Daily use of a high-frequency transcutaneous electrical nerve stimulation (hfTENS) device may reduce pain and improve function in patients with chronic low back pain (CLBP), according to a study published in Pain Practice.
Cutaneous stimulation was found to be associated with analgesic benefits in individuals with neuropathic or musculoskeletal pain, but the underlying mechanisms are not well understood. Investigators sought to evaluate the safety and efficacy of an hfTENS device for the treatment of mechanical CLBP.
A total of 68 individuals (mean age, 46.2 years; 60.3% women; 77.9% white; mean pain duration, 13.2 years) with persistent CLBP were enrolled in a prospective randomized controlled trial (Clinicaltrials.gov identifier: NCT02944513) and randomly assigned to receive a daily treatment with hfTENS (n=35; experimental group) or treatment as usual (n=33; control group) for a 3-month period.
Study participants were asked to complete validated questionnaires — including the Brief Pain Inventory, the Pain Disability Inventory, the Pain Catastrophizing Scale, and the Hospital Anxiety and Depression Scale — at baseline, at 6 weeks, and at the end of the study. Quantitative sensory testing (QST) used to determine pressure pain thresholds and temporal summation of pain was also performed on all patients prior to the trial. In addition, study participants were asked to record daily pain assessments, and participants in the experimental group were asked to track hfTENS usage using smartphone applications. Weekly phone interviews were conducted by a research assistant in both groups to ascertain clinical and functional progress using a 0 to 10 scale. Multivariate analyses were performed using regression models.
At 3 months, participants in the experimental vs control group reported reduced pain intensity (P <.01), lower activity interference (P <.025), and improved pain catastrophizing (P < .025). Pain-related disability, anxiety, and depression were comparable between groups. No long-term adverse effects associated with hfTENS were reported.
Older individuals (r=0.38), those with longer pain duration (r=0.39), and patients with greater pain sensitivity, as determined with QST, were found to use the hfTENS device more frequently compared with other individuals (P <.025 for all). Patients who reported that hfTENS treatment was particularly helpful had lower pain scores after 12 weeks (P <.025).
Study limitations include a small sample size, short study duration, lack of blinding, and the lack of a control comparator treatment.
“Despite these limitations, these results suggest that a device using high-frequency TENS technology can have a moderate effect in reducing pain and improving quality of life among persons with primary low back pain,” noted the study authors. They recommended that future research involve longer trials with larger samples that focus on the impact of QST results using repeat testing.
This study was funded in part through a grant from NeuroMetrix, Inc.
Jamison RN, Wan L, Edwards RR, Mei A, Ross EL. Outcome of a high-frequency transcutaneous electrical nerve stimulator (hfTENS) device for low back pain: a randomized controlled trial [published online January 12, 2019]. Pain Pract. doi: 10.1111/papr.12764