Spasmodic dysphonia

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Dysphonia refers to a change in the volume, quality, or pitch of the voice. Spasmodic dysphonia is a focal dystonia involving the articulatory musculature that causes a striking abnormality of voice production.(1-4) There are two types: adductor, the most common, and abductor. There is often a superimposed vocal tremor. The video, courtesy of the National Spasmodic Dysphonia Association, demonstrates both types, subtle and obvious, with and without tremor.(5)

Adductor spasmodic dysphonia causes erratic, involuntary adduction spasms of both vocal cords. As the patient strains to speak through the narrowed vocal tract, the voice takes on a high-pitched, strained, choked quality that varies markedly during the course of a sentence. The much rarer abductor spasmodic dysphonia is due to spasmodic contraction of the posterior cricoarytenoid, which causes a failure of normal adduction on phonation; the voice is breathy and hoarse. In both types, there is often a dramatic improvement in the voice during shouting, whispering, or singing. Direct and indirect laryngoscopy and videostroboscopy are valuable adjuncts to the routine examination. Both types may respond dramatically to the injection of botulinum toxin into the involved muscle.


1. Campbell WW. DeJong's the neurologic examination, 7th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2013.

2. Hintze JM, Ludlow CL, Bansberg SF, Adler CH, Lott DG. Spasmodic Dysphonia: A Review. Part 1: Pathogenic Factors. Otolaryngol Head Neck Surg. 2017;157:551-557.

3. Hintze JM, Ludlow CL, Bansberg SF, Adler CH, Lott DG. Spasmodic Dysphonia: A Review. Part 2: Characterization of Pathophysiology. Otolaryngol Head Neck Surg. 2017;157:558-564

4. Reich SG, Meyer T. Teaching Video NeuroImage: Spasmodic dysphonia: Adductor and abductor Neurology 2008 70:e78.