title: Paradoxical vocal cord motion: a review focused on multiple system atrophy.
abstract: OBJECTIVE
  Paradoxical vocal cord motion (PVCM) is a well recognized respiratory condition in which active adduction of the vocal cords during inspiration causes functional airway obstruction. It is considered that laryngeal reflex acceleration underlies the generation of nonorganic PVCM. In various situations producing PVCM, multiple system atrophy (MSA) is a representative neurological disease causing nocturnal laryngeal stridor attributed to PVCM. The purpose of this review is to identify the underlying mechanisms associated with nonorganic and MSA-related PVCM. The following issues are addressed in this review: (1) the pathophysiology of nonorganic and MSA-related PVCM, (2) the relationships between PVCM and airway reflexes, and (3) the treatment for MSA-related PVCM.
  
  
  METHODS
  Review.
  
  
  CONCLUSIONS
  An abnormality of the laryngeal output-feedback control underlies nonorganic PVCM, which is usually triggered by an excessive response to external and internal airway stimuli. Similarly, several clinical and experimental evidence suggest that MSA-related PVCM is attributed to the airway reflex as well as to paradoxical central outputs resulting from the MSA-induced damage to the pontomedullary respiratory center. Application of continuous positive airway pressure (CPAP), which suppresses the reflexive inspiratory activation of adductors, is recommended as the treatment for MSA-related PVCM.
authors.affiliation: Department of Otolaryngology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba City, Chiba 260-8670, Japan. shibak1963@yahoo.co.jp
authors.forename: Keisuke
authors.initials: K
authors.lastname: Shiba
authors.forename: Shiroh
authors.initials: S
authors.lastname: Isono
authors.forename: Ken
authors.initials: K
authors.lastname: Nakazawa
mesh_terms: D045422:Continuous Positive Airway Pressure; D006801:Humans; D007828:Laryngoscopy; D008526:Medulla Oblongata / Q000503:physiopathology; D009046:Motor Neurons / Q000502:physiology; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D011149:Pons / Q000503:physiopathology; D012125:Respiratory Center / Q000503:physiopathology; D012135:Respiratory Sounds / Q000503:physiopathology*; D020182:Sleep Apnea, Central / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D014826:Vocal Cord Paralysis / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D014827:Vocal Cords / Q000294:innervation / Q000503:physiopathology*