Treating low back pain with combined cerebral and peripheral electrical stimulation: A randomized, double-blind, factorial clinical trial

Abstract

Background: Recent evidence suggests that chronic low back pain is associated with plastic changes in the brain that can be modified by neuromodulation strategies. This study investigated the efficacy of transcranial direct current stimulation (tDCS) combined simultaneously with peripheral electrical stimulation (PES) for pain relief, disability and global perception in patients with chronic low back pain (CLBP). Methods: Ninety-two patients with CLBP were randomized to receive 12 sessions on nonconsecutive days of anodal tDCS (primary motor cortex, M1), 100 Hz sensory PES (lumbar spine), tDCS + PES or sham tDCS + PES. Pain intensity (11-point numerical rating scale), disability and global perception were applied before treatment and four weeks, three months and six months post randomization. Results: A two points reduction was achieved only by the tDCS + PES (mean reduction [MR] = −2.6, CI95% = −4.4 to −0.9) and PES alone (MR = −2.2, CI95% = −3.9 to −0.4) compared with the sham group, but not of tDCS alone (MR = −1.7, CI95% = −3.4 to −0.0). In addition to maintaining the analgesic effect for up to three months, tDCS + PES had a higher proportion of respondents in different cutoff points. Global perception was improved at four weeks and maintained three months after treatment only with tDCS + PES. None of the treatments improved disability and the affective aspect of pain consistently with pain reduction. Conclusion: The results suggest that tDCS + PES and PES alone are effective in relieving CLBP in the short term. However, only tDCS + PES induced a long-lasting analgesic effect. tDCS alone showed no clinical meaningful pain relief. Significance: Transcranial direct current stimulation combined simultaneously with PES leads to a significant and clinical pain relief that can last up to three months in chronic low back pain patients. For this article, a commentary is available at the Wiley Online Library.