Neural mechanisms of acupuncture for peripheral facial nerve palsy: A protocol for systematic review and meta analysis

Peripheral facial nerve palsy (PFNP) is a cranial neuropathy that occurs when the seventh facial nerve is damaged. PFNP seriously affects patients’ quality of life, and approximately 30% of patients suffer from sequelae, such as unrecovered palsy, synkinesis, facial muscle contracture, and facial spasm. Many studies have confirmed the effectiveness of acupuncture for the treatment of PFNP. However, the specific mechanism remains unclear and needs to be further explored. Therefore, the purpose of this systematic review is to investigate the neural mechanisms underlying acupuncture treatment for PFNP using neuroimaging methods. METHODS: We will search all published studies from inception to March 2023 using the following databases: MEDLINE, Cochrane Library, EMBASE, CNKI, KMBASE, KISS, ScienceON, and OASIS. All clinical studies evaluating the effectiveness of acupuncture for treating PFNP using functional neuroimaging will be selected without language restrictions. Two reviewers will independently conduct the study selection, data extraction, and risk of bias assessment, according to a predetermined protocol. The outcomes, including the types of functional neuroimaging techniques, brain function alterations, and clinical outcomes, such as the House-Brackmann scale and Sunnybrook Facial Grading System, will also be analyzed. Coordinate-based meta-analysis and subgroup analyses will be performed if possible. RESULTS: This study will analyze the effect of acupuncture on brain activity alterations and clinical improvement in patients with PFNP using functional neuroimaging. CONCLUSION: This study will provide a comprehensive summary and help elucidate the neural mechanisms of acupuncture treatment for PFNP. PROSPERO REGISTRATION NUMBER: CRD42022321827.