Exploring the Potential Central Regulatory Mechanisms of Acupuncture for Acute-Stage Bell's Palsy: An fMRI-Based Investigation

Xiao-shuang Xu¹Yating Zhang¹Xiao-Wei Li¹Yu-Ling Shu¹Jing-Can Zhang¹Ting-Ting Miao¹Yan-Yan Yang²JUN YANG²Haiping Shi^2*

• ¹Anhui University of Traditional Chinese Medicine, He Fei, China
• ²The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China

Objective: 1This study utilized resting-state functional magnetic resonance imaging (fMRI) to examine changes in brain functional activity following acupuncture treatment for acute Bell's palsy (BP) and to investigate the potential central regulatory mechanisms involved. Methods: A total of 55 patients with acute Bell's facial paralysis (within 1–7 days of onset) were enrolled in the patient group, while 48 individuals without the condition were included as the healthy control group. The patient group received acupuncture therapy at EX-HN16 (Qianzheng), SJ17 (Yifeng), ST2 (Sibai), GB14 (Yangbai), EX-HN4 (Yuyao), SI18 (Quanliao), ST6 (Jiache), ST4 (Dicang), ST8 (Touwei), and bilateral LI4 (Hegu) points on the affected side. Each session lasted 30 min and was administered three times a week (Wednesday, Friday, and Sunday) until day 28 of the disease course. The patient group underwent fMRI scans, House–Brackmann (H-B) grading, Sunnybrook scale evaluation, and Facial Disability Index (FDI) assessment both prior to the initial treatment and on the 28th day. The healthy group received a single fMRI scan after enrollment. MATLAB R2017 software was used to calculate the fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) in patients before and after treatment, as well as in healthy controls. Results: Following treatment, the patient group showed significant improvements in H-B, Sunnybrook, and FDI scores compared to pretreatment levels (P < 0.05), with an overall effective rate of 96.4% (53/55). This study provides preliminary evidence that acupuncture regulates brain function in BP patients. Changes in brain function emphasize that acupuncture treatment may exert a positive effect in BP patients by promoting better coordination between brain regions and enhancing the intensity of regional activity. Conclusion: Acupuncture demonstrates a clear therapeutic effect on acute BP and contribute to clinical symptom improvement. Marked differences in brain functional activity were observed between patients and healthy individuals. The therapeutic effect of acupuncture may be linked to its ability to facilitate functional reorganization in brain regions associated with sensation, movement, and emotion.