Chronic Mechanical Low Back Pain and Restorative Neurostimulation

In most cases, back pain begins as a simple strain or sprain of the small vertebral joints. To prevent this pain, the brain automatically responds by limiting muscle activation in the painful area. The reduced muscle activation worsens stability in the lower back, which then causes overuse and further wear and tear on the vertebral joints, leading to a continuous cycle of pain, worsening muscle control and increasing muscle breakdown. If this pain is recurrent or persists for months, it is referred to as chronic pain. One of the recognized causes of chronic back pain is the nervous system's impaired control of the muscles responsible for dynamic stabilization of the spine in the lower back. Reactivating these muscles is an important step in breaking the cycle of chronic back pain and muscle breakdown.

The best candidates for restorative neurostimulation are adults with severe, physically limiting, chronic, mechanical and axial lower back pain back pain (predominantly nociceptive pain, Numeric Rating Scale (NRS) ≥ 6, Oswestry Disability Index (ODI) ≥ 21% and severely impaired quality of life) as well as patients with persistent pain after unsuccessfully performed conventional treatment methods such as: medications, physical therapy, and no indication for back surgery, or previous back surgery at the level / or below T8.

To (re)activate and train one of the most important stabilizing muscles of the lower back, the multifidus muscle, two self-anchoring leads are placed adjacent to the medial branch of the dorsal ramus and are connected to a small, implantable, electronic device, similar to a pacemaker. The therapy is usually performed independently twice a day for 30 minutes each time. With a small hand-held device, comparable to a remote control, patients can start and stop the therapy themselves at any time. During the treatment, patients feel the muscles in their lower back contract and relax. Over time, the system assists in regaining control of the stabilizing muscles in lower back. However, it cannot be seen as an alternative to exercise and movement in everyday life. Rather, it is a treatment option for patients to address the cause of functional instability in addition to relieving pain.

It seems that as early as 4 months after the system implantation there is a clinically meaningful benefit (1). In this study, the treatment satisfaction questionnaire was answered as “Definitely satisfied” in 78% of participants and the Clinician Global Impression (CGI) was “Much better” in 73%. Of 37% participants on opioids at baseline, 28% had discontinued their use. Another study on 53 participants at one year follow-up showed that 57% had a Minimal Clinically Important Difference (MCID) of ≥2-point in NRS, 60% in ODI and 81% in Quality of Life (EQ-5D) (2). According to another recently published prospective, single-arm trial performed at nine sites in the United Kingdom, Belgium, and Australia, patients completing year 4 follow-up had a clinically meaningful improvement of ≥2 points in NRS, 76% of ≥10 points in ODI, and 62.5% in both NRS and ODI (3). Ninety-seven percent were (very) satisfied with treatment. However, the success of each therapy varied from patient to patient.

References:

1. Gilligan C, Volschenk W, Russo M, Green M, Gilmore C, Mehta V, Deckers K, De Smedt K, Latif U, Georgius P, Gentile J, Mitchell B, Langhorst M, Huygen F, Baranidharan G, Patel V, Mironer E, Ross E, Carayannopoulos A, Hayek S, Gulve A, Van Buyten JP, Tohmeh A, Fischgrund J, Lad S, Ahadian F, Deer T, Klemme W, Rauck R, Rathmell J, Levy R, Heemels JP, Eldabe S, ReActiv8-B investigators. An implantable restorative-neurostimulator for refractory mechanical chronic low back pain: a randomized sham-controlled clinical trial. Pain. 2021 Oct 1;162(10):2486-2498.

2. Deckers K, De Smedt K, Mitchell B, Vivian D, Russo M, Georgius P, Green M, Vieceli J, Eldabe S, Gulve A, van Buyten JP, Smet I, Mehta V, Ramaswamy S, Baranidharan G, Sullivan R, Gassin R, Rathmell J, Cilligan C. New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial. Neuromodulation. 2018 Jan;21(1):48-55. doi: 10.1111/ner.12741. Epub 2017 Dec 15.

3. Mitchell B, Deckers K, De Smedt K, Russo M, Georgius P, Green M, Gulve A, van Buyten JP, Smet I, Mehta V, Baranidharan G, Rathmell J, Gilligan C, Goss B, Eldabe S. Durability of the Therapeutic Effect of Restorative Neurostimulation for Refractory Chronic Low Back Pain. Neuromodulation. 2021 Aug;24(6):1024-1032. doi: 10.1111/ner.13477. Epub 2021 Jul 9.

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Restorative neurostimulation is an emerging therapy aimed at reducing pain and disability from chronic mechanical low back pain (LBP) by improving the function of muscles that stabilize the lumbar spine . . .


Nov. 7, 2021
Georgios K. Matis MD, MSc, PhD, FINR(CH)
Senior Consultant
Department of Stereotactic & Functional Neurosurgery, University Hospital of Cologne, Cologne, Germany