Researchers conducted a case study to explore the potential of high-frequency spinal cord stimulation to treat severe phantom limb pain. Following treatment, the patient reported significant improvement in pain intensity, overall function, and in his ability to tolerate his prosthesis.
“Phantom limb pain remains incredibly common, affecting roughly two-thirds of individuals with limb loss, and it can be one of the biggest barriers to meaningful functional recovery,” said coauthor F. Clay Smither, MD, chair, Physical Medicine and Rehabilitation, Mayo Clinic, who specializes in helping people with limb loss adjust to prosthetic devices and return to everyday activities.
The participant, a 52-year-old man, presented with phantom limb pain following a transhumeral amputation with concurrent targeted muscle reinnervation. Despite trialing several medications and pain management therapies, including physical and occupational therapy, the severity of his pain continued to increase. The patient reported a numeric rating scale (NRS) pain score of 9/10 and was able to tolerate his myoelectric prosthesis for only three hours a day.
Surgeons implanted a high-frequency spinal cord stimulator with bilateral leads positioned at the C1-C2 vertebral levels. To mitigate the risk of stimulation-induced paresthesia in the upper limbs, a known adverse effect of spinal cord stimulation, they programmed the device to 10,000 Hz.
At the 12-day postoperative follow-up, the patient reported a 70 percent improvement in average pain intensity and an NRS score of 0/10, and a 70 percent improvement in overall function, which included longer uninterrupted periods of sleeping, sitting, reading, and retaining more information. He was able to tolerate use of his prosthesis for up to 17 hours a day.
At the two-year follow-up, the patient reported an NRS score of 0/10 and wore his prosthesis daily.
“Pain improved dramatically and with that came better muscle control, which is critical for using a myoelectric prosthesis,” Smither said. “It really reinforces that if we can effectively treat pain, we can unlock the full potential of these advanced technologies.”
This case study built on earlier research by Jon M. Hagedorn, MD, pain medicine specialist, Mayo Clinic.1 In a review article, Hagedorn and his team determined that high-frequency spinal cord stimulation had a meaningful advantage over traditional low-frequency spinal cord stimulation for treating chronic and neuropathic pain. Whereas low-frequency spinal cord stimulation creates paresthesia to mask pain, the high-frequency device provides pain relief without paresthesia.
“What our case adds is a clear functional outcome: showing how effective pain control can directly enable sustained, real-world use of advanced myoelectric prostheses,” Smither said.
He noted that future research should focus on understanding the underlying mechanism of phantom limb pain and how spinal cord stimulation works. Research should also prioritize standardized functional outcomes and not just pain scores to better capture meaningful improvements in quality of life.
“Ultimately, the opportunity is to develop more integrated models of care that combine neuromodulation, surgical techniques, and advanced prosthetic design to optimize outcomes for patients with limb loss,” Smither said.
Editor’s note: This story was adapted from materials provided by the Mayo Clinic.
The open-access study, “Case report: Spinal cord stimulation for phantom limb pain facilitates upper limb myoelectric prosthesis use,” was published in Frontiers in Pain Research.
References
- Tieppo, F. V., et al. 2021. Management of chronic and neuropathic pain with 10 kHz spinal cord stimulation technology: Summary of findings from preclinical and clinical studies. Biomedicines 9:644. https://www.mdpi.com/2227-9059/9/6/644
