Cervical Spinal Cord Associative Plasticity

May 19, 2026 updated by: Jason Carmel, Columbia University

Paired Non-invasive Stimulation of Hand Motor Cortex and Median Nerve to Induce Plasticity in the Cervical Spinal Cord

Associative plasticity has been used to promote functional recovery from conditions affecting movement. Prior work from the Carmel laboratory has shown that paired associative stimulation protocols timed to converge in the cervical spinal cord induce significantly larger upper limb motor responses than if timed to converge in the motor cortex.

The goal of this prospective experimental study in typically developing adults is to test the effects of pairing sub-threshold hand motor cortical and median nerve stimulation targeted to induce plasticity in the cervical spinal cord, rather than in the motor cortex. Based on preliminary data, the investigators are performing a confirmatory study to test the physiological and behavioral effects of the paired brain and peripheral nerve protocol, called the SCAP-Nerve protocol.

This study will first be conducted in typically developing adults to confirm the cervical spinal cord as the ideal target and verify the present stimulation parameters are sufficient to promote induction of associative plasticity of sensorimotor connections for manual dexterity. The outcomes from this study could then be translated to efficacy studies in people with spinal cord injury and cerebral palsy to promote clinically meaningful improvements in dexterity.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Associative plasticity has been used to promote functional recovery in patient populations, such as adults with spinal cord injuries (SCI). Using non-invasive neuromodulation approaches, pairing of motor cortical stimulation and peripheral nerve stimulation has been shown to augment motor responses and promote plasticity, primarily through the convergence of sensory afferent stimuli and descending cortical stimuli in the motor cortex.

However, prior work from the Carmel laboratory has shown that paired associative stimulation timed to converge in the cervical spinal cord induces significantly larger upper limb motor responses than if timed to converge in the motor cortex. While paired associative stimulation has shown promise for strengthening motor responses, it is unclear if plasticity from convergence of non-invasive stimuli in the spinal cord (termed spinal cord associative plasticity or SCAP) instead of the motor cortex can produce greater motor effects, and potentially greater promotion of movement recovery.

The goal of this present study is to test the effects of pairing sub-threshold hand motor cortical and median nerve stimulation targeted to induce plasticity in the cervical spinal cord, rather than in the motor cortex. The investigators aim to fill a knowledge gap regarding the ideal target of non-invasive stimulation to maximize associative plasticity for upper limb movement recovery. The study hypothesis is that pairing low-intensity stimulation of the hand motor cortex with low-intensity median nerve stimulation will produce associative plasticity in the cervical spinal cord measured through augmentation of motor responses in upper limb muscles.

Based on preliminary data, the investigators are performing a confirmatory study to test the physiological and behavioral effects of the paired brain and peripheral nerve protocol, called the SCAP-Nerve protocol. This protocol uses a specific set of TMS (transcranial magnetic stimulation) and PNS (peripheral nerve stimulation) parameters: targeting hand motor cortex at 90% resting motor threshold and targeting median nerve sensory afferents (with a nerve stimulus pulse duration of 1000 microseconds) at 90% resting motor threshold, precisely timed to converge in the cervical spinal cord.

This study will first be conducted with a single session of 90 trials of pairing in typically developing adults to confirm the cervical spinal cord as the ideal target and verify the present stimulation parameters as sufficient to promote induction of associative plasticity of sensorimotor connections for manual dexterity. Prior work from the Carmel laboratory has shown that the magnitude and duration of lasting effects of paired motor cortex and afferent stimulation is similar in rodents with and without neural injury.

This then drives the premise for this study that the identification of the cervical spinal cord as an ideal target for associative plasticity involving cortical and sensory afferents would inform translation to people suffering from neurological injuries such as spinal cord injury and cerebral palsy. The outcomes from this study could be translated to efficacy studies in these patient populations to determine if this plasticity is present in those populations as well. This could then lead to the investigation of whether pairing brain and afferent-targeted nerve stimulation for convergence in the cervical spinal cord can lead to clinically meaningful improvements in manual dexterity.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • New York
      • New York, New York, United States, 10040
        • Recruiting
        • Columbia University Irving Medical Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Willingness to participate in up to 4 sessions
  • Maintenance of caffeine and exercise levels at time of sessions
  • Ability to provide informed consent
  • No known central or peripheral neurological disease or injury
  • No known musculoskeletal injury of the tested arm or hand

Exclusion Criteria:

  • Personal or family history of seizures
  • Use of medications that lower seizure threshold
  • History of implanted equipment including stimulators/pacemakers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SCAP
With this session, participants will receive 90 trials of 0.1hz paired motor cortical stimulation and median nerve stimulation for 15 minutes at sub-threshold intensities, timed to converge in the cervical spinal cord simultaneously.
Other: SCAP
This utilizes pairing of repetitive transcranial magnetic stimulation (rTMS) and peripheral nerve stimulation (rPNS) timed to converge in the cervical spinal cord.
Active Comparator: Cortical stimulation only
With this session, participants will receive 90 trials of 0.1hz motor cortical stimulation for 15 minutes at sub-threshold intensities.
Device: MagPro X100
This stimulator will be use to provide repetitive transcranial magnetic stimulation (rTMS).
Active Comparator: Median nerve stimulation only
With this session, participants will receive 90 trials of 0.1hz median nerve stimulation for 15 minutes at sub-threshold intensities.
Device: Digitimer DS8R
This stimulator will be used to provide repetitive peripheral nerve stimulation (rPNS).
Active Comparator: Paired non-associative stimulation
With this session, participants will receive 90 trials of 0.1hz paired motor cortical stimulation and median nerve stimulation for 15 minutes at sub-threshold intensities, timed to be 40 milliseconds apart in the cervical spinal cord.
Other: Paired non-associative stimulation
This utilizes pairing of repetitive transcranial magnetic stimulation (rTMS) and peripheral nerve stimulation (rPNS) timed to arrive at a pairing interval of 40 msec.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Size of muscle response to brain stimulation after SCAP (percentage)
Time Frame: 30 minutes after SCAP
Size of muscle response will be measured in response to brain stimulation. This value will be normalized to the equivalent measure taken before the SCAP protocol.
30 minutes after SCAP

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Size of muscle response to nerve stimulation during combined brain and nerve stimulation after SCAP (percentage)
Time Frame: Immediately after intervention, up to 1 minute
Size of muscle response will be measured in response to brain and median nerve stimulation timed to converge in the spinal cord. This value will be normalized to the equivalent measure taken before the SCAP protocol.
Immediately after intervention, up to 1 minute
Size of muscle response to nerve stimulation during combined brain and nerve stimulation (percentage)
Time Frame: Immediately after intervention, up to 1 minute
Size of muscle response will be measured in response to brain and median nerve stimulation timed to converge in the spinal cord. This value will be normalized to the muscle response for nerve only stimulation.
Immediately after intervention, up to 1 minute
Size of muscle response to nerve stimulation during combined brain and nerve stimulation after SCAP (percentage)
Time Frame: 30 minutes after SCAP
Size of muscle response will be measured in response to brain and median nerve stimulation timed to converge in the spinal cord. This value will be normalized to the equivalent measure taken before the SCAP protocol.
30 minutes after SCAP
Duration of effect of SCAP on subsequent responses to brain stimulation
Time Frame: 30 minutes after SCAP
Time in minutes taken for the size of muscle response to fall to 50% of its maximal post-SCAP level.
30 minutes after SCAP
Pinch force variability
Time Frame: 30 minutes after SCAP
The coefficient of variation of the pinch opposition strength between the tips of the thumb and the second finger using a handheld dynamometer. This will be recorded and compared to baseline measurements.
30 minutes after SCAP
Pinch force speed
Time Frame: 30 minutes after SCAP
The rate of force development of the pinch opposition strength between the tips of the thumb and the second finger using a handheld dynamometer. This will be recorded and compared to baseline measurements.
30 minutes after SCAP

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Columbia University

Investigators

  • Principal Investigator: Jason Carmel, MD, PhD, Columbia University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 9, 2026

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

June 1, 2029

Study Registration Dates

First Submitted

April 13, 2026

First Submitted That Met QC Criteria

April 13, 2026

First Posted (Actual)

April 20, 2026

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 19, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AAAV2760-TD

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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