Trial Outcomes & Findings for Epidural Spinal Cord Stimulation for Sensory Restoration and Phantom Limb Pain in Upper-Limb Amputees (NCT NCT02684201)

Results Overview

Quantify the threshold (minimum charge) stimulus required to evoke sensation and neurophysiological responses during epidural spinal nerve stimulation, and monitor changes in those percepts and responses over time.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

4 participants

Primary outcome timeframe

30 days

Results posted on

2025-10-08

Participant Flow

Participants were met in amputee clinics, referred by prosthetics representatives, or responded to advertisements posted at amputee support groups. The study team spoke with approximately 25 interested patients. Of these, four completed the consent process.

Eligibility checking ruled out participants due to congenital missing limb (not amputation), taking prescription blood thinners, or unable to refrain from physical exertion during the duration of the experiment. These individuals were either excluded, or withdrew. Others declined the surgery.

Participant milestones

Participant milestones
Measure	Boston Scientific Cord Stimulator Lead A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Overall Study STARTED	4
Overall Study COMPLETED	4
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Epidural Spinal Cord Stimulation for Sensory Restoration and Phantom Limb Pain in Upper-Limb Amputees

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	3 Participants n=5 Participants
Age, Categorical >=65 years	1 Participants n=5 Participants
Sex: Female, Male Female	3 Participants n=5 Participants
Sex: Female, Male Male	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	4 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants
Race (NIH/OMB) White	3 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	4 participants n=5 Participants
Participants with phantom limb pain	3 Participants n=5 Participants

PRIMARY outcome

Timeframe: 30 days

Population: Participants implanted with stimulator leads

Quantify the threshold (minimum charge) stimulus required to evoke sensation and neurophysiological responses during epidural spinal nerve stimulation, and monitor changes in those percepts and responses over time.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Stimulation Thresholds to a Variety of Stimulus Parameters	2.13 milliamps Interval 1.25 to 3.75

PRIMARY outcome

Timeframe: first 7 days of implant

The average stimulus (nC) required to evoke sensation during week 1 of implant duration.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Week 1 Average Stimulus Charge for All Subjects	647 nC Interval 174.0 to 4000.0

PRIMARY outcome

Timeframe: During days 7-14 of implant

The average stimulus (nC) required to evoke sensation during week 2 of implant duration.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Week 2 Average Stimulus Charge for All Subjects	807 nC Interval 300.0 to 4384.0

PRIMARY outcome

Timeframe: During days 15 to 21 of implant

Population: Participant 2 had the stimulator removed before week 3. Participants 1, 3, and 4 were included in this analysis.

The average stimulus (nC) required to evoke sensation during week 3 of implant duration.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=3 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Week 3 Average Stimulus Charge for All Subjects	1115 nC Interval 500.0 to 4800.0

PRIMARY outcome

Timeframe: During days 22-28 of implant

Population: Participant 2 had the stimulator removed before week 3. Participants 1, 3, and 4 were included in this analysis.

The average stimulus (nC) required to evoke sensation during week 4 of implant duration.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=3 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Week 4 Average Stimulus Charge for All Subjects	902 nC Interval 300.0 to 3775.0

SECONDARY outcome

Timeframe: 30 days

Population: Participants with implanted spinal cord stimulator who were able to discern specific regions of the spinal cord that evoked sensations

Evaluate the relationship between stimulation parameters and the modality and naturalness of perceived sensations.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations Felt stimulation	4 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations Felt stim in hand	4 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations Felt stim in elbow	3 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations Felt stim in shoulder	2 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations Felt stim in fingers	4 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations C6 evoked stim	3 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations C7 evoked stim	3 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations C8 evoked stim	4 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations T1 evoked stim	4 Participants
Number of Participants Who Were Able to Discern Specific Regions of the Spinal Cord That Evoked Sensations T2 evoked stim	2 Participants

SECONDARY outcome

Timeframe: 30 days

Population: Participants implanted with spinal cord stimulator who reported sensations felt

Document the subjective perception of cervical 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.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=4 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Qualitative Self-report of Evoked Sensations Paresthetic sensation (primarily)	1 Participants
Qualitative Self-report of Evoked Sensations Mixed Modality (paresthetic and naturalistic)	2 Participants
Qualitative Self-report of Evoked Sensations Naturalistic (primarily)	1 Participants

SECONDARY outcome

Timeframe: 30 days

Population: Participants were asked to complete the McGill pain questionnaire at baseline, and weekly throughout implant. We expected to see a decrease in the pain level due to electrical stimulation. A positive score indicates a decrease in level of pain (baseline - study end). Three participants reported having phantom limb pain prior to the study.

Participants were asked to complete the McGill pain questionnaire at baseline, and weekly throughout implant. We expected to see a decrease in the pain level due to electrical stimulation. A positive score indicates a decrease in level of pain (baseline - study end). Minimum score is 0. Maximum score is 80. The higher the number, the greater the pain. This outcome measure suntracts the baseline pain score from the final pain score. A positive score indicates a reduction in pain from baseline.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=3 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Change in Pain Ratings After Study Completion Change in Pain Score (baseline - final)	14.3 score on a scale Interval 6.0 to 20.0
Change in Pain Ratings After Study Completion Baseline Pain Score	32.3 score on a scale Interval 29.0 to 35.0
Change in Pain Ratings After Study Completion Final Pain Score	18 score on a scale Interval 12.0 to 29.0

SECONDARY outcome

Timeframe: 30 days

Population: Person with upper limb amputation for over two years. This subject had a high trans-humeral amputation and did not have sufficient musculature in the residual limb to achieve reliable myoelectric control of the prosthesis. Instead, she wore a Data Glove (Fifth Dimension Technologies, 5 DT) on her contralateral, intact hand, and the grasp aperature from the Data Glove was used to proportionally control the aperture of the real and cirtual DEKA hand.

Investigators will test the subject's ability to use a myoelectric prosthetic hand 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 such as pressure at the finger tips or joint angles. In both the presence and absence of stimulation, subjects will be asked to perform tasks such as manipulating blocks, opening a jar, or identifying the stiffness and size of various objects.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=1 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Success Rate During Control of Prosthetic Hand to Identify Object Size	74 percentage of success identifying size

SECONDARY outcome

Timeframe: 30 days

Population: Person with upper limb amputation for over two years. This subject had difficulty achieving reliable prosthesis control, even with simple control schemes such as parallel dual-site control. As such, a highly simplified control scheme was implemented, in which the subject was instructed to attempt a hand grasp, and when this signal crossed a manually defined threshold, the DEKA hand was commanded to close at a constant velocity of 15 degrees/second.

Investigators tested the subject's ability to use a myoelectric prosthetic hand 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 was modulated based on signals recorded from the limb such as pressure at the finger tips or joint angles. In both the presence and absence of stimulation, subjects were asked to perform tasks such as manipulating blocks, opening a jar, or identifying the stiffness (soft, medium, hard) and size of various objects.

Outcome measures

Outcome measures
Measure	Boston Scientific Cord Stimulator Lead n=1 Participants A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Success Rate During Control of Prosthetic Hand to Identify Object Compliance (Soft, Medium, Hard)	60 percentage of success identifying compli

Adverse Events

Boston Scientific Cord Stimulator Lead

Serious events: 0 serious events

Other events: 2 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Boston Scientific Cord Stimulator Lead n=4 participants at risk A Boston Scientific Stimulator Lead (PMA P030017) will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance. Boston Scientific Stimulator Lead: A Boston Scientific (PMA P030017) spinal cord stimulator lead will be placed in the cervical epidural space of ten upper-limb amputees and steered laterally towards the dorsal spinal roots under fluoroscopic guidance.
Surgical and medical procedures Lead migration	50.0% 2/4 • 30 days (duration of implant)

Additional Information

Dr. Lee Fisher, PhD

University of Pittsburgh

Phone: 412-383-1077

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place