Spinal Cord Stimulators: What They Are, How They Work, and When They’re Used
Utilization Management Insights
By Kathryn Kolonic, , DO, MPH, CPHQ
AllMed Vice President & Medical Director
In pain management spinal cord stimulation (SCS) isn’t new—the first stimulators hit the market decades ago. But with recent advancements, they’ve become among the trendiest of pain treatments.
The implantable technology sends user-controlled electrical impulses through the body, seemingly changing how the brain perceives pain. We say “seemingly” because it’s still a mystery—researchers don’t fully understand how these impulses work.
But they presumably do: Many patients have sung SCS’ praises, calling the technology “liberating” in helping them get back to life with less pain. Stimulators are low-profile, relatively easy-to-use, and an opioid alternative, advantages that have made these systems popular among pain specialists.
Recently, we explored what’s new in SCS technology with Mercy Udoji, MD, CMQ, FASA, of Atlanta Veterans Affairs Medical Center. In this thought-leadership webinar about all things pain, we discussed the evolution, risks, benefits, and indications for this standout technology.
How Spinal Cord Stimulation Works
Spinal cord stimulation consists of three parts: electrodes implanted in the back’s epidural area, a battery pack generator implanted in the abdomen or buttocks, and a controller operated by the patient.
When a person feels pain, they adjust the controller to send impulses through the electrodes. In so doing, the stimulator interrupts the signals sent to the brain, which can remove pain altogether or at least replace it with a more subdued and tingly feeling known as paresthesia.
“It’s known as the gate control theory of pain,” Dr. Udoji said. “The spinal cord is the gate that controls painful signals from your body. Unless pain gets past the spinal cord and is transmitted toward your brain, you don’t feel or perceive pain. That’s the basis upon which SCS works. Electrodes stimulate larger nerve fibers that block the gate and keep those pain signals from getting past them.”
Recent SCS Advances of Note
Though many basic mechanisms are the same, today’s technology differs from legacy SCS. For one thing, batteries are slimmer and many last up to 10 years, providing a more practical solution for patients’ day-to-day lives.
Manufacturers have also evolved their programming with so-called “burst” or high-frequency stimulation. Compared to earlier “tonic” stimulation, these new protocols mimic the body’s signaling and have shown clinical promise even without paresthesia.
“We’re talking about frequencies in the tens of hundreds of thousands in terms of millihertz,” Dr. Udoji said. “These programs can change how patients react to stimulation because patients are taught to develop less tolerance over time.”
And as one final innovation noted by Dr. Udoji, dorsal root ganglion stimulation has also moved the needle for SCS technology. This technique places leads in different areas of the spinal column to target pain in the lower body, like the feet or knees.
Indications for Use of Spinal Cord Stimulation
SCS offers promise for cases more resistant to conservative measures like medications, physical therapy, facet injections, nerve ablations, and alternative medicine. Even so, it’s not just something used for back or neck pain. Many other patients may be good candidates for stimulators, and the list of indications is steadily growing: Just recently, the FDA approved SCS use for diabetic peripheral neuropathic pain, for example.
Common Indications for SCS
- Treatment-resistant neck or back pain
- Cervical radiculopathy
- Lumbar radiculopathy
- Complex regional pain syndrome
- Chronic angina
- Failed back surgery
- Visceral abdominal pain
- Nondiabetic peripheral neuropathic pain
Getting Started With SCS Technology
Establishing SCS with a patient involves a complex process:
- Patients receive a behavioral health assessment to ensure they understand the steps and responsibilities required for stimulation.
- Selected patients participate in a trial for the technology. During this step, clinicians will insert temporary lead wires into the back with external placement of the generator. For seven to 10 days after that, patients should live normally and do as many activities as possible that would ordinarily trigger pain.
- After the trial ends, patients return to have leads removed and discuss how well the stimulator worked for them.
- If the stimulator is determined an effective option, patients undergo the procedure to implant the electrodes and battery.
- Clinicians follow up with patients over four to six weeks until the patient heals. After that point, long-term surveillance of the stimulator takes place. As pain evolves, stimulation usually will be adjusted.
Balancing Risks and Benefits
As with any pain treatment, SCS requires a thorough assessment of risks and benefits. While the benefits are striking—a life with less pain with the potential for reduced new-onset opioid use—risks can include procedural complications. These rare events can include bleeding, infection, device movement, and other issues. SCS also requires some lifestyle modifications, such as taking precautions during medical imaging and powering off the device while driving.
What Success Looks Like
SCS effectiveness ranges from 50 to 75 percent, Dr. Udoji says, with better rates typically seen for people whose devices are implanted earlier in their pain journey.
“The longer you wait, the more that pain signaling and wiring is imprinted into your brain and the harder it is for these systems to override that imprint,” she said. “While we don’t want to rush and give everybody a stimulator, as we see more complex patients who present for interventions, that’s something we should consider.”
Over time, pain may change, so SCS programming will need to adjust accordingly. Ultimately, these treatments are lifelong things and regular surveillance and reconfiguration can help them stay effective long-term.
In understanding these and other tools, clinicians can better explore which treatments best match to which patients—and utilization reviewers can assess care plans accordingly. The next recap article explores other techniques in treating neck and low back pain, such as platelet-rich plasma, prolotherapy, and other emerging technologies.
Watch the Webinar
Watch our 45-minute on-demand webinar about modern approaches to pain management, including the latest in spinal cord stimulation. Watch on Demand >