Multimodal cerebral imaging study on the effects of "Adjust Zang Dredge Meridian" electroacupuncture on cerebral central sensitization in PDPN patients: a study protocol for a sham-controlled, randomized trial

Background: Painful diabetic peripheral neuropathy (PDPN) has a great impact on an individual's quality of life. The current researchers' previous trial suggested that acupuncture was a promising adjunctive treatment for PDPN. However, the underlying mechanism of action of acupuncture treatment for PDPN is still unclear, especially its effects at the cerebral level. The aim of this trial will be to explore how acupuncture works in treating PDPN by using multimodal cerebral imaging. Method and design: This will be a randomized controlled trial. A total of 150 participants will be recruited and assigned to one of three groups: the healthy group, the DM without PDPN group and the DM with PDPN group. Participants in the DM without PDPN and the DM with PDPN groups will each be further divided between an electroacupuncture group and a sham electroacupuncture group. Participants will receive six treatment sessions per week for 4 weeks. Multimodal cerebral imaging includes resting-state functional magnetic resonance imaging (rs-fMRI), diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS); this neurophysiological testing will be the primary outcome measure. Subjective pain scales and blood analysis will be a secondary outcome measure and will be used to assess the clinical efficacy of the intervention. Multimodal cerebral imaging will be used to detect cerebral activity changes in each treatment group. The clinical data and fMRI data will be analysed for all the groups. Multiple correlation regression analyses will be used to assess the association between changes in cerebral functional activity and the improvement of clinical outcomes after acupuncture treatment. Discussion: This study is based on the results of the researchers' previous study, and using combined clinical and cerebral function changes, it will help evaluate the effects of acupuncture on PDPN. The investigation of acupuncture's central mechanism of action will further expand the understanding of acupuncture treatment of PDPN.