Neurostimulation for Chronic Neuropathic Pain

Educational Objectives

The goal of this program is to improve the management of chronic back pain using spinal cord stimulation (SCS). After hearing and assimilating this program, the clinician will be better able to:

1. Apply evidence-based strategies to the management of chronic back pain using SCS.
2. Differentiate between the various types of SCS systems available for chronic neuropathic pain.

Summary

Introduction: back pain is a leading cause for disability; pain is an electric signal that goes through the body, from receptors in the spine to the brain; a person withdraws or protects themselves when pain is constant; sometimes, the brain’s representation of the pain becomes exaggerated, making the sensation much stronger than it should be; individuals may develop a heightened sensitivity to pain; neuropathic pain is characterized by an abnormally high reaction to pain that is not justified by the actual tissue damage

Pain management: highly individualized; what is “typical” varies greatly based on age, sex, medical history, and the specific condition; the patient’s overall condition and subjective experience of pain must be prioritized; in some cases, eg, L2-L3 disc issues, surgery may not be necessary, even if imaging shows abnormalities; imaging may reveal issues that may not necessarily cause the patient’s pain, eg, disc indentation; focus on treating the patient’s functional limitations and overall well-being

Spinal cord stimulation (SCS): existing treatments for neuropathic pain are often ineffective; SCS involves the implantation of a device that delivers electrical signals to the spinal cord; it does not “cure” the pain but rather disrupts the pain signals traveling to the brain; this creates confusion in the brain, reducing its ability to perceive the pain, similar to background noise interfering with a phone call; SCS may interfere with other sensory signals, leading to potential adverse effects

Evidence: a study by North et al (2005) involved 51 participants and showed significantly higher success rates with SCS (48%) vs repeat surgery (9%); the low success rate of repeat surgery was attributed to incorrect surgical indications and inadequate patient selection; another study showed significantly higher crossover rates in surgical groups with better long-term outcomes and decreased opioid use; SCS reduced opioid use (42%) more than other treatments (13%); the brain releases endorphins to block pain in dangerous situations; chronic opioid use desensitizes the body’s natural pain control mechanisms; SCS helps restore the body’s natural pain management system; Kumar et al (2005; PROCESS study) showed that SCS was effective for failed back surgery syndrome; Deer et al (2024) comparing SCS to conventional medical management showed significant improvements in mental health with SCS at 6 mo; newer high-frequency (10 kHz) SCS devices are more effective (80% success rate at 2 yr) than traditional SCS (50%), likely because they better disrupt pain signals to the brain; back and leg pain respond well to SCS

Indications: SCS is indicated for postlaminectomy syndrome and other unexplained chronic back pain; high-frequency (10 kHz) SCS is significantly more effective than traditional SCS; diabetic peripheral neuropathy, where damaged nerves send faulty pain signals, is another indication for SCS; these patients often rely on visual cues for balance because of nerve damage; SCS disrupts the faulty signals and offers pain relief when nerve repair is not possible

Types: closed-loop spinal cord stimulators are more effective than open-loop systems because they deliver a more consistent signal, regardless of patient activity; Mekhail et al (2024) showed that closed-loop systems achieve ≈80% back and leg pain reduction vs≈50% with open-loop at 12 mo; effectiveness of SCS increases over time, likely because of the brain adapting and becoming less sensitive to pain signals; this suggests SCS may have long-term positive effects on pain processing in the brain; in a sham controlled study, Gulisano et al (2024) confirmed the efficacy of SCS, showing significantly better outcomes (57% improvement) in the treatment group vs the sham group (22%)

Readings

Gulisano HA, Eriksen E, Bjarkam CR, et al. A sham-controlled, randomized trial of spinal cord stimulation for the treatment of pain in chronic pancreatitis. Eur J Pain. 2024;28(9):1627-1639. doi:10.1002/ejp.2315; Kumar K, North R, Taylor R, et al. Spinal cord stimulation vs. conventional medical management: a prospective, randomized, controlled, multicenter study of patients with failed back surgery syndrome (process study). Neuromodulation. 2005;8(4):213-218. doi:10.1111/j.1525-1403.2005.00027.x; Mekhail N, Levy RM, Deer TR, et al. Durability of clinical and quality-of-life outcomes of closed-loop spinal cord stimulation for chronic back and leg pain: a secondary analysis of the evoke randomized clinical trial [published correction appears in JAMA Neurol. 2022 Apr 1;79(4):420. doi: 10.1001/jamaneurol.2022.0022]. JAMA Neurol. 2022;79(3):251-260. doi:10.1001/jamaneurol.2021.4998; Mekhail NA, Levy RM, Deer TR, et al. ECAP-controlled closed-loop versus open-loop SCS for the treatment of chronic pain: 36-month results of the EVOKE blinded randomized clinical trial. Reg Anesth Pain Med. 2024;49(5):346-354. Published 2024 May 7. doi:10.1136/rapm-2023-104751; North RB, Kidd DH, Farrokhi F, et al. Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial. Neurosurgery. 2005;56(1):98-107. doi:10.1227/01.neu.0000144839.65524.e0; Ramanayake RP, Dilanka GV, Premasiri LW. Palliative care; role of family physicians. J Family Med Prim Care. 2016;5(2):234-237. doi:10.4103/2249-4863.192356; Russo M, Brooker C, Cousins MJ, et al. Sustained long-term outcomes with closed-loop spinal cord stimulation: 12-month results of the prospective, multicenter, open-label Avalon study [published correction appears in neurosurgery. 2020 Sep 1;87(3):611. doi: 10.1093/neuros/nyaa332]. Neurosurgery. 2020;87(4):E485-E495. doi:10.1093/neuros/nyaa003; Thomson S, Huygen F, Prangnell S, et al. Appropriate referral and selection of patients with chronic pain for spinal cord stimulation: European consensus recommendations and e-health tool. Eur J Pain. 2020;24(6):1169-1181. doi:10.1002/ejp.1562.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Zarzour was recorded at the 7th Annual New Jersey Neurovascular and Neurosciences Symposium, held November 14, 2024, in Mount Laurel, NJ, and presented by Thomas Jefferson University. For information on upcoming CME activities from this presenter, please visit jefferson.edu. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0.50 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0.50 CE contact hours.

Lecture ID:

NE160602

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.