Advances in Spinal Cord Stimulation
Misconceptions aside, clinicians should be open to using SCS as an early treatment option
Patients who suffer from chronic pain and the clinicians who treat them are always on the lookout for better treatment options, but some effective therapies have been overlooked or are only administered late, long after other trials have failed. Of the estimated 100 million Americans living with chronic pain,1 epidural spinal cord stimulation (SCS) may provide significant pain reduction, restoring productivity and quality of life.
SCS is an FDA-approved therapy that has been available for nearly 50 years. It blocks pain by delivering a continuous low-voltage electrical current to nerves along the spinal cord, reducing the number of pain sensations reaching the brain. SCS involves a surgical procedure in which electrical leads are placed in the epidural space using guided imagery.
Local anesthesia and light patient sedation are employed. Before permanent implantation, patients typically undergo a one-week trial. Currently, SCS is an accepted treatment for chronic pain of the back, arms, and legs.2 It is most commonly used for neuropathic pain conditions such as failed back surgery syndrome (FBSS), in which pain is unresolved or arises following surgery, and complex regional pain syndrome (CRPS), in which chronic arm or leg pain develop, usually after an injury, surgery, stroke, or heart attack.
Ivano Dones, MD, and Vincenzo Levi, MD, of the Functional Neurosurgery Department at the Carlo Besta Neurological Institute in Milan, Italy, highlight “an ongoing revolution” in the treatment of neuropathic pain using “new [and] different patterns of electric stimulation.”3
Conventional SCS stimulation employs a tonic waveform in which electrical pulses are delivered at a constant frequency, pulse width, and amplitude. It has been found effective for approximately 50% of neuropathic pain patients.4 To help more sufferers, including those who develop a tolerance to conventional stimulation, the researchers say that new types and patterns of stimulation, such as burst and high frequency, should be considered.
To date, only small studies have been performed on burst stimulation, but Drs. Dones and Levi say the results have been promising. “When compared to conventional SCS,” they state, “burst stimulation gave remarkable long-term pain higher suppression.” In addition to providing greater pain control than the traditional tonic pattern, it was also associated with a decreased incidence of paresthesia (a pins-and-needles sensation).
Studies have also shown that burst stimulation may be more effective in reducing pain in the axial midline region, an area that conventional tonic stimulation often fails to treat effectively.5 Dr. Dones told PPM that this is because “burst stimulation can recruit more nerve fibers in the spinal cord, thus interfering with their transmission of pain to the brain.”
The authors cite a small study using high-frequency stimulation that showed 70% of patients “experienced a significant and sustained low back pain and leg pain relief.”6 They note, however, that another study showed no significant difference between the high-frequency mode and a placebo. More studies need to be conducted, they say.
Joshua Rosenow, MD, director of Functional Neurosurgery and Epilepsy Surgery at Northwestern Medicine in Chicago, IL, applauds these recent advances. New patterns of stimulation, including combinations, he says, “have allowed us to provide a wider population of patients with a significant amount of pain relief.” They have also enabled clinicians to “more precisely match the therapy to the patient,” both now and as pain changes over time.
Changing the Treatment Paradigm
In addition to advances in SCS stimulation, experts in the field urge clinicians to consider using it sooner. Misconceptions and a lack of education about SCS, says Dr. Rosenow, have led clinicians to offer it only after all other therapies have failed. He says we now know that “the earlier someone undergoes a neurostimulation in their pain syndrome course, the more likely they are to have success.” In addition to its safety profile and good response rate, Dr. Rosenow says SCS can also help pain patients reduce or even eliminate medications, including addictive opioids.
Recent advances promise greater pain relief for more patients, and improvements continue to be made. “This is a tremendously exciting time in the world of neurostimulation,” says Dr. Rosenow.
Drs. Dones and Levi are also confident about SCS’s role in pain management. “SCS may be considered as an effective, safe, well-tolerated and reversible treatment option for severe drug-refractory neuropathic pain,” they wrote.