Spasmodic dysphonia

Information for patients with neurologic spasms of the vocal folds

• Causes of spasmodic dysphonia
• Focal dystonias
• Laryngeal dystonias
  • ADductor spasmodic dysphonia
  • ABductor spasmodic dysphonia
  • Respiratory dysphonia
• Is it psychologic?
• Sensory tricks
• Treatment
  • Botulinum toxin A
  • Post injection information for ADductor spasmodic dysphonia
  • Post injection information for ABductor spasmodic dysphonia
  • The art of an injection makes a difference
• Other sites for information on SD

Cause

Spasmodic dysphonia is a neurologic disorder that science does not yet know the cause or exactly how it works. There seems to be some emerging research that points to a problem in the feedback loop between the brain and the organ with the dystonia - in this case the voice box. Because of a problem with this feedback loop, there is over control with resultant spasms or overly tight muscle contractions. Some of the interesting research I have seen has been from PET scans showing a decrease in activation of the brain after treatment has decreased the effortfulness of using the muscles. Despite this lack of knowledge, there is a good treatment for the symptoms of the disorder.

Focal dystonias

Spasmodic dysphonia is one type of a family of disorders called focal dystonias. When a single muscle or small group of muscles contract spontaneously and irregularly without good voluntary control, those muscles are dystonic. While there are dystonias where a large number of muscles or a complete region of the body is involved, focal dystonias are limited to a small area or single muscle. Examples would include torticollis where a spasm of a neck muscle causes the head to rotate. Blepharospasm is when the muscle around the eye spontaneously twitches. Writers cramp is when the muscles of the hand spasm. Spasms of the muscles in the voice box are a laryngeal dystonia.

Interestingly dystonias are not even disorders of muscle tone that the name [dys] [tonia] might seem to imply. Early in the twentieth century, a physician thought the disorders were a problem with muscle tone and the name has stuck even though etymologically incorrect.

Laryngeal dystonias

There are several types of laryngeal dystonia. The most common type is when the muscles that bring the vocal folds together for speaking intermittantly spasm. Since the voice box serves several functions, including speaking, breathing and preventing food from getting into the lungs when swallowing; laryngeal dystonias can affect more than the voice. When the voice is the primary site affected, then the laryngeal dystonia is called spasmodic dysphonia. It has also been referred to as spastic dysphonia.

ADductor spasmodic dysphonia

Adductor spasmodic dysphonia is the most common type of laryngeal dystonia and involves spasms of the muscles that close the vocal folds. It could be appropriately called the strain-strangled voice. The spasms cause a choking off of the voice or interruptions of the voice. Hear samples of ADductor spasmodic dyphonia . Adductor spasmodic dysphonia may also sound just like a tightness or effortfulness without any obivous cutting out type symptoms.

ABductor spasmodic dysphonia

Abductor spasmodic dysphonia (notice the second letter is different - ABductor) involves the muscles that open the voice box for breathing. If they spasm while speaking the person develops an involuntary whisper while trying to speak. For more detail. Hear samples of ABductor spasmodic dyphonia

Respiratory dysphonia

Respiratory spasmodic dysphonia is from a spasms of the vocal fold muscles belonging to the adductor group but instead of spasming during speaking, they spasm during breathing. Theses spasms create noisy and difficult breathing. This noise despite not wanting to make a noise.

Is it psychologic?

As recently as the 1970’s most people thought that spasmodic dysphonia was a psychologic disorder. Though this has been proven not to be the case, many people still tend to be diagnosed as having a psychologic disorder. This happens for several reasons. Spasms cannot clearly be seen like a polyp or nodule could be so are often missed on a visual examination. Since spasmodic dysphonia is an uncommon disorder when compared to say heart disease, many physicians have never heard of it. One does not tend to diagnose a disease that one has never heard of. Spasmodic dysphonia presents in several variations and may not be a single disease. Spasmodic dysphonia tends to vary in its severity daily and weekly so both patient and physician may question how real the illness really is.

Some of the most common complaints or symptoms that patients have include the following.

• I got a cold/bronchitis/laryngitis and it didn’t go away like it usually does.
• My voice varies all the time.
• It is a struggle to get the words out.
• I can sing easily but I can’t talk easily.
• If I speak at a higher pitch, the spasms go away.
• I hate to use the phone.
• I have good weeks and I have bad weeks.
• I have had to give up working, speaking, teaching, etc.

Sensory tricks

Dystonias often can be relieved by sensory tricks, perhaps at first glance making the patient or examiner believe the problem is psychologic. A better explanation is probably that some sensations cause an input to the brain that changes the impulses causing the spasms. While examing patients throats, a physican will often hold the tongue and this may relieve the spasms. Spraying numbing medicine on the back of the throat has changed the spasms temporarily.

Treatment

The mainstay of therapy starting in the late 1980’s has become botulinum toxin injections into the muscles that are spasming. The injections are temporary causing a beneficial effect for about four months. Other treatments tried include cutting a nerve to the voice box, cutting a nerve to the voice box and hooking up another nerve, changing the shape of the voice box, speech therapy. While each of these treatments have been successful in some, they have not been successful in others. Additionally, other physicians and scientists have not been able to consistently repeat the successes described by some.

A video covering various types of injections I perform (Botox as well as other substances) is available for viewing here.

Botulinum toxin A

Botulinum toxin A is a protein produced by the bacteria botulinum. It is indeed, the same one that causes food poisoning. Botulinum toxin A has been produced primarly by Allergan corporation under the trade name Botox. Other variations of this protein are being developed by other corporations. The medication works by weaking the muscle into which it is injected. It interrupts the junction of the nerve with the muscle. Nerves, fortunately or unfortunately are very good at resprouting and making new attachments to muscle. Thus the botulinum injection is only temporary because over several months, about four, the nerve hooks itself back up to the muscle. This is good if you have food poisoning since your muscles will work again, not so good if you have spasmodic dysphonia since you need to make a return trip for another injection.

Doses of botulinum toxin A used depend on both how the injection is done and on some unknown property of the disease. One or both muscles of the paired voice box muscles may be injected. Dosage does not depend on severity of the spasm, age or sex of the patient, weight or any other factor that we presently know of. Thus the first injection a patient receives is something of a trial since it may be a bit too much or not enough.

What should I expect after an injection with botulinum toxin A for ADductor spasmodic dysphonia? ABductor spasmodic dysphonia?

To some extent the larger the dose, the longer the duration of the beneficial effect though on average, this is limited to about four months. Additionally the larger the dose, the longer the initial breathiness. Depending on the patients needs a dose is ultimately chosen that balances the initial side effects while obtaining a reasonable duration of benefit. See the art of an injection.

Other sources of information

National Spasmodic Dysphonia Association (NSDA)produces a newsletter and sponsors annual conferences. Most larger cities have a local support group and the NSDA has a list of these. Since dosages of botulinum toxin are small and the medication expensive, patients are usually treated on the same day. This can be an opportunity to meet other patients with the disorder in the waiting area. See list of web resources. For physicians who may be performing injections in your area see list.

Medical Diagnostic Information

Information for physicians, medical students, residents and other voice professionals using the symptom complexes and the three part model for voice disorder diagnosis.