Dystonia is a movement disorder in which forceful sustained muscle contractions cause twisting and repetitive movements or abnormal postures. These involuntary and sometimes painful movements may affect a single muscle; a group of muscles such as those in the arms, legs or neck; or the entire body.
Dystonia causes varying degrees of disability and pain, from mild to severe. It is a chronic disorder, but does not impact cognition or intelligence in the majority of patients. While there is presently no cure for dystonia, there are multiple treatment options available that reduce the severity of the symptoms.
What are the types of dystonias?
There are many different forms of dystonia and dozens of diseases and conditions that include dystonia as a major symptom. The forms of dystonia are classified by muscle location and distribution.
- Focal dystonia forms during adulthood and affects the muscles in a specific area of the body, such as the eyes, mouth, vocal cords, neck, hands and feet.
- Task specific dystonia is related to the occurrence of focal dystonia, but only during a specific task. For example, musicians’ dystonia is most often diagnosed in professional musicians and affects the mouth, cheeks, jaw and tongue. Similarly, writer’s cramp happens only in the hands and fingers.
- Early-onset generalized dystonia is characterized by involuntary muscle contractions that begin in the limbs and eventually cause twisting contractions in other parts of the body. There are two main categories: DYT1 generalized dystonia, which is caused by a specific mutation in the DYT1 gene; and non-DYT1 generalized dystonia, which does not have the gene mutation.
- Dopa-responsive dystonia is a form of dystonia in which the brain does not produce enough dopamine and is usually characterized by a progressive worsening of dystonia throughout the day. This form of dystonia responds to the medication levodopa, which relieves the symptoms.
- Myoclonic dystonia is a genetic form of dystonia that affects the central part of the body, including the shoulders, arms, neck and trunk. It is characterized by rapid jerking movements in combination with the sustained muscular contractions and postures of dystonia.
- Paroxysmal dyskinesias are episodic dystonias in which abnormal movements are only present during an actual attack with normal functionality between spells. This form of dystonia might be precipitated by movement (kinesigenic) or prolonged exercise (exercise induced). It can also occur spontaneously (nonkinesigenic).
- X-linked dystonia-parkinsonism is a genetic form of dystonia and exhibits symptoms of both dystonia and slowness of movement as seen in Parkinson’s disease. It is one of the few degenerative forms of dystonia and primarily affects males of Filipino descent.
- Rapid-onset dystonia-parkinsonism is a hereditary form of dystonia characterized by the abrupt onset of slowness of movement and dystonic symptoms.
- Secondary dystonia is dystonia that develops as the result of other neurological conditions, certain medications or injury. Secondary dystonias may be produced by more than 50 neurological and metabolic diseases, many of which may be genetic.
- Psychogenic dystonia refers to the uncommon situation where the dystonia is secondary to psychological disturbances. In the majority of cases, the process is subconscious, and the patient may not be aware of causing the abnormal movements.
What are the symptoms of dystonia?
Early symptoms of dystonia may include deterioration in handwriting, foot cramps or a dragging foot after running or walking a significant distance. Other possible symptoms include tremor and voice or speech difficulties. About half of the cases of dystonia have no connection to disease or injury and are called primary or idiopathic dystonia. Of the primary dystonias, many cases appear to be inherited. Dystonias can also be symptoms of other diseases, some of which may be hereditary. In some individuals, symptoms of dystonia appear in childhood. For others, symptoms may not appear until later in life.
Dystonias often progress through various stages. Initially dystonic movements are intermittent and appear only during voluntary movements or stress. Later, individuals may show dystonic postures and movements while walking or even while relaxed. Dystonic motions may lead to permanent physical deformities by causing the muscles or tendons to shorten.
What causes dystonia?
Dystonia typically occurs as a result of mutated genes, trauma, infection, stroke and certain medications. While an exact cause has yet to be determined, investigators believe that dystonia results from an abnormality in the area of the brain called the basal ganglia, where some of the messages that initiate muscle contractions are processed. Physicians and scientists continue to research this disorder to determine what exactly happens in the body that triggers the symptoms.
How is dystonia diagnosed?
At this time, there is no single test to confirm the diagnosis of dystonia. Instead, the diagnosis is determined by an analysis of the patient’s symptoms and a thorough review of his or her medical history by an experienced clinician. Videotaping either at home or in the clinic with an expert reviewing the movements is very important. In certain instances, tests may be ordered to rule out other associated conditions or disorders.
What treatment options are available for dystonia?
No one treatment has been found to be universally effective. Instead, doctors use a variety of therapies (medications, surgery and other treatments such as physical therapy, splinting, stress management and biofeedback) aimed at reducing or eliminating muscle spasms and pain. Since the response to drugs varies among individuals and even in the same person over time, the most effective therapy is often individualized. The medication response in children is marginally better than in adults. For primary dystonia with normal brain MRI studies, deep brain stimulation of the deeper part of the basal ganglia has been proven to be extremely beneficial when no other treatments work. Cleveland Clinic’s Center for Neurological Restoration has a dedicated team of experts with vast experience in deep brain stimulation for various neurological and psychiatric disorders including dystonia.
Dystonia-related research and clinical trials
The National Institute of Neurological Disorders and Stroke (NINDS) conducts research related to dystonia in its laboratories at the National Institutes of Health (NIH) and also supports additional dystonia research through grants to major medical institutions across the country. Investigators believe that dystonia results from an abnormality in the area of the brain called the basal ganglia, where some of the messages that initiate muscle contractions are processed. Scientists at the NINDS laboratories have conducted detailed investigations of the pattern of muscle activity in persons with dystonia. Studies using EEG analysis and neuroimaging are probing brain activity. The search for the gene or genes responsible for some forms of dominantly inherited dystonia continues.
- Learn more about dystonia and treatment options available at Cleveland Clinic
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Related Links and Organizations
Source: Dystonia Medical Research Foundation