Brain Changes in Blepharospasm

December 13, 2019 updated by: National Institute of Neurological Disorders and Stroke (NINDS)

Suppression and Facilitation of the Motor Cortex by Stimulation of the Cerebellum in Patients With Dystonia and Healthy Controls

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.

TMS

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.

EMG

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.

Study Overview

Status

Terminated

Conditions

Detailed Description

Objective

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.

Design

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.

Study Type

Observational

Enrollment (Actual)

47

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

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center, 9000 Rockville Pike

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

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

  • INCLUSION CRITERIA:

PATIENTS:

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

HEALTHY CONTROLS:

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

EXCLUSION CRITERIA:

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

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

Collaborators and Investigators

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

Sponsor

National Institute of Neurological Disorders and Stroke (NINDS)

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

June 12, 2007

Study Completion

June 29, 2012

Study Registration Dates

First Submitted

June 15, 2007

First Submitted That Met QC Criteria

June 15, 2007

First Posted (Estimate)

June 18, 2007

Study Record Updates

Last Update Posted (Actual)

December 16, 2019

Last Update Submitted That Met QC Criteria

December 13, 2019

Last Verified

June 29, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 070165
  • 07-N-0165

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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