[Auditory event-related potentials (ERPs) in healthy subjects and patients with dementia]

To study the effects of aging and gender differences of ERP components, auditory ERPs were recorded in 106 healthy subjects. Forty-three patients with dementia of the Alzheimer type and 24 patients with vascular dementia were also studied. In healthy subjects, there was a significant positive linear correlation between P300 latency and age, with P300 latency increasing at the rate of 1.5 msec/year. Neither N100 nor P200 component was correlated with age. The amplitudes of N100, P200 and P300 components in females were slightly larger than those in males, but the differences were not significant. Not only P300 latencies but also P200 latencies were significantly different in healthy subjects, patients with dementia of the Alzheimer type and those with vascular dementia. In 74.4% of patients with dementia of the Alzheimer type and 62.5% of those with vascular dementia, the P300 latency was over 2 SE above the age-estimated regression line. The difference of the P300 latency prolongation may have resulted from the severity of dementia but not from the etiology of dementia.