Overview of Dystonias
Dystonia is a condition characterized by involuntary muscle contractions that cause repetitive or twisting movements of an affected body part and often result in abnormal postures. Contractions can affect one muscle, groups of muscles, or muscles throughout the body. These uncontrollable movements are often accompanied by pain and can interfere with the ability to perform day-to-day tasks.
Dystonia can be classified by the parts of the body affected:
- Focal dystonia is localized to a specific part of the body (for example, the left hand or the neck).
- Segmentalized dystonia affects two or more adjacent parts of the body (for example, the left arm and left hand).
- Multifocal dystonia involves two or more unrelated body parts.
- Hemidystonia involves the arm and the leg on the same side of the body.
- Generalized dystonia affects most or all of the body.
Forms of focal dystonia include:
- Cervical dystonia affects the muscles in the neck that control the position of the head, causing the head to turn to one side or be pulled forward or backward. This condition is often called spasmodic torticollis.
- Blepharospasm affects muscles in the eyes, causing rapid blinking or spasms that force the eyelids to involuntarily close completely.
- Craniofacial dystonia affects the muscles of the head, face, and neck.
- Spasmodic dysphonia affects the muscles of speaking.
- Task-specific dystonia occurs during a particular repetitive activity, such as handwriting or playing an instrument.
Involuntary muscle contractions are the primary symptom of dystonia. They can cause your body to assume twisting, repetitive, or painful postures. Symptoms may be progressive, and they may be aggravated by stress, anxiety, or fatigue.
Depending on the form of dystonia, symptoms may include:
- Foot cramps and posturing when walking in lower extremity dystonia
- Tendency of one foot to turn or drag in lower extremity dystonia
- Rapid blinking and eyelid spasm seen in blepharospasm
- Dry eyes and light sensitivity seen in blepharospasm
- Uncontrollable head movements seen in cervical dystonia
- Tremor, often seen in cervical dystonia (head tremor)
- Difficulties opening and closing your mouth seen with oromandibular dystonia
- Difficulty swallowing
- Strained, breathy, or slurred speech seen with spasmodic dystonia
- Cramps or problems with motor control while doing a particular activity, such as handwriting or playing an instrument
Symptoms of dystonia vary depending on which muscles are affected and can signal a serious underlying condition. Contact a medical professional if you believe you are experiencing involuntary muscle contractions.
Treatments for dystonia are aimed at decreasing spasms, pain, and disturbed postures.
Botulinum Toxin (Botox, Dysport, Myobloc, Xeomin) for Dystonia
Chemical denervation using Botox is a common treatment for dystonia. It temporarily and partially paralyzes the muscles involved and is most effective when used for focal dystonia. During this outpatient procedure, the overactive muscles involved in dystonia are injected using a fine needle.
There are many oral medications that might be used to treat dystonia, including benzodiazepines (for example clonazepam) or anticholinergics (for example, trihexyphenidyl).
Deep Brain Stimulation (DBS) for Dystonia
Deep brain stimulation (DBS) describes a treatment in which a neurosurgeon implants a device called a neurostimulator in your brain to deliver a small electrical stimulus to your basal ganglia. Once the device is turned on, your symptoms may diminish.
It usually takes several months for your doctor to program your stimulator to give you the most relief.
How common is dystonia?
As many as 300,000 Americans are living with dystonia.
Who gets dystonia?
Dystonia can occur at any age, with generalized dystonia often starting in childhood and focal dystonia starting in adulthood.
Some forms of dystonia are genetic, but the cause of most cases is unknown (idiopathic). The disease may be linked to dysfunctional communication between nerve cells in the basal ganglia, a region at the base of the brain where muscle contraction commands originate.
Secondary dystonia describes when symptoms of dystonia are caused by another disorder or condition. Diseases that can cause symptoms of dystonia include:
- Parkinson’s disease
- Huntington’s disease
- Wilson’s disease
- Traumatic brain injury
- Birth injury (cerebral palsy)
- Brain tumor
- Paraneoplastic syndromes
- Oxygen deprivation
- Infections, such as TB or encephalitis
- Reactions to certain medications (tardive dystonia)
- Heavy metal or carbon monoxide poisoning
How is dystonia diagnosed?
There is no single test that can definitively diagnose dystonia. Your doctor will review your symptoms and medical history during a physical examination and may order any of the following tests:
- Blood tests
- Urine tests
- CT scan
- MRI scan
- Electromyography (EMG)