Gender factor in longer P100 latency of elderly persons

Monocular pattern-shift visual evoked potentials (PSVEPs) were obtained in 26 neurologically and ophthalmologically normal elderly community volunteers (mean age 59.4, males 15, females 11), and compared with similarly obtained data in 26 sex-matched young subjects (mean age 28.1). Elderly males were age-matched with elderly females, and young males were age-matched with young females. Data analyses at both the midoccipital-linked ears and midoccipital-midcentral derivations revealed that the combined-eye mean P100 latency in the elderly as a whole was significantly longer than the young sex-matched controls (P less than 0.02). However, the latency in the elderly males was not significantly different from that of sex-matched young males, or age-matched elderly females. The latency in young female subjects, on the other hand, was significantly shorter both when compared to that of age-matched young males (P less than 0.01) and sex-matched elderly females (P less than 0.01). The differences in other PSVEP variables, namely, interocular P100 latency differences, P100 amplitudes and interocular P100 amplitude ratios were not significant between the groups and subgroups studied. It is concluded that females account for the major contribution towards the longer P100 latency in the elderly.