Therapeutic impact of motor cortex rTMS in patients with chronic neuropathic pain even in the absence of an analgesic response. A case report.

OBJECTIVE:To show that repetitive transcranial magnetic stimulation (rTMS) delivered at high frequency over the motor cortex can improve patients with chronic pain syndrome even if this procedure does not provide an analgesic response. CASE REPORT:A 77-year-old woman presented with drug-resistant chronic neuropathic pain affecting both lower limbs due to segmental spine compression at T9-T10 level. She underwent an rTMS protocol with an induction phase of 12 rTMS sessions during three weeks and a maintenance phase of 3 additional rTMS sessions for 5 weeks. Stimulation was delivered over the vertex using a MCF-B70 coil at 10Hz and 80% of rest motor threshold, with 2000 pulses per session. Assessment was based on pain, quality of life, anxiety-depression, and walking abilities. RESULTS:Although pain intensity remained stable throughout the study period (8/10 on a numerical rating scale), the quality of life (physical and mental components of the SF-36 scale), anxiety and depression scores, and walking capacity dramatically improved at the end of the treatment and up to 6 weeks after the last rTMS sessions. DISCUSSION:This case shows that repeated sessions of high-frequency motor cortex rTMS delivered on the bihemispheric cortical representation of the lower limb muscles can improve daily functioning in patients with chronic neuropathic pain affecting the lower limbs, even in the absence of pain relief. Motor cortex rTMS may have a therapeutic impact in pain patients by acting on different brain circuits and the various induced changes can contribute to overall patient satisfaction in the long-term.