In their study on event-related potentials (ERPs) in patients infected with human immunodeficiency virus (HIV), Fein et al1 report on the correlation of P3a latency with different cognitive stages of the patients. Their data suggest that P3a latency increases with worsening of the effects of HIV on the central nervous system. These findings are in concordance with other studies2-14 showing a progressive worsening of ERP parameters during the natural course of HIV infection and the acquired immunodeficiency syndrome. In 1 study5 the increase of ERP latencies was found to be less progressive in patients treated with antiretroviral substances. Only 2 studies15,16 performed by the same research group did not reveal any significant cognitive disturbances in HIV-infected asymptomatic patients.
However, most of these studies were cross-sectional; only in a few studies3,6,7,15 was the worsening of ERP parameters evaluated in a longitudinal setting with observation periods between