An implantable spinal cord stimulation device was effective at relieving diabetic neuropathy pain, a researcher reported.
In the randomized SENZA-PDN trial of over 200 adults with diabetes, those who were treated with high frequency (10 kHz) spinal cord stimulation plus conventional medical management saw a 76.3% reduction in pain over 6 months (7.6 cm at baseline vs 1.7 cm at 6 months), said Erika A. Petersen, MD, of the University of Arkansas for Medical Sciences in Little Rock.
“This is the largest randomized controlled trial evaluating spinal cord stimulation for refractory painful diabetic neuropathy,” she stated in a presentation at the American Association of Clinical Endocrinology virtual meeting.
In total, more than 85% of patients treated with 10 kHz stimulation were considered responders to treatment — experiencing 50% or greater reduction in pain. On top of that, 60% achieved remission, defined as a pain visual analog scale (VAS) of less than 3.0 cm for 6 consecutive months.
On the other hand, those who were only treated with conventional medical management saw no significant reduction in average pain scores (7.0 at baseline vs 6.9 at 6 months). More than half of those conventionally treated experienced worsening of their pain, and only about 5% were responders to this type of treatment. Overall, only 1% of patients achieved pain remission with conventional medical management.
Beyond pain improvement, those receiving high frequency spinal cord stimulation plus medical management also saw a 62% improvement in neurological examination versus 3.3% of conventional treatment-only patients (P<0.001). The neurological examination included tests of lower limb motor strength, light touch sensation, reflex testing of the patellar, Achilles, and Babinski reflexes, and a 10-point foot assessment with a pinprick and 10-g monofilament.
Patients with the stimulation device also reported a reduction in dysesthesias, including improvement in numbness, burning, tingling, and cold sensations. These individuals also reported a 62% improvement in sleep disturbances, while there was no sleep improvement in the conventional treatment group.
Overall, 92% patients in the stimulation group said they were satisfied with their treatment, whereas 6% of those on the conventional treatment group said the same.
The 18-center, prospective trial included 216 adults with painful diabetic neuropathy of the lower limbs, refractory to conservative treatments including gabapentinoids and at least one other analgesic class. For inclusion, participants had a slower limb pain intensity score of 5 cm or higher on VAS (range of 0-10 cm). All participants also had an HbA1c under 10% and a BMI under 45.
Half of participants received only conventional medical management, which included pharmacotherapies such as first-line agents (pregabalin, gabapentin, duloxetine), second-line agents (other anticonvulsants like carbamazepine, other SNRIS like venlafaxine, or TCAs), or other agents like oral opioids or IV analgesics.
The other half of participants received 10-kHz SCS therapy delivered by a Senza SCS System. These participants underwent temporary stimulation for 5 to 7 days with percutaneous leads placed epidurally along T8 to T11. If they were deemed responders (50% or more pain relief), they were considered eligible for permanent placement of the pulse generator, usually implanted in the low back. Stimulation was then delivered via 10-kHz frequency, 30-μs pulse width delivered via bipole, and amplitude range of 0.5 to 3.5 mA, which was adjusted according to patient feedback.
In terms of safety, three infections occurred in the stimulation group, two of which required explant of the device (2%).
There was no change in BMI or HbA1c in either group during the trial.
After the 6-month trial, 82% of patients on conventional treatment were eligible to crossover — meaning they had less than 50% pain relief, were dissatisfied with treatment, and the investigator agreed it was medically appropriate — and chose to receive the stimulation device.
In this extension phase, those with the stimulation device continued to experience pain relief, achieving an average VAS of 1.7 at 12 months out.
“The responder rate remained stable as well, with 86% at 12 months suggesting the attrition seen with other stimulation approaches is not a concern with 10 kHz stimulation,” said Petersen. “We will continue our follow-up to 24 months, with further evaluation of health economic data and other indicators.”
The study was funded by Nevro.
Petersen disclosed relationships with Medtronic, Nevro, Abbott, SynerFuse, Neuros Medical, ReNeuron, and Saluda.