Interhemispheric Asymmetries and Theta Activity in the Rostral Anterior Cingulate Cortex as EEG Signature of HIV-Related Depression

Abstract

Resting EEGs of 40 people living with HIV (PLWH) on long-term antiretroviral treatment were examined for z-scored deviations from a healthy control (normative database) to examine the main and interaction effects of depression and gender. Regions of interest were frontal (alpha) and central (all bands) for interhemispheric asymmetries in quantitative EEGs and theta in the rostral anterior cingulate cortex (rACC) in low-resolution electromagnetic tomography (LORETA). Z-scored normed deviations of depressed PLWH, compared with nondepressed, showed right-dominant interhemispheric asymmetries in all regions. However, after adjusting for multiple testing, significance remained only central for theta, alpha, and beta. Reversed (left-dominant) frontal alpha asymmetry is a potential EEG marker of depression in the HIV negative population that was not reversed in depressive PLWH; however, corresponding with extant literature, gender had an effect on the size of frontal alpha asymmetry. The LORETA analysis revealed a trending interactional effect of depression and gender on theta activity in the rACC in Brodmann area 32. We found that compared to men, women had greater right-dominant frontal alpha-asymmetry and elevated theta activity in voxels of the rACC, which may indicate less likelihood of depression and a higher likelihood of response to antidepressants. In conclusion, subtle EEG deviations, such as right-dominant central theta, alpha, and beta asymmetries and theta activity in the rACC may mark HIV-related depressive symptoms and may predict the likelihood of response to antidepressants but gender effects need to be taken into account. Although this study introduced the use of LORETA to examine the neurophysiological correlates of negative affect in PLWH, further research is needed to assess the utility of this tool in diagnostics and treatment monitoring of depression in PLWH.

Prediction of Human Empathy based on EEG Cortical Asymmetry

“…Moreover, in future studies, the potential influence of gender on the relationship between cortical asymmetry and empathy should be considered. Previous literature found that women in general show greater right-dominant frontal alpha asymmetry than men [39].…”

Resting-state connectivity and spontaneous activity of ventromedial prefrontal cortex predict depressive symptomology and peripheral inflammation in HIV

“…Previous work has shown elevated activity within the sgACC to be a signature of depressive symptomology in HIV-infected individuals (Kremer, Lutz et al 2016). We expected that altered rsFC between the sgACC and regions of interest within the bilateral amygdala would correspond to the greater depressive symptomology in HIV+ participants.…”

“…Another potential limitation is the disproportionate number of males among the HIV+ participants. It is possible that the low number of females in this sample may have obscured some of the HIV-related findings, as gender effects have been observed for resting-state perigenual cingulate activity associated with depressive symptomology in HIV (Kremer et al, 2016).…”

“…A more recent study of treatment-naïve adolescents diagnosed with first-episode depression uncovered greater rsFC between sgACC and the insula when compared to well-matched control subjects (Connolly, Wu et al 2013). This rsFC work has not been replicated in an HIV+ cohort, however, low-resolution electromagnetic tomography was recently used to show elevations in depressive symptomology were associated with greater resting activity in the rostral and sgACC (Kremer, Lutz et al 2016). Rather, the emphasis of neuroimaging findings with respect to the presentation of cognitive-affective symptoms in persons living with HIV/AIDS (PLWH) has been structural and functional alterations of the bilateral amygdala (Ances, Ortega et al 2012, Spies, Ahmed-Leitao et al 2016, Clark, Sweet et al 2017, Thames, Kuhn et al 2018).…”

Alexithymia, Assertiveness and Psychosocial Functioning in HIV: Implications for Medication Adherence and Disease Severity

“…Neuroimaging studies have uncovered paucity in cortical activations associated with the decoding of affect in persons with higher levels of AL [132][133][134][135]. Because altered activity and volumetric reductions within brain structures associated with AL, such as anterior cingulate, are also observed in persons living with HIV [136] including those demonstrating an emotion recognition impairment [137] and patients with high negative affect [138], therapies that target cognitive and emotional functioning will are needed. Some of the more promising treatment options that may promote the mental representation of affect for persons with HIV may include Mentalization-based therapy [139] and Emotion Focused Therapy [140].…”