Is it possible to generate an additional pleasant and pain-relieving muscle stimulation when using a low-frequency...

The combined use of spinal cord stimulation (SCS) and muscle stimulation, in the treatment of chronic pain, using the same probe, could improve the clinical results. However, this technique has not been established as yet. It was our hypothesis that it is possible to generate muscle stimulation by using low frequencies with SCS electrodes and use it to additionally treat chronic back pain.

We generated muscle stimulation in patients with previously implanted SCS electrodes, for the treatment of lower back pain, by using low frequencies (2, 4, 6, and 8 Hz) and different contact combinations of the electrodes. The results were evaluated by using visual inspection (videos), haptic control, surface electromyography (EMG), and sonographic recordings.

This pilot study (17 patients, seven females, age 36-87 years, 11 percutaneous paddle leads, and 6 octrodes) was performed at the Neurosurgical Department of the University of Tuebingen. The most preferred frequencies were 6 Hz (45.5% of percutaneous paddle leads) and 8 Hz (50% of octrodes) at contacts 3&4 or 5&6. The preference of frequencies differed significantly among genders (p = 0.023). Simultaneous EMG and ultrasonic recordings demonstrated the generation of muscle potentials and the stimulation of deeper muscle groups.

In this study, it has been shown that with low-frequency SCS stimulation, pleasant and pain-relieving muscle contractions of the lower and upper back can also be generated. This combined method has been coined by us as "MuscleSCS" technique. Clinical trials are necessary to establish the value of this combined technique and its subtypes.