Definition

Spasmodic dysphonia (SD) is a voice disorder. It occurs when the muscles of the throat freeze or go into spasms. Words are strangled and strained or they don’t get out at all. Sounds are also distorted.

Main types of SD include:

• Adductor spasmodic dysphonia—spasms cause muscles to stiffen and close
• Abductor spasmodic dysphonia—spasms cause muscles to spastically open
• Mixed spasmodic dysphonia

Throat

Spasmodic dysphonia affects the throat muscles.

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Causes

The exact causes of SD are unknown. It is labeled as a disorder of the central nervous system. The areas of the brain that control these muscle movements are deep within the brain.

Risk Factors

Factors increase your chance of developing SD include:

• Degenerative brain diseases (eg, amyotrophic lateral sclerosis)
• Another movement disorder (eg, tardive dyskinesia)
• Family history of SD—In some families, a gene on chromosome 9 may be connected to SD.
• Brain infection (eg, encephalitis)
• Exposure to toxins or certain medications (eg, phenothiazines)
• Gender: female
• Age: between 30-50 (typical age group when the first signs appear)

Symptoms

If you have any of these symptoms do not assume it is due to SD. These symptoms may be caused by other conditions. Contact your doctor if you have any of these:

• Squeaky, strained speech
• No speech at all
• Speech with the wrong pitch and tone
• Breaks in speech
• Breathy voice

Diagnosis

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

• Blood and urine tests to find toxins
• DNA testing for related genes
• MRI scan —a test that uses magnetic waves to make pictures of structures inside the brain
• CT scan —a type of x-ray that uses a computer to make pictures of structures inside the brain

Your doctor may refer you to a team of specialists, including:

• Neurologist—to evaluate your brain function
• Speech pathologist—to evaluate your speech and how it’s produced
• Otolaryngologist—to evaluate your vocal cords

Treatment

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

• Local injections of botulinum toxin (Botox)—to weaken and calm the muscles
• Medication—to increase dopamine, a chemical in the brain that influences muscle movement
• Speech therapy techniques—to relax muscles
• Brain stimulation—to prevent muscles from freezing and going into spasm
• Counseling—to help deal with the condition
• Surgery (in severe cases)—to cut or remove nerves connected to the vocal cords

Prevention

Since the causes are unknown, it is difficult to prevent SD. Talk to your doctor if you have any of the risk factors.