New procedure of high-frequency repetitive transcranial magnetic stimulation for central neuropathic pain: a placebo-controlled randomized crossover study

Abstract

Repetitive transcranial magnetic stimulation (rTMS) is a procedure increasingly used to treat patients with central neuropathic pain, but its efficacy is still under debate. Patients with medically refractory chronic central neuropathic pain were included in 2 randomized phases (active/sham), separated by a wash-out period of 8 weeks. Each phase consisted of 4 consecutive rTMS sessions and a final evaluation session, all separated from one another by 3 weeks. High-frequency (20 Hz) rTMS was delivered over the primary motor cortex (M1) contralateral to the patient's pain using a neuronavigated robotic system. Patients and clinicians assessing outcomes were blinded to treatment allocation during the trial. The primary outcome measured the percentage of pain relief (%R) from baseline. Secondary outcomes were VAS score, Neuropathic Pain Symptom Inventory, analgesic drug consumption, and quality of life (EQ-5D). Thirty-six patients performed the entire study with no adverse effects. The analgesic effect for the main criterion (%R) was significantly higher in the active (33.8% confidence interval [CI]: [23.88-43.74]) than in the sham phase (13.02% CI: [6.64-19.76]). This was also the case for the secondary outcome VAS (−19.34% CI: [14.31-25.27] vs −4.83% CI: [1.96-8.18]). No difference was observed for quality of life or analgesic drug consumption. Seventeen patients (47%) were identified as responders, but no significant interaction was found between clinical and technical factors considered here and the analgesic response. These results provide strong evidence that 3 weeks spaced high-frequency rTMS of M1 results in a sustained analgesic effect and support the clinical interest of this stimulation paradigm to treat refractory chronic pain.

Neuromodulation for Pain Management in the Inpatient Setting: A Narrative Review

“…For central neuropathic pain (CNP), rTMS has been successfully applied to the M1 of the hemisphere contralateral to the pain site. Most recently, Quesada et al [37] demonstrated an analgesic effect of rTMS on CNP patients while using a longer stimulation period than any other study before it (roughly two months versus one to two weeks). Instead of utilizing the standard daily treatment approach, this study looked at the effects of "4 consecutive rTMS sessions over the course of 2 months."…”

Analgesic Effects of Repetitive Transcranial Magnetic Stimulation at Different Stimulus Parameters for Neuropathic Pain: A Randomized Study

“…Stimulation of the primary motor cortex (M1) using repetitive transcranial magnetic stimulation (rTMS) is a noninvasive, safe method of stimulating the brain, [9][10][11] and several studies have investigated the analgesic effects of rTMS for various refractory disorders using different stimulation intensities, frequencies, number of pulses, and number of sessions. [12][13][14][15][16][17][18] We previously reported that M1 was a more effective stimulation target than other cortices, 19 high-frequency (5-or 10-Hz) rTMS was more effective than low-frequency (1-Hz) rTMS, 14 and the effects of a single session of rTMS were short-lasting. 20 Moreover, in our pilot randomized, blinded, controlled, crossover trial of patients with neuropathic pain in seven centers in Japan, ten daily rTMS treatments produced transient, modest pain relief.…”

Repetitive transcranial magnetic stimulation: an innovative medical therapy

“…It has been shown that rTMS is promising treatment option for many neuropsychiatric conditions like depression, 2,24,25 OCD, 28 BD, 36,37 negative symptoms 29 and auditory hallucinations 30,31 in schizophrenia, addiction,s [33][34][35] anxiety and anxiety related disorders, [39][40][41] fibromyalgia, 44,45 chronic pain, 42,43 and dementia/Alzheimer's disease. [46][47][48][49] It is also very important that many studies reported that rTMS causes significant improvement of cognition.…”

“…42 A recent study showed that four consecutive HF-rTMS sessions (20 Hz ) every 3 weeks in the primary motor cortex have as a result a sustained analgesic effect. 43 HF-rTMS over the primary motor cortex in patients with fibromyalgia produce positive long-lasting improvements in their quality of life and reduction of chronic pain. rTMS is an effective treatment for fibromyalgia patients without adverse effects on pain and mood levels.…”