Unless you are engaged in an activity that requires conscious movement—like physical therapy or learning a new dance move—you probably don’t spend much time thinking about how to control your muscles. That’s because your brain and nervous system are working smoothly together—but, though it is unusual, problems sometimes arise. Dystonia is a neurological movement disorder that results in unwanted muscle contractions or spasms. The involuntary twisting, repetitive motions, or abnormal postures associated with dystonia can affect anyone at any age. The movements can be slow or fast, range from mild to debilitating and happen predictably or randomly. An estimated 300,000 people in North America have dystonia, according to the National Organization for Rare Disorders.
Dystonia is a multi-faceted, complex disorder. Different subtypes affect areas across the body, and its symptoms can vary significantly from person to person. In its early stages and in milder forms, dystonia might register as an annoyance. For example, dystonia that affects only the vocal cords may mean a person has to make an extra effort to talk. But other forms of dystonia can interfere with a person’s ability to walk or eat and are severe enough to require surgery.
Adding a layer of complexity to the condition, researchers are unsure of its cause. Dystonia can develop in multiple ways, ranging from genetic mutations or as a side effect of a medication. It can be a symptom of another disease, like Huntington’s or Parkinson’s diseases. In many cases, dystonia emerges for unknown reasons.
While the disorder has no cure, some forms of it can be well-managed through personalized treatment plans that may include medication, botulinum toxin injections, or deep brain stimulation (DBS) surgery.
At Yale Medicine, a team of expert neurologists and neurosurgeons work together to find solutions for each patient. Your doctor will perform a detailed interview and examination to understand your symptoms and how best to help you. “One goal will be to identify the underlying cause of your dystonia and any treatments,” says Yale Medicine neurologist Christine Kim, MD. “An equally important goal will be the development of a treatment plan for your symptoms that will be carefully tailored to your individual needs by a doctor with extensive experience in the treatment of dystonia. This may involve trying oral medications, botulinum toxin injections, or considering DBS surgery in appropriate cases. Treatment often involves a combination of approaches.”
What causes dystonia?
It’s unclear, but research points to possible dysfunction in areas of the brain that help control movement and their inter-connections, including the basal ganglia and, more recently, the cerebellum and motor cortex. Some cases of dystonia are hereditary. Acquired dystonia can be the result of brain damage through an injury, such as lack of oxygen at birth, stroke, or another type of trauma. Acquired dystonia is also associated with exposure to certain medications or, rarely, heavy metals or carbon monoxide poisoning. However, in many cases, dystonia is idiopathic, which means the cause is simply unknown.
What are the different types of dystonia?
There are several kinds of dystonia that affect different areas of the body. In its early stages, dystonia may show up only during certain movements or periods of stress or even at random. As it progresses, the disorder’s symptoms may become constant, even when the patient isn’t attempting to engage his or her muscles.
- Generalized dystonia: Muscle contractions that affect the entire body.
- Segmental dystonia: Two or more neighboring body parts are affected (for example, the head and neck).
- Multifocal dystonia: Spasms affect unrelated parts of the body.
Primary focal dystonia: When the contractions are limited to one part of the body. (Any affected body part can also be affected in generalized, segmental, or multifocal dystonia types.) Some common forms of this dystonia include the following:
- Cervical dystonia: Affecting the neck muscles, this can cause the head to twist or turn to one side.
- Blepharospasm: Causes the eyes to blink or close uncontrollably.
- Oromandibular dystonia: Affects the jaw, tongue, and face, often with the ability to eat and talk.
- Laryngeal dystonia: Affects the voice box (larynx) muscles and can make a person’s voice sound strained or, in severe cases, barely audible.
- Task-specific dystonia: Dystonia occurs only during a particular activity. Common forms include writer’s cramp, affecting muscles in the forearm and hand, and musician’s dystonia, which affects just the muscles used to play the musical instrument.
- Hemidystonia: The arm and leg on the same side of the body are affected.
- Cranio-facial dystonia: Muscles in the head, face, and neck are impacted.
Who is affected by dystonia?
Dystonia affects people of all ages. Early-onset dystonia can begin during infancy or childhood, and the muscle contractions may worsen over time and spread to other parts of the body. Adult-onset dystonia begins later in life and often involves the neck and facial muscles.
How is dystonia diagnosed?
Your doctor will perform a detailed physical exam to identify symptoms of the disorder and take a medical history and family history in case the condition might have a genetic component. If the dystonia is suspected to be inherited, genetic testing may be used to confirm the diagnosis. Blood or urine tests may be conducted to evaluate for the possibility of associated diseases or conditions. Neuroimaging may be recommended to look for underlying structural injuries in the brain.
What treatment options are available for dystonia?
Personalized treatment based on each patient’s condition (dystonia subtype) brings the best results as there are no treatments yet available to cure the condition. Treatment options include the following:
- Oral medications: Your doctor may prescribe a medication that acts on neurotransmitters, based on your symptoms. Options include drugs that act on the neurotransmitter GABA (benzodiazepines and baclofen); drugs that affect dopamine levels (tetrabenazine and levodopa); and drugs that block the effects of acetylcholine (trihexyphenidyl and benztropine).
- Botulinum toxin: For prominent dystonia in one particular body part, doctors may try botulinum injections in small amounts in the affected muscles, which can bring significant but temporary relief.
- Deep brain stimulation (DBS) surgery: This surgical procedure involves inserting small electrodes into your brain. These send pulses of electricity into the specific areas of the brain that control movement in the affected body part. DBS surgery is usually considered only after all other treatment possibilities have been exhausted but can be effective in appropriate cases.
What makes Yale Medicine unique in its approach to dystonia?
At Yale, a team of experienced movement disorders specialists have expertise in the diagnosis of dystonia and its clinical management, including electromyography (EMG)-guided botulinum toxin injection—which helps pinpoints the source of a nerve problem—and DBS surgery in appropriate cases.
“Our treatment approaches are highly individualized,” Dr. Kim says. “We are fortunate to be practicing during a time of extensive growth in dystonia research. We conduct research in the causes and treatment of focal dystonia and are committed to providing the most current advances across the field to our patients.”