Abnormal cortical sources of resting state electroencephalographic rhythms in single treatment-naïve HIV individuals: a statistical z-score index

Objective: This study tested a simple statistical procedure to recognize single treatment-naïve HIV individuals having abnormal cortical sources of resting state delta (<4 Hz) and alpha (8–13 Hz) electroencephalographic (EEG) rhythms with reference to a control group of sex-, age-, and education-matched healthy individuals. Compared to the HIV individuals with a statistically normal EEG marker, those with abnormal values were expected to show worse cognitive status. Methods: Resting state eyes-closed EEG data were recorded in 82 treatment-naïve HIV (39.8 ys. ± 1.2 standard error mean, SE) and 59 age-matched cognitively healthy subjects (39 ys. ± 2.2 SE). Lowresolution brain electromagnetic tomography (LORETA) estimated delta and alpha sources in frontal, central, temporal, parietal, and occipital cortical regions. Results: Ratio of the activity of parietal delta and high-frequency alpha sources (EEG marker) showed the maximum difference between the healthy and the treatment-naïve HIV group. Z-score of the EEG marker was statistically abnormal in 47.6% of treatment-naïve HIV individuals with reference to the healthy group (p < 0.05). Compared to the HIV individuals with a statistically normal EEG marker, those with abnormal values exhibited lower mini mental state evaluation (MMSE) score, higher CD4 count, and lower viral load (p < 0.05). Conclusions: This statistical procedure permitted for the first time to identify single treatment-naïve HIV individuals having abnormal EEG activity.