The first-ever randomised, controlled trial to compare spinal cord stimulation technologies found that high-frequency stimulation using 10kHz (HF10) exceeded lower-frequency, traditional stimulation in response rate and pain relief. Further, this was achieved without the paraesthesia that may cause discomfort with traditional treatment, the researchers reported in a scientific poster at the 31st Annual Meeting of the American Academy of Pain Medicine (19–22 March, Washington, DC, USA).
Traditional spinal cord low-frequency (~50 Hz) stimulation is an attempt to mask the sensation of pain with paraesthesia. Therefore, the therapeutic goal with traditional stimulation is to cover the areas of pain with paraesthesias, explained B Todd Sitzman, medical director of Advanced Pain Therapy, PLLC, in Hattiesburg, USA.
In contrast, “high-frequency HF10 therapy utilises a stimulation frequency that is orders of magnitude higher than traditional spinal cord stimulation,” Sitzman said. “HF10 therapy does not produce paraesthesias and achieves superior back and leg pain relief.”
More importantly, HF10 therapy was shown to be superior to traditional stimulation in all of the study-related primary and secondary endpoints, including response rate and pain relief. The magnitude of back pain relief was consistent with previous European research of HF10 therapy.
The use of spinal cord stimulation, introduced in 1967, has expanded as a treatment for difficult pain syndromes, encompassing peripheral neuropathies, complex regional pain syndromes, peripheral vascular disease and other disorders in addition to failed back surgery syndrome.
Traditional low-frequency stimulation systems are widely used in clinical practice. However, the scientific literature indicates that achieving back pain coverage with traditional spinal cord stimulation is technically difficult and is often not sustained over time. According to one report, 71% of patients who received an implant with traditional stimulation experienced discomfort from the stimulation of paraesthesia. In the current study, 44% of patients receiving traditional spinal cord stimulation reported uncomfortable stimulation.
The study was a prospective, randomised, multicentre, comparative trial of the investigational HF10 vs the standard stimulation therapy, designed in consultation with and monitored by the Food and Drug Administration (FDA). Institutional review board approval was obtained for each study site.
The 12-month follow-up data indicated that the responder rate with HF10 therapy was twice that with traditional stimulation for both back and leg pain. Also, the average degree of pain relief with HF10 therapy was more than 50% greater than with traditional stimulation. The level-1 evidence with 12-month follow-up meets the current rigorous standards for evidence-based healthcare and complies with regulatory agency and payer preference for comparative effectiveness, the investigators said.
“These results provide important comparative effectiveness data for healthcare providers and clinically relevant information for pain physicians, patients and payers,” Sitzman said.
At present, HF10 therapy is investigational in the USA. The manufacturer of the device, Nevro Corp, which funded this study, anticipates obtaining market approval from the FDA by mid-2015.