Spinal cord stimulation (SCS) device recently made news [1] when FDA expanded the indication for Abbott Laboratories’ SCS device to include treatment of chronic back pain in patients who have not had, or are not eligible for, back surgery, the company has announced. This article is going to provide a brief review into SCS device’s efficacy, adverse effects, and current markets in Asia.
Spinal cord stimulation has been well established as a safe and effective treatment of pain derived from a wide variety of aetiologies [2]. Randomized clinical trials for failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), and refractory angina pectoris (RAP) suggest that SCS has successful outcomes for symptom control. Here is a guideline published in 2008 and reviewed in 2014 from UK’s National Institute for Health and Care Excellence (NICE) [3]:
1.1 Spinal cord stimulation is recommended as a treatment option for adults with chronic pain of neuropathic origin who:
- continue to experience chronic pain (measuring at least 50 mm on a 0–100 mm visual analogue scale) for at least 6 months despite appropriate conventional medical management, and
- who have had a successful trial of stimulation as part of the assessment specified in recommendation 1.3.
1.2 Spinal cord stimulation is not recommended as a treatment option for adults with chronic pain of ischaemic origin except in the context of research as part of a clinical trial. Such research should be designed to generate robust evidence about the benefits of spinal cord stimulation (including pain relief, functional outcomes, and quality of life) compared with standard care.
1.3 Spinal cord stimulation should be provided only after an assessment by a multidisciplinary team experienced in chronic pain assessment and management of people with spinal cord stimulation devices, including experience in the provision of ongoing monitoring and support of the person assessed.
1.4 When assessing the severity of pain and the trial of stimulation, the multidisciplinary team should be aware of the need to ensure equality of access to treatment with spinal cord stimulation. Tests to assess pain and response to spinal cord stimulation should take into account a person’s disabilities (such as physical or sensory disabilities), or linguistic or other communication difficulties, and may need to be adapted.
1.5 If different spinal cord stimulation systems are considered to be equally suitable for a person, the least costly should be used. Assessment of cost should take into account acquisition costs, the anticipated longevity of the system, the stimulation requirements of the person with chronic pain and the support package offered.
1.6 People who are currently using spinal cord stimulation for the treatment of chronic pain of ischaemic origin should have the option to continue treatment until they and their clinicians consider it appropriate to stop.
The guidelines are designed based on multiple randomized clinical trials (RCT) over the past decades. The primary outcomes of the studies involve a variety of factors, including 50% pain relief, quality of life index, daily function index and health care resource use. The SCS intervention was compared with other forms of traditional intervention such as physiotherapy, pain medication (mainly opioid), and invasive surgery. The review [2] published by Rock et al. in 2018 indicated that all of the RCTs ended up with the conclusion that SCS is superior to the traditional form of intervention for patients with chronic back pain in terms of the above-mentioned primary outcomes. Meanwhile, another review article [4] published by Gupta et al. in 2020 summarized studies on the use of SCS and reduction in opioid medication, with all of them achieving substantial overall reduction in the cohort.
So far, there are two types of waveform used by SCS devices. Traditional systems deliver continuous stimulation at low frequency around 50 Hz and provide pain relief together with paraesthesia. However, over the past decades, a variety of different waveforms (tonic, burst, and/or different frequencies) came to market each with its own unique features [2, 5-7]
Table 1 Results from RCTs of various waveforms for spinal cord stimulation, adapted from Rock et al. published on Neurosurgery Clinics of North America
| First Author, Year | Exposures | Diagnosis | Main Findings |
| Yearwood et al, 2010 | Wide range (50–1000 μs); n = 19 | Neuropathy/radiculopathy; CRPS | 7/19 patients selected new pulse width programming and achieved significantly increased paraesthesia-pain overlap |
| Perruchoud et al, 2013 | High vs sham; n = 33 | Chronic low back pain | High frequency was equivalent to sham for improvement of pain and QoL outcomes |
| Washburn et al, 2014 | Constant current vs constant voltage; n = 30 | FBSS; radiculopathies; CRPS | More patients preferred constant voltage, which produced larger decrease in pain scores |
| Van Havenbergh et al, 2015 | 500 Hz vs 1000 Hz; n = 15 | FBSS; radiculopathies; CRPS | No significant difference between two modes of stimulation |
| North et al, 2016 | Supraperception vs subperception; n = 22 | Chronic pain | Subperception provided greater pain relief than paraesthesia-based SCS at lower frequencies, suggesting that 1-kHz subperception stimulation is an effective alternative |
| Kapural et al, 2016 | HF10 therapy vs traditional low-frequency; n = 179 | Chronic intractable pain of the trunk or limbs | HF10 therapy exhibits a long-term superiority to traditional SCS in treating back and leg pain |
| Tjepkema-Cloostermans et al, 2016 | Burst vs tonic; n = 40 | Neuropathic pain in lower limbs | Burst stimulation was more effective than tonic, but therapeutic range of amplitudes requires individual assessment |
| Kriek et al, 2017 | Standard 40 Hz vs 500 Hz vs 1200 Hz vs burst vs placebo; n = 29 | CRPS | Pain reduction was found in all settings compared with placebo but the 4 settings did not differ from each other |
| Kinfe et al, 2016 | Burst vs HF10; n = 16 | FBSS | 6/8 HF10 and 8/8 burst patients experienced significant back pain reduction; both were safe and effective in treating intractable FBSS patients |
| Deer et al, 2018 | Tonic vs burst; n = 100 | FBSS; radiculopathies | 70.8% of the subjects preferred burst over tonic; burst provided superior pain relief compared with tonic |
In recent decade, due to its clinically proved efficacy and easy-to-use feature, the market has boomed with a variety of brand for consumers to choose from, some well-known ones in Asia include:
- Medtronic: Medtronic is a leading medical device company that manufactures various healthcare products, including spinal cord stimulation systems. They offer a range of SCS devices (VANTA, INTELLIS) designed to manage chronic pain.
- Abbott (formerly St. Jude Medical): Abbott is another prominent medical device company that offers spinal cord stimulation systems. They provide innovative SCS devices (Proclaim Plus, Proclaim XR) designed to address chronic pain conditions.
- Boston Scientific: Boston Scientific is a multinational medical technology company that manufactures and markets a wide range of medical devices, including spinal cord stimulators. Their SCS devices (Precision Plus, Spectra WaveWriter) aim to provide pain relief and improve quality of life.
- Nevro: Nevro Corporation is a company focused on developing and commercializing innovative spinal cord stimulation systems. Their SCS devices (HFX iQ) utilize high-frequency stimulation to target chronic pain.
Different medical systems might subsidize different brands for specific indications, patients are always encouraged to consult their treating team on the best type of SCS designed for their need. More dynamic and combined waveforms for SCS are new areas of research in the field, with more promising products to be released for consumers soon.
Reference
1. FDA OKs Spinal Cord Stim Devices for Chronic Back Pain [Internet]. Medscape. 2023 [cited 2023 May 21]. Available from: https://www.medscape.com/viewarticle/992053?ecd=WNL_trdalrt_pos1_ous_230518&uac=461279BG&impID=5439765
2. Rock AK, Truong H, Park YL, Pilitsis JG. Spinal Cord Stimulation. Neurosurgery Clinics of North America. 2019 Apr;30(2):169–94.
3. Guidance | Spinal cord stimulation for chronic pain of neuropathic or ischaemic origin | Guidance | NICE [Internet]. www.nice.org.uk. Available from: https://www.nice.org.uk/guidance/ta159/chapter/1-Guidance
4. Gupta M, Abd-Elsayed A, Knezevic NN. Improving care of chronic pain patients with spinal cord stimulator therapy amidst the opioid epidemic. Neurological Sciences. 2020 May 4;41(10):2703–10.
5. Baranidharan G, Edgar D, Bretherton B, Crowther T, Lalkhen A-G, Fritz A-K, Vajramani G. Efficacy and Safety of 10 kHz Spinal Cord Stimulation for the Treatment of Chronic Pain: A Systematic Review and Narrative Synthesis of Real-World Retrospective Studies. Biomedicines. 2021; 9(2):180. https://doi.org/10.3390/biomedicines9020180
6. Megía García A, Serrano-Muñoz D, Taylor J, Avendaño-Coy J, Gómez-Soriano J. Transcutaneous Spinal Cord Stimulation and Motor Rehabilitation in Spinal Cord Injury: A Systematic Review. Neurorehabil Neural Repair. 2020;34(1):3-12. doi:10.1177/1545968319893298
7. Karri J, Orhurhu V, Wahezi S, Tang T, Deer T, Abd-Elsayed A. Comparison of Spinal Cord Stimulation Waveforms for Treating Chronic Low Back Pain: Systematic Review and Meta-Analysis [published correction appears in Pain Physician. 2022 Mar;25(2):221]. Pain Physician. 2020;23(5):451-460.
