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.

Condition
Myotonia Congenita Myotonic Disorders

Further study details as provided by Office of Rare Diseases (ORD):

Expected Total Enrollment:  75

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 above,  Genders Eligible for Study:  Both

Criteria

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

Please refer to this study by ClinicalTrials.gov identifier  NCT00244413

Laura Herbelin      913-588-6970    lherbelin@kumc.edu

Kansas
      University of Kansas Medical Center, Department of Neurology, Kansas City,  Kansas,  66160,  United States
Maryland
      National Institutes of Health, NINDS, Neuromuscular Diseases Section, Bethesda,  Maryland,  20892,  United States
Massachusetts
      Brigham & Women''''s Hospital, Department of Neurology, Boston,  Massachusetts,  02115,  United States
New York
      University of Rochester School of Medicine and Dentistry, Department of Neurology, Rochester,  New York,  14642,  United States
United Kingdom
      Center for Neuromuscular Disease, Institute of Neurology and National Hospital for Neurology, London,  WC1N 3BG,  United Kingdom

Study chairs or principal investigators

Richard Barohn, MD,  Principal Investigator,  University of Kansas   

Study ID Numbers:  5U54RR019482-01
Last Updated:  December 29, 2005
Record first received:  October 24, 2005
ClinicalTrials.gov Identifier:  NCT00244413
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2006-01-10