LONG-LATENCY EVENT-RELATED POTENTIALS IN ASYMPTOMATIC HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTION

As part of the Medical Research Council prospective study of the neuro logical and neuropsychological complications of human immunodeficiency virus (HIV) infection, long-latency event-related potentials were rec orded in a cohort of homosexual and bisexual men. The latencies and am plitudes of the potentials, recorded from three scalp sites, were comp ared with the scores from neuropsychological tests of memory, attentio n, and concentration and with markers of immune function. The findings from 94 men were analyzed in the cross-sectional study of whom 47 wer e HIV seropositive without symptoms or signs of HIV type 1 (HIV-1) inf ection, 24 had progressed to the symptomatic stages of the disease, an d 23 were persistently HIV seronegative. There were no consistently si gnificant differences between the three subject groups in mean latenci es and amplitudes of the P300 and N200 or in the numbers of abnormal P 300 latencies. There were no significant correlations between either t he neuropsychological tests scores or the immune measures (CD4 lymphoc yte count and beta(2) microglobulin level) and the neurophysiological parameters. On repeated testing an average of 2 years later, there was no evidence of a significant trend towards deterioration in 30 HIV-se ropositive subjects who remained asymptomatic compared with 22 HIV ser onegatives. These findings indicate that there is no neurophysiologica l evidence of cognitive dysfunction in the asymptomatic stages of HIV- 1 infection.