Modifications of Functional Human Brain Networks by Transcutaneous Auricular Vagus Nerve Stimulation: Impact of Time of Day

Author: Randi von Wrede1, Timo Bröhl1,2, Thorsten Rings1,2, Jan Pukropski1, Christoph Helmstaedter1, Klaus Lehnertz1,2,3
1 Department of Epileptology, University Hospital Bonn, 53127 Bonn, Germany.
2 Helmholtz-Institute for Radiation and Nuclear Physics, University of Bonn, 53115 Bonn, Germany.
3 Interdisciplinary Center for Complex Systems, University of Bonn, 53117 Bonn, Germany.
Conference/Journal: Brain Sci
Date published: 2022 Apr 26
Other: Volume ID: 12 , Issue ID: 5 , Pages: 546 , Special Notes: doi: 10.3390/brainsci12050546. , Word Count: 162

Transcutaneous auricular vagus nerve stimulation (taVNS) is a novel non-invasive treatment option for different diseases and symptoms, such as epilepsy or depression. Its mechanism of action, however, is still not fully understood. We investigated short-term taVNS-induced changes of local and global properties of EEG-derived, evolving functional brain networks from eighteen subjects who underwent two 1 h stimulation phases (morning and afternoon) during continuous EEG-recording. In the majority of subjects, taVNS induced measurable modifications of network properties. Network alterations induced by stimulation in the afternoon were clearly more pronounced than those induced by stimulation in the morning. Alterations mostly affected the networks' topology and stability properties. On the local network scale, no clear-cut spatial stimulation-related patterns could be discerned. Our findings indicate that the possible impact of diurnal influences on taVNS-induced network modifications would need to be considered for future research and clinical studies of this non-pharmaceutical intervention approach.

Keywords: biological rhythms; epilepsy; functional brain networks; transcutaneous auricular vagus nerve stimulation.

PMID: 35624933 DOI: 10.3390/brainsci12050546