The Effect of Noninvasive Brain Stimulation to Reduce Nonspecific Low Back Pain: A Systematic Review and Meta-analysis.

Abstract

We conducted a systematic review/meta-analysis to evaluate noninvasive brain stimulation (NIBS) efficacy to alleviate pain and improve disability in low back pain (LBP). A systematic literature search was performed by a librarian in MEDLINE, Embase, EBM Reviews, CINAHL, and Web of Science databases (last search: January 14, 2021). Data were pooled by the number of sessions and follow-up periods. Independent reviewers performed screening, data extraction, and risk of bias. Pain reduction and disability were used as outcomes. Twelve articles were included in the qualitative synthesis and 8 in the meta-analysis. A single session of NIBS reduced pain compared with sham (standardized mean difference: -0.47; P<0.001; very low-quality evidence). Repeated sessions of NIBS did not impact pain at short-term (mean difference [MD]: -0.31; P=0.23) or midterm (MD: -0.56; P=0.33; moderate quality evidence). Combining NIBS with cointerventions did not influence pain (MD: -0.31; P=0.30; moderate quality evidence). NIBS did not have a statistically significant impact on disability. There is very low-quality evidence suggesting that a single NIBS session reduces LBP intensity. In contrast, there is moderate quality evidence that repeated NIBS sessions or combination with cointervention did not improve pain or disability. Thus, current results do not support NIBS use to treat chronic LBP. Considering that tDCS was tested in 8 of 12 studies with little success, studies focusing on different NIBS techniques or innovative parameters are required to determine their potential to improve pain and disability in chronic LBP.