Clinical Trial: Study of Air Stream in Voice Production

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Laryngeal Resistance in Abductor Spasmodic Dysphonia

Brief Summary:

This study will investigate and compare the air stream during voice production in patients with abductor spasmodic dysphonia and in normal volunteers. People with abductor spasmodic dysphonia have uncontrolled muscle spasms during speech, resulting in a weak voice. A better understanding of the abnormalities of this disorder may help in the development of more effective treatments.

Healthy volunteers and patients with abductor spasmodic dysphonia may be eligible for this study. Candidates will have a physical examination and medical history. (Patients will be videotaped and voice-recorded during the medical interview for review by specialists who will identify the type and severity of their speech disorder.) All candidates will also undergo a procedure called flexible fiberoptic laryngoscopy to record the movement of the vocal folds during speech, breathing and other tasks such as singing, whistling and prolonging vowels. For this test, the inside of the nose is sprayed with an anesthetic (lidocaine) to numb the nasal cavity and a decongestant (oxymetazoline) to widen the nasal passage. Then, a thin flexible tube called a nasolaryngoscope is passed through the nose to the larynx (voice box). A camera attached to the eyepiece of the nasolaryngoscope records the movements of the vocal folds.

Participants will then have an airway interruption test to detect pressure changes in the voice box during production of continuous sounds. A nose clip is placed over the subject's nose and two sensor devices are placed on the neck to pick up changes in movement and position of the vocal cords during voicing. A mouthpiece is placed in the mouth, and subjects are asked to say "ah" continuously at a specified sound level. This voicing is repeated 33 times with periodic breaks.

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Detailed Summary:

Persons with abductor spasmodic dysphonia (ABSD) have difficulties with phonation onset after voiceless consonants resulting in breathy breaks. Previously, ABSD was thought to involve heightened activity of the laryngeal abductor muscle, the posterior cricoarytenoid. Botulinum toxin injection of the posterior cricoarytenoid muscle in this disorder, however, only provides a partial benefit in about 50% of persons with ABSD. An electromyographic study of the laryngeal muscles in ABSD found asymmetries in the adductor muscle (the thyroarytenoid muscle) in ABSD. Thyroarytenoid (TA) activation levels differed between the two sides in persons with ABSD. An electromyographic study of the laryngeal muscles in ABSD found asymmetries in the adductor muscle (the thyroarytenoid muscle) in ABSD. Thyroarytenoid (TA) activation levels differed between the two sides in persons with ABSD in comparison with controls; the right TA showed greater activity than the left. This suggested that ABSD might involve increased tone on one side of the larynx, and that treatment should address any such asymmetry in muscle tone. We hypothesize that if TA muscle activity was greater on one side in ABSD, then

A) phonation threshold pressures should be greater than normal in persons with ABSD, and

B) that treatment with botulinum toxin in those with phonation threshold pressures greater than normal should show symptom reduction following injection of the TA muscles on one side.

Both normal volunteers and persons with ABSD will be studied. Phonation Threshold Pressure (PTP) will be measured using the brief interruption of supraglottal airflow with a valve during phonation into a tube. The electroglottographic signals will be used to determine when vocal fold vibration ceases after the valve closes. The PTP wi
Sponsor: National Institute of Neurological Disorders and Stroke (NINDS)

Current Primary Outcome:

Original Primary Outcome:

Current Secondary Outcome:

Original Secondary Outcome:

Information By: National Institutes of Health Clinical Center (CC)

Dates:
Date Received: May 4, 2001
Date Started: May 2001
Date Completion: June 2003
Last Updated: March 3, 2008
Last Verified: June 2003