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Surround Inhibition in Patients With Dystonia

This study has been completed.
Information provided by:
National Institutes of Health Clinical Center (CC) Identifier:
First received: January 15, 2002
Last updated: March 3, 2008
Last verified: July 2002

This study will use transcranial magnetic stimulation (TMS) to examine how the brain controls muscle movement in dystonia. Dystonia is a movement disorder in which involuntary muscle contractions cause uncontrolled twisting and repetitive movement or abnormal postures. Dystonia may be focal, involving just one region of the body, such as the hand, neck or face. Focal dystonia usually begins in adulthood. Generalized dystonia, on the other hand, generally begins in childhood or adolescence. Symptoms begin in one area and then become more widespread.

Healthy normal volunteers and patients with focal [or generalized] dystonia [between 21 and 65 years of age] may be eligible for this study.

Participants will have transcranial magnetic stimulation. For this test, subjects are seated in a comfortable chair, with their hands placed on a pillow on their lap. An insulated wire coil is placed on the scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. (This may cause muscle, hand or arm twitching if the coil is near the part of the brain that controls movement, or it may induce twitches or transient tingling in the forearm, head or face muscles.) During the stimulation, subjects will be asked to either keep their hand relaxed or move a certain part of the hand in response to a loud beep or visual cue. Metal electrodes will be taped to the skin over the muscle for computer recording of the electrical activity of the hand and arm muscles activated by the stimulation.

There are three parts to the study, each lasting 2-3 hours and each performed on a separate day.

Dystonic Disorders

Study Type: Observational
Official Title: The Study of Surround Inhibition in Patients With Dystonia

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 60
Study Start Date: January 2002
Estimated Study Completion Date: July 2002
Detailed Description:
The purpose of this study is to evaluate modulation of inhibition within the motor cortex before and during movement in patients with focal dystonia. For a selective movement or task, certain muscles are normally recruited and others are inhibited at the cortical level. We hypothesize that a disturbance in this cortical inhibitory control could result in a failure to focus the desired motor action within the motor cortex (disturbed center surround inhibition) and may account for co-contraction of antagonist muscles and overflow into extraneous muscles in dystonic patients. Intracortical inhibition (ICI) and silent period (SP) are two major cortical inhibitory mechanisms demonstrated by transcranial magnetic stimulation (TMS). Alteration in these inhibitory mechanisms have been studied in dystonia at rest, however, as dystonic symptoms mainly occur with selective tasks or movements we plan to study intracortical inhibitory mechanisms before and during movement using different TMS paradigms.

Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Healthy volunteers entering the study must be free of serious somatic disease.

Patients must have focal dystonia.

Subjects who have a pacemaker, an implanted medication pump, a metal plate in the skull, metal objects inside the eye or skull (for example, after brain surgery or a shrapnel wound) or any recent (less than 3 months) brain lesions, will be excluded.

  Contacts and Locations
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Please refer to this study by its identifier: NCT00029601

United States, Maryland
National Institute of Neurological Disorders and Stroke (NINDS)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
  More Information

Publications: Identifier: NCT00029601     History of Changes
Other Study ID Numbers: 020088
Study First Received: January 15, 2002
Last Updated: March 3, 2008

Keywords provided by National Institutes of Health Clinical Center (CC):
Focal Dystonia
Magnetic Stimulation
Intracortical Inhibition
Intracortical Facilitation
Motor Evoked Potential
Reaction Time
Transcranial Magnetic Stimulation
Healthy Volunteer
Normal Control

Additional relevant MeSH terms:
Dystonic Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Movement Disorders
Central Nervous System Diseases processed this record on April 21, 2017