Exploring the therapeutic potential of transcranial direct current stimulation for chronic low back pain: a scoping review

INTRODUCTION: Chronic low back pain (CLBP) is a common disabling condition, inflicting a substantial socioeconomic burden. Given its association with neuroplastic changes, as evidenced by central and peripheral sensitization, neuromodulatory techniques such as transcranial direct current stimulation (tDCS) have emerged as potential treatments. This scoping review aimed to identify and map the existing literature on tDCS studies for CLBP to provide insight into how these studies are conducted, and to address their potential gaps in knowledge. EVIDENCE ACQUISITION: PubMed, Embase, Web of Science, and Cochrane Library were searched for relevant studies from inception to 23 March 2025. Eligible studies included were those examining tDCS alone or with other interventions in adults with CLBP, regardless of the outcome evaluated and included adults with CLBP. The review was conducted using Arksey and O’Malley’s six-stage framework and was guided by the PRISMA for scoping review framework. EVIDENCE SYNTHESIS: Of 134 screened records, 26 studies were included: 23 randomized controlled trials and 3 quasi-experimental studies. Half of the studies (50%) had a low risk of bias while one-third (34.6%) showed a high or serious risk of bias. Outcomes evaluated varied and included clinical, biophysical, biomechanical, and psychosocial measures. There was considerable variability in tDCS treatment protocols across studies. The effectiveness of tDCS was inconsistent, particularly for clinical outcomes, with some studies indicating positive effects while others reported no significant effects. CONCLUSIONS: Overall, this review reveals inconsistent results for tDCS effectiveness in CLBP, likely due to variability in study designs, sample characteristics, treatment protocols, and outcome measures. Future well-designed trials are needed to clarify the therapeutic potential of tDCS for CLBP, particularly in combination with other interventions.