Jingwei Wang, Zhuqing Huang, Yujie Lu, Ke Sha
Mirror visual feedback relieves TBPI-related chronic neuropathic pain and may partially normalize disordered sensorimotor cortical activation. Its analgesic effect is correlated with the recovery of sensorimotor cortical function, while no significant psychological improvements were seen over the short follow-up. As an easy, affordable non-invasive intervention, MVF exerts preliminary pain-relieving effects for refractory TBPI neuropathic pain.
OBJECTIVE: This study aimed to investigate the clinical efficacy of mirror visual feedback (MVF) therapy in treating neuropathic pain following total brachial plexus injury (TBPI), and to explore its effects on brain structure and functional activation of the sensorimotor cortex using functional magnetic resonance imaging (fMRI).
METHODS: In this prospective single-arm interventional study, 18 right-handed TBPI patients with chronic neuropathic pain were enrolled. All patients received a standardized MVF therapy (20 min/d) for 6 weeks. Pain intensity and psychological status were assessed using the Visual Analogue Scale (VAS), Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), and Symptom Checklist 90 (SCL-90). Structural MRI and task-based fMRI with unilateral and bilateral hand motor tasks were performed at baseline and post-intervention to evaluate gray matter volume (GMV) and sensorimotor network activation. Twenty-five demographically matched healthy volunteers were recruited specifically as neuroimaging reference controls, having no role in the interventional comparison.
RESULTS: Visual Analogue Scale scores decreased significantly (5.917 ± 1.574 to 3.306 ± 2.860, p < 0.001) following MVF therapy, while psychological scales showed no marked changes. Post-treatment GMV increased in the superior temporal gyrus, parahippocampal gyrus, inferior frontal gyrus, and supplementary motor area (SMA). The movement of the affected hand resulted in increased activation in the contralateral primary motor and somatosensory cortices, showing a tendency toward a healthy activation pattern, particularly in non-dominant limb injury patients.
CONCLUSION: Mirror visual feedback relieves TBPI-related chronic neuropathic pain and may partially normalize disordered sensorimotor cortical activation. Its analgesic effect is correlated with the recovery of sensorimotor cortical function, while no significant psychological improvements were seen over the short follow-up. As an easy, affordable non-invasive intervention, MVF exerts preliminary pain-relieving effects for refractory TBPI neuropathic pain.