Parietal resting-state EEG alpha source connectivity is associated with subcortical white matter lesions in HIV-positive people.

OBJECTIVE: Parietal resting-state electroencephalographic (rsEEG) alpha (8-10 Hz) source connectivity is abnormal in HIV-positive persons. Here we tested whether this abnormality may be associated with subcortical white matter vascular lesions in the cerebral hemispheres. METHODS: Clinical, rsEEG, and magnetic resonance imaging (MRI) datasets in 38 HIV-positive persons and clinical and rsEEG datasets in 13 healthy controls were analyzed. Radiologists visually evaluated the subcortical white matter hyperintensities from T2-weighted FLAIR MRIs (i.e., Fazekas scale). In parallel, neurophysiologists estimated the eLORETA rsEEG source lagged linear connectivity from parietal cortical regions of interest. RESULTS: Compared to the HIV participants with no/negligible subcortical white matter hyperintensities, the HIV participants with mild/moderate subcortical white matter hyperintensities showed lower parietal interhemispheric rsEEG alpha lagged linear connectivity. This effect was also observed in HIV-positive persons with unimpaired cognition. This rsEEG marker allowed good discrimination (area under the receiver operating characteristic curve > 0.80) between the HIV-positive individuals with different amounts of subcortical white matter hyperintensities. CONCLUSIONS: The parietal rsEEG alpha source connectivity is associated with subcortical white matter vascular lesions in HIV-positive persons, even without neurocognitive disorders. SIGNIFICANCE: Those MRI-rsEEG markers may be used to screen HIV-positive persons at risk of neurocognitive disorders.

Parietal intrahemispheric source connectivity of resting-state electroencephalographic alpha rhythms is abnormal in Naïve HIV patients.

Previous evidence showed abnormal parietal sources of resting-state electroencephalographic (EEG) delta (< 4 Hz) and alpha (8-12 Hz) rhythms in treatment-Naïve HIV (Naïve HIV) subjects, as cortical neural synchronization markers in quiet wakefulness. Here, we tested the hypothesis that these local abnormalities may be related to functional cortical dysconnectivity as an oscillatory brain network disorder. The present EEG database regarded 128 Naïve HIV and 60 Healthy subjects. The eLORETA freeware estimated lagged linear EEG source connectivity (LLC). The area under receiver operating characteristic (AUROC) curve indexed the accuracy in the classification between Healthy and HIV individuals. Parietal intrahemispheric LLC solutions in alpha sources were abnormally lower in the Naïve HIV than in the control group. Furthermore, those abnormalities were greater in the Naïve HIV subgroup with executive and visuospatial deficits than the Naïve HIV subgroup with normal cognition. AUROC curves of those LLC solutions exhibited moderate/good accuracies (0.75-0.88) in the discrimination between the Naïve HIV individuals with executive and visuospatial deficits vs. Naïve HIV individuals with normal cognition and control individuals. In quiet wakefulness, Naïve HIV subjects showed clinically relevant abnormalities in parietal alpha source connectivity. HIV may alter a parietal "hub" oscillating at the alpha frequency in quiet wakefulness as a brain network disorder.

Cortical sources of resting state electroencephalographic rhythms probe brain function in naïve HIV individuals.

OBJECTIVE: Here we evaluated the hypothesis that resting state electroencephalographic (EEG) cortical sources correlated with cognitive functions and discriminated asymptomatic treatment-naïve HIV subjects (no AIDS). METHODS: EEG, clinical, and neuropsychological data were collected in 103 treatment-naïve HIV subjects (88 males; mean age 39.8 years ±â€¯1.1 standard error of the mean, SE). An age-matched group of 70 cognitively normal and HIV-negative (Healthy; 56 males; 39.0 years ±â€¯2.0 SE) subjects, selected from a local university archive, was used for control purposes. LORETA freeware was used for EEG source estimation in fronto-central, temporal, and parieto-occipital regions of interest. RESULTS: Widespread sources of delta (<4 Hz) and alpha (8-12 Hz) rhythms were abnormal in the treatment-naïve HIV group. Fronto-central delta source activity showed a slight but significant (p < 0.05, corrected) negative correlation with verbal and semantic test scores. So did parieto-occipital delta/alpha source ratio with memory and composite cognitive scores. These sources allowed a moderate classification accuracy between HIV and control individuals (area under the ROC curves of 70-75%). CONCLUSIONS: Regional EEG abnormalities in quiet wakefulness characterized treatment-naïve HIV subjects at the individual level. SIGNIFICANCE: This EEG approach may contribute to the management of treatment-naïve HIV subjects at risk of cognitive deficits.

Brain and cognitive functions in two groups of naïve HIV patients selected for a different plan of antiretroviral therapy: A qEEG study.

OBJECTIVE: Cortical sources of electroencephalographic (EEG) rhythms were investigated in two sub-populations of naïve HIV subjects, grouped based on clinical criteria to receive different combination anti-retroviral therapies (cARTs). These EEG sources were hypothesized to reflect beneficial effects of both regimes. METHODS: Eyes-closed resting state EEG data were collected in 19 (Group A) and 39 (Group B) naïve HIV subjects at baseline (i.e. pre-treatment; T0) and after 5months of cART (T5). Compared with the Group A, the Group B was characterized by slightly worse serological parameters and higher cardiovascular risk. At T0, mean viral load (VL) and CD4 count were 87,694copies/ml and 435cells/µl in the Group A and 187,370copies/ml and 331cells/µl in the Group B. The EEG data were also collected in 50 matched control HIV-negative subjects. Cortical EEG sources were assessed by LORETA software. RESULTS: Compared to the Control Group, the HIV Groups showed lower alpha (8-12Hz) source activity at T0 while the Group B also exhibited higher delta source activity. The treatment partially normalized alpha and delta source activity in the Group A and B, respectively, in association with improved VL, CD4, and cognitive functions. CONCLUSIONS: Different cART regimens induced diverse beneficial effects in delta or alpha source activity in the two naïve HIV Groups. SIGNIFICANCE: These sources might unveil different neurophysiological effects of diverse cART on brain function in naïve HIV Groups as a function of clinical status and/or therapeutic compounds.

Antiretroviral therapy affects the z-score index of deviant cortical EEG rhythms in naïve HIV individuals.

OBJECTIVE: Here we tested the effect of combined antiretroviral therapy (cART) on deviant electroencephalographic (EEG) source activity in treatment-naïve HIV individuals. METHODS: Resting state eyes-closed EEG data were recorded before and after 5 months of cART in 48 male HIV subjects, who were naïve at the study start. The EEG data were also recorded in 59 age- and sex-matched healthy subjects as a control group. Frequency bands of interest included delta, theta, alpha1, alpha2 and alpha3, based on alpha frequency peak specific to each individual. They also included beta1 (13-20 Hz) and beta2 (20-30 Hz). Low-resolution brain electromagnetic tomography (LORETA) estimated EEG cortical source activity in frontal, central, temporal, parietal, and occipital regions. RESULTS: Before the therapy, the HIV group showed greater parietal delta source activity and lower spatially diffuse alpha source activity compared to the control group. Thus, the ratio of parietal delta and alpha3 source activity served as an EEG marker. The z-score showed a statistically deviant EEG marker (EEG +) in 50% of the HIV individuals before therapy (p < 0.05). After 5 months of cART, delta source activity decreased, and alpha3 source activity increased in the HIV subjects with EEG + (about 50% of them showed a normalized EEG marker). CONCLUSIONS: This procedure detected a deviant EEG marker before therapy and its post-therapy normalization in naïve HIV single individuals. SIGNIFICANCE: The parietal delta/alpha3 EEG marker may be used to monitor cART effects on brain function in such individuals.