Reduction of intractable deafferentation pain by navigation-guided repetitive transcranial magnetic stimulation of the primary motor cortex

Abstract

The precentral gyrus (M1) is a representative target for electrical stimulation therapy of pain. To date, few researchers have investigated whether pain relief is possible by stimulation of cortical areas other than M1. According to recent reports, repetitive transcranial magnetic stimulation (rTMS) can provide an effect similar to that of electrical stimulation. With this in mind, we therefore examined several cortical areas as stimulation targets using a navigation-guided rTMS and compared the effects of the different targets on pain. Twenty patients with intractable deafferentation pain received rTMS of M1, the postcentral gyrus (S1), premotor area (preM), and supplementary motor area (SMA). Each target was stimulated with ten trains of 10-s 5-Hz TMS pulses, with 50-s intervals in between trains. Intensities were adjusted to 90% of resting motor thresholds. Thus, a total of 500 stimuli were applied. Sham stimulations were undertaken at random. The effect of rTMS on pain was rated by patients using a visual analogue scale (VAS) and the short form of the McGill Pain Questionnaire (SF-MPQ). Ten of the 20 patients (50%) indicated that stimulation of M1, but not other areas, provided significant and beneficial pain relief (p<0.01). Results indicated a statistically significant effect lasting for 3 hours after the stimulation of M1 (p<0.05). Stimulation of other targets was not effective. The M1 was the sole target for treating intractable pain with rTMS, in spite of the fact that M1, S1, preM, and SMA are located adjacently.

Transcranial Direct Current Stimulation Targeting Primary Motor Versus Dorsolateral Prefrontal Cortices: Proof-of-Concept Study Investigating Functional Connectivity of Thalamocortical Networks Specific to Sensory-Affective Information Processing

“…M1 is commonly targeted because stimulating M1 is believed to modulate lateral thalamic hyperactivity associated with sensory-discriminative information processing (Boggio et al, 2008;Lefaucheur et al, 2006;Tsubokawa et al, 1991aTsubokawa et al, ,b, 1993Yamashiro et al, 1994). Stimulation of other sensorimotor structures, such as the primary somatosensory cortex (S1), premotor, and supplementary motor area have failed to produce similar effects as M1 (Hirayama et al, 2006;Koyama et al, 1993). Although M1 is commonly targeted, benefits of M1 stimulation remain modest and variable (Lefaucheur et al, 2014), suggesting that networks other than the known sensory-discriminative components may be involved (Machado et al, 2013).…”

(343) Dose-response effect of isometric force production on the perception of pain

“…Electrical or magnetic stimulation of primary motor cortex has been associated with analgesia, leading to the suggestion that the primary motor cortex is an entry port for the modulation of pain processing circuits [31]. Animal work has shown that activation of Table 3.…”

Effect of Repetitive Transcranial Magnetic Stimulation on Malignant Visceral Pain

“…It has also been regularly observed that, even in cases of bilateral or midline pain, stimulation on only one side of the brain is sufficient to modulate pain bilaterally [13]. Thus, Hirayama et al showed that relief of neuropathic pain was observed only when targeting M1, but not other areas [14]. Louppe et al [13] previously reported a beneficial analgesic effect of motor cortex stimulation with rTMS in two cases of noncancer pelvic pain [13].…”