Idiopathic Unilateral True Vocal Fold Paresis

Question 1

Useful maneuvers to elucidate VF weakness

Answer 1

• “/i/-sniff” to observe full adduction & abduction
• “unloading technique” by Koufman
• “repetitive phonatory tasks” by Rubin

Question 2

Findings of VF paresis on videostroboscopy

Answer 2

• Vocal fold hypomobility
• Asymmetry in VF movement (ab/adduction)
• Incomplete glottal closure
• Vocal fold bowing
• Increased vibratory amplitude on the affected side (2/2 decreased thyroarytenoid tone)
• Phase asymmetry

Question 3

How often does laryngeal EMG verify neuropathy in patients w/ laryngoscopic signs of VF hypomobility?

Answer 3

83-86%

Simpson; Heman-Ackah 2006

Question 4

Should CT neck/chest be performed for UVFParesis?

Answer 4

No. Only for paralysis.

Question 5

What muscles are adductors

Answer 5

thyroarytenoid and lateral cricoarytenoid

Question 6

How does one determine sidedness in unilateral adductor paresis?

Answer 6

Interarytenoid spatial relationship (IASR)

• As the vocal folds are adducted, the corniculate should rotate posteriorly and superiorly creating a curve in the overlying mucosa
• On the impaired side (LCA muscle paresis), the arytenoid fails to rotate and forms a straight line b/w cuneiform and corniculate

Sufyan 2013

Question 7

Describe the innervation of the laryngeal muscles and how adductor paresis can occur

Answer 7

• RLN branches to the posterior cricoarytenoid (PCA) before it traverses behind the cricothyroid joint
• Thus, nerve injuries at the level of the CT joint may readily result in adductor VF paresis despite normal PCA muscle fnc
• The VF motion may be perceived as nl and symmetric despite presence of an adductor paresis
• Pts complain of vocal fatigue, increased effort for voice production, dyspnea with speaking, inability to inc amplitude of voice, breathy hoarseness