Nerve Stimulation to Modify a Spinal Reflex

Plasticity of Reciprocal Inhibition

This study will determine whether stimulating the nerves or the brain can modify the spinal reflex that controls the muscles that flex and extend the ankle. Training spinal nerve networks with sensory input may provide a way of re-establishing movements, such as walking, in patients with spinal injury.

Healthy normal volunteers with no history of peripheral neuropathy or radiculopathy, ankle contractures or tendon surgery may be eligible for this study. Participants will undergo three stimulation procedures, each in a different session, to measure leg muscle reflexes. The procedures are:

  • Reflex testing - Metal electrodes are taped to the skin over the leg muscles. A small electrical pulse is delivered through the electrodes to stimulate two nerves to the muscles. This evokes a reflex between the ankle flexor and extensor muscles. The responses to several dozen stimuli are averaged.
  • Nerve stimulation - The nerve to the muscle that flexes the leg is electrically stimulated near the knee through electrodes taped to the skin. The strength of the stimulus is adjusted to produce little or no muscle movement. The stimulation is repeated every few seconds for 45 minutes.
  • Transcranial magnetic stimulation - An insulated wire coil is placed on the subject's scalp. A brief electrical current passes through the coil, creating a magnetic pulse that travels through the scalp and skull and causes small electrical currents in the outer part of the brain. There may be twitching in the muscles of the arm or leg. During the stimulation, the subject may be asked to tense certain muscles slightly or perform other simple actions to help determine the best position for the coil over the part of the brain that controls the leg. The leg is then stimulated once every 10 seconds, combined with nerve stimulation every 1 to 2 seconds.

Study Overview

Status

Completed

Conditions

Detailed Description

Training of spinal interneuronal networks may offer a means for re-establishing movements such as locomotion in patients with spinal injury. Sensory feedback in the pattern which results from the leg movement is hypothesized to be the critical component for training spinal networks. This protocol will address the basic assumption underlying such training: can a specific pattern of sensory input modify the strength of a spinal cord circuit? We will test whether peripheral nerve stimulation can modify the strength of the spinal reflex mediating reciprocal inhibition between ankle flexor and extensor muscles in normal subjects, comparing patterned and unpatterned stimulation.

Study Type

Observational

Enrollment

25

Contacts and Locations

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

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institute of Neurological Disorders and Stroke (NINDS)

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

INCLUSION CRITERIA:

Healthy adult volunteers willing to participate

EXCLUSION CRITERIA:

History of peripheral neuropathy or radiculopathy

Implanted devices, including pacemakers, pumps, and defibrillators

Ankle contractures or tendon surgery

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?

Collaborators and Investigators

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

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.

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

June 1, 2002

Study Completion

May 1, 2003

Study Registration Dates

First Submitted

June 11, 2002

First Submitted That Met QC Criteria

June 11, 2002

First Posted (Estimate)

June 12, 2002

Study Record Updates

Last Update Posted (Estimate)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

May 1, 2003

More Information

Terms related to this study

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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