CE/CME
Spondylolysis and Spondylolisthesis Primary Care Clinicians' Role
Although accreditation for this CE/CME activity has expired, and the posttest is no longer available, you can still read the full article....
The symptoms of vocal cord dysfunction (VCD) can be mistaken for those
of asthma or other respiratory illnesses. As a result, VCD is often misdiagnosed,
leading to unnecessary, ineffective, costly, or even dangerous treatment. Here are
the facts that will enable you to avoid making an erroneous diagnosis, choosing
potentially harmful treatment, and delaying effective treatment.
A 33-year-old oncology nurse, JD, had moved from Seattle to Phoenix about six months earlier for a job opportunity. Shortly after starting her new job, she had developed intermittent dyspnea on exertion, with a cough lasting several minutes at a time, along with a sensation of heaviness over the larynx and a choking sensation. These symptoms were precipitated by gastroesophageal reflux disease (GERD), postnasal drainage, stress, and significant environmental change (ie, Seattle to Phoenix). She noticed that, since moving to Phoenix, she frequently cleared her throat but denied any hoarseness, dysphagia, chest tightness, chest pain, or wheezing. She noted nasal congestion and clear nasal discharge on exposure to inhaled irritants (eg, woodstove smoke) and strong fragrances (eg, perfume or cologne).
On physical examination, the patient was alert, oriented, and in no acute distress. She was coughing intermittently but was able to speak in complete sentences. No stridor or dyspnea was noted, either on exertion (jogging in place) or at rest.
HEENT examination was normal, with no scalp lesions or tenderness; face, symmetric; light reflex, symmetric; conjunctivae, clear; sclera white, without lesions or redness; pupils, equal, reactive to light and accommodation; tympanic membranes and canals, clear with intact landmarks; no nasal deformities; nasal mucosa, mildly erythematous with mild engorgement of the turbinates; no nasal polyps seen; nasal septum midline without perforation; no sinus tenderness on percussion; pharynx, clear without exudate; uvula rises on phonation; and oral mucosa and gingivae, pink without lesions. Neck was supple without masses or thyromegaly, and trachea was midline. Lungs were clear to auscultation with normal respiratory movement and no accessory muscle use, with normal anteroposterior diameter. Heart examination revealed regular rate and rhythm, without murmur, clicks, or gallops.
Examination of the skin was normal, without rashes, hives, swelling, petechiae, or significant ecchymosis. There was no palpable cervical, supraclavicular, or axillary adenopathy.
Results of laboratory studies included a normal complete blood count with differential and a normal IgE level of 46.3 IU/mL. Spirometry testing revealed normal values without obstruction; however, there was a flattening of the inspiratory flow loop, with no reversibility after bronchodilator, which was highly suggestive of vocal cord dysfunction (VCD). Perennial nonallergic rhinitis (formerly called vasomotor rhinitis) was confirmed because the patient experienced fewer symptoms to perfume after nasal corticosteroid use. The patient’s GERD was generally well controlled with esomeprazole but was likely a contributing factor to her vocal cord symptoms.
On laryngoscopy, abnormal vocal cord movement toward the midline during both inspiration and expiration was visualized, confirming the diagnosis of VCD.
BACKGROUND
VCD is a partial upper airway obstruction caused by paradoxical adduction (medial movement) of the vocal cords.1 Although it is primarily associated with inspiration, it sometimes manifests during expiration as well.
The true incidence of VCD is uncertain; different studies have found incidence rates varying from 2% to 27%, with higher rates in patients with asthma.1,2 However, highlighting the risk for misdiagnosis, some 10% of patients evaluated for asthma unresponsive to aggressive treatment were found, in fact, to have VCD alone.2
Similarly, although VCD is generally more common in women than in men, the reported female-to-male ratio has varied from 2:1 to 4:1.1,2,4 Some reports suggest that VCD is seen more frequently in younger women, with average ages at diagnosis of 14.5 in adolescents and 33 in adults.2,3 Others identify a broader age range, with most patients older than 50.4
Historically, VCD has been known by a variety of names and has been observed clinically since 1842. In that year, Dunglison referred to it as hysteric croup, describing a disorder of the laryngeal muscles brought on by “hysteria.”5 Later, Mackenzie was able to visualize adduction of the vocal cords during inspiration in patients with stridor by using a laryngoscope.6 Osler demonstrated his understanding of the condition in 1902, stating, “Spasm of muscles may occur with violent inspiratory effort and great distress, and may even lead to cyanosis. Extraordinary cries may be produced either inspiratory or expiratory.”7
More recently, in 1974, Patterson et al reported finding laryngoscopic evidence of VCD, which they termed Munchausen’s stridor.8 They used this descriptor to report on the case of a young woman with 15 hospital admissions for this condition. At the time, the etiology of the condition was believed to be largely psychologic, and its evaluation was consigned to psychiatrists and other mental health practitioners.
As laryngoscopy became more widely available in the 1970s and 1980s, diagnosis of VCD increased, although the condition remains underrecognized.9 Ibrahim et al suggest that primary care clinicians may not be as aware of VCD as they should be and may not consider laryngoscopy for possible VCD in patients whose asthma is poorly controlled.2
Disagreement persists with regard to the preferred name for the condition. Because numerous disorders involve abnormal vocal cord function, Christopher proposed moving away from the broad term VCD and toward a more descriptive term: paradoxical vocal fold motion (PVFM) disorder.10 Interestingly, use of the two terms seems to be divided along specialty lines: VCD is preferred by allergy, pulmonology, and mental health specialists, while PVFM is favored by otolaryngology specialists and speech-language pathologists.11
Further complicating awareness and recognition of VCD is its longstanding reputation as a psychologic disorder. In fact, the paradigm has shifted away from defining VCD as a purely psychopathologic entity to the identification of numerous functional etiologies for the disorder. This, however, has resulted in many new terms to describe the condition, including nonorganic upper airway obstruction, pseudoasthma, irritable larynx syndrome, factitious asthma, spasmodic croup, functional upper airway obstruction, episodic laryngeal dyskinesia, functional laryngeal obstruction, functional laryngeal stridor, and episodic paroxysmal laryngospasm.1
Regardless of its name, an understanding of VCD is essential for both primary care and specialty clinicians because of its frequent misdiagnosis as asthma, allergies, or severe upper airway obstruction. When it is misdiagnosed as asthma, aggressive asthma treatments—to which VCD does not respond—may be prescribed, including high-dose inhaled and systemic corticosteroids and bronchodilators. Patients may experience multiple emergency department (ED) visits and hospitalizations and, in some cases, may be subjected to tracheostomies and intubation.
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