Brain-to-brain patient-clinician connectivity is directionally modulated by chronic low back pain therapy: an electroencephalography hyperscan approach

In chronic pain management and treatment, a positive patient-clinician relationship is associated with higher patient satisfaction and treatment efficacy. In this study, we investigated synchronization of brain activity between patients and clinicians during an experimentally controlled augmented (empathetic) compared to limited (business-like) clinical interaction context. We recorded EEG simultaneously (hyperscanning, 16 dyads, 64 channels per subject) from low back pain patients and acupuncturists during a task with treatment trials (acupuncture) and no-treatment trials in conjunction with evoked cuff pain. EEG data were reconstructed using the algorithm exact LORETA on 17 Regions of Interest (ROIs) defined by our previous fMRI study (Ellingsen et al. 2020) and directed statistical connectivity patterns were obtained by comparing Granger Causality-based estimates for treatment and no-treatment trials (α=0.05, FDR corrected). Patients in the augmented group, compared to the limited group, rated therapeutic alliance and clinician warmth significantly higher. Low back pain intensity decreased after acupuncture treatment, irrespective of clinical context. EEG analysis suggested that in Theta band (linked with empathy for pain in prior EEG studies), inter-brain network density within social mirroring and pain/sensorimotor brain regions was altered when acupuncturists treated evoked pain. The number of significant inter-brain clinician-to-patient connections was higher in the no-treatment condition, while the number of patient-to-clinician connections were greater during treatment trials. Also, the density of patient-to-clinician inter-brain connections increased during treatment relative to no-treatment irrespective of clinical context, yet statistical significance was noted only for the augmented group. Both behavioral and simultaneous brain-to-brain responses across the patient/clinician dyad reflect clinical interaction context. EEG hyperscanning is an ecologically valid approach to identify inter-brain networks whose density and directionality within the dyad is altered by treatment and clinical context, highlighting new brain mechanisms linking therapeutic alliance and chronic pain therapy. Research supported by NIH - National Center for Complementary and Integrative Health, NIH-NIBIB National Institute of Biomedical Imaging and Bioengineering and Korea Institute of Oriental Medicine (KIOM).