Spasmodic Dysphonia

History

Characteristics

ADSD primarily involves the thyroarytenoid and the lateral cricoarytenoids in which they randomly and uncontrollably adduct, producing a voice that is described as "strangled" or "squeezed."

ABSD is less common than ADSD and is charachterized by irregular and unconrollable contraction of the laryngeal abductors, the posterior cricoarytenoids. The voice of someone with ABSD may be distinguished by phonatory breaks, pitch alterations and breathiness.

Prior to the 1970's spasmodic dysphonia was believed to be a psychological disorder.

Someone with SD can speak and show symptoms of the disorder, but when singing, laughing, and whispering there will be no problems. In addition, onset of the disorder often coincided with stressful periods in a person's life and traditional speech therapy did nothing to improve the symptoms.

During this period, traditional voice therapy coincided with psychological counseling.

It wasn't until the late 1970's-early 1980's that enough evidence accumulated, suggesting that SD was neurological in origin.

By the mid 1980's SD was established as a neurological disorder as opposed to a psychological one.

Spasmodic Dysphonia

What is it?

Spasmodic Dysphonia is a neurological voice disorder, called a dystonia, that is characterized by harsh , inappropriate contraction of muscle groups.

The etiology of Spasmodic Dysphonia (SD) is unknown, therefore treatment involves controlling the symptoms of SD.

Onset of SD is in adult hood between the ages of 30-50, with the average age being about 45years.

SD occurs more often in women than in men.

Spasmodic Dysphonia is an uncommon voice disorder, with two main types being recognized: Adductor Spasmodic Dysphonia (ADSD) and Abductor Spasmodic Dysphonia (ABSD). ADSD is 10 times more common than ABSD.

Retrieved from Youtube

Diagnosis

Diagnosis of SD can be difficult and usually requires a team of specialists including an ENT, SLP and a neurologist.

The SLP's role would be to do a voice evaluation, specifically listening for pitch breaks, excessive tension in the voice, and breathiness (if listening for ABSD type)

In addition to a subjective evaluation of the voice, the clinician can have the client read a "loaded" passage which contains certain sounds that would help differentiate the two SD types and confirm the diagnosis of Spasmodic Dysphonia.

• If the clinician suspected Adductor-type SD, then an example of a loaded loaded passage would be:

"Early one morning a man and a women were ambling along a one-mile lane running near Rainy Island Avenue"

Someone with ADSD would have difficulty saying the above sentence because it contains only voiced phonemes

• If the clinician suspected Abductor type SD, then an example of a loaded passage would be:

"He saw half a shape mystically cross a simple path at least 50 or 60 steps in front of his sister Kathy's house."

The symptoms of ABSD are most promenently heard when the speaker transitions from a voiced to a voiceless phoneme. Therefore, someone with ABSD would have difficulty saying this sentence becasue it contains voiced and voiceless phoneme transitions.

Treatment

The gold standard treatment for spasmodic dysphonia is Botox injections.

• Unilateral
• Bilateral

Reference List:

Other treatment options to help manage the symptoms of Adductor-type spasmodic dysphonia include:

• Recurrent Laryngeal Nerve Section and Innervation
• The recurrent branch of the laryngeal nerve is severed bilaterally, and then the nerve to the thyroarytenoid is attached or reinnervated to the ansa cervicalis, a nerve located in the cervical vertebrae of the spine.
• Surgical Myectomy
• Muscle fibers of the thyroarytenoid and lateral cricoarytenoid are removed, weakening the vocal folds and preventing spasms.
• Type II Thyroplasty
• The thyroid cartilage is split in half and then titanium bridges are inserted, thereby widening the space between the vocal folds, so that they cannot close and/or approximate as tightly.

Deem, J. F., & Miller, L. (2000). Manual of voice therapy (2nd ed.). Austin, TX: Pro-Ed, Inc.

Ferrand, C. T. (2014). Speech science: an integrated approach to theory and clinical practice

(3rd ed.). Upper Saddle River, NJ: Pearson Education, Inc.

Deem, E. J., & Sapienza, C. M. (2003). Historical approaches to the treatment of adductor-type

spasmodic dysphonia (adsd): Review and tutorial. NeuroRehabilitation, 18, 325-338.

Chan, S. W., Baxter, M., Oates, J., & Yorston, A. (2004). Long-term results of type II

thyroplasty for adductor spasmodic dysphonia. Laryngoscope, 114, 1604-1608.

Pitman, M. J., & Meyers, A. D. (2013, July 12). Spasmodic dysphonia: Treatment &

management. Retrieved from http://emedicine.medscape.com/article/864079-treatment#a1128

NSDA: Spasmodic Dysphonia: Diagnosis. (n.d.). Retrieved from http://www.dysphonia.org/diagnosis.php