Mexiletine for the Treatment of Focal Dystonia

Dystonia refers to a condition characterized by involuntary muscle contractions that may cause pain, abnormal posture, or abnormal movements. The cause of dystonia is unknown, but some researchers believe it is a result of overactivity in the areas of the brain responsible for movement (basal ganglia).

Lidocaine is a drug used for the treatment of irregular heartbeats. It is given by injection. Recent studies have shown that lidocaine is also effective for the treatment dystonia. Mexiletine is a drug similar to lidocaine used for irregular heartbeats that can be taken by mouth.

Researchers would like to test the effectiveness of Mexiletine for the treatment of dystonia. Patients participating in the study will be divided into two groups;

Group 1 will take Mexiletine for six weeks then stop. They will remain drug free for one week then begin taking a placebo "inactive sugar pill" for an additional six weeks.

Group 2 will take a placebo "inactive sugar pill" for six weeks then stop. They will remain drug free for one week then begin taking a Mexiletine for an additional six weeks.

Throughout the study researchers will test the effectiveness of the treatment by evaluating patients using clinical rating scales and neurophysiological studies. In addition, researchers will test patient's reflexes in an attempt to find out where mexiletine works in the nervous system.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

Dystonia is a complex neurological disorder with an unknown pathogenesis likely involving the basal ganglia. There is no adequate treatment for dystonia. Recent studies using intramuscular and intravenous lidocaine have shown improvement in dystonic movements. It has been proposed that patients with dystonia have reduced presynaptic inhibition of alpha motoneurons leading to overactivation in response to movement. This may also reflect a hyperexcitability at the cortical level, which can be reduced by altering peripheral input.

Mexiletine, an antiarrhythmic similar to lidocaine, but available orally, may benefit patients with dystonia, as has been shown in several recent open-label studies. This trial offers the possibility of treating dystonia as well as further elucidating the level of dysfunction in the nervous system in dystonic patients. We propose a double-blind cross over study comparing mexiletine to placebo in the treatment of patients with idiopathic dystonia. The patients will be evaluated by clinical rating scales as well as neurophysiological studies. In order to study the physiologic effect and attempt to localize the neuroanatomic sight of action of mexiletine, studies of peripheral reflexes, reciprocal inhibition and cortical excitation will be performed. These studies will include blink reflex recovery curves, tonic vibration reflex, H-reflex and transcranial magnetic stimulation.

Study Type

Interventional

Enrollment

24

Phase

  • Phase 2

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

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institute of Neurological Disorders and Stroke (NINDS)

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

INCLUSION CRITERIA:

Patients with focal dystonia, specifically writer's cramp and blepharospasm, will be eligible for study.

Patients will need medical clearance, specifically, cardiac clearance, by their primary care physician. This will include an EKG within the past 12 months and no history of underlying cardiac disease.

EXCLUSION CRITERIA:

Patients with any of the following conditions will be excluded from the study: structural brain lesions, identifiable etiology for dystonia (such as stroke, trauma, Parkinson's Disease, Wilson's Disease, or peripheral neuropathy), contractures or fixed joint deformities, current or past use of neuroleptics, seizures, prior neurosurgery, or co-existent neurologic or general medical illness, including history of cardiovascular disease or peptic ulcer disease and pregnant or breast-feeding women.

Patients who are taking or have taken mexiletine will be excluded as well.

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

  • Primary Purpose: Treatment

Collaborators and Investigators

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

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.

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

July 1, 1998

Study Completion

July 1, 2002

Study Registration Dates

First Submitted

November 3, 1999

First Submitted That Met QC Criteria

November 3, 1999

First Posted (Estimate)

November 4, 1999

Study Record Updates

Last Update Posted (Estimate)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

July 1, 2002

More Information

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.

Clinical Trials on Dystonia

Clinical Trials on Mexiletine

3
Subscribe