Definition

Focal dystonia is an irregular movement disorder specific to one part of the body. In dystonia, muscle contractions cause irregular movements, twitches, tics, and twisted or repetitive postures. These may be continuous or off and on. The most common types of focal dystonia are:

• Blepharospasm—an eye twitch
• Cervical dystonia or spasmodic torticollis—affecting the neck
• Segmental cranial dystonia, also known as Meige syndrome—affecting the jaw, tongue and eyes
• Oromandibular dystonia—affecting the jaw
• Spasmodic dysphonia—affecting the vocal cords
• Axial dystonia—affecting the trunk
• Dystonia of the hand/arm, such as writer’s cramp

Causes

In many cases, the cause of primary dystonia is not known. In others, it may be genetic.

Secondary dystonia is caused by an existing health condition, injury, or genetic disorder. Some of these include:

• Birth injury, such as lack of oxygen
• Infection
• Reactions to medication
• Heavy metal poisoning
• Carbon monoxide poisoning
• Trauma
• Stroke
• Other diseases

Risk Factors

Family history increases your chance of developing primary dystonia.

Having a specific health condition, injury, or genetic disorder increases your chance of developing secondary dystonia.

Symptoms

Symptoms may include:

• Eyelid spasms
• Rapid or uncontrollable blinking of both eyes
• Neck twisting
• Difficulty writing
• Foot cramps
• Pulling or dragging of a foot
• Tremor
• Voice or speech difficulties

Factors that may worsen dystonia include:

• Excitement or agitation
• Stress
• Talking
• Fatigue

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done.

This may include a complete neurologic exam and an eye exam.

You may be referred to a speech-language pathologist, physical or occupational therapists, and/or genetic counselors.

Tests may include:

• Blood tests
• Urine tests
• Genetic tests
• Lumbar puncture
• Biopsy

The electrical activity of your muscles, nerves, and brain may need to be measured. This can be done with:

• Electromyography
• Nerve conduction study
• Electroencephalography

Pictures may need to be taken of your head. This can be done with:

• MRI scan
• CT scan
• Transcranial ultrasound

Treatment

Talk with your doctor about the best treatment plan for you. Options include:

Prevention

There are no current guidelines to prevent focal dystonia. If you take any medications that may cause dystonia, talk with your doctor about your risk of developing dystonia as a side effect.

International Parkinson and Movement Disorder Society http://www.movementdisorders.org/MDS.htm

Health Canada http://www.hc-sc.gc.ca

Dystonia. International Parkinson Movement Disorder Society website. Available at:
http://www.movementdisorders.org/MDS/About/Movement-Disorder-Overviews/Dystonia.htm
Updated May 26, 2013. Accessed July 11, 2013.

Dystonia. The Canadian Movement Disorder Group website. Available at:
http://www.cmdg.org/Movement_/dystonia/dystonia.htm
Accessed July 11, 2013.

Dystonias fact sheet. National Institute of Neurological Disorders and Stroke website. Available at:
http://www.ninds.nih.gov/disorders/dystonias/detail_dystonias.htm#221673257http://www.ninds.nih.gov/disorders/dystonias/detail_dystonias.htm#221673257
Updated July 2, 2013. Accessed July 11, 2013.

Gaenslen A. Transcranial sonography in dystonia. Int Rev Neurobiol. 2010;90:179-187.

Meige Syndrome. National Organization for Rare Disorders. Available at:
http://rarediseases.org/rare-diseases/meige-syndrome
Accessed July 11, 2013.

NINDS dystonias information page. National Institute of Neurological Disorders and Stroke website. Available at:
http://www.ninds.nih.gov/disorders/dystonias/dystonias.htm
Updated July 2, 2013. Accessed July 11, 2013.

What is dystonia? Dystonia Medical Research Foundation website. Available at: https://www.dystonia-foundation.org/what-is-dystonia. Accessed July 11, 2013.