EARLY AND LATE COGNITIVE EVENT-RELATED POTENTIALS MARK STAGES OF HIV-1 INFECTION IN THE DRUG-USER RISK GROUP

HIV-1 (Human immunodeficiency virus) infection of the brain causes del ays in auditory event-related potential (ERP) components. We recorded auditory ERPs from 38 former parenteral drug users (PDUs) at three sta ges of HIV-1 infection: seronegative; seropositive; stage II; and sero positive, stage IV. There were five response conditions: Go Nogo, Coun t, Simple Response, Simple Count, and Ignore. P3 peak latencies were s ignificantly delayed and P3 amplitudes were significantly reduced for all seropositives, including asymptomatics, when compared to PDU seron egative controls. In contrast, the P1 and N1 peak latency measures wer e delayed only for seropositives with acquired immunodeficiency syndro me (AIDS) qualifying illnesses. There was a significant negative corre lation between the CD4 count and the latency of P1, N1, and the MMN. A lso, increased P1 and N1 amplitudes correlated with indices of disease progression (Choice RT and CD4 counts, respectively). The results ext end previous findings by clarifying the pattern of auditory ERP marker s of disease progression. Early, as well as late, brain involvement ca used by HIV-1 is marked by delays and decreased amplitudes in cognitiv e components. In addition, late brain involvement is marked by delays and increased amplitudes in specific, automatic, and/or obligatory com ponents.