Mechanism of Transcranial Magnetic Stimulation Therapy for Neuropathic Pain

Neuropathic pain (NP) is a persistent and refractory chronic pain condition resulting from damage or disease of the somatosensory nervous system. Its complex pathogenesis, coupled with low clinical remission rate, significantly impairs the physical and mental well-being of the affected individuals. As a mature non-invasive neuromodulation technique, transcranial magnetic stimulation (TMS) can generate transient magnetic pulses penetrating through the skull, induce changes in cortical neuronal potentials, and affect the function and structure of the nervous system, which can not only alleviate NP-related symptoms, but also improve NP-related emotional disorders. However, there is no consensus on the neurobiological mechanism of TMS-induced analgesia. This study reviews the neurobiological mechanisms of TMS in alleviating NP from the aspects of regulation of synaptic plasticity, functional reorganization of neural network (inducing cortical-cortical functional connectivity and subcortical brain region functional connectivity), sensitivity of afferent nerve fibers, neurotransmitter levels and neuroimmunity based on the mechanism of TMS, in order to provide a basis for the treatment of NP by TMS. However, there are still some shortcomings, such as insufficient in-depth study of synaptic plasticity, the lack of further refinement in the research of the sensitivity of afferent nerve fibers, and the limitation of neuroimmune research. It is necessary to carry out multi-center and large sample studies, explore the mechanism of TMS regula-ting neural network by using new techniques such as cranial electroencephalogram, and promote the application of paired-pulse TMS in clinical research related to NP, so as to provide more reliable evidence for the treatment of NP with TMS.