Antiretroviral therapy effects on sources of cortical rhythms in HIV subjects: responders vs. mild responders

We tested the hypothesis that 5months of combined anti-retroviral therapy (cART) affect cortical sources of resting state cortical electroencephalographic (EEG) rhythms in naïve HIV subjects.Eyes-closed resting state EEG data were recorded at baseline (i.e. pre-treatment; T0), T1 (after 4weeks of cART), T2 (after 8weeks of cART), and T5 (after 5months of cART) in 38 naïve HIV subjects. EEG data were also recorded in 40 age-matched cognitively normal subjects for control purposes. EEG rhythms of interest were delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), and beta 2 (20-30Hz). Cortical EEG sources were estimated by LORETA software.Compared to the control group, the HIV group at T0 showed greater delta sources and lower widespread alpha sources. cART induced a global improvement of biological (viral load, CD4 count) and EEG (delta, alpha) markers, remarkable even after 4weeks. Compared to HIV Responders (>100cells/μl at 5-month follow up), the HIV Mild Responders (<100cells/μl) showed greater parietal delta sources at baseline and lower occipital alpha sources at 5-month follow up.In naïve HIV subjects, 5months of successful cART affect brain synchronization mechanisms at the basis of the generation of delta and alpha rhythms.The present EEG markers may be useful secondary neurophysiological end points for pharmacological clinical trials in naïve HIV subjects.