What is spasmodic dysphonia?
Spasmodic dysphonia (SD) is a neurologic voice disorder that is considered a focal dystonia specific to the larynx and similar to other dystonias such as blephorospasms and torticollis. There are two types of spasmodic dysphonia: Adductor and Abductor.
Spasmodic dysphonia is often accompanied with a vocal tremor.
What are the types and symptoms of spasmodic dysphinia?
Adductor spasmodic dysphonia (ADSD)
This is the most common type of spasmodic dysphonia and results in a severely hyperfunctional voice, sounding “strained-strangled” with frequent pitch or voice breaks and occasional voicing “blocks” or tension/effort that interrupt the continuity of phonation. ADSD tends to affect voiced sounds most often (such as /d/ /a/ /e/). Intermittent periods of normal voicing may occur during speech production, during both laughter and singing, or during angry outbursts. Some patients are able to reduce the frequency and severity of spasms by speaking at a pitch that is higher than normal. The severity of symptoms of ADSD can vary greatly between patients.
Abductor spasmodic dysphonia (ABSD)
This is a virtual “mirror image” of the adductor type. Instead of the vocal folds spasming closed, the vocal folds spasm open creating an involuntary moment of no voice, which is accompanied by a burst of air. Voice onset may appear normal, and then loss of voice ensues with continued speaking. The vocal fold spasms appear to occur primarily during the production of unvoiced consonants (such as /p/, /f/, /s/). Often, patients report that their voices improve when they are angry, increase intensity, or alter pitch. Voice quality tends to worsen when patients are anxious or fatigued.
How is spasmodic dysphonia treated?
Spasmodic dysphonia is most commonly treated with Botox. Some patients choose not to treat their SD at all.