Non-invasive brain stimulation in chronic pelvic pain: a systematic review

Chronic pelvic pain (CPP) is increasingly recognized as a disorder of altered central pain processing, providing a strong rationale for non-invasive brain stimulation (NIBS) as a therapeutic approach. However, use of transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) for CPP remains uncertain. This systematic review aimed to evaluate the evidence for NIBS in CPP.

A comprehensive search of PubMed, Web of Science, Ovid MEDLINE, Embase, Scopus, and Cochrane CENTRAL was conducted till July 2026. Studies evaluating tDCS or rTMS in adults with CPP were included. Cochrane RoB-2 and ROBINS-I were used to assess methodological quality. Owing to a low number of studies, substantial clinical and methodological heterogeneity, a structured narrative approach was used.

Fifteen studies involving 295 participants, of whom 264 completed the respective studies, met the inclusion criteria, including nine tDCS and six rTMS studies. Inter-rater agreement for data extraction was almost perfect (Cohen's kappa = 0.878). Considerable heterogeneity was observed across clinical conditions, protocols, comparator interventions, outcome measures, and follow-up durations. Most randomized controlled trials (RCT) were rated at high or some risk of bias. Across studies, tDCS demonstrated favorable effects in some conditions, although findings were inconsistent and benefits beyond the treatment period were not consistently demonstrated. Evidence for rTMS was more limited and heterogeneous.

Current evidence is insufficient to support NIBS for routine CPP care because of methodological limitations, small samples, and substantial heterogeneity in stimulation protocols and populations. Well-designed RCT using standardized intervention protocols and outcome measures are needed.

CRD420251058830.