An interventional study of Spinal cord stimulator in Traumatic Amputation of Lower Extremity and Phantom Limb Pain, sponsored by Lee Fisher, PhD. Terminated at 1 site in United States. Open to participants aged 22 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-01-07.
Sponsored by Lee Fisher, PhD · Not applicable, Interventional, and Treatment
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.
During the study, FDA-cleared spinal cord stimulator leads will be placed in the lumbar epidural space of lower limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. This approach is essentially identical to the FDA-cleared procedure in which these devices are placed in the lumbar epidural space for treatment of intractable low back and leg pain. In that procedure, it is common clinical practice to place 2-3 leads temporarily in the epidural space through a percutaneous approach and perform a multiday trial to determine if the patient experiences any pain reduction from spinal cord stimulation. Following the trial, the percutaneous leads are surgically removed, and the patient is referred to a neurosurgeon for permanent surgical implantation.
Similarly, in this study, the device will be tunneled percutaneously through the skin and anchored in place. Using the stylet included with the spinal cord stimulator leads, the devices will be steered laterally under fluoroscopic guidance to target the dorsal spinal nerves. During lab experiments, the leads will be connected to an external stimulator. In this study, the devices will remain in the epidural space for up to 90 days and will be surgically removed. Throughout the study, the investigators will perform a series of psychophysical evaluations to characterize the sensory percepts evoked by epidural stimulation, along with functional evaluations of the effects of stimulation on the ability to control a prosthetic limb. In addition, the investigators will perform surveys to characterize changes in phantom limb sensation and pain that occur during stimulation.
Exclusion Criteria:
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.
Device: Spinal cord stimulator
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.
Number of Participants Experiencing Serious Device-related Adverse Events up to 90 Days Following Implantation
Investigators will track the number of participants experiencing serious device-related adverse events, such as unresolved superficial infection resulting in lead removal, deep infection, inpatient hospitalization, withdrawal from the study due to worsening pain or intolerable dysesthesia, or fracture due to falls related to the study interventions, that occur during the course of and up to 90 days following implantation.
Time frame: 90 days
Minimum Amplitude of Pulse Required to Evoke Sensory Percepts
Quantify the threshold stimulus required to evoke sensory percepts during epidural spinal nerve stimulation.
Time frame: 90 days
Minimum Charge Required to Evoke a Neurophysiological Response
Quantify the threshold (minimum charge) stimulus required to evoke neurophysiological responses during epidural spinal nerve stimulation
Time frame: 90 days
Location of Evoked Sensation - Missing Toes
Participants reporting sensation on missing toes from spinal cord stimulation.
Time frame: 90 days
Location of Evoked Sensation - Plantar Surface of Missing Foot
Participants perceiving sensation on the plantar surface of missing foot
Time frame: 90 days
Change in Phantom Limb Pain Using the McGill Pain Questionnaire
The McGill Pain Questionnaire is a questionnaire used to evaluate the severity of pain experienced by the participant. The questionnaire is scaled, with a minimum and maximum pain score of 0 and 78, respectively. The higher the score on the questionnaire, the more intense the pain felt by the participant. A lower score than previously reported represents a decrease in experienced phantom limb pain. Before placement of the spinal cord stimulator leads, investigators will document the subject's description of their history of perceived phantom limb. Investigators will ask them to periodically update their perception of the limb throughout experimental sessions, as well as within a month after the device has been removed.
Time frame: Pre-implant (baseline), Weeks 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and post-explant (90 days)
Qualitative Self-report of Evoked Sensations
Document the subjective perception of lumbosacral epidural spinal nerve stimulation for restoration of sensation. The investigators will ask each subject to provide subjective feedback on their perceived utility of the sensory feedback provided by the device. A total of 13 natural descriptors and 5 paresthetic descriptors were presented to participants weekly to describe the sensation provided via spinal cord stimulation. The goal of the study is to elicit more natural than paresthetic descriptors from participants. Natural: pressure, tickle, flutter, warm, sharp, prick, cool, pulsing, vibration, itch, urge to move, touch, tap Parethetic: buzz, tingle, shock, electric current, numb
Time frame: 90 days
Able to Use a Prosthetic Limb With Neural Signals
Investigators will test the subject's success rate during control of prosthetic limb with and without sensory feedback provided by electrical stimulation of the spinal roots. Using either a virtual prosthetic limb or an instrumented prosthesis, stimulation of the spinal roots will be modulated based on signals recorded from the limb.
Time frame: 90 days
Subjects were enrolled from 2021 to 2023 from affiliated amputee clinics. Recruitment continued through 2025, but no additional subjects were enrolled.
| Milestone | Spinal Cord Stimulation |
|---|---|
| Started | 1 |
| Completed | 1 |
| Not completed | 0 |
Investigators will track the number of participants experiencing serious device-related adverse events, such as unresolved superficial infection resulting in lead removal, deep infection, inpatient hospitalization, withdrawal from the study due to worsening pain or intolerable dysesthesia, or fracture due to falls related to the study interventions, that occur during the course of and up to 90 days following implantation.
| Participants | Spinal cord stimulation |
|---|---|
| Number of Participants Experiencing Serious Device-related Adverse Events up to 90 Days Following Implantation | 0 |
Quantify the threshold stimulus required to evoke sensory percepts during epidural spinal nerve stimulation.
| milliamps | Spinal Cord Stimulation |
|---|---|
| Minimum Amplitude of Pulse Required to Evoke Sensory Percepts | 2 |
Quantify the threshold (minimum charge) stimulus required to evoke neurophysiological responses during epidural spinal nerve stimulation
| uC (microcoulombs) | Spinal cord stimulation |
|---|---|
| Minimum Charge Required to Evoke a Neurophysiological Response | 1.23 |
Participants reporting sensation on missing toes from spinal cord stimulation.
| Participants | Spinal Cord Stimulation |
|---|---|
| Location of Evoked Sensation - Missing Toes | 1 |
Participants perceiving sensation on the plantar surface of missing foot
| Participants | Spinal Cord Stimulation |
|---|---|
| Location of Evoked Sensation - Plantar Surface of Missing Foot | 1 |
The McGill Pain Questionnaire is a questionnaire used to evaluate the severity of pain experienced by the participant. The questionnaire is scaled, with a minimum and maximum pain score of 0 and 78, respectively. The higher the score on the questionnaire, the more intense the pain felt by the participant. A lower score than previously reported represents a decrease in experienced phantom limb pain. Before placement of the spinal cord stimulator leads, investigators will document the subject's description of their history of perceived phantom limb. Investigators will ask them to periodically update their perception of the limb throughout experimental sessions, as well as within a month after the device has been removed.
| score on a scale | Spinal Cord Stimulation |
|---|---|
| Pre-implant (baseline) | 48 |
| Week 1 (after implant) | 32 |
| Week 2 | 45 |
| Week 3 | 45 |
| Week 4 | 23 |
| Week 5 | 38 |
| Week 6 | 32 |
| Week 7 | 34 |
| Week 8 | 17 |
| Week 9 | 46 |
| Week 10 | 41 |
| Week 11 | 65 |
| Post-explant (90 days) | 47 |
Document the subjective perception of lumbosacral epidural spinal nerve stimulation for restoration of sensation. The investigators will ask each subject to provide subjective feedback on their perceived utility of the sensory feedback provided by the device. A total of 13 natural descriptors and 5 paresthetic descriptors were presented to participants weekly to describe the sensation provided via spinal cord stimulation. The goal of the study is to elicit more natural than paresthetic descriptors from participants. Natural: pressure, tickle, flutter, warm, sharp, prick, cool, pulsing, vibration, itch, urge to move, touch, tap Parethetic: buzz, tingle, shock, electric current, numb
| Participants | Spinal Cord Stimulation |
|---|---|
| More natural than paresthetic descriptors. | 1 |
| More paresthetic than natural descriptors. | 0 |
Investigators will test the subject's success rate during control of prosthetic limb with and without sensory feedback provided by electrical stimulation of the spinal roots. Using either a virtual prosthetic limb or an instrumented prosthesis, stimulation of the spinal roots will be modulated based on signals recorded from the limb.
| Participants | Spinal Cord Stimulation |
|---|---|
| Able to Use a Prosthetic Limb With Neural Signals | 1 |
Collected over 90 days. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Spinal Cord Stimulation | 0/1 (0%) | 0/1 (0%) | 1/1 (100%) |
| Event | Spinal Cord Stimulation |
|---|---|
| Incision painSurgical and medical procedures | 1/1 |
| Chest pain after surgerySurgical and medical procedures | 1/1 |
| Age, Categorical(Participants) | Spinal Cord Stimulation |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 1 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | Spinal Cord Stimulation |
|---|---|
| Female | 1 |
| Male | 0 |
| Race (NIH/OMB)(Participants) | Spinal Cord Stimulation |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 0 |
| White | 1 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(participants) | Spinal Cord Stimulation |
|---|---|
| United States | 1 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — The investigators may share data with researchers at other centers for the purpose of data analysis and collaboration.
Supporting information: Sap, Icf
This study is terminated, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
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Lee Fisher, PhD