Dystonia

Dystonia is a disorder characterized by involuntary muscle contractions that cause slow repetitive movements or abnormal postures. The movements may be painful, and some individuals with dystonia may have a tremor or other neurologic features. There are several different forms of dystonia that may affect only one muscle, groups of muscles, or muscles throughout the body. Some forms of dystonia are genetic but the cause for the majority of cases is not known. Dystonia can affect many different parts of the body, and the symptoms are different depending upon the form of dystonia.

The symptoms mainly includes:

• Foot cramps

• Neck may turn or pull involuntarily

• Rapid blinking of eyes

• Spasms

Symptoms may also include tremor or difficulties speaking. In some cases, dystonia can affect only one specific action, while allowing others to occur unimpeded. The initial symptoms can be very mild and may be noticeable only after prolonged exertion, stress, or fatigue. Over a period of time, the symptoms may become more noticeable or widespread; sometimes, however, there is little or no progression. Dystonia typically is not associated with problems thinking or understanding, but depression and anxiety may be present.

Currently, there are no medications to prevent dystonia or slow its progression. There are, however, several treatment options that can ease some of the symptoms of dystonia, so physicians can select a therapeutic approach based on each individual’s symptoms. Several classes of drugs that affect different neurotransmitters may be effective for various forms of dystonia. These medications are used “off-label”, meaning they are approved by the U.S. Food and Drug Administration to treat different disorders or conditions but have not been specifically approved to treat dystonia. Anticholinergic agents block the effects of the neurotransmitter acetylcholine. Dopaminergic agents act on the dopamine system and the neurotransmitter dopamine, which helps control muscle movement. Botulinum injections often are the most effective treatment for the focal dystonias. Deep brain stimulation (DBS) may be recommended for some individuals with dystonia, especially when medications do not sufficiently alleviate symptoms or the side effects are too severe.

The relative frequencies of primary and secondary forms of dystonia are not known.The prevalence of primary torsion dystonia is difficult to estimate because of the variation in its expression and the tendency for mild cases to go undiagnosed.The finding suggested that patients with focal dystonia should not be treated as a homogeneous group and that sex-linked factors may play a role. Investigators found a crude annual prevalence of 15.2 cases per 100,000 individuals, the majority of whom had focal dystonia at a rate of 11.7 cases per 100,000 individuals.