. Furthermore, discrepancy between P300 latency by A-ERPs and V-ERPs suggests that the mechanism responsible for P300 generation is not identical between these two stimulus modalities.