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Tonic muscular spasm occurring after injury or infection.



a hereditary neuromuscular disease in which a contracted muscle is unable to relax for a long time; muscular relaxation proceeds very slowly. Depending on the clinical course of the disease, congenital, atrophic, cold, and paradoxical forms of myotonia are distinguished. The disease may occur in several members of a family; males are more often affected. There are no marked morphological changes in the nervous system or the muscles. There may be dysfunctions of the autonomic nervous system and the endocrine glands. Increased sensitivity to acetylcholine and potassium are characteristic of the disease. The principal sign of myotonia is impaired myofibril contractility, that is, relaxation of contracted muscles is greatly impaired. The muscles are firm to the touch. Myotonia progresses slowly, with general deterioration frequently setting in after overexposure to low temperatures, mental stress, and excessive fatigue. Treatment includes hormone therapy, vitamin therapy, and physical therapy.


Badalian, L. O., V. A. Tabolin, and Iu. V. Vel’tishchev. Nasledstvennye bolezni u detei. Moscow, 1971.
References in periodicals archive ?
Spectrum of CLCN1 mutations in patients with myotonia congenita in Northern Scandinavia.
Functional consequences of chloride channel gene (CLCN1) mutations causing myotonia congenita.
Mutations in the human skeletal muscle chloride channel gene (CLCN1) associated with dominant and recessive myotonia congenita.
However, it differs from myotonia congenita in being more readily triggered by cold and in that the myotonia in paramyotonia congenita becomes worse rather than better with repetitive activity.
A number of different defects in this same gene have been found to be associated with hyperkalemic periodic paralysis, at least one form of myotonia congenita and paramyotonia congenita.