1

Introduction

Paradoxical vocal fold motion (PVFM) is a condition in which the true vocal cords exhibit inappropriate adduction during the inspiratory phase of the respiratory cycle resulting in inspiratory stridor, dyspnea, cough, and anxiety. The disorder was first described in 1842 by Robley Dunglsion who described laryngeal spasms induced by “hysteria”. Literature from the 1970s further depicted a syndrome frequently mimicking asthma and carrying numerous misnomers including “Munchausen’s stridor” and “factitious asthma” . Rodgers and Stell first employed the more physiologic terminology “paradoxical vocal cord movement” in 1978 . However, it is only in the last decade that terminology, diagnostic criteria, and treatment have begun to move toward a universal standard.

The true incidence and prevalence of PVFM in the general population has not been defined likely due to limited awareness and challenges associated with diagnosis. While felt to be relatively uncommon, certain subgroups demonstrate significant prevalence. Newman et al. reported that 30% of patients diagnosed with refractory or persistent asthma had some component of PVFM, and 10% of the patients had PVCM as the sole cause of their symptoms . A notable 2:1 predominance exists amongst female patients diagnosed with PVFM and studies suggest that about 30% of patients are under the age of 18 .

Symptomatology typically consists of dyspnea, stridor, throat tightness, voice changes, and cough . Pediatric patients often have normal pulse oximetry, blood gas values, and chest radiographs . Flow volume loops obtained during attacks may show a blunted inspiratory component. Patients frequently are non-responsive to methacholine and histamine challenges and refractory to standard asthma treatment regimens. While diagnosis can be made based on history, flexible laryngoscopy with visualization of paradoxical vocal fold motion during inspiration has been considered by most the gold standard. However, the attacks are frequently unwitnessed by physicians, and the symptoms are often misdiagnosed as asthma. Patel et al. in 2004 reported an average time between symptom onset and diagnosis of over four years .

Misdiagnoses often result in inappropriately directed treatment which may include bronchodilators, corticosteroids, intubation, or even tracheostomy with associated side effects and iatrogenic morbidity. Frequent comorbidity of asthma, GERD, and psychiatric disorders with PVFM has been well described and the treatment of such comorbid conditions is pivotal. However, speech language pathology (SLP) techniques and behavioral intervention have demonstrated widespread success in the treatment of the PVFM population and remain the mainstay of treatment. Despite reports establishing the effectiveness of treatment with SLP approaches, these techniques have not been well described in the literature.

The purpose of this study was to characterize the typical pediatric patient with PVFM, review treatment methods used with specific focus on SLP techniques, and report success rates achieved using a multidisciplinary approach at a tertiary care facility.

2

Methods

Retrospective chart review was conducted of all pediatric patients, age ≤ 18 years, who had been diagnosed by a pediatric otolaryngologist and doctor of speech pathology over a 5-year period at a single tertiary care center. An initial cohort was identified by reviewing all patients diagnosed at the Cleveland Clinic Head and Neck Institute from August 2008 to August 2012 with ICD codes including shortness of breath (786.05), respiratory distress (786.09), laryngeal spasm (478.75), other forms of asthma (493.8), or paradoxical vocal fold motion (478.5). Patients who were ultimately diagnosed with PVFM by the senior author and a doctor of speech pathology either by clinical history or flexible laryngoscopy were included. Patients were excluded if the practitioner did not specifically state the diagnosis of PVFM or if another cause for their respiratory distress was eventually identified. The final cohort was then analyzed for demographics, coexisting conditions, and time from presentation of symptoms to diagnosis. Prescribed treatment regimens, compliance, and outcomes were also reviewed.

2

Methods

Retrospective chart review was conducted of all pediatric patients, age ≤ 18 years, who had been diagnosed by a pediatric otolaryngologist and doctor of speech pathology over a 5-year period at a single tertiary care center. An initial cohort was identified by reviewing all patients diagnosed at the Cleveland Clinic Head and Neck Institute from August 2008 to August 2012 with ICD codes including shortness of breath (786.05), respiratory distress (786.09), laryngeal spasm (478.75), other forms of asthma (493.8), or paradoxical vocal fold motion (478.5). Patients who were ultimately diagnosed with PVFM by the senior author and a doctor of speech pathology either by clinical history or flexible laryngoscopy were included. Patients were excluded if the practitioner did not specifically state the diagnosis of PVFM or if another cause for their respiratory distress was eventually identified. The final cohort was then analyzed for demographics, coexisting conditions, and time from presentation of symptoms to diagnosis. Prescribed treatment regimens, compliance, and outcomes were also reviewed.