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:

The Process of Carbon Monoxide Poisoning Decreasing Available Oxygen

Carbon monoxide poisoning
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Risk

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:

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

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

Electroencephalography

EEG
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Treatment

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

Medications

Your doctor may recommend one or more of the following to help ease symptoms:

  • Over-the-counter or prescription pain relievers
  • Anticholinergics
  • Benzodiazepines
  • Dopaminergic agents
  • Dopamine-depleting agents
  • Anticonvulsants

Botulinum toxin injections

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

Surgery

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

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.