Vocal Cord Dysfunction: Rapid Evidence Review.

Vocal cord dysfunction (i.e., vocal cords closing when they should be opening, particularly during inspiration) should be suspected in patients presenting with inspiratory stridor or wheezing; sudden, severe dyspnea (without hypoxia, tachypnea, or increased work of breathing); throat or chest tightness; and anxiety, particularly in females. Common triggers include exercise, asthma, gastroesophageal reflux disease, postnasal drip, upper or lower respiratory tract infection, and irritants. Nasolaryngoscopy and pulmonary function testing, with provocative exercise and methacholine, can help diagnose vocal cord dysfunction and are helpful to evaluate for other etiologies. Conditions that can trigger vocal cord dysfunction should be optimally treated, particularly asthma, gastroesophageal reflux disease, and postnasal drip, while avoiding potential irritants. Therapeutic breathing maneuvers and vocal cord relaxation techniques are first-line therapy for dyspnea that occurs with vocal cord dysfunction. A subset of vocal cord dysfunction leads to dysphonia, as opposed to dyspnea, secondary to abnormal laryngeal muscle spasms (vocal cord closure is less severe). OnabotulinumtoxinA injections may be helpful for spasmodic dysphonia and for treating dyspnea in certain cases, although evidence is limited.