Effect of acupuncture on pain-emotion related brain regions in patients with cervical spondylosis of cervical type: a fMRI study

Abstract

To observe the changes of functional connectivity of brain pain-emotion regulation region in patients with cervical spondylosis of cervical type by functional magnetic resonance imaging (fMRI). Thirty-two subjects were selected. Of them, 16 patients with cervical spondylosis of cervical type were divided into an observation group and 16 healthy subjects into a control group. The patients in the observation group were treated with acupuncture at Tianzhu (BL 10), Jingbailao (EX-HN 15), Jianzhongshu (SI 15) and ashi points for 30 min. The rest-state fMRI data was collected before and after acupuncture in the observation group. The subjects in the control group received no treatment, and the rest-state fMRI data was collected once. The visual analogue scale (VAS) score before and after treatment and the pain catastrophizing scale (PCS) score before treatment in the observation group were recorded. The resting-state brain functional imaging characteristics between the observation group and control group before treatment, between the observation group before and after treatment, were compared. Based on the brain functional connectivity of region of interest (ROI) the changes of functional connectivity in insula and ventral tegmental area (VTA) in emotional regulation brain region were observed, and the correlation between functional connectivity changes and VAS、PCS scores in patients of the observation group was analyzed. In the observation group, the VAS score was (1.94±1.12) after the treatment, which was lower than (5.62±1.20) before treatment (P<0.05). The PCS score before treatment was (19.18±8.42) in the observation group. Compared with the control group, the areas with increased functional connectivity with insula in the observation group before acupuncture included bilateral dorsolateral prefrontal lobe and right middle cingulate gyrus, and the areas with increased functional connectivity with VTA included right central posterior gyrus and right insula. In the observation group, the connectivity coefficient of left insula and left dorsolateral prefrontal lobe (r=0.438, P<0.05), the connectivity coefficient of right insula and right dorsolateral prefrontal lobe (r=0.483, P<0.05) were positively associated with the VAS score. In the observation group, the connectivity coefficient between the right insula and the right middle cingulate gyrus (r=-0.560, P<0.05), the connectivity coefficient between the right VTA and the right insula (r=-0.525, P<0.05) were negatively associated with the PCS score. After acupuncture, the areas with decreased functional connectivity with insula included bilateral posterior central gyrus, right anterior central gyrus, middle cingulate gyrus and left corpus callosum, while the bilateral suboccipital gyrus and left cerebellum showed increased functional connectivity with right insula. The areas with decreased functional connectivity with VTA included bilateral dorsomedial prefrontal cortex, left anterior cingulate gyrus, right middle temporal gyrus and left anterior cingulate gyrus. After acupuncture in the observation group, the functional connectivity of left VTA left dorsomedial prefrontal cortex and left anterior cingulate cortex (r=-0.548, P<0.05), the functional connectivity of right VTA-bilateral dorsomedial prefrontal cortex and left anterior cingulate cortex (r=-0.547, P<0.05) were negatively associated with the PCS score. Pain involves the formation and expression of "pain-emotion-cognition". Acupuncture can systematically regulate the brain functional connections between cognitive regions such as dorsal prefrontal lobe and anterior cingulate gyrus and emotional regions such as insula and VTA in patients with cervical spondylosis of cervical type, suggesting that acupuncture has a multi-dimensional and comprehensive regulation effect on pain.