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Characteristics of Nondystrophic Myotonias

This study has been completed.
Office of Rare Diseases (ORD)
Rare Diseases Clinical Research Network
Information provided by (Responsible Party):
Richard Barohn, MD, University of Kansas Medical Center Research Institute Identifier:
First received: October 24, 2005
Last updated: March 5, 2013
Last verified: March 2013
Nondystrophic myotonias (NDM) are muscle disorders caused by genetic abnormalities in certain muscle cell membrane proteins. Individuals with NDM experience limited muscle relaxation, which causes pain, weakness, and impaired physical activity. The purpose of this study is to better characterize the clinical features and symptoms of NDM.

Nondystrophic Myotonias
Myotonia Congenita
Myotonic Disorders

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Nondystrophic Myotonias: Genotype-phenotype Correlation and Longitudinal Study

Resource links provided by NLM:

Further study details as provided by Richard Barohn, MD, University of Kansas Medical Center Research Institute:

Primary Outcome Measures:
  • Examine the frequency applicable events related to Nondystrophic Myotonia [ Time Frame: Baseline - 3 yrs ]
    We will measure by an interactive voice response to measure stiffness, pain, weakness, and fatigue.

Biospecimen Retention:   Samples With DNA
Blood samples

Enrollment: 94
Study Start Date: February 2006
Study Completion Date: September 2012
Primary Completion Date: September 2012 (Final data collection date for primary outcome measure)
Detailed Description:

Nondystrophic myotonias are muscle disorders caused by abnormal muscle cell membrane proteins that affect the control of muscle fiber contraction. These disorders are extremely rare, and little is known about how to best treat the various subtypes of NDM. The purpose of this study is to characterize the clinical features and symptoms of NDM as well as to pair this data with specific NDM subtypes. In turn, this may lead to the development of improved treatments. The study will also establish clinical endpoints for use in future studies.

This multi-center observational study will involve both a cross-sectional data analysis and a prospective longitudinal analysis. Participants will initially attend a one-day outpatient study visit. Various baseline measurements will be collected, including demographics, medical history, and quality of life measures. Blood samples will be taken to evaluate laboratory values and genetic factors. Participants will undergo manual muscle testing (MMT), clinical myotonia assessments, and functional movement assessments. Routine nerve conduction studies and electromyography (EMG) will also be performed in order to test for the presence of myotonia in specific muscles. Annual follow-up evaluations will occur 1 and 2 years following the first study visit.


Ages Eligible for Study:   6 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Individuals with nondystrophic myotonia

Inclusion Criteria:

  • Clinical symptoms or signs suggestive of myotonia
  • Presence of myotonic potentials on electromyography (EMG)
  • Persistence of symptoms and signs after discontinuation of medications that produce myotonia; such medications include fibric acid derivatives, hydroxymethylglutaryl CoA reductase inhibitors, chloroquine, and colchicine
  • Absence of features suggestive of myotonic dystrophy, including ptosis, temporal wasting, mandibular weakness, cataracts occurring before age 50, and evidence of multisystem defects (cardiac conduction defects, hypogonadism)

Exclusion Criteria:

  • Any other neurologic condition that might affect the assessment of the study measurements
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00244413

United States, Kansas
University of Kansas Medical Center, Department of Neurology
Kansas City, Kansas, United States, 66160
United States, Massachusetts
Brigham & Women's Hospital, Department of Neurology
Boston, Massachusetts, United States, 02115
United States, New York
University of Rochester School of Medicine and Dentistry, Department of Neurology
Rochester, New York, United States, 14642
United States, Texas
University of Texas Southwestern Medical Center
Dallas, Texas, United States, 75390-9036
Canada, Ontario
London Health Sciences Centre, University Hospital
London, Ontario, Canada
United Kingdom
Center for Neuromuscular Disease, Institute of Neurology and National Hospital for Neurology
London, United Kingdom, WC1N 3BG
Sponsors and Collaborators
Richard Barohn, MD
Office of Rare Diseases (ORD)
Rare Diseases Clinical Research Network
Principal Investigator: Richard Barohn, MD University of Kansas Medical Center
  More Information

Responsible Party: Richard Barohn, MD, Gertrude and Dewey Zeigler Professor of Neurology and Chair, University of Kansas Medical Center Research Institute Identifier: NCT00244413     History of Changes
Other Study ID Numbers: 10263
Study First Received: October 24, 2005
Last Updated: March 5, 2013

Keywords provided by Richard Barohn, MD, University of Kansas Medical Center Research Institute:
Paramyotonia Congenita
Thomsen's Disease

Additional relevant MeSH terms:
Myotonia Congenita
Myotonic Disorders
Neuromuscular Manifestations
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Muscular Diseases
Musculoskeletal Diseases
Heredodegenerative Disorders, Nervous System
Neurodegenerative Diseases
Neuromuscular Diseases
Genetic Diseases, Inborn processed this record on May 25, 2017