Spasmodic dysphonia, also called laryngeal dystonia, is a voice disorder. It is characterized by involuntary spasms or movements in the muscles of the larynx (voice box) that cause the voice to break, and have a tight, strained, or strangled sound.
Difficulties that result from spasmodic dysphonia range from occasional problems with saying a word or two to complete inability to communicate.
Spasmodic dysphonia is a chronic condition that most often affects women, particularly between the ages of 30 and 50.
There are three types of spasmodic dysphonia:
Adductor spasmodic dysphonia. This is the most common type and is characterized by sudden involuntary spasms that cause the vocal cords to slam together and stiffen. The spasms interfere with vibration of the vocal cords and production of sound is difficult. Stress can make spasms more severe.
Speech sounds are strained and full of effort. Spasms do not occur when whispering, laughing, singing, speaking at a high pitch, or speaking while breathing in.
Abductor spasmodic dysphonia. This type is characterized by sudden involuntary spasms that cause the vocal cords to open. Vibration cannot occur when cords are open so production of sound is difficult. Also, the open position allows air to escape during speech.
Speech sounds are weak, quiet, and whispery. Spasms do not occur when laughing or singing.
Mixed spasmodic dysphonia. This type is characterized by symptoms of both adductor and abductor spasmodic dysphonia.
The exact cause of spasmodic dysphonia is not known. Most cases are believed to be caused by a nervous system disorder, and may occur with other movement disorders. Researchers believe it may be caused by abnormal functioning in the basal ganglia of the brain, which helps coordinate movements of muscles throughout the body. Spasmodic dysphonia may be a genetic disorder, or may begin following an upper respiratory infection, injury to the larynx, a long period of voice use, or stress.
Spasmodic dysphonia will generally be diagnosed by an otolaryngologist, a doctor who specializes in the ear, nose, and throat. In addition to a complete medical history and physical examination, examination of the vocal folds by fiberoptic nasolaryngoscopy may be performed. This procedure involves using a lighted tube, passed though the nose into the larynx to evaluate movement of the vocal folds during speech.
Specific treatment for spasmodic dysphonia will be determined by your doctor based on:
Your age, overall health, and medical history
Extent of the disease
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
The goal of treatment is to reduce symptoms of the disorder. Surgery to cut one of the nerves of the vocal fold has been used, as well as counseling. Some success has been achieved with the injection of the botulinum toxin directly into the affected muscles of the larynx. Speech therapy is also an important part of treatment of spasmodic dysphonia.