Unilateral Vocal Fold Immobility Disorders

Karen Kost, MD

This collection contains 133 articles, encompassing unilateral vocal fold paralysis (UVFP), paresis and immobility. The term immobility is sometimes used interchangeably with paralysis. The vast majority of the articles pertain to paralysis and immobility, with only a few on paresis, which appears to have gained interest in the last 15 years.  A review of the number and breadth of the articles provides an appreciation of the sheer wealth and depth of information found in this particular collection. There are references covering a wide range of topics related to UVFP from the etiology, vocal evaluation, diagnosis, and treatment, to voice outcomes and prognosis.

The etiology of UVFP has been addressed in some of the articles, describing the importance of iatrogenic causes arising from thoracic and thyroid operations, as well as anterior c-spine approaches. Malignancies involving the chest also account for a substantial number of cases. Less frequent causes which have been reported include intubation, cardiomegaly, syphilis, myasthenia gravis and Lyme disease.  As described in some of the articles, the diagnosis of UVFP is often based on visual inspection with videostroboscopy, with the addition of a large number and variety of acoustic voice measures and phonatory tasks, such as maximum phonation time, perturbation measures, aerodynamic evaluation, cepstral analysis, GRBAS, Voice Handicap Index and Voice related Quality of life. Such measures also are used to evaluate voice outcomes, both perceptually and objectively, following various interventions.  In the last decade, laryngeal electromyography (EMG) has gained considerable attention in the literature as a very useful tool in both the evaluation, diagnosis, management and prognostication of laryngeal movement disorders such as paralysis and paresis.

The value of voice therapy in UVFP as the sole intervention or in conjunction with other therapeutic options has been reviewed extensively in several references. Almost uniformly, the overriding theme is that voice therapy is extremely beneficial with measurable improvements in voice outcomes, particularly when introduced early.   

Treatment of UVFP has been a subject of great interest and debate from very early in the history of the Journal of Voice. Some of the earlier references reported successful laryngeal pacing in canines and suggested that this approach could have clinical applications in UFVP. Anatomic studies of the recurrent laryngeal nerve (RLN), as well as work on the effects of transecting branches to intrinsic laryngeal muscles, may have been precursors to later substantial interest in reinnervation strategies using nerve transfer techniques and free nerve grafts.

Throughout the 24-year span of this collection, a great deal of attention has been focused on the treatment of UVFP using the Ishiiki Type I thyroplasty with or without additional measures. Several modifications of the originally described technique have been suggested, including alterations in window placement/size, implant design and materials, and management of the strap muscles and perichondrium.  Many of these continue to be subjects of ongoing debate. Implants have been described as successful in conjunction with injection augmentation, both pre and postoperatively. Technical innovations continued early in the millenium with the description of an ‘adjustable laryngeal implant’ as well as a paper describing the use of expanded polytetrafluoroethylene (Goretex) strips through a minifenestration or very small window. The addition of arytenoid adduction (AA) to Type I thyroplasty for the treatment of UVFP with a large posterior gap also was described; it continues to generate controversy regarding the need, indications and benefits of AA. Type I thyroplasty with concurrent nerve muscle pedicle reinnervation has been advanced as a means of providing stable long-term results.

Injection laryngoplasty as a medialization technique features very prominently in this collection, and has been the subject of intense interest, particularly in the last 2 decades. With the increasing appreciation of Teflon-related complications came the search for improved biocompatible materials. Lipoinjection using autologous fat was initially touted as a ‘permanent’, well tolerated procedure with excellent results. However, the procedure usually is performed in the operating room, and it has become clear that variable resorption often necessitates reinjection.  Several other injection materials of various longevity were introduced, including collagen, gelfoam, Cymmetra. These have largely been supplanted by the relatively more recent hyaluronic acid-based injections which are extremely well tolerated and can be repeated as required. Also described is the longer lasting calcium hydroxylapatite (CaHA) injection. Although initially described as very safe, there have been some articles describing complications associated with the product. Injection laryngoplasty is both attractive and popular because it can be done safely in the office, often at the first visit, providing immediate results. Indeed, early intervention with injection augmentation has been noted, in several articles, to preclude the need for Type I thyroplasty. The choice of injection material, the method of injection, and the fate of the injected substance continue to be subjects of much debate in the articles within this collection.