What is dystonia?
Dystonia is a movement disorder characterized by nonstop (sustained) or occasional (intermittent) muscle contractions that cannot be controlled. Children with dystonia may experience contractions (appearing as spasms or convulsions) in opposing muscles, resulting in twisted or abnormal positioning of the body. Individuals with dystonia may also appear to shake or have a tremor. Dystonia can interfere with a child’s ability to speak, eat or walk, and may cause pain.
Types of dystonia
Dystonias are classified based the parts of the body affected:
- Focal dystonia affects only one part of the body.
- Segmental dystonia affects two or more connected parts of the body (the neck, shoulder and arm, for example).
- Multifocal dystonia affects two or more parts of the body that are not connected (the eyes and jaw, for example).
- Hemidystonia affects muscles on one side of the body.
- Axial dystonia affects the muscles of the torso.
- Generalized dystonia affects all or most of the body.
Dystonias are also classified by the frequency and timing of the muscle contractions:
- Task-specific dystonia: Muscle contractions occur only when engaged in a specific task. Writer’s cramp and musician’s dystonia are examples.
- Paroxysmal dystonia and dyskinesia: Muscle contractions and abnormal movements occur only during attacks.
Causes of dystonia
Some types of dystonia are inherited, while others (idiopathic dystonias) have no known cause.
Acquired dystonia, or secondary dystonia, is used to describe dystonia that occurs as a result of damage to the brain from injury (including trauma and birth injury), infection, stroke or a reaction to a toxin or medication.
Dystonia can also be associated with diseases and conditions that affect the brain and nervous system, including brain tumors, metabolic conditions, neurodegenerative disorders and demyelinating diseases.
The biochemical mechanism that causes dystonia when brain injuries occur is not fully known.
Signs and symptoms of dystonia
Dystonia can affect different parts of the body, and symptoms vary widely depending on the type of dystonia and the area of the body affected. Early signs of dystonia may include:
- A foot cramp or a tendency to drag one foot
- Involuntary turning or twisting of the neck
- Tension, movement or twisting in an arm or leg
- Uncontrolled rapid blinking or involuntary closing of the eyes
- Slurred speech, drooling or difficulty swallowing
- Voice tremor, a whispering voice or difficulty speaking
Dystonia symptoms may be mild at first. They may appear only when the child is tired or anxious. Over time, symptoms of dystonia may become more noticeable, or they may not progress.
Testing and diagnosis of dystonia
The first step in diagnosis of dystonia is to identify the nature of the abnormal movement or muscle contractions. A neurologist will need to examine the child carefully, interview the family to get a history and description of the behavior, and sometimes to study video recordings. When movements occur only occasionally, the child may need to be observed for an extended period in a clinic.
Other diagnostic tools used to identify the type and cause of dystonia include:
- Blood or urine tests
- Brain imaging, such as magnetic resonance imaging (MRI), to look for tumors, lesions or evidence of stroke
- Electromyography (EMG) to measure electrical activity in the muscles
- Genetic testing
Treatment for dystonia is based on the type and cause of the condition and is tailored to reduce the symptoms, which vary widely from patient to patient.
When dystonia is found to be caused by a medication taken for another health problem, for example, the first line of treatment is to stop or reduce the dose of that medication. If this is done quickly, the dystonia may stop with no further treatment.
More typically, dystonia is treated with a combination of medications and therapy, and in some cases with surgery.
Physical therapy, including stretching, strengthening and range-of-motion exercises can be helpful, as can therapy to adjust posture.
Speech therapy can be helpful if dystonia affects the child’s voice.
The intensity of dystonia symptoms may be reduced with medication. Medication options include:
- Botulinum toxin (Botox®), injected into affected muscles every three or four months
- Baclofen, a medication that suppresses abnormal nerve signals from the spinal cord
- Medications that affect levels of the neurotransmitter dopamine such as trihexyphenidyl, benztropine, tetrabenazine, diazepam and clonazepam.
Surgery for dystonia
In severe cases, when medication does not provide adequate relief, deep brain stimulation may be used. In some patients with genetic dystonia, DBS is the best treatment. This treatment involves surgical implantation of electrical leads in the brain, connected to a battery-powered stimulator.
Selective denervation surgery is another option. This treatment works by interrupting the nerve signals causing the muscle contractions.
Complementary integrative health treatments
Massage and the application of heat and cold can ease muscle pain. Touch therapy can reduce contractions. Meditation, deep breathing, yoga, acupuncture and biofeedback can help ease tension and reduce muscle spasms.
Pain and frustration caused by dystonia can lead to depression and anxiety in some patients. Support services and mental health therapy may be part of the treatment plan to help your child maintain a positive outlook. Your child’s care team may include a psychologist, psychiatrist, social worker, child life specialist, or other providers as needed.
Dystonia progresses in different ways for each patient. It may affect only the part of the body where it first appears, or it may progress to other body parts over time. When it progresses to other parts of the body, it typically stabilizes later, without further progression.
While there is no cure for dystonia, treatment can substantially reduce symptoms and improve quality of life.
Dystonia is not typically associated with problems in thinking or understanding.
Because there are so many types of dystonia, and such a wide range of severity, patients’ families should consult a medical specialist for useful information about their child’s outlook.
Ongoing treatment with medication or therapy may be required, with periodic examination by the child’s doctor to adjust the treatment plan.
Why choose CHOP for dystonia treatment?
Children’s Hospital of Philadelphia (CHOP) has a skilled team of pediatric neurologists, neurosurgeons, physiatrists, child and adolescent psychiatrists, psychologists, neuropsychologists, nurse practitioners, social workers and others who work in collaboration to recognize and help a child or adolescent deal with dystonia.
The medical team at CHOP can help children and adolescents with dystonia, and help their parents navigate the emotional and practical issues they may face, from initial diagnosis through treatment and long-term follow-up care.