Identifying potential scalp acupuncture targets for chronic pain and comorbid disorders using functional and anatomical connectivity of critical deep brain structures

Scalp acupuncture is an innovative approach that integrates acupuncture needling stimulation with the modern understanding of brain function. In recent decades, scalp acupuncture has been applied to treat chronic pain and has achieved promising results. This study aimed to identify potential brain surface targets for scalp acupuncture based on the functional and anatomical connectivity of the hippocampus, amygdala, and nucleus accumbens, three deep brain structures that are believed to play an important role in the pathophysiology of chronic pain, as well as multiple comorbid psychiatric and neurological disorders. Resting-state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) datasets from 119 healthy participants were included in our analysis. We found that the medial prefrontal cortex (mPFC), corresponding to the acupoints EX-HN3 (Yintang) / BL2 (Cuanzhu), is functionally and anatomically connected to all three subcortical regions, while the precuneus, corresponding to the acupoints GV19 (Houding) / GV20 (Baihui) and the MS12 scalp acupuncture line, is connected to the hippocampus and amygdala. Our results suggest that the mPFC and precuneus, two key hubs of the default mode network (DMN), and other cortical areas distributed at the prefrontal, parietal, and temporal cortices may hold potential as novel targets for scalp acupuncture in the treatment of chronic pain and its comorbidities. These identified locations may also be used for the treatment of psychiatric and neurological disorders, such as anxiety, depression, insomnia, and cognitive decline, in which the three corresponding deep brain structures play a crucial role.