Brain plasticity after peripheral nerve injury treatment with massage therapy based on resting-state functional magnetic resonance imaging

Massage therapy is an alternative treatment for chronic pain that is potentially related to brain plasticity. However, the underlying mechanism remains unclear. We established a peripheral nerve injury model in rats by unilateral sciatic nerve transection and direct anastomosis. The experimental rats were treated over the gastrocnemius muscle of the affected hindlimb with a customized massage instrument (0.45 N, 120 times/min, 10 minutes daily, for 4 successive weeks). Resting-state functional magnetic resonance imaging revealed that compared with control rats, the amplitude of low-frequency fluctuations in the sensorimotor cortex contralateral to the affected limb was significantly lower after sciatic nerve transection. However, amplitudes were significantly higher in the massage group than in a sham-massage group. These findings suggest that massage therapy facilitated adaptive change in the somatosensory cortex that led to the recovery of peripheral nerve injury and repair. This study was approved by the Animal Ethics Committee of Shanghai University of Traditional Chinese Medicine of China (approval No. 201701001) on January 12, 2017.