Spasmodic dysphonia is involuntary tightening of muscles in the voice box (larynx) that control the vocal cords, resulting in an abnormal voice.
In spasmodic dysphonia, people may not be able to speak, or their voice may sound strained, quavery, hoarse, whispery, jerky, creaky, staccato, or garbled and difficult to understand. Doctors do not know what causes spasmodic dysphonia, which is most common between ages 30 and 50 years and is more common in women. Doctors think it may be a form of dystonia, a type of movement disorder involving involuntary contraction of various muscles in the body.
There are 3 forms of spasmodic dysphonia:
Adductor spasmodic dysphonia
Abductor spasmodic dysphonia
Mixed spasmodic dysphonia
In adductor spasmodic dysphonia, the laryngeal muscles spasm and the vocal cords close together, usually when vowel sounds are being formed at the beginning of words, making a squeezed or strained sound. Injections of botulinum toxin into the laryngeal muscles provide improvement lasting up to 3 months in most people. Because the effect of the injections is temporary, injections must be repeated to maintain the improvement. Surgery is also a treatment option in some cases.
In abductor spasmodic dysphonia, spasms cause the vocal cords to open too far, making the voice sound weak and breathy. Injections of botulinum toxin into specific laryngeal muscles provide temporary improvement. Surgery is also a treatment option in some cases.
In mixed spasmodic dysphonia, people may have symptoms of both adductor and abductor spasmodic dysphonia to varying degrees and at different times.
