Effects of repeated transcranial magnetic stimulation in the dorsolateral prefrontal cortex versus motor cortex in patients with neuropathic pain after spinal cord injury: a study protocol

Abstract

IntroductionNeuropathic pain is one of the common complications of spinal cord injuries (SCI), which will slow down the recovery process and result in lower quality of life. Previous studies have shown that repeated transcranial magnetic stimulation (rTMS) of the motor cortex (M1) can reduce the average pain and the most severe pain of neuropathic pain after SCI. The dorsolateral prefrontal cortex (DLPFC) area is a common target of rTMS. Recently, a few studies found that rTMS of DLPFC may relieve the neuropathic pain of SCI. Compared with the M1 area, the efficacy of rTMS treatment in the DLPFC area in improving neuropathic pain and pain-related symptoms in patients with SCI is still unclear. Therefore, our study aims to evaluate the non-inferiority of rTMS in the DLPFC vs M1 in patients with neuropathic pain after SCI, in order to provide more options for rTMS in treating neuropathic pain after SCI.Methods and analysisWe will recruit 50 subjects with neuropathic pain after SCI. They will be randomly assigned to the DLPFC- rTMS and M1-rTMS groups and be treated with rTMS for 4 weeks. Except for the different stimulation sites, the rTMS treatment programmes of the two groups are the same: 10 Hz, 1250 pulses, 115% intensity threshold, once a day, five times a week for 4 weeks. VAS, simplified McGill Pain Questionnaire, Spinal Cord Injury Pain Date Set, Pittsburgh Sleep Quality Index and Hamilton Anxiety Scale will be evaluated at baseline, second week of treatment, fourth week of treatment and 4 weeks after the end of treatment. And VAS change will be calculated.Ethics and disseminationThe Ethics Committee of the Affiliated Hospital of Southwest Medical University has approved this trial, which is numbered KY2020041. Written informed consent will be provided to all participants after verification of the eligibility criteria. The results of the study will be published in peer-reviewed publications.Trial registration numberChiCTR2000032362.

Repetitive transcranial magnetic stimulation regulates neuroinflammation, relieves hyperalgesia and reverses despair‐like behaviour in chronic constriction injury rats

“…Moreover, it may be necessary to observe the effects between the left DLPFC and M1 in pain management (Brighina et al, 2011). Previously, we have published a study protocol titled 'Effects of repeated transcranial magnetic stimulation in the dorsolateral prefrontal cortex versus motor cortex in patients with neuropathic pain after spinal cord injury: a study protocol', a single-blind randomized controlled trial to observe the non-inferiority of rTMS in DLPFC and M1 in patients with NP after SCI (Trial registration number: ChiCTR2000032362) (Huang et al, 2022).…”

Research progress on the application of transcranial magnetic stimulation in spinal cord injury rehabilitation: a narrative review

“…NP was significantly alleviated after ten courses of treatment; the mechanism of pain relief may be related to the activation of the anterior cingulate gyrus and pain control circuits as well as the release of endogenous opioids during rTMS ( 12 , 80 ). However, current research findings cannot explain the best target of rTMS for NP treatment, and a comparative study on the effects of M1 and prefrontal cortex stimulation is in progress ( 73 ).…”

Choosing the optimal target area for repeated transcranial magnetic stimulation in treating neuropathic pain in spinal cord injury patients: a comparative analysis

“…However, there is a dearth of studies that have directly compared the analgesic effects produced by these two stimulus targets. Notably, Huang et al ( 7 ) reported a protocol to examining the analgesic effect of these stimulus targets on individuals with SCI-NP, yet the study remained in the experimental phase and did not furnish conclusive evidence for the application in clinical settings.…”