Shy-Drager syndrome

Abstract

We describe the case of a woman who had been referred to us with a history of breathing difficulties and snoring and a suspicion of obstructive sleep apnea (OSA). Our investigation revealed that she did indeed have severe OSA in addition to undiagnosed bilateral vocal fold paralysis of unknown origin. Nocturnal polysomnography found that her apnea/hypopnea index was 120 and her minimum arterial oxygen saturation level was 63%. She was treated with laterofixation of the right vocal fold, and her OSA resolved immediately. During 10 years of follow-up with nocturnal polysomnography, no recurrence of apnea or low oxygen saturation levels was noted. However, she did experience a recurrence of her snoring 4 years postoperatively, along with the onset of progressively worsening daytime fatigue. When these conditions persisted, we performed a repeat laterofixation of the same vocal fold. Following the repeat surgery, subjectively and objectively assessed results were good.

Introduction

Obstructive sleep apnea (OSA) caused by bilateral vocal fold paralysis has only occasionally been described in the literature. In 1987, Ruff et al reported a case of bilateral vocal fold paralysis and sleep apnea in a patient with type I Chiari malformation. (1) In 1996, McBrien et al reported a case of bilateral vocal fold paralysis in a patient with Shy-Drager syndrome who had sought treatment for snoring and sleep apnea. (2) In this article, we describe a new case of vocal fold paralysis as a cause of OSA.

Case report

A 48-year-old woman first came to us in 1989 after she was referred by a general practitioner for evaluation of an 8-year history of breathing difficulties, which were especially pronounced at night. She snored and was able to sleep only in an upright position. She also had a history of hypertension, but she was otherwise healthy.

On examination, we discovered that the patient had undiagnosed bilateral vocal fold paralysis. She exhibited no signs of any peripheral or central nervous system disease, and other findings were normal. Nocturnal polysomnography over a full night revealed that her apnea/ hypopnea index (AHI) was 120 and her minimum arterial oxygen saturation (Sa[O.sub.2]) level was 63% (table). Spirometry revealed that her forced inspiratory volume in 1 second (FI[V.sub.1]) was 0.6 L, her forced expiratory volume in I second (FE[V.sub.1]) was 1.8 L, her vital capacity (VC) was 2.2 L, her peak inspiratory flow (PIF) rate was 0.5 L/sec, and her peak expiratory flow (PEF) rate was 4.9 L/sec. She was diagnosed with severe OSA caused by bilateral vocal fold paralysis of unknown origin.

In April 1990, the patient underwent laterofixation of the right vocal fold. This operation was technically simple. (3) Two needles were inserted through the thyroid cartilage--one above the vocal fold and the other below--and a nylon thread was passed through the needles. When the needles were withdrawn, the thread formed a permanent loop around the vocal fold. The patient's condition improved considerably after the operation, and for the first time in many years she was able to sleep in a recumbent position. Postoperative nocturnal polysomnography revealed no residual OSA. On spirometry, her FI[V.sub.1] was 1.1 L, her FE[V.sub.1], was 1.8 L, her VC was 2.3 L, her PIF was 1.0 L/sec, and her PEF was 4.6 Llsec.

In 1994, the patient returned to us because her snoring had recurred. Repeat nocturnal polysomnography revealed no episodes of apnea or desaturation, and her minimum Sa[O.sub.2] was normal (94%) (table). On spirometry, her FI[V.sub.1], was 1.0 L and her FE[V.sub.1], was 1.5 L.

By the end of 1998, the snoring problem had become distressing, and the patient complained of daytime fatigue. Nevertheless, repeat nocturnal polysomnography again detected no episodes of desaturation or apnea (table). One year later, her subjective problem with snoring and daytime fatigue became worse, but nocturnal polysomnography again revealed that her AHI and spirometric indices were still normal. Nevertheless, in April 2000, we performed a repeat laterofixation of the right vocal fold in an attempt to improve her sleep quality and reduce her snoring. The postoperative sleep quality was good, and spirometry 4 months postoperatively revealed that her [FIV.sub.1] 1.3 L and her [FEV.sub.1] was 2.0 L. Her voice quality was subjectively satisfactory, and she has experienced no aspiration problems since.

Discussion

OSA is defined as a cessation of air flow for at least 10 seconds combined with a 4% or greater desaturation of arterial blood oxygenation during sleep as a result of an obstruction of the upper airway. (4) Young et al conducted a study of adults whose apnea index was greater than 5 and found that the prevalence of OSA was 24% among men and 9% among women. (5) Shepard and Thawley reported that approximately 50% of patients with OSA experienced a collapse confined to the velopharynx during sleep, while the other half experienced a collapse confined to a more caudal part of the anatomy (e.g., the base of the tongue or the hypopharynx). (6) Wilms et al reported that some patients experienced obstruction at both levels. (7) Any space-occupying lesion between the nose and the glottis can cause an obstruction and predispose a patient to OSA. (8)

In rare cases, congenital or acquired factors have resulted in a collapse of glottic structures, which in tutn has resulted in an obstruction at the larynx. For example, Woo reported two cases of progressive OSA in which the epiglottis prolapsed after surgery on the larynx and pharynx (9) Bonilla et al reported a case of OSA in a child with epiglottic aplasia. (10) Finally, as mentioned, Ruff et al (1) and McBrien et al (2) each reported a case of OSA that was caused by bilateral vocal fold paralysis.

References

(1.) Ruff ME, Oakes WJ, Fisher SR. Spock A. Sleep apnea and vocal cord paralysis secondary to type I Chiari malformation. Pediatrics 1987;80:23 1-4.

(2.) McBrien F, Spraggs PD, Harcourt JP, Croft CB. Abductor vocal fold palsy in the Shy-Drager syndrome presenting with snoring and sleep apnoea. J Laryngol Otol 1996;110:681-2.

(3.) Ejnell H, Mansson I, Hallen O, et al. A simple operation for bilateral vocal cord paralysis. Laryngoscope 1984;94:954-8.

(4.) Maniglia AJ, Davis JA, Maniglia JV. Obstructive sleep apnea syndrome. In: Lee KJ, ed. Essential Otolaryngology-Head and Neck Surgery. Stamford, Conn.: Appleton and Lange, 1999: 859-73.

(5.) Young T, Palta M, Dempsey J, et al. The occurrence of sleep-disordered breathing among middle aged adults. N Engl J Med 1993;328:1230-5.

(6.) Shepard JW, Jr., Thawley SE. Localization of upper airway collapse during sleep in patient with obstructive sleep apnea. Am Rev Respir Dis 1990;141(Pt 1): 1350-5.

(7.) Wilms D, Popovich J, Conway W, et al. Anatomic abnormalities in obstructive sleep apnea. Ann Otol Rhinol Laryngol 1982;91:595-6.

(8.) Kerr AG, ed. Scott-Brown's Otolaryngology. Vol. 4. Oxford; Boston: Butterworth-Heinemann, 1997:1-22.

(9.) Woo P. Acquired laryngomalacia: Epiglottis prolapse as a cause of airway obstruction. Ann Otol Rhinol Laryngol 1992;101:314-20.

(10.) Bonilla JA, Pizzuto MP, Brodsky LS. Aplasia of the epiglottis: A rare congenital anomaly. Ear Nose Throat J 1998;77:51-5.

From the Department of Otorhinolaryngology-Head and Neck Surgery, Sahlgrenska University Hospital, Goteborg, Sweden.

Reprint requests: Luaay Aziz, MD, Department of Otorhinolaryngology-Head and Neck Surgery, Sahlgrenska University Hospital, S-431 45, Goteborg, Sweden. Phone: 46-31-342-1587; tax: 46-31-416-734; e-mail: luaay.aziz@orlforum.com

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