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Brain Changes in Blepharospasm

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. Read our disclaimer for details. Identifier: NCT00487383
Recruitment Status : Terminated
First Posted : June 18, 2007
Last Update Posted : December 16, 2019
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

This study will examine the role of certain areas of the brain in blepharospasm, a type of dystonia (abnormality of movement and muscle tone) that causes unwanted or uncontrollable blinking or closing of the eyelids. The study will compare brain activity in healthy volunteers and in people with blepharospasm to find differences in the brain that may lead to better treatments for dystonia.

Healthy volunteers and people with blepharospasm who are 18 years of age and older may be eligible for this study. All candidates are screened with a medical history. People with blepharospasm also have a physical examination and blepharospasm rating.

Participants undergo transcranial magnetic stimulation (TMS) and electromyography (EMG) in two 4-hour sessions, separated by 1 to 7 days.


A wire coil is held on the subject s scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. The subject hears a click and may feel a pulling sensation on the skin under the coil. There may be a twitch in muscles of the face, arm or leg. During the stimulation, subjects may be asked to tense certain muscles slightly or perform other simple actions. Repetitive TMS involves repeated magnetic pulses delivered in short bursts of impulses. Subjects receive 60 pulses per minute over 15 minutes.


Surface EMG is done during TMS to measure the electrical activity of muscles. For this test, electrodes (small metal disks) are filled with a conductive gel and taped to the skin of the face.

Condition or disease
Dystonia Focal Dystonia Cerebellar Disease

Detailed Description:


Besides alterations in the basal ganglia, substantial evidence identifies cerebellar dysfunction as a possible cause for dystonia. Pathophysiological findings suggest that the cerebellar influence on the primary motor cortex is modified in patients with different forms of dystonia. The objective of this study is to find out whether this cerebellar influence plays a role in dystonic disorders.

Study population

20 patients with blepharospasm, 20 patients with focal hand dystonia, 20 patients with DYT-1 Primary generalized dystonia and 60 healthy volunteers age and sex matched.


Paired pulse transcranial magnetic stimulation (TMS) will be performed at rest and during tonic activation of the first dorsal interosseus muscle (FDI). The conditioning stimulus (CS) will be applied to the ipsilateral cerebellum using different intensities and will precede the test stimulus by intervals from 3 to 10 ms, respectively. The test stimulus (TS) will be applied over the motor hot spot of FDI in the primary motor cortex.

Outcome measures

The primary outcome measure will be the motor evoked potential (MEP) in FDI after a conditioning cerebellar stimulus in relation to the unconditioned MEP size. Each different patient group will be compared separately to the age- and sex-matched healthy controls and between each other. Secondary outcome parameters will be the influence of different interstimulus intervals and different stimulation intensities of the conditioning stimulus on the MEP.

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Study Type : Observational
Actual Enrollment : 47 participants
Time Perspective: Prospective
Official Title: Suppression and Facilitation of the Motor Cortex by Stimulation of the Cerebellum in Patients With Dystonia and Healthy Controls
Study Start Date : June 12, 2007
Study Completion Date : June 29, 2012

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:   18 Years to 85 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes


  • Age 18 years or older
  • Normal findings in the medical history, physical and neurological examination, except for dystonia


  • Age 18 years or older
  • Absence of dystonia or other neurological disorder with any effect on the motor or sensory systems


Any of the following will exclude patients and controls from the study:

  • Secondary forms of dystonia, including tardive dyskinesia
  • History of seizure disorder
  • Symptoms of a clinically relevant illness in the 2 weeks before the first study day, including history of any other neurological disorders or conditions requiring the use of anti-depressants, neuroleptic medications, anti-seizure medications, anticholinergic drugs, and muscle relaxants
  • Taking the following medications: antidepressants, anxiolytics, anticonvulsants, antipsychotics, antiparkinson, hypnotics, stimulants, and/or antihistamines
  • History of neuroleptic medications
  • Presence of pacemaker, implanted medical pump, metal plate or metal object in skull or eye
  • Botulinum toxin injection within 3 months of starting the protocol
  • Known hearing loss

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): NCT00487383

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United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
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Principal Investigator: Mark Hallett, M.D. National Institute of Neurological Disorders and Stroke (NINDS)
Layout table for additonal information Identifier: NCT00487383    
Other Study ID Numbers: 070165
First Posted: June 18, 2007    Key Record Dates
Last Update Posted: December 16, 2019
Last Verified: June 29, 2012
Keywords provided by National Institutes of Health Clinical Center (CC):
Transcranial Magnetic Stimulation (TMS)
DYT-1 Generalized Dystonia
Focal Dystonia
Healthy Volunteer
Additional relevant MeSH terms:
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Dystonic Disorders
Cerebellar Diseases
Neurologic Manifestations
Nervous System Diseases
Movement Disorders
Central Nervous System Diseases
Eyelid Diseases
Eye Diseases
Brain Diseases