Treatment of central neuropathic pain by rTMS associated to self-rehabilitation of imagined movement or mirror therapy

Abstract

Neuropathic pain are frequent and often drug resistant in patients with lesion of central nervous system. It has an important impact on quality of life. The aim of this study was to assess the efficacy of rTMS protocol associated with an education to self-exercise of imagined movement or mirror therapy among patients with central neuropathic pain (CNP). Between December 2014 and August 2016, 39 patients with CNP were included in the study. Exclusion criteria were contraindication to rTMS: epileptic seizure or contraindication to magnetic field. We recorded age, gender, and disease and pain duration. A DN4 score (defining the CNP) and a BPI score (assessing pain and impact of pain on life activities) were performed at day 0, 48 hours after a first rTMS session, at the beginning and at the end of 5 days with a daily rTMS session, then one month (M1), three month (M3) and six month (M6) later. A first rTMS session was realized at day 0 for testing tolerance to magnetic stimulation. Then an rTMS session was performed each a day during 5 days, associated with an education to imagined movement or mirror therapy regarding the impairment of patients. Back home, patients were engaged to continue daily self-rehabilitation with imagined movement or mirror therapy. The primary outcome was a decreasing of the most intense pain of at least 2 points, defining well responders. Twenty-six male and 13 women, 56.5 years old, with CNP from 7.5 years on average, were included. Seventeen had a stroke, 16 were spinal cord injury, 6 had another central neuropathic disease. Twelve patients finished the all study. There was 30.6% of well responders at 48 hours, 35.5% at M1, 32% at M3 and 25% at M6. The distribution of the most intense pain was significantly shifted after five days of stimulation and during at least 3 months (Kruskal test, P < 0.001). There was a significant association between results at 48 hours and at M1 and M3, as well as between pain duration and results at M3 (Chi 2 , P < 0.001). This study show that rTMS associated with imagined movement or mirror therapy is a promising treatment to reduce CNP with an effect during at least 3 months.