Office-based arytenoid palpation for diagnosis of disorders of bilateral vocal fold immobility.

Abstract

Bilateral vocal fold immobility is an uncommon but serious condition with many causes. Accordingly, accurate diagnosis is essential in order to treat patients promptly and avoid long-term sequelae. Historically, diagnosis has been performed in the operating room with the patient under general anesthesia. We present the case of a patient who was diagnosed with bilateral vocal fold immobility by in-office arytenoid palpation that required only topical anesthesia of the larynx. The patient subsequently underwent appropriate treatment. In our opinion, office-based arytenoid palpation is a simple, safe, and accurate procedure for diagnosing bilateral vocal fold immobility.

Introduction

Bilateral vocal fold immobility is a potentially life-threatening disorder. Therefore, a prompt and accurate diagnosis followed by appropriate treatment is imperative. Vocal fold immobility or fixation has several etiologies that should be distinguished from one another because treatments vary. Four conditions account for nearly all cases of bilateral vocal fold immobility: (1) neurogenic bilateral vocal fold paralysis, (2) cricoarytenoid joint fixation, (3) laryngeal synkinesis, and (4) interarytenoid scar/posterior glottic stenosis. (1) Differentiation of these etiologies is based on the history and findings on flexible laryngoscopy, direct laryngoscopy (with arytenoid palpation), and laryngeal electromyography (EMG). (2) Historically, diagnostic laryngoscopy has been performed in the operating suite. Recently, an advanced technology called chip-tip flexible laryngoscopy has made it possible to move the setting for many diagnostic procedures from the operating suite to the office. We present the case of a patient who was diagnosed with posterior glottic stenosis during an in-office arytenoid palpation procedure.

Case report

The patient was a 69-year-old woman who had presented to an outside facility with a 6-month history of breathing difficulty and hoarseness. She complained that the quality of her voice would change intermittently. She would experience shortness of breath, particularly when supine. She also complained of a globus sensation and frequent throat clearing. Her medical history was significant for breast cancer (she had undergone a mastectomy 9 years earlier), hypothyroidism, hypertension, and coronary artery disease. She had no history of neck or chest surgery. She had been initially seen by a pulmonologist, who made a diagnosis of chronic obstructive pulmonary disease. She was then referred to an otolaryngologist, who noted bilateral vocal fold immobility with a small glottic airway. She underwent a tracheotomy and was subsequently referred to our institution.

Our examination by flexible laryngoscopy confirmed the bilateral vocal fold immobility (figure 1). Tracheoscopy performed via the tracheotomy opening revealed a normal distal airway and subglottis. Findings on laryngeal EMG were essentially normal except for the detection of a few large-amplitude motor units within the left thyroarytenoid muscle that were not consistent with a focal laryngeal mononeuropathy. (2) Arytenoid palpation and examination of the posterior glottis were required to complete the evaluation.

[FIGURE 1 OMITTED]

During the procedure, an assistant used a chip-tip flexible laryngoscope with a working channel (EndoEYE model CYF-V; Olympus Surgical America; Orangeburg, N.Y.). A flexible Silastic spray catheter (model PW-6P-1; Olympus Surgical America) with an inner diameter of 1.8 mm and a working length of 19 cm was inserted through the working channel of the laryngoscope. Topical lidocaine 4% droplets were administered to the endolarynx by the surgeon. A total of 1.5 ml of lidocaine was applied to the base of the tongue, laryngeal surface of the epiglottis, aryepiglottic folds, posterior glottis, and the true and false vocal folds (figure 2). An Abraham cannula from a peroral approach was used to palpate the endolarynx to test for adequate depth of anesthesia. Once anesthesia was confirmed, two Abraham cannulas passed perorally were used simultaneously to passively move the arytenoids laterally and expose the posterior glottis (figure 3). The arytenoids displayed minimal mobility on simultaneous passive movement. When one arytenoid was pushed laterally, the other moved medially. An interarytenoid scar band was noted with lateral retraction of the arytenoids.

[FIGURES 2-3 OMITTED]

The patient tolerated the procedure well and experienced no complications. She ultimately underwent C[O.sub.2]-assisted laser lysis of the scar band with application of mitomycin C, and she was decannulated. She was prescribed a daily proton-pump inhibitor and a behavior-modification regimen to treat gastroesophageal reflux disease.

Discussion

Bilateral vocal fold immobility is a broad term that is used to describe any condition in which both vocal folds do not exhibit purposeful motion. From among the four most common general etiologic categories--paralysis, cricoarytenoid joint fixation, synkinesis, and interarytenoid scar/posterior glottic stenosis--the most important specific causes are iatrogenic or surgical trauma, intubation trauma, neoplasms, neurologic disorders, inflammatory diseases, and psychogenic disorders. (1,3)

Patients with bilateral vocal fold immobility present with one of two histories: (1) a worsening of stridor over weeks to months culminated by a rapid onset of dyspnea or (2) a gradually progressive dyspnea over the course of months. Patients with gradual dyspnea are frequently misdiagnosed as having asthma or chronic obstructive pulmonary disease, but the misdiagnosis becomes evident when they do not respond to a bronchodilator or other standard therapy. A flow-volume loop on pulmonary testing may indicate extrathoracic obstruction and prompt a referral to an otolaryngologist. (4)

Historically, diagnosis has been based on the results of one or more assessments from among laryngeal EMG, operative evaluation, and imaging studies. If the history does not suggest a probable cause, it is best to proceed with laryngeal EMG and arytenoid palpation. Laryngeal EMG evaluates neuromuscular activity and integrity of the laryngeal muscle adductors (thyroarytenoid and lateral cricoarytenoid) and abductors (posterior cricoarytenoid). (2,5)

A normal laryngeal EMG rules out paralysis and narrows the diagnosis to posterior glottic stenosis (interarytenoid scar) and/or cricoarytenoid joint fixation. The next step after a normal EMG is evaluation of the cricoarytenoid joints and posterior laryngeal area. Traditionally, this examination is done in the operating room by direct laryngoscopy and with either local or general anesthesia.

Imaging with computed tomography (CT) has been used (1) to evaluate the position of the arytenoids if there is a suspicion of dislocation and (2) to investigate the distal airway, because patients with posterior glottic stenosis are usually at risk for subglottic or tracheal stenosis from previous intubation trauma. (6) CT of the cricoarytenoid joints can be more difficult to interpret when there is insufficient mineralization of the laryngeal cartilages, as is the case with younger patients. A study that is nondiagnostic does not exclude a diagnosis of cricoarytenoid joint derangement. The value of imaging for definitive information about the cricoarytenoid joint is therefore limited. (7)

Indirect laryngoscopic procedures were performed as early as the mid-1800s without the benefit of topical anesthetics. Patients today have the luxury of undergoing painless procedures, and interest is high in performing laryngeal procedures in awake, sitting patients prepped with local anesthesia. Our technique for arytenoid palpation completely obviates the need for external injections (i.e., superior laryngeal nerve blocks and transtracheal injections) and significantly decreases the amount of topical anesthetic required to provide 30 to 45 minutes of targeted mucosal anesthesia. (8,9) To the best of our knowledge, the use of topical anesthesia for arytenoid palpation in the awake patient has not been previously reported.

The amount of resting muscle tone in our patient was insignificant because passive motion of the arytenoids (when palpated separately) was easily demonstrated, indicating that the cricoarytenoid joint itself was not fixed. The essentially normal laryngeal EMG ruled out paralysis and synkinesis. Our patient did not require an operative evaluation as a further means of establishing the diagnosis. Ultimately, our technique of office-based palpation of the arytenoids can be used as part of the initial evaluation. A fiberoptic laser beam (e.g., C[O.sub.2]) can then be delivered through the flexible scope to the posterior glottic scar or web at the same sitting if such a finding is noted.

In conclusion, time is of the essence in treating patients with bilateral vocal fold immobility. Our method of in-office arytenoid palpation is safe and expedient and therefore can obviate the need for a costly alternative procedure requiring an operating suite. This technique warrants incorporation into the armamentarium of tests to assist in the diagnosis of bilateral vocal fold immobility.

References

(1.) Hillel AD, Benninger M, Blitzer A, et al. Evaluation and management of bilateral vocal cord immobility. Otolaryngol Head Neck Surg 1999;121:760-5.

(2.) Munin MC, Murry T, Rosen CA. Laryngeal electromyography: Diagnostic and prognostic applications. Otolaryngol Clin North Am 2000;33:759-70.

(3.) Yin SS, Qui WW, Stucker FJ, et al. Evaluation of bilateral vocal fold dysfunction: Paralysis versus fixation, superior versus recurrent, and distal versus proximal to the laryngeal nerves. Am J Otolaryngol 1997;18:9-18.

(4.) Gardner GM. Posterior glottic stenosis and bilateral vocal fold immobility: Diagnosis and treatment. Otolaryngol Clin North Am 2000;33:855-78.

(5.) Rontal E, Rontal M, Silverman B, Kileny PR. The clinical differentiation between vocal cord paralysis and vocal cord fixation using electromyography. Laryngoscope 1993;103:133-7.

(6.) Alexander AE Jr., Lyons GD, Fazekas-May MA, et al. Utility of helical computed tomography in the study of arytenoid dislocation and arytenoid subluxation. Ann Otol Rhinol Laryngol 1997;106: 1020-3.

(7.) Sataloff RT, Bough ID Jr., Spiegel JR. Arytenoid dislocation: Diagnosis and treatment. Laryngoscope 1994;104:1353-61.

(8.) Sulica L, Blitzer A. Anesthesia for laryngeal surgery in the office. Laryngoscope 2000;110:1777-9.

(9.) Hogikyan ND. Transnasal endoscopic examination of the subglottis and trachea using topical anesthesia in the otolaryngology clinic. Laryngoscope 1999;109:1170-3.

Priya Krishna, MD; Clark A. Rosen, MD, FACS

From the Voice Center, Department of Otolaryngology, University of Pittsburgh.

Reprint requests: Priya Krishna, MD, Eye and Ear Institute, 200 Lothrop St., Suite 500, Pittsburgh, PA 15213. Phone: [phone]; fax: [phone]; e-mail: [e-mail]