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Limb Dystonia

What are limb dystonias?

The limb dystonias are characterized by excessive pulling of the muscles of a limb, such as the hand or foot. The arm or leg may also be involved. The manifestations depend on the combinations of muscles affected, and how hard each one is pulling. In its mildest forms, it can be expressed only as stiffness or soreness of a limb. In moderate forms, it is characterized by unwanted movements or postures of the limb. In its most severe forms, abnormal postures may become fixed. Some common examples include writer’s cramp causing difficulty writing or arm soreness with writing, musician’s dystonia that interferes with playing a musical instrument, or dystonia of one foot that makes walking awkward.

Who gets limb dystonias?

People of all ages and both sexes and all races all over the world get limb dystonias. It may begin in children, where it most commonly affects one leg, and it may spread to other body parts over months or years. It may also begin in adults of any age. Those who write a lot, play a musical instrument very frequently, or participate in some other repetitive skilled activity seem to be most affected.

What causes limb dystonias?

In most cases, the cause of limb dystonia is unknown.

How are the limb dystonias diagnosed?

The diagnosis of the limb dystonias depends on recognition of its characteristic features by an expert, such as a neurologist. There are no medical tests for proving the diagnosis, but several tests may be conducted to rule out other possible problems. These tests may include scans of the affected limb or head, or electrical tests of the affected muscles.

Are there treatments for the limb dystonias?

Treatments for the limb dystonias are challenging. Some may respond to quieting the overactive muscles by injecting them with a muscle relaxer, such as the botulinum toxins. Some patients take pills. Others go for special exercises or physical therapy.

Frequently Asked Questions about Limb Dystonia

Why did I get a limb dystonia?

The reasons why some people get limb dystonias are unknown. In some cases, it may be inherited through a change in the genes. In others, it may be caused by something that happened to the brain, like exposure to some infection, chemical, or injury. Experts believe most cases come from a combination of inheritance and some exposure.

The limb dystonias usually reach their worst level of severity over a period of weeks or months; then they become stable. In some cases, the problem may worsen over years or spread to another region of the body. Worsening is common when a limb dystonia occurs in a child. In other cases, a limb dystonia can be the first sign of some other disorder, such as Parkinson’s disease, which is more common in adults.

In a few fortunate people, limb dystonias may go away. When it does go away, there always is the risk that it may come back.

Most people with injuries to a limb or head do not develop a limb dystonia. People with a limb dystonia are no more likely to have such injuries than those without a limb dystonia. Though a limb dystonia may develop after some trauma, it is not possible to know for sure if the trauma caused the problem.