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Transcranial Electrical Polarization to Treat Focal Hand Dystonia

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: NCT00106782
Recruitment Status : Completed
First Posted : March 30, 2005
Last Update Posted : July 2, 2017
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

This study will evaluate the effect of transcranial electrical polarization (TEP), also called direct current (DC) stimulation, on focal hand dystonia in people with writer's cramp. In dystonia, muscle spasms cause uncontrolled twisting and repetitive movement or abnormal postures. Focal dystonia involves just one part of the body, such as the hand, neck or face. When people with focal hand dystonia make small and repeated movements with their hands, there is extra activity in the part of the brain called the motor cortex. TEP is a method of brain stimulation that slows down the activity of the nerve cells in the motor cortex. This study may help researchers develop new ways to treat focal hand dystonia.

People 18 years of age and older with focal hand dystonia may be eligible for this study. Participants have a neurological examination and are randomly assigned to one of two treatment groups: TEP or placebo stimulation. The TEP group receives stimulation to the parts of the brain used for hand movement, and the placebo group receives sham stimulation, which does not affect any area of the brain. There are three TEP/placebo sessions over a period of 7 to 10 days. The first session may last up to 2-1/2 hours; the other two sessions last 1-2 hours.

For TEP, sponge electrodes are placed on the scalp and an electrical current is passed through the scalp and skull to the outer part of brain. Before and after each session, participants have a neurological examination, including an evaluation of the rate and severity of their movement problems. For this assessment, participants do a writing test while the electrical activity of their hand muscles is recorded using surface electromyography (EMG). For EMG, small metal disks (electrodes) filled with a conductive gel are taped to the skin over the muscles being tested.

Patients are followed in the clinic the day after the end of TEP treatment for evaluation of their movement abilities and the effects of therapy, such as improvement of handwriting.

Condition or disease Intervention/treatment Phase
Dystonia Focal Hand Dystonia FHD Procedure: Transcranial Electrical Polarization (TEP) Phase 2

Detailed Description:

Objective: The treatment of focal hand dystonia (FHD) needs further improvement. A deficiency of inhibition was demonstrated in patients with writer's cramp. The passage of weak DC currents across the head, or transcranial electrical polarization (TEP) has been done for many years with numerous effects described in healthy subjects and mentally diseased patients. Recently, it has been shown by objective means, in controlled experiments, that this type of treatment has robust and lasting effects on the excitability of the motor cortex in healthy humans.

Study population: 40 subjects with focal hand dystonia.

Design: We hypothesize that TEP will have a beneficial effect on hand writing in patients with FHD because it will decrease the excitability of the motor cortex compensating the deficiency of inhibition. Specifically, we propose to look at the effect of 2 mA TEP with cathode position over the hand projection in the contralateral to the affected hand primary motor cortex. Anodes will be placed over the orbit and mastoid process ipsilateral to the affected hand (contralateral to the cathode). Over a two-year period, we will enroll 40 patients with FHD and evaluate the acute TEP effects over a period of 1 week (3 TEP sessions).

Outcome measures: Symptoms will be evaluated by kinematic analysis of the handwriting and with dystonia scales.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 12 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Placebo Controlled Study of the Therapeutic Effect of the Transcranial Electrical Polarization in Patients With Focal Hand Dystonia
Study Start Date : March 18, 2005
Actual Primary Completion Date : May 14, 2010
Actual Study Completion Date : May 14, 2010

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Dystonia

Arm Intervention/treatment
Real TEP
Procedure: Transcranial Electrical Polarization (TEP)
Sham Stimulation
Procedure: Transcranial Electrical Polarization (TEP)

Primary Outcome Measures :
  1. The Fahn Dystonia Scale before and after real and placebo TEP course. [ Time Frame: 1 week post-TEP ]

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 and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
  • Subjects with focal hand dystonia 18 years old or older will be included.


Exclusion criteria will include the standard exclusions for TEP as well as exclusions specific to this study.

We will exclude subjects with:

  • Any significant medical or psychiatric illness (other than FHD).
  • Patients with a positive pregnancy test will be excluded because the effects of TEP on the fetus is unknown. A urine sample for pregnancy testing will be obtained prior to the TEP, and on the day of the first TEP session.
  • History of epilepsy.
  • Concurrent use of neuroleptic agents.
  • Any other licit or illicit drugs other that could lower the seizure threshold.
  • Metal implants.
  • Who have received botulinum toxin injection within 10 weeks of starting the protocol.
  • Secondary hand dystonia.
  • Mentally impaired patients having no capacity to provide their own consent will be excluded from the study because such patients may have difficulty performing the required test.
  • If participation in the study would, in the opinion of the investigators, cause undue risk or stress for reasons such as excessive fatigue, general frailty, or excessive apprehension.
  • Unable or unwilling to refrain from alcohol for 24 hours prior to study days.

Patients may continue taking muscle relaxants, artane and other anticholinergic drugs, L-DOPA and dopamine agonists.

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): NCT00106782

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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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Responsible Party: Mark Hallett, M.D./National Institute of Neurological Disorders and Stroke, National Institutes of Health Identifier: NCT00106782     History of Changes
Other Study ID Numbers: 050122
First Posted: March 30, 2005    Key Record Dates
Last Update Posted: July 2, 2017
Last Verified: May 14, 2010
Keywords provided by National Institutes of Health Clinical Center (CC):
Focal Hand Dystonia
Additional relevant MeSH terms:
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Dystonic Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Movement Disorders
Central Nervous System Diseases