Spasmodic dysphonia is a disorder of the muscles that control the vocal cords. The muscles spasm as the person tries to speak. This makes the voice quality irregular and sometimes difficult to understand.

The average onset of this disorder is between ages 30 and 50. Women are more prone to the problem than men.

Successful treatment for spasmodic dysphonia took a major step forward when Botox injections started. Botulinum toxin (Botox) weakens muscles. By injecting it into the laryngeal muscles, the spasm breaks. Voice quality usually returns to normal. The Botox injections are usually needed every 3 to 4 months.

Voice therapy sometimes helps. It is useful in mild cases, but has little effect in severe cases. Since the introduction of Botox, the role of voice therapy has greatly diminished.

Hopefully, research will find other therapies that may be longer lasting and as effective as Botox.