Differential diagnosis of paradoxical vocal fold movement.

PURPOSE To present the differential diagnosis of paradoxical vocal fold movement (PVFM) and its distinguishing features. METHODS The authors provide an overview of PVFM by drawing from 30 years of clinical and research experience, and relating that experience to literature in this area. CONCLUSION PVFM is characterized by inappropriate adduction of the vocal folds during inspiration. PVFM is an uncommon and sometimes confusing cause of airway obstruction. The resultant obstruction may be intermittent or continuous, mild or severe. Most patients with PVFM have a specific etiology--inflammatory, neurological, neoplastic, iatrogenic, or psychological--that influences type of treatment and outcome.