People who have muscle disorders that cause excessive contraction or tightening of the muscles are said to have dystonia. When these kinds of contractions take place in the muscles that control the vocal cords, the patient may have a neurological disorder known as spasmodic dysphonia.
Spasmodic dysphonia, or SD, is a disorder of the central nervous system. There is no known cause for this disorder, although it is believed to be a type of dystonia, which originates in the portion of the brain that coordinates muscle movement. People of all ages, races, and ethnicities can have SD. Symptoms usually appear between age 30 and 50 and are more common in women than in men.
The anatomy of talking
During normal speech, air passes through the larynx or voice box in the throat. Inside the larynx, two vocal cords or folds lie opposite each other. The vocal folds are bands of smooth muscle that are attached to other muscles in the larynx. When we breathe, these folds open to allow the air to pass through. When we speak, the folds press against each other. The air passing between them causes them to vibrate, which produces the sounds of speech or singing.
What happens during spasmodic dysphonia
There are three types of spasmodic dysphonia:
• Adductor SD – In this type of SD, the muscles that control the vocal folds spasm and force the folds to slam together and stiffen. This makes it difficult for them to vibrate and produce sounds. People with this type of SD may have speech that is choppy and may sound similar to stuttering. The voice may sound strained, as though it takes great effort to speak. Stress can make these spasms worse. Symptoms may go away while whispering, laughing, singing, or speaking in a high pitch voice or speaking while breathing in.
• Abductor SD – In this type of SD, spasms in the muscles cause the vocal folds to open, which prevents them from vibrating. The open folds also allow air to escape during speech, so people with this type of SD may sound whispery, breathy, quiet, or weak. Again, these symptoms often go away while laughing or singing.
• Mixed SD – As the name implies, people with this type of SD may experience the symptoms of both Adductor SD and Abductor SD at different times.
People with spasmodic dysphonia typically have times when speech is affected and other times when speech is normal. Some people begin to have symptoms after an infection, injury to the larynx, or stress. There is no test that conclusively indicates that someone has spasmodic dystonia, which means it is frequently misdiagnosed. If your doctor suspects that you have SD, you should be evaluated by a team of medical personnel including a Speech-Language Pathologist, Neurologist, Otolaryngologist, or an ear, nose and throat doctor.
Treating spasmodic dysphonia
There is no cure for spasmodic dysphonia, but there are treatments that can be effective in controlling the symptoms.
• Oral medications - Certain medicines can help relieve some of the symptoms of the muscle contractions of some types of dystonia, but they tend not to be as effective for treating spasmodic dysphonia.
• Botulinum toxin – Marketed under the brand name Botox, injections of this toxin have proven to be the most effective way to temporarily ease the spasms of SD, especially for patients with adductor SD. When injected into the specific muscles that are spasming, Botox weakens the muscles by blocking nerve signals. This treatment can reduce breathiness and make it easier to speak. However, the injections wear off over time and must be repeated as symptoms return, which can vary from six weeks to six months.
• Surgery – An operation can be performed to cut through the nerves that are causing the spasms. This treatment is more commonly used in people who stop having success with Botox injections. While this surgery may relieve symptoms, some people have found that the spasms come back over time, resulting in more Botox injections.
Many people with spasmodic dysphonia find that support groups, either in person or Online, can be very effective in helping them deal with the symptoms and difficulty communicating caused by SD.
Sources:
National Spasmodic Dysphonia Association
National Institute on Deafness and Other Communication Disorders
BOTOX is a registered trademark of Allergan.