Spasmodic Dysphonia


Involuntary, abnormal motion (spasms) of the vocal folds (vocal cords) causes the characteristic voice changes of SD. In adductor spasmodic dysphonia (AdSD), the vocal folds come together with too much force and at inappropriate times, producing strained, strangled breaks in connected speech. In abductor spasmodic dysphonia (AbSD), the vocal folds spread apart inappropriately during speech, causing breathy or soundless breaks. In both cases, voice breaks, or spasms in the voice, occur irregularly, and the severity of the symptoms usually varies from day to day, and even over the course of a single day. Public speaking, telephone use, or fatigue causes symptoms to be more severe.


SD is diagnosed based on what the patient sounds like and by examining the vocal folds and larynx. Physicians will also perform a neurologic exam to make sure there’s nothing else going on.


There is no cure for SD, and available treatment is intended only to improve symptoms. The main treatment for SD is laryngeal injections of botulinum toxin, which has helped thousands of SD sufferers return to happy, productive lives.


In most cases, treatment can substantially improve symptoms, often resulting in a near-normal voice. Patients with SD almost never completely lose the ability to communicate, and if a person elects not to be treated, the SD will not become worse. At the Voice and Swallowing Institute, we are currently performing unique and groundbreaking research in the development of better treatments for SD.

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