Repetitive Transcranial Magnetic Stimulation in the Treatment of Central Post-Stroke Pain Syndrome: Evidence Base and Prospects. A Review

Abstract

INTRODUCTION. Central post-stroke pain (CPSP) is a neuropathic pain syndrome that results from damage to the central somatosensory system as a result of a cerebral circulation disorder. Up to half of patients do not achieve a clinically significant reduction in pain intensity when using anticonvulsants and antidepressants. Neuromodulation technologies are an alternative to pharmacotherapy. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation method based on the excitation of neurons in the stimulated area induced by a high-induction alternating magnetic field. The effects of rTMS are mediated through synaptic plasticity-like mechanisms, as well as changes in the secretion of endogenous opioids and dopamine. OBSERVATIONS. The most studied and effective rTMS target is the primary motor cortex contralateral to the localization of pain. Among the other studied targets, a significant effect has been shown only for the stimulation of secondary somatosensory cortex. An effect has been demonstrated for high-frequency protocols, while low-frequency rTMS is not effective. The duration of the effect of one session can reach 3 hours, and a series of sessions up to several weeks. The use of maintenance sessions allows extending the effect up to 1 year. Clinical characteristics of the pain syndrome, parameters of intracortical interactions, and preservation of thalamocortical pathways can be used as predictors of rTMS efficacy. CONCLUSION. Repetitive transcranial magnetic stimulation is a promising and safe method that has an extensive evidence base of effectiveness in CPSP.