Nerve Stimulation to Modify a Spinal Reflex

NCT00039819 | Completed

• 2 other identifiers: 02022802-N-0228
• Study Type: observational
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Healthy

Keywords

Spinal Cord; Sensory Stimulation; Locomotion; Magnetic Stimulation; Reflexes; Healthy Volunteer; HV; Normal Control

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy adult volunteers willing to participate

You may not qualify if:

• History of peripheral neuropathy or radiculopathy
• Implanted devices, including pacemakers, pumps, and defibrillators
• Ankle contractures or tendon surgery

Sponsors & Collaborators

• National Institute of Neurological Disorders and Stroke (NINDS): lead

Study Sites (1)

National Institute of Neurological Disorders and Stroke (NINDS)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Burke RE. The central pattern generator for locomotion in mammals. Adv Neurol. 2001;87:11-24. No abstract available.

  PMID: 11347213 BACKGROUND

• Wirz M, Colombo G, Dietz V. Long term effects of locomotor training in spinal humans. J Neurol Neurosurg Psychiatry. 2001 Jul;71(1):93-6. doi: 10.1136/jnnp.71.1.93.

  PMID: 11413270 BACKGROUND

• Rossignol S. Locomotion and its recovery after spinal injury. Curr Opin Neurobiol. 2000 Dec;10(6):708-16. doi: 10.1016/s0959-4388(00)00151-3.

  PMID: 11240279 BACKGROUND

Study Design

• Study Type: observational
• Sponsor Type: NIH

Study Record Dates

• First Submitted: June 11, 2002
• First Posted: June 12, 2002
• Study Start: June 1, 2002
• Study Completion: May 1, 2003
• Last Updated: March 4, 2008

Record last verified: 2003-05

Locations

US (1)