The effect of different transcranial magnetic stimulation protocols on pain scores in patients with neuropathic pain: a systematic review and meta-analysis

Objective To evaluate the effects of various transcranial magnetic stimulation (TMS) parameters—including stimulation duration, intensity, pulse number, frequency, and target region—on pain scores in patients with neuropathic pain (NP). Methods Randomized controlled trials (RCTs) assessing the effects of TMS on NP were identified through searches of PubMed, Embase, Web of Science, and the Cochrane Library. Data were analyzed using Stata 18.0 with a random-effects model. Meta-regression, subgroup, sensitivity, and publication bias analyses were also performed. Results A total of 14 studies met the eligibility criteria and were included in the meta-analysis. Overall, the pooled findings showed that rTMS was associated with significant improvements in pain outcomes, as reflected by reductions in VAS scores (SMD = -0.86, 95% CI: -1.51 to -0.22, P = 0.01) and SF-MPQ scores (MD = -5.79, 95% CI: -6.36 to -5.22, P 0.001) in patients with NP. By contrast, no significant effect was detected for NRS scores (MD = -0.41, 95% CI: -1.07 to 0.25, P = 0.22). Further subgroup analyses suggested that studies characterized by a shorter intervention period (2 weeks), fewer total pulses (2000), higher stimulation frequency (≥10 Hz), and lower motor threshold (90% RMT) were more likely to report significant reductions in VAS scores. Nevertheless, none of these subgroup comparisons demonstrated a statistically significant difference when compared with their respective reference categories, including intervention period ≥2 weeks, total pulse number ≥2000, stimulation frequency 10 Hz, and motor threshold ≥90% RMT. In contrast, stimulation delivered to non-M1 targets also produced a significant decrease in VAS scores, and the between-subgroup comparison indicated a significant difference relative to stimulation over the M1 region. Conclusion rTMS is effective in reducing VAS pain scores in patients with NP. However, given the limited sample size, further large-scale randomized controlled trials are needed to confirm these results. Systematic review registration https://www.crd.york.ac.uk/prospero/ , identifier CRD420251013132.