Is it common?

Spasmodic dysphonia is a neurological condition that affects your speech. It affects all ages and can develop at any time. Approximately 50,000 people in North America are affected, and this number may be even higher.

That’s because some cases may go undiagnosed or misdiagnosed as another speech disorder. For example, older adults who develop the condition may believe that the changes in their voice are simply age-related.

When you speak, the air that leaves your lungs is pushed between your two vocal cords. These elastic cords stretch from the front of your throat to the back. Air pressure causes them to vibrate in just the right way to produce your voice.

If you have spasmodic dysphonia, the muscles inside your vocal cords receive abnormal nerve signals from the brain. These can cause your vocal cords to vibrate uncontrollably at times. Regular speech can become hoarse and uneven.

Keep reading to learn more.

Are there different types?

There are three main types of spasmodic dysphonia.

Adductor spasmodic dysphonia

This is the most common type of spasmodic dysphonia.

In this type, the uncontrolled muscle spasms cause your vocal cords to close and stiffen. This can make it difficult for sounds to emerge. You may have trouble starting a sentence, or you may find that your words cut out halfway through your remarks.

You may only experience these symptoms when you speak in a normal tone of voice and not when you shout or laugh.

Abductor spasmodic dysphonia

In this type, your vocal cords open too far. This prevents your vocal cords from vibrating. It also allows extra air to leave your lungs while you speak. This type of dysphonia may cause your voice to sound weak. It’s symptoms are less common when you shout, cry, or laugh.

Mixed spasmodic dysphonia

In this type, neither the muscles that open the vocal cords nor the ones that close them work correctly. It’s the rarest form of this disorder. It causes symptoms tied to both adductor and abductor spasmodic dysphonia.

What are the symptoms?

The main symptom of spasmodic dysphonia is an involuntary movement or spasm of the muscles inside the vocal cords. This can cause your speech to sound strained. Words may be dragged out or interrupted while you talk.

You may also sound:

  • hoarse
  • like you can’t produce enough air when you speak
  • like there’s too much air behind your words

Spasmodic dysphonia usually starts out with mild symptoms that appear infrequently. As the disease progresses, your speech may become difficult to understand. Every word or every other word may be affected by a muscle spasm.

This progression typically stops after a year and a half, allowing your symptoms to stabilize.

What causes it and who is at risk?

Although this condition can develop at any age, the first signs usually appear between the ages of 30 and 50 years.

During this time, you may assume that there’s a structural problem with your larynx (voice box), vocal cords, or some other part of your throat. But symptoms tend to appear without any other health problems. For example, polyps, inflammation, and other obvious causes of speech difficulties typically aren’t present. People with spasmodic dysphonia usually don’t have any problems with swallowing or breathing, either.

The causes and risk factors for spasmodic dysphonia aren’t well understood. Some people with the condition appear to have an abnormality with their nervous system, which may cause the vocal cords to spasm.

In some cases, spasmodic dysphonia may be a form of dystonia. Dystonia is a different type of neurological condition that affects muscle tone.

The specific source of spasmodic dysphonia may be in the basal ganglia, a part of the brain that controls movement. The brainstem, which connects the brain to the spinal cord, may also be involved.

How is it diagnosed?

After discussing your symptoms, your doctor will listen to you speak to hear how the spasms affect your voice.

From there, they will check your vocal cords with fiberoptic nasolaryngoscopy. To do this, your doctor will guide a thin, flexible, lighted tube through one of your nostrils and down your throat. It allows your doctor to look at your vocal cords while you speak.

The obvious speech symptoms are similar to other voice disorders, such as vocal cord paresis or paralysis. These disorders can be caused by an infection or by a stroke or cancer. Performing a fiberoptic nasolaryngoscopy will help your doctor make an accurate diagnosis.

What treatment options are available?

There isn’t a cure for spasmodic dysphonia, but there are treatments available to help relieve your symptoms.

Your treatment will depend on several factors, including your:

  • age
  • overall health
  • condition severity

Your ability to handle certain procedures, such as surgery, will also be considered. Your personal feelings about treatment are important as well. Surgery on your vocal cords carries some risk of permanent damage.

In most cases, speech or voice therapy is preferred over surgery. Therapy can teach you how to improve your muscle control and correct your breathing, which can help you speak more clearly.

Your doctor may also recommend regular injections of botulinum toxin (Botox) into the affected muscles. This is the same type of material that is used in cosmetic treatments to give the face a more youthful appearance.

In people with spasmodic dysphonia, the toxin blocks the nerve signal to the muscle. This can help prevent spasms. However, the effects of this treatment are temporary. Symptoms typically return after a few months, so repeat treatment would be necessary to maintain the effects.

While it has been done, surgery on one of the nerves to the vocal cords is not a common procedure for this rare condition. The long-term effects aren’t yet well known.

Outlook

Living with spasmodic dysphonia can be a challenge, especially if your job requires a lot of speaking. Occupational therapy may help you develop strategies for clearer communication.

You can also look into technology that can help you communicate more clearly. There are phone devices that help amplify the voice. For serious cases, software is available for computers or handheld devices that can translate text into artificial speech.

Research into the causes and treatments for spasmodic dysphonia is ongoing. The National Institute on Deafness and Other Communication Disorders has resources on all aspects of this disorder. You may also want to ask your otolaryngologist for information about local support groups for people with communication disorders.