Dysphonia - spasmodic
Spasmodic dysphonia involves difficulty speaking because of repetitive or continuous spasms (dystonia) of the muscles that control the vocal cords.
The excessive activity of the vocal cord muscles drives the vocal cords either too close or too far apart.
This causes a hoarse or grating sounding voice, often with pauses (known as adductor dysphonia) or a whispery, breathy voice (abductor dysphonia), which is less common.
Some people will find that the problem goes away when they sing or shout. Botulinum toxin (Botox) treatments may help.
Goetz, CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007: chap 13.