what is spasmodic dysphonia?

Spasmodic dysphonia (SD) is a neurological voice disturbance that causes spasming of the vocal folds. It is also considered a focal dystonia of the larynx.

What causes SD?

At this point, we are not absolutely certain as to what causes SD. However, it is believed to be caused by a lesion in the brain involving the basal ganglia, which is responsible for coordinating movement.

Is there only one type of SD?

No. There are actually three types of SD: adductor, abductor, and mixed. With adductor SD, the muscles of the larynx (voice box) spasm closed when activated, yielding a squeezed and choked voice quality. With abductor SD, the muscles of the vocal folds spasm open during activation, resulting in a breathy loss of voice during speech. Abductor is more difficult to treat due to the location of the muscles involved. Mixed SD involves symptoms of both adductor and abductor SD. Any of these can occur with or without a tremor of the entire larynx.

How do I know if I have SD?

This disorder is typically identified by an otolaryngologist (ENT) with input from a speech-language pathologist (SLP). The most telling indicator of SD is the distinctive vocal quality that a trained professional can easily identify. Spasming of the vocal folds is also visualized during the laryngeal examination.

There is no test that can definitively determine the presence of SD; however, patients can be diagnosed with SD by identifying common factors shared with other SD patients such as symptoms, age of onset, factors that worsen or improve vocal quality, and vocal characteristics.

What is the onset and progression of SD?

Typically the disorder is identified in individuals in their 40’s; however, SD can affect people of all ages. Once the SD symptoms begin they progress gradually and continue to worsen for a period of approximately six to nine months, at which time the symptoms typically stabilize. However, symptoms can easily be exacerbated by stress. Additionally, symptoms vary according to speaking environments.

What is the treatment for SD?

Currently, Botulinum toxin (BOTOX®) injections and voice/speech therapy are the most widely-used treatment options. A surgery called recurrent laryngeal nerve resection has been used in the past. A new surgery called selective laryngeal adductor denervation-reinnervation is available; however, this is still largely experimental. There is currently no cure for SD.

How does BOTOX® work?

BOTOX® is injected into the vocal folds by an ENT specialist. It works by interrupting signals from the nerve to the muscles in the vocal folds, resulting in temporary weakness that allows for smoother voicing. Typically the effects of the infection will last three to four months before reinjection is necessary.

Are there any side effects with BOTOX®?

Most patients experience a short period of breathiness during speech. This is followed by a gradual onset of a strong voice over a two- to four-week period. Occasionally, patients may experience short-lived, mild, flu-like symptoms and swallowing difficulty.

What are other names for SD that may help me to research this topic?

  • Spastic dysphonia
  • Focal dystonia of the larynx
  • Laryngeal dystonia

Spasmodic Dysphonia Support Group Meetings

Join us at our SouthPark location for a support group meeting on the following dates. All meetings are from 7:00 pm to 9:00 pm and are held on the second floor unless otherwise specified below.

  • February 9, 2017
  • April 13, 2017
  • June 8, 2017
  • August 10, 2017
  • October 12, 2017
  • December 14, 2017

For the schedule of BOTOX® injections and more information about BOTOX® for SD, visit our BOTOX® For Spasmodic Dysphonia page.

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