Early-onset primary dystonia
Early-onset primary dystonia is a condition characterized by progressive problems with movement, typically beginning in childhood. Dystonia is a movement disorder that involves involuntary tensing of the muscles (muscle contractions), twisting of specific body parts such as an arm or a leg, rhythmic shaking (tremors), and other uncontrolled movements. A primary dystonia is one that occurs without other neurological symptoms, such as seizures or a loss of intellectual function (dementia). Early-onset primary dystonia does not affect a person's intelligence.On average, the signs and symptoms of early-onset primary dystonia appear around age 12. Abnormal muscle spasms in an arm or a leg are usually the first sign. These unusual movements initially occur while a person is doing a specific action, such as writing or walking. In some affected people, dystonia later spreads to other parts of the body and may occur at rest. The abnormal movements persist throughout life, but they do not usually cause pain.The signs and symptoms of early-onset primary dystonia vary from person to person, even among affected members of the same family. The mildest cases affect only a single part of the body, causing isolated problems such as a writer's cramp in the hand. Severe cases involve abnormal movements affecting many regions of the body.