Spasmodic dysphonia is otherwise known as Laryngeal Dystonia. It is a Voice Disorder where one or more muscles of the larynx (voice box or vocal cords) move automatically unwillingly during speaking.
Types of Spasmodic Dysphonia:
- Adductor Spasmodic Dysphonia
- Mixed Spasmodic Dysphonia
- Abductor Spasmodic Dysphonia
Adductor Spasmodic Dysphonia:
When any sudden unwilling spasms or movement of muscles occur, the vocal folds shuts together and gets stiff. These spasms make the vibration of the vocal folds difficult and hence it gets difficult to produce sounds. Words are incomplete and starting of a words or sentence gets difficult due to these sudden muscle cramps. Stuttering-like speech may be heard. The patient appears to have a strained voice as if got strangles of putting lot of effort to speak. But singing, laughing, speaking while breathing in or talking at high pitch does not experience sudden spasms. But stress can even worsen the condition.
Abductor Spasmodic Dysphonia:
Our vocal folds open due to sudden unwilling muscle activity. So vocal muscles cannot vibrate. Air escapes from the lungs. A weak and quiet voice is common in such patients. They also posses breathy and whispered voices. But these spasms are absent during laughing and singing like the Adductor Spasmodic Dysphonia.
Mixed Spasmodic Dysphonia:
When muscle spasms open the muscles closing the vocal folds and our vocal folds, Mixed Spasmodic Dysphonia occurs. It has symptoms of both the Adductor and Abductor Spasmodic Dysphonia.
What Causes It?
Though the accurate cause is unknown, but studies have shown the involvement of neurological factors (brain and nerves) in occurrence of this voice disorder. Some Psychological factors may also be involved. Studies are still ongoing to detect the exact cause.
Diagnosis:
Diagnosis becomes difficult and is often delayed. Recognition of the symptoms itself gets delayed. A team pf specialists; an otolaryngologist, a neurologist and a speech-language pathologist. The otolaryngologist examines any possible cause for the voice disorder.
Fiberoptic laryngoscopy is performed. A small lighted flexible tube is allowed to pass through our nose, into throat. This device helps in studying the movement of the vocal cords while talking.
Stroboscopy is another method. The physician analyses the vibrations of the vocal cords in a very slow motion.
The Speech-Language Pathologist checks the quality and complications of the patients voice.
The neurologist tries to find presence of any other movement disorders.
Treatment:
No cure is available for the disorder but symptoms may be treated. Injections made up with extremely low amount of Botulinum toxin are injected into the affected muscle of the patients larynx. This toxin can block the nerve activity to that muscle, hence weakening it. But Voice Therapy is not usually effective in treating this disorder.
Surgery may also be recommended. One nerve of the vocal cord is cut off by operation. This can improve the voice, but this effect is temporary.
