Introduction

In a pilot study we showed that it is possible to generate pleasant and pain relieving muscle stimulation in the back by using low frequency SCS stimulation (MuscleSCS). In this following study we wanted to examine whether this technique can improve the treatment of lower back pain.

Materials / Methods

Patients with chronic low back pain had an SCS system (lamitrode) implanted after a trial phase and were then randomly treated with only Burst SCS as defined by De Ridder stimulation, only muscle stimulation or Burst SCS as defined by De Ridder and muscle stimulation combined for 2 weeks respectively.
Thereafter, the patients were treated for another 4.5 months with one of the 3 methods (cross-over possible). Pain ratings (Visual Analogue Scale VAS) were recorded daily, and Questionnaires (Pain Disability Index, PDI; Pain Catastrophizing Scale, PCS; Brief Pain Inventory, BPI) were used at baseline, at 3 and at 6 months.

Results

This is a prospective, multicentric, single-blinded, randomized crossover study. We included 58 patients (9 dropouts) (25 females, mean age 62.3 yrs). All 3 stimulation methods, including muscle stimulation alone, showed a highly significant pain relief when compared to the baseline value (p=0.001). The combined application of Burst SCS as defined by De Ridder with muscle stimulation showed the best results (p=0.032) (Fig.1). PDI, PCS and BPI improved significantly during this treatment. No serious adverse events occurred during this study. 75.5% of the subjects experienced an improvement in their pain as a result of this muscle stimulation.

Figure 1:

A bar graph shows the mean pain scores during study phase 1. The combined use (BM) of Burst SCS as defined by De Ridder (B) and MuscleSCS (M) showed the best results.

Discussion

SCS can adequately treat back pain [1]. So far, however, it has not been possible to adequately treat muscle pain with SCS neuromodulation. However, with low-frequency stimulation of 2-8 Hertz it is possible to reach the muscles by directly stimulating the motor neurons in the anterior horn of the spinal cord. This type of stimulation triggers a massage-like effect in the patient's muscles, which most patients describe as pleasant and pain-relieving.

Conclusions

This study showed that the combined use of SCS and additional low frequency muscle stimulation (MuscleSCS) could significantly improve the outcome of patients suffering from chronic back pain.

References

Eckermann JM, Pilitsis JG, Vannaboutathong C, Wagner BJ, Province-Azalde R, Bendel MA. Systematic Literature Review of Spinal Cord Stimulation in Patients With Chronic Back Pain Without Prior Spine Neuromodulation. 2021 Aug 18

Learning Objectives

MuscleSCS can further improve the treatment of back pain.