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Improving Spinal Cord Stimulation With ECAPS

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04938245
Recruitment Status : Recruiting
First Posted : June 24, 2021
Last Update Posted : December 6, 2021
Information provided by (Responsible Party):
University of Minnesota

Brief Summary:
The purpose of this study will be to investigate the optimization of spinal cord stimulation with ECAPs in patients with spinal cord implants.

Condition or disease Intervention/treatment
Chronic Pain Device: Spinal Cord Stimulation

Detailed Description:
Spinal cord stimulation (SCS) or electrical stimulation in the epidural space of the spinal canal has been used for more than 50 years to treat chronic pain by modulating the activity of the spinal cord or spinal cord roots. While originally conceived out of gate theory, the precise effects of spinal cord stimulation are still an active area of research. Certainly there are multiple factors contributing to this unchanged responder rate including diagnosis, psychosocial factors, comorbidities, and implementation gaps, but a major technical hurdle remains personalizing therapy to engage in the precise pain circuits for each individual patient in anatomic location and over time. The delivery of spinal cord stimulation varies significantly with changes in position due to the movement of the spinal cord and its associated nerve roots. Existing spinal cord stimulation platforms rely on tonic stimulation with minimal adjustment with movements of the spinal cord or any adjustment due to changing physiology. Tonic stimulation assumes a stationary system that does not account for short or long-term effects of plasticity or movement. However, the effect of stimulation on the circuits of the spinal cord as with all stimulation of the nervous system can be measured through an event-related potential (ERP) synchronized to stimulation pulses, called the evoked compound action potential (ECAP). As an evoked-response, it is clear that ECAPs may provide a more dynamic insight into the underlying electrophysiologic system underlying the anatomic pathways of chronic pain, and some reports have correlated ECAPs to measures of pain relief, which is difficult to disassociate in patients with stable patterns of pain. The spatial variance of ECAP may imply that spinal cord stimulation for the purposes of pain relief is not homologous to features available in the ECAP signal but could be accessible in the variability of ECAP signal. Similarly, very little experimental evidence exists to incorporate the complex role of pain processing and valuation systems into a model of ECAP electrophysiology. Namely, the correlation between top-down control and higher-order (cognitive/mood) circuit interactions with ECAP features and chronic pain. Understanding the electrophysiology of evoked responses in the spinal cord in the competitive market of non-opioid pain relief should be grounded in basic pain phenotype modeling. This proposal represents the first step in that pathway by studying the feasibility of capturing ECAPs during clinical externalization while collecting the necessary data for behavioral modeling for future causal analysis with ECAP features. This protocol establishes the first step towards closed-loop stimulation through open-loop measurement and stimulation during an existing clinical paradigm. This study aims to understand the feasibility of implementing ECAP during the externalization period of a clinical trial while simultaneously providing clinical feedback for optimal settings discovered during testing.

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Study Type : Observational
Estimated Enrollment : 15 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Improving Spinal Cord Stimulation With ECAPS
Actual Study Start Date : August 18, 2021
Estimated Primary Completion Date : August 2023
Estimated Study Completion Date : August 2023

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Chronic Pain

Group/Cohort Intervention/treatment
Observed Cohort
Participants with chronic pain scheduled to undergo externalized trial for assessment of spinal cord stimulation will undergo intraoperative stimulation and up to three postoperative visits where already externalized electrodes (used clinically for stimulation) will be used to record and stimulate using evoked complex action potentials (ECAPs) while also measuring other electrophysiological responses.
Device: Spinal Cord Stimulation

Intraoperatively, stimulation at 12 Hz will be performed as the leads are moved into the targeted position. Amplitude will be increased to 15 mA maximum total until a response is seen on any electrode and held for 10 seconds. Stimulation and recording will be performed using the Neuralynx stim/record system.

Post-operatively, the electrodes will be tested for impedance by the clinical system and then they will be connected to the Neuralynx stim/record system. Electrode stimulation patterns will be applied with increasing amplitude until ECAPs responses are seen on recording electrodes. 42 Hz stimulation will be performed with an amplitude sweep of 0mA-10mA. At each amplitude, stimulation will be applied for 4 seconds followed by 2 seconds of rest. Pulse width will be varied from 30-450 microseconds to test effective amplitude. Bursting stimulation will be applied to detect differences in ECAPs as above.

Primary Outcome Measures :
  1. Feasibility Assessed by Enrollment [ Time Frame: 2 weeks ]
    Feasibility will be measured as a number of the number of enrolled participants who complete at least 80% of the planned assessments.

Secondary Outcome Measures :
  1. Acceptability Assessed by Survey [ Time Frame: 2 weeks ]
    Acceptability will be measured as the average rating of a five-point qualitative scale ranging from "Excellent" to "Very Poor." Scores range with 1-5 with lower scores indicating greater acceptability.

Other Outcome Measures:
  1. Correlation of ECAP peak to peak signals to programming parameters [ Time Frame: 2 weeks ]
  2. Correlation of ECAP signals to pain relief [ Time Frame: 2 weeks ]
  3. Stability and reliability of ECAP sensing [ Time Frame: 2 weeks ]
  4. Reliability of ECAP across various levels intraoperatively [ Time Frame: 2 weeks ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   22 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Adults scheduled to undergo externalization of spinal cord stimulation.

Inclusion Criteria:

  • Medically stable as determined by the principal investigator
  • Scheduled to undergo externalization of spinal cord stimulation
  • English-speaking

Exclusion Criteria:

  • Scheduled for permanent implantation only without trial
  • Have pacemakers or other neurostimulators
  • Pregnancy

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04938245

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Contact: David Darrow, MD, MPH (612)-634-6666
Contact: Alexander Herman, MD, PhD 612-625-1194

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United States, Minnesota
University of Minnesota Recruiting
Minneapolis, Minnesota, United States, 55455
Sponsors and Collaborators
University of Minnesota
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Principal Investigator: David Darrow, MD, MPH University of Minnesota Medical School Department of Neurosurgery
Principal Investigator: Alexander Herman, MD, PhD University of Minnesota Medical School Department of Psychiatry
Principal Investigator: Tay Netoff, PhD University of Minnesota Department of Biomedical Engineering
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Responsible Party: University of Minnesota Identifier: NCT04938245    
Other Study ID Numbers: NEUROSURG-2021-29717
First Posted: June 24, 2021    Key Record Dates
Last Update Posted: December 6, 2021
Last Verified: December 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description:

In line with recent requirements of scientific journals, preprocessed and anonymized data will be made available for the research community.

It will be deposited on the public repository Zenodo (or equivalent) for 5 years.

Time Frame: 5 years

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Additional relevant MeSH terms:
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Chronic Pain
Neurologic Manifestations