Dystonia (patient information)
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Dystonias are movement disorders in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The movements, which are involuntary and sometimes painful, may affect a single muscle; a group of muscles such as those in the arms, legs, or neck; or the entire body. Those with dystonia usually have normal intelligence and no associated psychiatric disorders.
What are the symptoms of Dystonia?
Dystonia can affect many different parts of the body.
Symptoms may include:
- deterioration in handwriting after writing several lines
- foot cramps
- tendency of one foot to pull up or drag; this may occur "out of the blue" or may occur after running or walking some distance.
- the neck may turn or pull involuntarily, especially when the patient is tired or stressed.
- both eyes may sometimes blink rapidly and uncontrollably, rendering a person functionally blind
- tremor
- voice or speech difficulties, possibly with a hoarse voice
- Tiredness and soreness due to the excessive muscle contractions
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 and widespread and be unrelenting. Sometimes, however, there is little or no progression.
Dystonias are sometimes classified according to the parts of the body they affect:
- Generalized dystonia affects most or all of the body.
- Focal dystonia is localized to a specific part of the body.
- Multifocal dystonia involves two or more unrelated body parts.
- Segmental dystonia affects two or more adjacent parts of the body.
- Hemidystonia involves the arm and leg on the same side of the body.
What causes Dystonia?
It is not exactly clear what causes dystonias. There are two types of dystonia: acquired dystonia and idiopathic dystonia.
Acquired dystonia, also called secondary dystonia, results from environmental or disease-related damage to the basal ganglia. Birth injury (particularly due to lack of oxygen), certain infections, reactions to certain drugs, heavy-metal or carbon monoxide poisoning, trauma, or stroke can cause dystonic symptoms. Dystonias can also be symptoms of other diseases, some of which may be hereditary.
About half 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 in a dominant manner; i.e., only one carrier parent need contribute the dystonia gene for the disease to occur, each child having a 50% chance of being a carrier. In dystonia, however, a carrier may or may not develop a dystonia and the symptoms may vary widely even among members of the same family. The product of one defective gene appears to be sufficient to cause the chemical imbalances that may lead to dystonia; but the possibility exists that another gene or genes and environmental factors may play a role. Researchers have identified more than 15 different genetic mutations that may contribute to dystonia.
Whether you have acquired or idiopathic dystonia, researchers think that it is caused by a problem in the part of the brain that handles messages about muscle contractions. Scientists suspect a defect in the body's ability to process a group of chemicals called neurotransmitters, which help cells in the brain communicate with each other.
The ultimate goals of research are to find the cause(s) of the dystonias so that they can be prevented, and to find ways to cure and/or more effectively treat people now affected. Scientists at the National Institute of Neurological Disorders and Stroke (NINDS) laboratories have conducted detailed investigations of the pattern of muscle activity in persons with focal dystonias. One of the most important characteristics is the failure of reciprocal inhibition, a normal process in which muscles with opposite actions work without opposing each other. In dystonia, the tightening of muscles is associated with an abnormal pattern of muscles fighting each other. The search for the gene or genes responsible for some forms of dominantly inherited dystonias continues.
Who is at highest risk?
Different dystonias are caused by different factors. Those who have a family history of idiopathic dystonia have a higher risk of inheriting it. Some cases of primary dystonia may have different types of hereditary patterns. Knowing the pattern of inheritance can help families understand the risk of passing dystonia along to future generations.
When to seek urgent medical care?
Call your doctor is you are having any type of involuntary muscle contractions, even if they are mild or occur irregularly.
Diagnosis
A visit to your primary care physician may be helpful After your visit, s/he may refer you to a neurologist.
At your appointment, you will be asked to provide a medical and family history. You may also be asked to provide a urine sample or blood sample to determine if you’ve had exposure to toxins. Your doctor will want to know when your symptoms started, the nature of your symptoms, whether you’ve had a stroke or head injury, and if you you’ve been exposed to certain drugs or toxins.
It is also possible that your doctor will want you to have a magnetic resonance imaging (MRI) scan to determine if you have evidence of a stroke, tumor, or other lesion.
Treatment options
There is no cure, and no one treatment has been found universally effective. Instead, doctors use medicines, surgery, physical therapy and other treatments to reduce or eliminate muscle spasms and pain.
- Medication- Several classes of drugs that may help correct imbalances in neurotransmitters have been found useful. But response to drugs varies among patients and even in the same person over time. Some patients who have a specific form of dystonia may experience considerable relief by taking levodopa, a drug that the body uses to synthesize the nerve chemical dopamine. Drugs that interfere with another neurochemical, acetylcholine (which stimulates muscle movements), may also be effective. The most effective therapy is often individualized, with physicians prescribing several types of drugs at different doses to treat symptoms and produce the fewest side effects.
- Botulinum toxin- Minute amounts of this familiar toxin can be injected into affected muscles to provide temporary relief of focal dystonias. First used to treat blepharospasm, such injections have gained wider acceptance among physicians for treating other focal dystonias. The toxin stops muscle spasms by blocking release of the excitatory neurotransmitter acetylcholine. The effect lasts for up to several months before the injections have to be repeated.
- Surgery- Surgery may be recommended for some patients when medication is unsuccessful or the side effects are too severe. In selected cases, advanced generalized dystonias have been helped, at least temporarily, by surgical destruction of parts of the thalamus, a structure deep in the brain that helps control movement. Speech disturbance is a special risk accompanying this procedure, since the thalamus lies near brain structures that help control speech. Surgically cutting or removing the nerves to the affected muscles has helped some focal dystonias, including blepharospasm, spasmodic dysphonia and torticollis. The benefits of these operations, however, can be short-lived. They also carry the risk of disfigurement, can be unpredictable, and are irreversible.
- Deep brain stimulation (DBS)– The electrical stimulation of very small regions of brain tissue by surgically implanted electrodes is effective for some people with dystonia. DBS has reduced the use of older, usually less effective forms of surgery that create permanent damage to the nervous system.
Some patients with spasmodic dysphonia may benefit from treatment by a speech-language pathologist. Physical therapy, splinting, stress management, and biofeedback may also help individuals with certain forms of dystonia
Where to find medical care for Dystonia?
Directions to Hospitals Treating Dystonia
What to expect (Outlook/Prognosis)?
The initial symptoms can be very mild and may be noticeable only after prolonged exertion, stress, or fatigue. 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 and ultimately even while they are relaxed.
Response to treatment is different for every person, and can even change for a person over time.
Possible complications
In some patients, dystonic motions may lead to permanent physical deformities by causing tendons to shorten. Dystonia can also make everyday activities more difficult and can even cause functional blindness if your dystonia affects your eyelids. Additionally, surgeries carry many risks which should be discussed with your doctor if you are considering surgical treatment.
Dystonia is often misunderstood by other people who assume that the dystonic movements are caused by mental retardation or other mental disorder. Unfortunately, the difficulties that come along with dystonia can cause patients to feel depressed and frustrated by their condition.
Sources
http://www.ninds.nih.gov/disorders/dystonias/detail_dystonias.htm
http://www.nlm.nih.gov/medlineplus/dystonia.html
http://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=39
http://www.mayoclinic.com/health/dystonia/DS00684/DSECTION=symptoms
http://www.mayoclinic.com/health/dystonia/DS00684/DSECTION=complications
http://www.mayoclinic.com/health/dystonia/DS00684/DSECTION=preparing-for-your-appointment