Spasmodic Dysphonia

Multidisciplinary Care for Spasmodic Dysphonia

Spasmodic dysphonia, also known as a focal laryngeal dystonia, is a neurological voice disorder that causes involuntary muscle spasms in the larynx (voice box). The spasms interfere with the normal movement and vibration of the vocal cords, making the voice sound hoarse, strained, or shaky.

Our team brings together the expertise of fellowship-trained laryngologists, neurologists, and speech-language pathologists to treat spasmodic dysphonia. At the Voice Center, our comprehensive medical resources provide patients with consultations, follow-up visits, and medical treatments and procedures, all in one convenient location.

Types of Spasmodic Dysphonia

The various types of this condition cause a range of symptoms because the spasms cause different problems with the vocal cords. The three types of spasmodic dysphonia and their associated symptoms are:

• Adductor spasmodic dysphonia: The most common form, this type causes spasms that make the vocal cords stiffen and close suddenly. These spasms often cause words to be cut off or difficult to start, resulting in choppy, strained speech.
• Abductor spasmodic dysphonia: This type involves spasms that cause the vocal folds to open, preventing them from vibrating to make sound. In this open position, air escapes from the lungs during speech, resulting in a weak, breathy voice.
• Mixed spasmodic dysphonia: In very rare cases, people have a combination of the two types. Because the muscles that open and the muscles that close the vocal folds are not working properly, this type has a mix of symptoms.

In all three types, the spasms usually do not occur and the voice sounds normal while laughing, crying, or shouting (these are examples of emotional expression, which is spared in spasmodic dysphonia). Stress often makes the muscle spasms more severe. Breathing and swallowing are usually unaffected. In some people, tremor of the voice box will accompany spasmodic dysphonia.

Cause of Spasmodic Dysphonia

The exact causes of this condition are unknown, but some researchers believe it could be related to problems in areas of the brain that control specific muscle movement.

Diagnosis of Spasmodic Dysphonia

The symptoms of spasmodic dysphonia can be similar to those of other voice conditions. Our multidisciplinary team, which includes laryngologists, speech-language pathologists, and neurologists, works together to thoroughly evaluate each patient and confirm an accurate diagnosis.

At UT Southwestern’s Voice Center, our team conducts a comprehensive evaluation, which includes a:

• Physical exam, with a visual inspection of the vocal cords
• Review of personal medical history
• Discussion of symptoms

To examine the vocal cords and larynx, our otolaryngologists often use one or more instruments, such as a:

• Flexible laryngoscope: A narrow, flexible tube with a light and camera, inserted through the nose
• Rigid laryngoscope: A narrow, rigid viewing tube inserted through the mouth
• Videostroboscope: A camera with a flashing light that provides a slow-motion view of the vocal cords as they vibrate

Our speech-language pathologists assess patients’ voice production and quality. Our neurologists sometimes evaluate patients for signs of muscle movement disorders. When needed, the team sometimes orders additional tests, such as a:

• Magnetic resonance imaging (MRI) scan: Equipment that uses a large magnet and radio waves to produce detailed images of the brain to rule out other neurological disorders
• Sound (acoustic) analysis: Computer analysis that identifies abnormalities in the sounds produced by the vocal cords

Treatment for Spasmodic Dysphonia

Although spasmodic dysphonia has no cure, treatment can relieve the symptoms to help improve voice quality and produce better speech. Treatments that we offer include:

• Botulinum toxin (Botox) injections, repeated at various intervals, into the affected larynx muscles for a smoother voice
• Speech therapy to improve voice and speech quality
• Surgery, such as selective laryngeal adduction denervation-reinnervation (SLAD-R), which restores function in vocal cords that spasm shut during connected speech (a continuous sequence of sounds in speech)