What is Dystonia
Dystonia is a neurological movement disorder characterized by involuntary muscle contractions, which force certain parts of the body into abnormal, sometimes painful, movements or postures. Dystonia can affect any part of the body including the arms and legs, trunk, neck, eyelids, face, or vocal cords.
Dystonia may cause impairment as muscle contractions interfere with normal function. It can also be painful and socially embarrassing. Features such as cognition, strength, and the senses, including vision and hearing, are usually normal. While dystonia is not fatal, it is a chronic disorder and prognosis is difficult to predict.
Dystonia can be “secondary” meaning it is due to some other condition (for example, stroke or cerebral palsy) or “primary”. Dystonia can also be categorized as “focal” if it affects only one part of the body or “generalized” if it affects much of the body.
Examples of focal dystonias include the following:
- Blepharospasm - forceful involuntary closure of the eyelids
- Spasmodic torticollis, or cervical dystonia - muscle spasm in the neck that causes the head to turn to one side, and sometimes forward or backward
- Oromandibular dystonia - continuous spasms of the face, jaw, neck, or tongue
- Spasmodic dysphonia - spasm of the vocal cords that causes sudden disruption of speech
- Focal dystonias of the limbs - specific to a certain repetitive task, including writer’s cramp and musician’s dystonia
Who Gets Dystonia?
Dystonia is the third most common movement disorder after Parkinson's Disease and Essential Tremor, affecting more than 300,000 people in North America. It can start at any age, from childhood to older adults. When it starts in childhood, it is often due to genetic abnormalities. Over 15 genetic mutations causing dystonia have been identified. Although genetic mutations are more common in certain populations, dystonia can occur in any race or ethnicity.
What Are the Treatments for Dystonia?
Although there currently are no cures for dystonia, there are a number of symptomatic treatments that can provide relief. These include oral medications, and botulinum toxin injection therapy. For patients for whom medications and botulinum toxin give inadequate relief, deep brain stimulation (DBS) surgery may be an effective option. The Food and Drug Administration approved DBS for primary dystonia in 2003 under an Huminatrian Device Exemption. Although generally less effective, DBS can be used for secondary dystonias as an off-label indication.