Altered brain functional networks after Quchi (LI 11) acupuncture: An EEG analysis

BACKGROUND: As a unique traditional Chinese medicine therapy, the central effect of acupuncture has received increasing attention. Functional brain networks can provide connectivity information among brain regions. OBJECTIVE: The study goal is to explore the regulatory effect of acupuncture on the brain functional network. METHODS: This paper analyzes the electroencephalography (EEG)-based power spectrum and brain functional network elicited by acupuncture at Quchi (LI 11). RESULTS: The power spectrum results showed that acupuncture at LI 11 decreased the energy in the alpha frequency, mainly in the central region, left parietal lobe, left temporal lobe and left frontal lobe. Moreover, functional brain networks converted from the magnitude-squared coherence matrix in the alpha band are reconstructed. The results show that acupuncture did not alter the basic properties of the brain functional connection network. During acupuncture, the average node degree, average clustering coefficient, and small-world property of the brain functional connection network decreased after acupuncture compared with that before it. However, the average characteristic path length increased after acupuncture compared with before. CONCLUSION: Acupuncture at LI 11 altered the brain’s electrical activity. In the meantime, this acupuncture reduced the network’s internal connectivity and information transfer efficiency.