Special Characteristics
- Voluntary muscles do not relax after intense effort applied
- Classified by Thomsen Disease and Becker Disease
- Thomsen Disease
- Becker Disease-appears in late childhood; more common in males
- 1 in 100,000 in the US; 1 in 10,000 in Switzerland
Causes
- Genetic disorder; subjects have at least parent with myotonia
- autosomal dominant pattern
- Two types (Becker disease and Thomsen disease) differentiated by physical characteristics for microscopic similarities
Signs and Symptoms
- Occurs most often in legs, thought can happen in any skeletal muscle
- Usually starts at birth or early childhood
Diagnosis
- Tested with EMGs, genetics testing, and muscle biopsies
Treatment
- Prescribed medication including phenytoin, procainamide, quinine, and tocainide.
References
Cure Byte. (2011, August 29). Clinical trials and related photos for Myotonia congenita. Retrieved September 15, 2013, from http://trialx.com/curetalk/wp-content/blogs.dir/7/files/2011/05/diseases/Myotonia_Congenita-2.jpg
DM1 - Myotonic Dystrophy type 1. (n.d.). Prosensa. Retrieved November 15, 2013, from http://www.prosensa.eu/patients-and-family/myotonic-dystrophy
Myotonia Congenita. (n.d.). The New York Times: Health guide. Retrieved November 14, 1996, from http://www.nytimes.com/health/guides/disease/myotonia-congenita/
Myotonia congenita. (n.d.). Genetics Home Reference. Retrieved November 15, 2013, from http://ghr.nlm.nih.gov/condition/myotonia-congenita
