Spurred by the opioid crisis, a once marginalized therapy that relies on electrical stimulation to treat chronic pain is undergoing a renaissance as device makers race to upgrade their products for a wider population of patients.
The companies believe the therapy, known as neuromodulation, can reduce reliance on opioid painkillers, which laid the foundation for a spike in overdose deaths and led to a fierce debate over how best to treat patients with chronic pain. It is also seen as a significant business opportunity, with one research firm predicting that the market for neuromodulation will grow by 15 percent a year, to more than $16 billion by 2024.
Over the past four years, device makers have introduced products that deliver stimulation at different frequencies and levels of intensity, expanding the number and type of patients that may be candidates for neuromodulation. The therapy involves the surgical implantation of a spinal cord stimulator that, when turned on, delivers mild electric pulses to nerve fibers in the spinal cord. The electricity interrupts the pain signals that are carried to the brain, providing relief to patients.
In addition to improvements in stimulation techniques, device markers are adding wireless bluetooth technology to spinal cord stimulators to allow doctors and patients to adjust the intensity levels in real time; tablets and smartphones are also making it easier to collect and report data on patient progress and outcomes.
“That’s where the field is turning — there’s been a movement to make sure we have validated outcomes that accurately represent what patients are telling us,” said Dr. Mark Bicket, director of the pain fellowship program at Johns Hopkins University. “We have some active studies going on at Hopkins and other places looking at patient function with devices like Apple Watch and other wrist-based measurements.”
Medtronic sponsors a grant for pain fellows at Johns Hopkins, but Bicket does not receive direct payments from that program.
It would be impractical and incredibly expensive for every chronic pain patient now taking opioids to get these implants. But pain specialists say neuromodulation is part of the solution to alleviating pain and should be considered earlier in the treatment process, instead of as a last resort. Research is underway to determine which types of patients benefit most from the newer devices on the market.
Neuromodulation was the focus of a session at this year’s Consumer Electronics Show in Las Vegas, where device makers gathered for a discussion titled, “The Solution to the Opioid Crisis No One is Talking About.” The largest players in the market participated, including Boston Scientific, Medtronic, Abbott, and Nevro, which began marketing its products in the U.S. in 2015.
“What we are offering and talking about up here is a therapy that can be considered for patients who have chronic pain before they ever get on opioids,” said Dr. David Caraway, Nevro’s chief medical officer. “Or, if they are on opioids, we can get them off opioids or reduce their dose down to safer levels.”
Neuromodulation has been available since the 1960s, but pain specialists say the technology has advanced rapidly in the last few years, driven in part by the need to find alternatives to opioids. The introduction of painkillers such as OxyContin in the late 1990s made it easier and cheaper for doctors to prescribe a pill rather than a surgical implant or other types of therapy. Pain specialists said the cost of neuromodulation ranges from $15,000 to $30,000, depending on the device, the hospital, and the amount of follow-up care provided. Insurance coverage varies by the diagnosis and clinical circumstances, but most insurers pay for it and some are expanding coverage for the newer devices.
During their discussion in Las Vegas, executives for the the device makers emphasized their push to generate evidence to demonstrate the effectiveness and safety of neuromodulation for different categories of patients. Studies have reported substantial pain relief for patients with persistent pain after failed back surgery, while others have recorded similar benefits for patients with leg and other types of back pain, although the research is ongoing.
Researchers are also examining the usefulness of the therapy in treating nerve pain arising from diabetes. And some recent studies have reported that neuromodulation reduced the use of opioids in most patients who received the treatment. But that doesn’t mean it is a panacea.
“The world has a long history of opioid abuse, and I don’t think we’re going to be able to solve this with spinal cord stimulation alone,” said Dr. Sean Nagel, a neurosurgeon at Cleveland Clinic. “It is an option for the right person with a particular kind of pain.”
Doctors cautioned that the therapy must be used carefully, as it carries the risk of complications, such as the migration or fracturing of the implants in the body, which can require additional surgeries. Patients typically try some combination of physical therapy and medication before they become candidates for neuromodulation.
“We are seeing the devices being more applicable to patients … but patients still need to be informed and I think that discussion still needs to happen with each patient to make sure it’s the right step for them,” said Bicket. “The rates of complication are still not insignificant.”
Executives with the device markers said they are stepping up efforts to keep tabs on patients following implantation, both by reaching out to them directly and by using tablets and apps to collect data on the intensity of their pain and activity levels.
“Like monitoring a jet engine over the Atlantic, we can monitor how our devices are performing for the people that are using them,” said Ryan Lakin, vice president of neuromodulation research for Abbott. The company uses Apple products to allow users to adjust their levels of stimulation in response to discomfort.
“When we start to integrate [consumer technologies] in to what we see as these complex medical devices, we can simplify and improve outcomes,” Lakin said.
The ability to follow a patient’s progress not only enables doctors and device makers to adjust stimulation levels, it can also improve the quality of the evidence collected. Assessing the intensity of a patient’s pain has always been hindered by subjectivity. The widespread use of a 1-10 pain score is an imperfect measure, as one person’s 3 might be another person’s 8.
“Unfortunately in chronic pain we have patient-reported outcomes and then a gap” in the measurement system, said Matthew Thomas, vice president of pain stimulation and early interventions at Medtronic. “Creating objective outcome measures, like activity, stress, and sleep, is critical as we go forward and find ways to treat pain.”