This term is used to describe involuntary muscle contractions that produce abnormal postures or movements. In adults, dystonia most commonly affects the head and neck area, causing head turning or shaking (sometimes referred to as torticollis), or involuntary closing of the eyes (blepharospasm). Torticollis is the most common adult form of the disease. The National Spasmodic Torticollis Association, a non-profit organization, serves as clearing house for informations about scientific breakthrough and support group for patients with torticollis www.torticollis.org. Dystonia may affect almost any body part, and often is initially apparent during a specific movement. They result from an abnormality in an area of the brain called the basal ganglia where some of the messages that initiate muscle contractions are processed. Scientists suspect a defect in the body's ability to process a group of chemicals called neurotransmitters that help cells in the brain communicate with each other.
Although some of the dystonias are caused by another disease and therefore called secondary dystonia, the majority of dystonia cases are called primary or idiopathic dystonia because they have no connection to another disease or injury. Of the primary dystonias, many cases appear to be inherited in a dominant manner; i.e., only one carrier parent need contribute the dystonia gene for the disease to occur. Each child has a 50/50 chance of being a carrier.
In dystonia, however, a carrier may or may not develop a dystonia. Sometimes the symptoms are so mild that they are missed. The symptoms may vary widely even among members of the same family. This is due to the so-called low penetrance. That means low appearance of the symptoms despite the presence of the gene. The product of one defective gene appears to be sufficient to cause the chemical imbalances that may lead to dystonia. The possibility exists that another gene or genes and environmental factors may play a role as well. Dystonia is a symptom and thus could be caused by different diseases and specifically, idiopathic dystonia could be caused by different genes. Recently, different genes have emerged as the cause of different types of dystonia.
Physicians use a variety of therapies aimed at reducing or eliminating muscle spasms and pain. In recent years these symptoms have been successfully treated in many cases by injecting botulinum toxin (known as Botox) in a controlled manner into the contracting muscles in order to partially relax them.