Abstracts

Rationale: It is common for epilepsy patients to experience psychiatric co-morbidities such as anxiety and depression (Ann of Gen Psychiatry 6:28) which independently affect the quality of life. Targeting the location and onset of negatively associated emotions could provide treatment strategy to epileptics at-risk. Using intracranial encephalography (iEEG) recordings amygdala-hippocampus-prefrontal cortical brain rhythms have recently been used to define subjective mood states in patients with epilepsy. Identification of specific brain activity patterns may be exploited as targets for electrical stimulation to alter persistent negative emotional states. In this pilot study, we aimed to identify specific brain rhythms across different neural substrates that correspond to anxiety and threat-related behaviors across the threat imminence continuum

Methods: We conducted a pilot study using intracranial electrophysiology in epilepsy patients undergoing intracranial EEG (iEEG) for seizure onset localization to understand continuous spatial threat avoidance using in n=9 subjects. Subjects played a spatial avoidance game previously linked to state and trait anxiety (Wise & Dolan, 2020) with simultaneous recording of neural oscillations in the hippocampus, amygdala, and frontal circuits.

Results: Up to n=269 trials of continuous threat avoidance behavior in each subject (n=9) were acquired during iEEG monitoring. All subjects performed above chance level in threat avoidance. Preliminary analysis showed evoked potentials in the hippocampus linked to aversive game events. Subsequent analysis will be based on coherence between band-specific electrophysiological signals in a pairwise fashion between the hippocampus, amygdala, and several frontal cortical regions (orbitofrontal, medial prefrontal, cingulate, and insula).

Conclusions: These findings suggest that eliciting aversive experiences via repeated spatial avoidance behavior is feasible in iEEG subjects, permitting invasive recordings of trans-diagnostic negative emotion constructs in mental health. Understanding the network electrophysiology of threat processing using these approaches may yield insight into anxiety- and mood co-morbidity in epilepsy, subsequently, providing stimulation targets to alter negative emotions.

Funding: Please list any funding that was received in support of this abstract.: Kavli Foundation (Kaye and Damisah), VA National Center for PTSD (Kaye and Krystal), NARSAD Young Investigator (Kaye), The Glenn H. Greenberg Fund for Research on Stress and Resilience (Kaye), Integrated Mentored Patient-Oriented Research Training (IMPORT) in Psychiatry (McClurkin), The Swebilius Foundation (GS051384, Damisah).