Abstract:
Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for medication resistant depression (Boes et al., 2018; Trapp et al., 2020). Numerous studies have investigated the neurophysiological, neuroanatomical and functional connectivity effects relative to rTMS (Bailey et al., 2019; Ge, Downar, Blumberger, Daskalakis, & Vila- Rodriguez, 2020; Keuper, Terrighena, Chan, Junghoefer, & Lee, 2018; Noda et al., 2017; Song et al., 2019; Wu, Wang, & Baeken, 2020). The typical target for rTMS is the left dorsolateral prefrontal cortex (DLPFC) with effects seen in cortical thickness in rostral anterior cingulate cortex (rACC) (Boes et al., 2018; Trapp et al., 2020). Data evaluating EEG sources with low-resolution electromagnetic tomography (LORETA) are scarce. Thus, the current study aims to evaluate changes in functional connectivity of EEG frequency bands, with special emphasis on theta power in the prefrontal cortices as a result of rTMS (Esposito, Bortoletto, & Miniussi, 2020). This explorative study consists of 4 males between the age of 21 and 76, mean 52, SD = 23.84. All had diagnosis of Major Depressive Disorder (MDD) and met requirements for rTMS program using Neurostar (Malvern, PA).
TMS sessions were carried out daily for 30 consecutive weekdays. All clients completed
20 or more sessions of LORETA neurofeedback concurrently with rTMS or immediately following rTMS sessions. qEEG mapping was performed daily during the TMS sessions in 3 of the clients. Clients completed several assessment/screening instruments over the course of sessions of and the personality assessment inventory (PAI). Significant changes were seen in theta and alpha power between areas 24, 6, 10 and 33 in both theta and alpha current source density. Interestingly, one of the more significant differences across rTMS was a reduction in theta power shown both in topographical EEG measures and current source distributions. These theta excesses can in theory be thought of power distribution and energy consumption errors related to dysfunctional integrative loops that do not permit novel learning concerning the self and its positive and rewarding characteristics. Theoretical considerations will be discussed with emphasis on comorbid anxiety disorders and additive programmatic mechanisms to sustain rTMS/neurofeedback effects over time.
Presented by: Rex Cannon, Morgan Keith, Kelly Ownby, Kris Houser and Gena Bland
