Sensory Responses to Dorsal Root Stimulation

The goal of this project is to characterize the types of sensations that can be evoked via electrical stimulation of the spinal cord and spinal nerves. Patients will be recruited from a local pain clinic, each with a spinal cord stimulation device implanted, to participate in experiments to explore the ability to modulate and control the modality, intensity, focality, and location of the sensations evoked by stimulation through the spinal cord stimulator leads. Investigators will connect spinal cord stimulator leads to a custom stimulator system and will ask subjects to report the types of sensations felt. Invesigators will also perform detailed psychophysical metrics to examine participants' ability to discriminate sensations.

Study Overview

• Status: Withdrawn
• Conditions: Amputation; Sensation, Phantom
• Intervention / Treatment: Device: Spinal cord stimulation system

Detailed Description

For this study, investigators aim to determine whether DRG and spinal root stimulation might be viable techniques for restoring feedback. Investigators will focus on patients undergoing temporary percutaneous trials of DRG or lateral spinal cord stimulation with leads manufactured by either Boston Scientific (under PMA P030017) or St. Jude (under PMA P150004), which have FDA premarket approval for the management of chronic pain in the trunk and lower limbs. In this early experiment, investigators will not focus on individuals with limb loss, but rather will include patients already undergoing a percutaneous trial of DRG or spinal root stimulation to treat pain. Investigators will characterize the location, modality, and intensity of sensations evoked in the hands or feet with stimulation delivered by an external stimulator.

• Study Type: Observational
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Individuals undergoing a 7-day trial period of percutaneous DRG or spinal root stimulation.

Description

Inclusion Criteria:

1. Subjects must be between the ages of 18 and 70 years old.
2. Subjects must be undergoing an epidural spinal cord implanted electrode array clinical trial with Dr. Helm for the management of pain.
3. Persons must understand the consent and the procedures.

Exclusion Criteria:

1. Persons with open wounds;
2. Persons with implanted metal rods in the spine or limbs;
3. Persons with defibrillator or pacemaker;
4. Persons with permanent skin metal tags or decorations.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Stimulation in individuals with implanted stimulation systems; During psychophysical stimulation trials, an external stimulator will be connected to the SCS lead, a volley of stimulation will be performed, and the subject will be asked to respond to standard psychophysical questions, as well as to provide any additional comments.

Device: Spinal cord stimulation system; These systems are indicated as an aid in the management of chronic intractable pain of the trunk and/or limbs, including unilateral or bilateral pain associated with the following: failed back surgery syndrome, intractable low back pain and leg pain. Stimulation will be applied to the system using an external stimulator to see if sensations can be evoked in the participant's limb/foot.; Other Names: Boston Scientific; St. Jude

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Location of evoked sensory percepts	Document where on the body the subject perceives the stimulation locations.	up to 2 days
Stimulation perceptual thresholds to stimulus parameters	Quantify the threshold stimulus required to evoke sensory percepts during epidural spinal nerve stimulation.	up to 2 days
Stimulation neurophysiology thresholds to stimulus parameters	Quantify the threshold stimulus required to evoke neurophysiological responses during epidural spinal nerve stimulation	up to 2 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	up to 2 days

Collaborators and Investigators

• Sponsor: Lee Fisher, PhD
• Investigators: Principal Investigator: Lee Fisher, PhD, University of Pittsburgh

Study record dates

Study Major Dates

• Study Start (Actual): December 16, 2020
• Primary Completion (Actual): July 11, 2025
• Study Completion (Actual): October 7, 2025

Study Registration Dates

• First Submitted: January 21, 2021
• First Submitted That Met QC Criteria: January 21, 2021
• First Posted (Actual): January 26, 2021

Study Record Updates

• Last Update Posted (Estimated): October 15, 2025
• Last Update Submitted That Met QC Criteria: October 10, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: pain; spinal cord stimulation; sensation; amputation; dorsal root ganglia stimulation
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Neurobehavioral Manifestations; Perceptual Disorders; Pain, Postoperative; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Phantom Limb
• Other Study ID Numbers: STUDY20020043

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No