Definition

Spasmodic dysphonia (SD) is a voice disorder. 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.

The 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

Causes

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

Risk Factors

This condition is more common in women and people who are between 30 and 50 years of age.

Factors that may increase your chance of developing SD include:

• Degenerative brain diseases such as amyotrophic lateral sclerosis
• Another movement disorder such as tardive dyskinesia
• Family history of SD—In some families, a gene on chromosome 9 may be connected to SD.
• Brain infection such as encephalitis
• Exposure to toxins or certain medications such as phenothiazines

Symptoms

Symptoms of SD include:

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

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

Images may be taken of your bodily structures. This can be done with:

• MRI scan
• CT scan

You may be referred 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:

• Medication—to increase dopamine, a chemical in the brain that influences muscle movement
• Botulinum toxin injections—to reduce muscle spasms
• 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 a nerve that is connected to the vocal cords

Prevention

Since the causes are unknown, it is difficult to prevent SD.

National Spasmodic Dysphonia Association http://www.dysphonia.org

Speech-Language and Audiology Canada http://sac-oac.ca

Diagnosis. National Spasmodic Dysphonia Association website. Available at:
http://www.dysphonia.org/diagnosis.php
Accessed November 26, 2014.

Rosow DE, Parikh P, et al. Considerations for initial dosing of botulinum toxin in treatment of adductor spasmodic dysphonia. Otolaryngol Head Neck Surg. 2013; 148(6):1003-6.

Spasmodic dysphonia. American Speech-Language-Hearing Association website. Available at:
http://www.asha.org/public/speech/disorders/SpasmodicDysphonia.htm
Accessed November 26, 2014.

Spasmodic dysphonia. National Institute on Deafness and Other Communicative Disorders website. Available at:
http://www.nidcd.nih.gov/health/voice/Pages/spasdysp.aspx
Updated October 2010. Accessed November 26, 2014.