Antiretroviral therapy effects on sources of cortical rhythms in HIV subjects: Responders vs. Mild Responders

• Five months of combined anti-retroviral therapy (cART) enhance biological and source electroencephalographic (EEG) markers in naïve HIV subjects.
• Enhancement of EEG source markers is greater in the naïve HIV Responders to the 5-month therapy (ΔCD4 > 100 cells/μl) than in Mild Responders (ΔCD4 < 100 cells/μl).
• The present EEG source markers may be used as secondary end points for pharmacological clinical trials in naïve HIV subjects.

ObjectiveWe tested the hypothesis that 5 months of combined anti-retroviral therapy (cART) affect cortical sources of resting state cortical electroencephalographic (EEG) rhythms in naïve HIV subjects.MethodsEyes-closed resting state EEG data were recorded at baseline (i.e. pre-treatment; T0), T1 (after 4 weeks of cART), T2 (after 8 weeks of cART), and T5 (after 5 months 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 (2–4 Hz), theta (4–8 Hz), alpha 1 (8–10.5 Hz), alpha 2 (10.5–13 Hz), beta 1 (13–20 Hz), and beta 2 (20–30 Hz). Cortical EEG sources were estimated by LORETA software.ResultsCompared 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 4 weeks. Compared to HIV Responders (>100 cells/μl at 5-month follow up), the HIV Mild Responders (<100 cells/μl) showed greater parietal delta sources at baseline and lower occipital alpha sources at 5-month follow up.ConclusionsIn naïve HIV subjects, 5 months of successful cART affect brain synchronization mechanisms at the basis of the generation of delta and alpha rhythms.SignificanceThe present EEG markers may be useful secondary neurophysiological end points for pharmacological clinical trials in naïve HIV subjects.