Focal Dystonia
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Focal Dystonia

Pronounced: Fo-kul dis-tone -ee-uh

En Español (Spanish Version)

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 which may be sustained or intermittent.

Focal dystonia can be treated. If you suspect you have this condition, contact your doctor.

The most common types of focal dystonia are:

  • Blepharospasm (an eye twitch)—affecting the eyes
  • Cervical dystonia or spasmodic torticollis—affecting the neck
  • Segmental cranial dystonia (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 arm (eg, writer's cramp)

Causes

Dystonias are caused by an abnormality in the basal ganglia of the brain, which is where messages that initiate muscle contractions are processed. Factors that may cause focal dystonia include:

  • Birth injury (eg, lack of oxygen)
  • Infection
  • Reactions to medications
  • Heavy metal poisoning
  • Carbon monoxide poisoning
  • Trauma
  • Stroke
  • Other diseases
  • Inherited abnormalities of the basal ganglia
  • Vitamin B-12 deficiency

The Process of Carbon Monoxide Poisoning Decreasing Available Oxygen

Carbon monoxide poisoning

© 2008 Nucleus Medical Art, Inc.

Risk Factors

The following factors increase your chance of developing focal dystonia. If you have any of these risk factors, tell your doctor:

  • Family history of dystonia
  • Recent exposure to an antinausea or antipsychotic medication

Symptoms

If you experience any of these symptoms do not assume focal dystonia is the cause. These symptoms may be attributed to other, less serious health conditions. If you experience any one of them, see your physician.

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

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. Your doctor may refer you to a speech-language pathologist, physical or occupational therapists, and/or genetic counselors.

Tests may include the following:

  • A careful family history
  • Blood tests
  • Urine tests
  • Cerebrospinal fluid tests
  • Genetic tests
  • Electromyography—to determine the health of the muscles and nerves
  • Electroencephalography—a test that records the brain’s activity by measuring electrical currents through the brain, used to detect or rule out seizures
  • Skin, muscle, and/or nerve tissue biopsies
  • Eye examination
  • Neurologic evaluation—to rule out other neurological disorders
  • CT scan or MRI—two types of x-rays that use a computer (CT) or magnetic waves (MRI) to view the structures of the brain

Electroencephalography

EEG

© 2008 Nucleus Medical Art, Inc.

Treatment

Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Medications

Certain medications may help correct imbalances in neurotransmitters. Medications used to treat dystonia include:

  • Trihexyphenidyl
  • Benztropine
  • Procyclidine HCl
  • Muscle relaxants
  • Levodopa/carbidopa
  • Bromocriptine

Anticonvulsant medications may also help people with dystonia. Since these medications are associated with certain side effects, your physician will balance treating your symptoms with reducing the risk of side effects.

Botulinum Toxin Injections

Injecting botulinum toxin (eg, Botox) directly into the muscles affected by dystonia can weaken the muscle. This may help improve symptoms of dystonia for 3-4 months.

Surgery

Surgery to cut the nerves leading to muscles affected by dystonia or removing the muscles altogether may help reduce dystonic muscle contractions. In addition, surgery to destroy the small area within the brain that dystonia originates from may successfully stop or reduce the disorder. More recently, some success has been reported using surgically implanted deep brain stimulation to reduce symptoms of dystonia.

Factors that may worsen dystonia include:

  • Excitement or agitation
  • Stress
  • Talking
  • Fatigue

Prevention

There is no known way of preventing focal dystonia. To help reduce your chances of getting this condition, take steps to reduce your risk of infection, stroke, trauma, and carbon monoxide or heavy metal poisoning. In addition, if you take any of the following medications, talk with your doctor about your risk of developing dystonia as a side effect:

  • Levodopa
  • Bromocriptine
  • Antipsychotics
  • Metoclopramide
  • Dilantin
  • Calcium channel blockers
  • Selective serotonin reuptake inhibitors
  • Ergotamines
  • Antihistamines

RESOURCES:

Dystonia Medical Research Foundation
http://www.dystonia-foundation.org/

National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov

Worldwide Education and Awareness for Movement Disorders
http://www.wemove.org/

CANADIAN RESOURCES:

Canadian Institute for Health Information
http://www.cihi.ca/cihiweb/dispPage.jsp?cw_page=home_e

Canadian Movement Disorder Group
http://www.cmdg.org/

References:

Dystonia. The Canadian Movement Disorder Group website. Available at: http://www.cmdg.org/Movement_/dystonia/dystonia.htm . Accessed November 8, 2006.

Dystonias information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/dystonias/dystonias.htm . Accessed November 8, 2006.

Focal dystonia. EBSCO Dynamed website. Available at: http://www.ebscohost.com/dynamed/what.php . Accessed February 18, 2008.

Overview of dystonia. Worldwide Education and Awareness for Movement Disorders website. Available at: http://www.wemove.org/dys/dys.html . Accessed November 8, 2006.

Meige Syndrome. National Organization for Rare Disorders. Available at: http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Meige%20Syndrome . Accessed February 18, 2008.

Tsui JK. Cervical Dystonia. In: Gilman S, ed. MedLink Neurology. San Diego, CA: MedLink Corporation. Medlink website. Available at: http://www.medlink.com . Accessed February 18, 2008.



Last reviewed February 2008 by J. Thomas Megerian, MD, PhD, FAAP

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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