Vocal-cord dysfunction presenting as asthma

Histamine hyperresponsiveness of the extrathoracic airway in patients with asthmatic symptoms

Functional abnormalities of the extrathoracic airway (EA) may produce symptoms mimicking bronchial asthma. We assessed the bronchial (B) and EA responsiveness to inhaled histamine in 40 patients with asthmatic symptoms and in nine asymptomatic controls. FEV1 and maximal mid-inspiratory flow (MIF50) were used as index of bronchial and EA narrowing. Hyperresponsiveness of the intra-(BHR) or extra-(EA-HR) thoracic airway was diagnosed when the provocative concentrations of histamine (PC20FEV1 or PC25MIF50) were less than 8 mg/ml. Fiberoptic laryngoscopy was performed in nine patients and three controls. The glottal region was measured at mid-volume of maximal inspiration (AgMI) and expiration (AgME) before and after histamine. Predominant EA-HR was found in 13 patients, predominant BHR in 12, equivalent BHR and EA-HR in another 12; no significant airway narrowing was observed in three patients and in the nine controls. EA-HR was significantly associated with female sex, sinusitis, post-nasal drip, dysphonia; BHR with atopy, wheezing and lower MEF50. The percent change in AgMI after histamine was closely related to the PC25MIF50 (r = 0.87, P less than 0.001), that of AgME to the PC20FEV1 (r = 0.78, P less than 0.01). These findings suggest that the assessment of EA responsiveness may be useful in the evaluation of asthmatic symptoms, especially in patients with no BHR.

Vocal cord dysfunction in a child with asthma

Vocal cord dysfunction is uncommon in children. We present the case of a 12-year-old boy with a history of mild, intermittent asthma from 7 to 10 years of age. Subsequently, severe, rapid-onset attacks of respiratory distress occurred with increasing frequency. After a life-threatening attack of airway obstruction with 3 minutes of apnea, he was hospitalized for diagnostic studies. Although pulmonary function tests were normal, laryngoscopy under general anesthesia revealed extremely severe vocal cord spasm induced by minimal contact of the laryngoscope. It required intravenous lidocaine and muscle relaxant to reverse. Spasm was not demonstrable one week later on repeat laryngoscopy and bronchoscopy. No structural abnormalities were seen. There was considerable family stress exacerbated by anxiety about the patient's illness. Parents were told that the condition was different from asthma and probably functional in origin. There have been no further episodes, possibly due to counseling and education in relaxation techniques as well as oral pharmacotherapy for asthma with avoidance of inhaled medications.

Fiberoptic bronchoscopy for refractory cough

Fiberoptic bronchoscopy (FB) has a low yield in the diagnosis of chronic cough (greater than 3 weeks) in unselected patients. We assessed the yield of FB for cough during a four-year period in patients with nonlocalizing chest roentgenograms who were refractory to diagnostic efforts and empiric bronchodilator or antitussive therapy. Seven (28 percent) of 25 patients undergoing FB for cough (of greater than 1,500 bronchoscopies) had diagnostic findings (broncholithiasis, two; tracheobronchopathia osteochondroplastica, two; and tuberculous bronchostenosis, laryngeal dyskinesia, and arytenoid polyp, one each). No tracheobronchial neoplasms were detected. Age greater than 50 years and female sex independently predicted positive results (p = 0.02 Fisher's exact test), while duration of cough (two to 240 months), airflow, and smoking status did not. When patients with prior pulmonary or extrathoracic neoplasms were excluded, seven (35 percent) of 20 studies were diagnostic. Diagnoses potentially could have been made by thoracic computed tomographic scanning in four patients and indirect laryngoscopy in two. Fiberoptic bronchoscopy has a respectable yield for diagnosis of refractory chronic cough and is a reasonable procedure in carefully selected patients.

Effect of inhaled methacholine on inspiratory flow

One hundred consecutive outpatients with symptoms suggestive of asthma who came to the Pulmonary Function Laboratory for a methacholine challenge test were studied. In addition to the forced expiratory maneuvers, forced inspiratory maneuvers were performed before and after the maximal response to methacholine. In 24 patients, the methacholine challenge suggested that they had asthma (forced expiratory volume in 1 s [FEV1] decrease greater than or equal to 20 percent). Six of these 24 patients also had a decrease in maximal forced inspiratory flow (FIFmax) greater than or equal to 20 percent and nine had a decrease in forced inspiratory flow at 50 percent of vital capacity (FIF50) greater than or equal to 20 percent, suggesting that bronchoconstriction can cause decreased inspiratory as well as expiratory flows. In 76 patients, the methacholine challenges were "negative" (FEV1 decrease less than or equal to 20 percent), suggesting that they did not have asthma. Nevertheless, in 11 of these 76 patients the FIFmax decrease was greater than or equal to 20 percent, and in 14 patients the FIF50 decrease was greater than or equal to 20 percent, suggesting that intermittent central airway obstruction is responsible for these patients' symptoms.

Brief upper airway (laryngeal) dysfunction

We describe in six men, recurrent episodes recurring over months or years, of sudden, brief complete obstruction to respiration followed by dyspnoea with loud inspiratory stridor lasting two to five minutes. Attacks occurred during wakefulness and/or sleep. In one patient an episode was witnessed endoscopically: the initial obstruction was seen to be caused by complete laryngeal closure. The false vocal cords then opened, but the vocal cords remained adducted and caused inspiratory stridor. The similarity of the attacks described by the other patients suggests that they were all caused by laryngeal closure. Furthermore, they could simulate the episodes by voluntarily adducting their vocal cords. The symptoms were usually preceded by a sensation of throat irritation and in four cases symptoms of upper respiratory infection were present. Associated features present in some of the patients included post-nasal discharge, snoring, sleep apnoea and gastro-oesophageal reflux. None was hypocalcaemic. Although stimulation of laryngeal receptors is known to produce reflex laryngeal closure, cough is the usual response during wakefulness. Treatment aimed at reducing upper airway irritation and voluntary inhibition of coughing appeared successful in reducing the incidence and severity of the episodes. Recognition of the condition is important as it may be confused with other causes of acute dyspnoea and it appears to respond to specific management.

Functional airway obstruction presenting as stridor: a case report and literature review

We report the case of a young man who presented to 3 emergency departments with apparent upper airway obstruction and was intubated each time before being diagnosed with paradoxical vocal cord motion. His previous discharge diagnoses were laryngeal edema secondary to anaphylaxis, even though he had no other objective findings of IgE-mediated disease. Flexible fiberoptic laryngoscopy demonstrated tight apposition of the vocal cords during inspiration while symptomatic, but normal movement when asymptomatic. Psychiatric evaluation revealed severe posttraumatic stress disorder. Of the approximately 41 reported cases of functional airway obstruction in the medical literature, only two have been adult males and none have been associated with posttraumatic stress disorder. The current literature is reviewed, and an approach to evaluation and management of such patients is provided.

Continuous adventitious lung sounds

Recent research has increased the still limited understanding about the generation of continuous adventitious lung sounds. These sounds all have a definite pitch, such as in stridor and wheezing. With the use of waveform analysis, one can examine more closely the relationship between what is heard and the pathophysiology causing the sound. Clinical examples are given to show the utility and limitations of current lung sounds analysis techniques.

Hysterical stridor: a benign cause of upper airway obstruction

We present the cases of three patients with stridor that resolved spontaneously. Paradoxical vocal cord motion was documented in one patient. Normal vocal cord motion was present in the other two patients, but stridor had resolved in both cases. Many different terms have been used to describe this entity in the literature. Emergency physicians must recognize the subtle signs of hysterical stridor. Once more serious etiologies are ruled out, sedation and reassurance instead of aggressive airway intervention are required for this benign condition.

Respiratory muscle fatigue from functional upper airway obstruction

A case of functional upper airway obstruction is presented. The case is unusual because even though no identifiable organic cause could be found for dyspnea and stridor, the patient developed respiratory failure from respiratory muscle fatigue.

Psychogenic stridor

Obstruction of the laryngeal airway is a life threatening problem due normally to obstructive pathology within the upper aero-digestive tract. We describe four cases of laryngeal stridor (two adults and two children) of psychogenic origin, one of which required a tracheostomy. The literature is reviewed and the subsequent pattern of this disease documented on the basis of 28 patients previously described.

An unexpected functional cause of upper airway obstruction

A case of acute respiratory obstruction in the immediate postoperative period is described in a young woman who emerged from general anaesthesia after a Caesarean section for fetal distress. She had a pregnancy complicated by disabling polyhydramnios and anxiously anticipated the birth of a child with a diaphragmatic hernia, diagnosed antenatally. The cause of the airway obstruction was functional in nature as confirmed by flexible fibreoptic laryngoscopy. The diagnosis, paradoxical vocal cord motion, has to be considered as an infrequent cause of postoperative airway obstruction; its recognition and treatment are discussed. The patient did not have a history which might have indicated its possible occurrence. It is suggested that paradoxical vocal cord movement in a more mild form may be overlooked as cause for postoperative stridor and airway obstruction.

Paradoxical glottic narrowing in patients with severe obstructive sleep apnea

Most patients with obstructive sleep apnea have increased pharyngeal collapsibility (defined in the present study as an increased lung volume dependence of pharyngeal area), which predisposes them to upper airway occlusion during sleep. However, there are patients with severe obstructive sleep apnea who have low-normal pharyngeal collapsibility. The factors leading to nocturnal upper airway obstruction in such patients have not been ascertained. We studied 10 overweight male patients with severe obstructive sleep apnea and low-normal pharyngeal collapsibility to determine the site of upper airway pathology in these patients. We found that all 10 patients exhibited paradoxical inspiratory narrowing of the glottis during quiet tidal breathing. This phenomenon was not observed in a matched group of 10 snoring, nonapneic male controls. We conclude that paradoxical glottic narrowing may be a contributing factor in the pathogenesis of upper airway obstruction in patients with severe obstructive sleep apnea who have low-normal pharyngeal collapsibility.

Non-organic stridor in children

A 4.75-year-old male presented with several episodes of expiratory stridor leading, on one occasion, to a respiratory arrest and intubation. A detailed evaluation emphasizing physiological and anatomical studies revealed no organic basis for the patient's upper airway obstruction. Emphasis is placed on one method found to be helpful in the differentiation of an organic versus a psychogenic type of respiratory disorder. Recognition of functional airway obstruction in children may prevent inappropriate therapy and allow proper psychiatric intervention.

Episodic laryngeal dyskinesia. Clinical and psychiatric characterization

We have obtained physiologic and psychiatric evaluations on five subjects with episodic laryngeal dyskinesia (LD) and compared them with three patients with expiratory laryngeal stridor and asthma (ELS), and five with chronic asthma (CA). Laryngoscopy confirmed adduction of the vocal cords. Diminished inspiratory flow rates with an expiratory/inspiratory ratio of 1.5 to 3.3 was demonstrated by flow volume studies. Flows improved strikingly while breathing an 80 percent helium/20 percent oxygen mixture. Patients with LD showed varying degrees of depression and sought some form of secondary gain. A histrionic personality, conversion or factitious disorders are not an essential part of this syndrome. Tracheostomy may seldom be necessary in the managing of the acute crisis of LD. Reassurance, oxygen, intermittent positive pressure, and sedation may be sufficient. Mildly depressed patients decreased the frequency and severity of wheezing episodes after receiving reassurance and a clear explanation of ventilatory mechanics.

Laryngeal dysfunction and pulmonary disorder

The normal respiratory function of the larynx has been described in detailed reports in both the otolaryngology and the respiratory physiology literature. The role of the posterior cricoarytenoid muscle in vocal cord abduction has been shown to be paramount in laryngeal respiratory function. However, only in recent reports has attention been directed toward disordered laryngeal function as evidenced in pulmonary disorders, such as asthma, or in association with underlying pulmonary disorders, such as asthma (ROAD) or emphysema (COPD). In this article, cases will be presented to demonstrate the role of disordered laryngeal function appearing as pulmonary disease and associated with various degrees of underlying pulmonary disease. The effect on pulmonary function tests and the role of treatment will be discussed.

Stridor caused by vocal cord malfunction associated with emotional factors

We describe two adolescent patients in whom a disorder of the vocal cords associated with emotional factors resulted in acute episodes of stridor. Adduction of the vocal cords on inspiration and abduction on expiration was found on indirect laryngoscopy. The problem responded to either placebo treatment or psychotherapy. The similarity between vocal cord dysfunction presenting as stridor and that presenting as asthma is discussed. The importance of diagnosing these functional problems in children is emphasized in order to avoid unnecessary diagnostic procedures and hazardous treatment.

Upper airway obstruction presenting as exercise-induced asthma

A patient presented with a ten-year history of exercise-induced wheezing. After trials of metaproterenol and cromolyn failed to improve her symptoms, she was observed during exercise. She proved to have inspiratory stridor caused by collapse of the posterior aryepiglottic folds over the vocal cords during inspiration only following exercise. Symptoms primarily improved with physical conditioning. Further improvement came after treatment of her chronic rhinitis and post-nasal drip with a steroid nasal spray.