What is Myotonia?
Myotonia is a medical term that refers to a neuromuscular condition in which the relaxation of a muscle is delayed or slowed. It can affect any muscle group. Repeated effort will be needed to relax the muscle, although the condition usually improves after the muscles have warmed-up. Individuals with myotonia may have trouble releasing their grip on objects or may have difficulty rising from a seated position. They may walk with a stiff, awkward gait. Myotonia is caused by an abnormality in the muscle membrane, and is often associated with inherited neurological disorders. Myotonia is commonly seen in individuals with myotonic muscular dystrophy and in people who have one of a group of neurological disorders called the channelopathies, which are inherited diseases that are caused by mutations in the chloride sodium or potassium channels that regulate the muscle membrane. Myotonia may also be triggered by exposure to cold.
Is there any treatment?
Treatment for myotonia may include quinine, phenytoin, mexiletine, and other anticonvulsant drugs. Physical therapy and other rehabilitative measures may help muscle function.
What is the prognosis?
Myotonia is a chronic disorder. Symptoms may improve later in life.
What research is being done?
The NINDS supports and conducts an extensive research program on neuromuscular disorders. The goals of this research are to learn more about these disorders and to find ways to treat, prevent, and cure them.