Spasmodic dysphonia is a voice disorder in which the vocal cords close involuntarily, wherein the voice goes into periods of spasm.
Because there is no abnormality in the appearance of the vocal cords, many patients are diagnosed as normal or their complaint is considered "psychogenic," and proper treatment is delayed. The main treatments currently in use are described in the following.
This is the most common treatment and is used worldwide. BT injection temporarily weakens the vocal cord muscle, such that it cannot become spasmodic, and thus allows the voice to return to its original state. The injection can be administered in the out-patient unit, but its effectiveness is limited and repeat injection every 3–4 months may be necessary.
An incision of about 3 cm is made under local anesthesia. The thyroid cartilage is separated horizontally to avoid damage on the vocal fold. As the cartilage is separated gradually, the patient's strangled voice will improve. Depending on the patient’s voice quality, the vocal cords are optimally adjusted and their position is fixed with a titanium bridge. Usually, a 2-3mm separation is good.
This type is only 3% of spasmodic dysphonia. The vocal cord opens involuntarily causing the patient's voice to become breathy. The video below is a sample voice.
Symptoms are relieved by BT injection in the muscle that opens the vocal cords.