Spinal Cord Stimulation for Lower Extremity Amputation

(SCS-90 Trial)

Overseen By Sydney Bader

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Lee Fisher, PhD

Must not be taking: Blood thinners, Immunosuppressants

Disqualifiers: Pregnancy, Renal failure, Cardiac devices, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

10 Participants Needed

Trial Summary

What is the purpose of this trial?

The goals of this study are to provide sensory information to amputees and reduce phantom limb pain via electrical stimulation of the lumbar spinal cord and spinal nerves. The spinal nerves convey sensory information from peripheral nerves to higher order centers in the brain. These structures still remain intact after amputation and electrical stimulation of the dorsal spinal nerves in individuals with intact limbs and amputees has been demonstrated to generate paresthetic sensory percepts referred to portions of the distal limb. Further, there is recent evidence that careful modulation of stimulation parameters can convert paresthetic sensations to more naturalistic ones when stimulating peripheral nerves in amputees. However, it is currently unclear whether it is possible to achieve this same conversion when stimulating the spinal nerves, and if those naturalistic sensations can have positive effects on phantom limb pain. As a first step towards those goals, in this study, the investigators will quantify the sensations generated by electrical stimulation of the spinal nerves, study the relationship between stimulation parameters and the quality of those sensations, measure changes in control of a prosthesis with sensory stimulation, and quantify the effects of that stimulation on the perception of the phantom limb and any associated pain.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are taking medications that affect blood coagulation or are receiving immunosuppressive medications.

What data supports the effectiveness of the treatment Spinal Cord Stimulation for lower extremity amputation?

Research shows that spinal cord stimulation (SCS) has been used since the 1970s to relieve chronic pain after limb amputation, and it has been successful in many cases. Additionally, transcutaneous spinal cord stimulation (tSCS) has shown promise in improving muscle movement and strength in people with spinal cord injuries, suggesting potential benefits for other conditions affecting the lower limbs. ^{1 2 3 4 5}

Is spinal cord stimulation generally safe for humans?

Spinal cord stimulation (SCS) is generally considered safe for humans, as it is a reversible treatment used for various conditions like chronic pain and critical limb ischemia. However, specific risks and complications can occur, such as those related to electrode placement and removal, which need to be managed by healthcare professionals. ^{3 4 5 6 7}

How is spinal cord stimulation different from other treatments for lower extremity amputation?

Spinal cord stimulation (SCS) is unique because it uses electrical pulses to relieve chronic pain by targeting the spinal cord, which is different from typical pain medications that work throughout the body. This treatment is particularly useful when other options, like surgery, are not possible or have failed. ^{2 3 4 5 6}

Research Team

Lee Fisher, PhD

Principal Investigator

University of Pittsburgh

Eligibility Criteria

This trial is for lower-limb amputees aged 22-70 who are at least six months post-amputation, have been using their current prosthesis for over six months, and can walk with or without support. Pregnant women, those on blood thinners, with severe diseases, allergies to MRI contrast agents or renal failure, high hemoglobin A1c levels (>8.0 mg/dl), implanted devices not cleared for MRI (like pacemakers), immunosuppressed individuals or those in radiation-heavy professions cannot join.

Inclusion Criteria

I am between 22 and 70 years old.

I've used my current prosthesis for 6+ months and can walk with it.

It has been over 6 months since my amputation.

Exclusion Criteria

You have a high score on a questionnaire about your mental health and have been told by the study doctor and psychologist that you are not suitable for the study.

Your hemoglobin A1c level cannot be higher than 8.0 mg/dl when you get the implant.

I am not taking any blood-thinning medications.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Spinal cord stimulator leads are placed in the lumbar epidural space for up to 90 days to evaluate sensory feedback and pain reduction

12 weeks

Multiple visits for psychophysical and functional evaluations

Follow-up

Participants are monitored for safety and effectiveness after device removal

4 weeks

Treatment Details

Interventions

• Spinal cord stimulator

Trial Overview The study tests a spinal cord stimulator designed to provide sensory feedback and reduce phantom limb pain in lower-limb amputees. It aims to understand how electrical stimulation of the spinal nerves affects sensation quality and prosthetic control while also measuring its impact on phantom limb perception and associated pain.

Participant Groups

Group I: Spinal cord stimulation Experimental Treatment 1 Intervention

Spinal cord stimulator leads (2-3 leads) will be placed in the lumbar epidural space of lower limb amputees to determine if the patient experiences any pain reduction from spinal cord stimulation. Participants in this study receive spinal cord stimulation will be trans-tibial amputees that are at least six month post--amputation. Subjects will have varying levels of phantom limb sensation and pain, but should have no other significant neurological disorders.

Spinal cord stimulator is already approved in United States, European Union for the following indications:

Approved in United States as Spinal Cord Stimulation for:

• Chronic pain
• Phantom limb pain
• Neuropathic pain

Approved in European Union as Spinal Cord Stimulation for:

• Chronic pain
• Phantom limb pain
• Neuropathic pain

Who Is Running the Clinical Trial?

Lee Fisher, PhD

Lead Sponsor

Trials

4

Recruited

70+

National Institute of Neurological Disorders and Stroke (NINDS)

Collaborator

Trials

1,403

Recruited

655,000+

Findings from Research

In a study of 39 patients with nonreconstructable lower extremity ischemic vascular disease, spinal cord stimulation was successful in 77% of cases, significantly improving pain control and blood flow metrics like TcPO2 and peak blood flow velocity.

Patients with a pre-implantation TcPO2 of less than 30 mm Hg showed significant improvements post-stimulation, indicating that spinal cord stimulation can enhance perfusion and may be a valuable treatment option for severe cases without trophic changes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Improvement of limb circulation in peripheral vascular disease using epidural spinal cord stimulation: a prospective study. Kumar, K., Toth, C., Nath, RK., et al.[2013]

Spinal cord stimulation (SCS) has shown long-term effectiveness in providing pain relief for some patients with amputation-related pain, with a mean self-reported pain relief of 66% over a follow-up period of up to 19 years.

While some patients experienced technical issues or waning benefits, the overall results suggest that SCS remains a viable treatment option, warranting further refinement of techniques to enhance its efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Spinal cord stimulation for intractable pain following limb amputation. McAuley, J., van Gröningen, R., Green, C.[2022]

Noninvasive transcutaneous spinal cord stimulation (tSCS) has been shown to effectively induce muscle activation in individuals with spinal cord injury, based on a systematic review of 13 studies involving 55 participants.

While tSCS appears to enhance voluntary movement, muscle strength, and function, further research is needed to determine the optimal electrode placement and current intensity for maximum efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcutaneous Spinal Cord Stimulation and Motor Rehabilitation in Spinal Cord Injury: A Systematic Review. Megía García, A., Serrano-Muñoz, D., Taylor, J., et al.[2021]

Transcutaneous spinal cord stimulation (tSCS) shows potential for generating motor activity in individuals with spinal cord injury, but the overall quality of the studies reviewed was poor-to-fair, indicating a need for more rigorous research.

The review identified significant variability in stimulation parameters and outcome measurements across the 25 studies analyzed, highlighting the necessity for standardized methods to improve the reliability and comparability of tSCS research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcutaneous spinal cord stimulation and motor responses in individuals with spinal cord injury: A methodological review. Taylor, C., McHugh, C., Mockler, D., et al.[2022]

In a study of 72 patients with critical limb ischemia (CLI) who received spinal cord stimulation (SCS), 59.2% were alive without major amputation after an average follow-up of 17.1 months, indicating that SCS can lead to significant limb salvage rates.

Patients classified as Fontaine's Stage III showed particularly favorable outcomes, with a 94% survival rate without major amputation, suggesting that SCS may be especially effective for those with less severe ischemia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Spinal cord stimulation in non-reconstructable critical limb ischemia: a retrospective study of 71 cases. Piedade, GS., Vesper, J., Reichstein, D., et al.[2023]

Electrical spinal cord stimulation (ESCS) provides significant and sustained pain relief for patients with chronic painful diabetic neuropathy, with median pain scores showing a marked reduction when the stimulator is on compared to when it is off.

The procedure has a low complication rate, with only two late complications reported among the patients, indicating that ESCS is a safe long-term treatment option for managing chronic pain.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electrical spinal cord stimulation in the long-term treatment of chronic painful diabetic neuropathy. Daousi, C., Benbow, SJ., MacFarlane, IA.[2019]

In a study of 68 patients who had spinal cord stimulation paddle electrodes removed, the most common reason for removal was loss of coverage or effect (75%), indicating that while SCS is effective, it may not always provide lasting relief.

Postoperative complications occurred in 11.75% of patients, with two major complications requiring reoperation, highlighting that while SCS removal is generally safe, it does carry some risks that patients should be aware of.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rate of Complications Following Spinal Cord Stimulation Paddle Electrode Removal. Maldonado-Naranjo, AL., Frizon, LA., Sabharwal, NC., et al.[2022]

References

1. United States pubmed.ncbi.nlm.nih.gov

Improvement of limb circulation in peripheral vascular disease using epidural spinal cord stimulation: a prospective study. [2013]

2. United States pubmed.ncbi.nlm.nih.gov

Spinal cord stimulation for intractable pain following limb amputation. [2022]

3. United States pubmed.ncbi.nlm.nih.gov

Transcutaneous Spinal Cord Stimulation and Motor Rehabilitation in Spinal Cord Injury: A Systematic Review. [2021]

4. United States pubmed.ncbi.nlm.nih.gov

Transcutaneous spinal cord stimulation and motor responses in individuals with spinal cord injury: A methodological review. [2022]

5. Austria pubmed.ncbi.nlm.nih.gov

Spinal cord stimulation in non-reconstructable critical limb ischemia: a retrospective study of 71 cases. [2023]

6. England pubmed.ncbi.nlm.nih.gov

Electrical spinal cord stimulation in the long-term treatment of chronic painful diabetic neuropathy. [2019]

7. United States pubmed.ncbi.nlm.nih.gov

Rate of Complications Following Spinal Cord Stimulation Paddle Electrode Removal. [2022]