Dystonia: Symptoms & Causes

Dystonia causes muscles to contract involuntarily. It can occur on its own or as part of another disorder. Experts believe it's caused by problems with a brain region called the basal ganglia or an imbalance of neurotransmitters in the brain.

What Is Dystonia?

Dystonia is a movement condition characterized by sustained, involuntary muscle contractions. The contractions can cause you to move when you don't intend to, perform repetitive motions, or become stuck in unusual or uncomfortable positions.

The Dystonia Clinic at Massachusetts General Hospital offers expert care for adults and children with dystonia. Our researchers have a long history of leading discoveries, including identifying and cloning the gene for early-onset dystonia in 1997—a breakthrough that deepened understanding of the disease and advanced preventive treatments. We continue to drive research to uncover additional dystonia-related genes and use functional MRI to study how the condition affects brain function. Mass General was also among the first hospitals to perform deep brain stimulation (DBS) to treat dystonia.

To request an appointment, please call 617-726-3642.

Types of Dystonia

Currently, there isn't a standardized classification system for dystonia. Your doctor or health care center may classify your dystonia in any of the following ways:

• Age of onset: Dystonia may be described according to when a person first experiences symptoms, such as infantile (two years or younger), childhood (before adolescence), adolescence (puberty through age 20), early adult (21-40), or late adult (40+). When dystonia symptoms first occur in adults, they're more likely to be focal and less likely to progress than when they first appear in children.
• Area of effect: A common method of classifying dystonia is to describe the parts of the body affected. Dystonia can be focal (a specific body part), segmental (multiple connected body parts, such as arms and torso), multifocal (multiple unconnected body parts), hemidystonia (one side of the body), or generalized (torso and multiple other areas).
• Isolation: Dystonia can exist as a condition on its own (primary dystonia), be caused by another issue such as injury from a stroke or infection in the brain (secondary dystonia), or occur in combination with other symptoms or neurological conditions (dystonia plus).
• Temporal pattern: Dystonia is sometimes classified by the presence of symptoms. Possible descriptions include sustained (present for long periods with no variation), task-specific (occurring only while performing specific actions), diurnal fluctuation (following a regular rhythm of ups and downs throughout the day), or paroxysmal (sudden response to a specific trigger).

Symptoms of Dystonia

Symptoms of dystonia vary depending on the part of the body affected. In general, dystonia symptoms are involuntary twisting and bending movements that:

• Cause an unusual posture
• Can be uncomfortable or painful
• Are repetitive
• Get worse over time or when using the muscles involved

Focal Dystonia Symptoms

The specific way that dystonia symptoms manifest depends on which muscles are involved:

• Arms and hands: Hands and arms may experience task-specific symptoms. One example is hand cramping while writing, often called "writer's dystonia."
• Eyes: Some people with dystonia experience uncontrolled, repetitive blinking, making it difficult to see.
• Jaw and mouth: Dystonia in the jaw and mouth can cause speech difficulties, drooling, or difficulty swallowing. A task-specific dystonia called "embouchure dystonia" affects some musicians who play wind and brass instruments.
• Neck: Symptoms of cervical dystonia affect the neck, causing twisting or tilting of the head.
• Voice: Dystonia of the muscles controlling the voice (laryngeal dystonia) can make it hard to speak. People with laryngeal dystonia may have a quiet or strained voice.

Dystonia vs. Other Conditions

Simple descriptions of dystonia don't always make it clear how dystonia is different from other conditions or symptoms. Other issues that people may confuse for dystonia include:

• Ataxia: Ataxia symptoms affect movement and balance but aren't characterized by the sustained, involuntary contractions of dystonia. Instead, people with ataxia may lose the ability to sense their bodies in space or have trouble coordinating their movements.
• Chorea: Chorea is a symptom of several neurological disorders, such as Huntington's disease. Like dystonia, chorea involves involuntary muscle contractions. However, dystonia causes sustained twisting or repetitive motions, while chorea involves random sequences of multiple involuntary movements.
• Dyskinesia: Dyskinesia sounds similar to dystonia, and some people may mix up the two words. Dyskinesia is a broader term describing movement disorders in general. Dystonia is a form of dyskinesia.
• Seizures: There are many types of seizures, some of which cause involuntary muscle tension. However, seizures often involve a reduction in conscious awareness, while dystonia doesn't. Also, seizures are accompanied by abnormal electrical activity in the brain, while dystonia isn't.
• Tremor: Tremor is also caused by involuntary muscle contractions, but it's different from dystonia because it involves rhythmic shaking of a specific body part. By contrast, dystonia causes abnormal, repetitive movements or postures.

What Causes Dystonia?

The mechanism that causes dystonia isn't well understood, but experts believe it involves a brain region called the basal ganglia that controls movement. Abnormalities or imbalances in neurotransmitters in this brain region may be the reasons some people develop dystonia.

Regardless of the specific mechanism, there are numerous causes of dystonia that can be genetic (caused by genetic variants or errors), acquired (caused by something specific, such as an injury or other neurological condition), or idiopathic (no known cause). Possible causes of dystonia include:

• Drug use
• Genetic neurological conditions
• Infection
• Side effects of prescription drugs
• Traumatic injury
• Brain cancer

Treatment for dystonia varies depending on the cause. Contact our dystonia care team at 617-726-3642 to learn about our multidisciplinary approach to care.

FAQs About Dystonia