Merck Manual

Please confirm that you are a health care professional

honeypot link

Spasmodic Dysphonia

By

Hayley L. Born

, MD, MS, Columbia University

Reviewed/Revised Mar 2023
View PATIENT EDUCATION

Spasmodic dysphonia (vocal cord spasms) is intermittent spasm of laryngeal muscles that causes an abnormal voice.

Spasmodic dysphonia is an idiopathic dystonia that affects the muscles of the larynx during specific movements of the larynx. As a localized form of movement disorder Focal dystonias Dystonias are involuntary muscle contractions, which may be sustained or intermittent. Dystonias may result in abnormal postures, movements, or both; movements may resemble tremor. Dystonias... read more , spasmodic dysphonia has an onset between ages 30 and 50 years, and about 60% of patients are women.

There are 3 main forms:

  • Adductor spasmodic dysphonia

  • Abductor spasmodic dysphonia

  • Mixed spasmodic dysphonia

In adductor spasmodic dysphonia, a patient's voice sounds squeezed, effortful, or strained due to uncontrolled closure of the vocal folds during speech. These spasmodic episodes usually occur when vowel sounds are being formed, particularly at the beginning of words.

In abductor spasmodic dysphonia, which is less common, sudden interruptions of sound caused by uncontrolled opening of the vocal cords are accompanied by an audible escape of air during connected speech.

Those with mixed spasmodic dysphonia may display features of both adductor and abductor spasmodic dysphonia to varying degrees and at different times.

Treatment of Spasmodic Dysphonia

  • Botulinum toxin injection

  • Selective laryngeal nerve section and reinnervation surgery

For adductor spasmodic dysphonia, injection of botulinum toxin (BoNT) into vocal adductors has become the standard of care, with targeting injections achieving a normal voice in approximately 70% of patients for up to 3 months. Because the effect of BoNT is temporary, injections must be repeated to maintain the improvement. Selective laryngeal nerve section with reinnervation surgery is also an option in certain centers. Laryngeal nerve section without reinnervation has been shown to result in synkinesis and is not the preferred approach to this condition.

Treatment references

  • Mor N, Simonyan K, Blitzer A: Central voice production and pathophysiology of spasmodic dysphonia. Laryngoscope 128(1):177-183, 2018. doi:10.1002/lary.26655

  • Dharia I, Bielamowicz S: Unilateral versus bilateral botulinum toxin injections in adductor spasmodic dysphonia in a large cohort [published online ahead of print, 2019 Dec 14]. Laryngoscope 10.1002/lary.28457, 2019. doi:10.1002/lary.28457

  • Dewan K, Berke GS: Bilateral vocal fold medialization: a treatment for abductor spasmodic dysphonia. J Voice 33(1):45-48, 2019. doi:10.1016/j.jvoice.2017.09.027

View PATIENT EDUCATION
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz! 
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP