Clarifying optimal outcome measures in intermittent and continuous laryngeal neuromonitoring.

BACKGROUND: Intraoperative neuromonitoring (IONM) techniques have evolved over the past decade into intermittent IONM (I-IONM) and continuous IONM (C-IONM) modes of application. Despite many prior publications on both types of IONM, there remains uncertainty about what outcomes should be measured for each form of IONM. The primary objective of this paper is to define categories of benefit for I-IONM/C-IONM and to clarify and standardize their reporting outcomes. METHODS: Expert review consensus statement utilizing modified Delphi methodology. RESULTS: I-IONM provides diagnosis, classification, and prevention of nerve injury through accurate and early nerve identification. C-IONM provides real-time information on nerve functional integrity and thus may prevent some types of nerve injury but cannot assist in nerve localization. Sudden mechanisms of nerve injury cannot be predicted or prevented by either technique. CONCLUSIONS: I-IONM and C-IONM are complementary techniques. Future studies evaluating the utility of IONM should focus on outcomes that are appropriate to the type of IONM being utilized.

Arytenoid abduction: indications and limitations.

OBJECTIVES: I report further experience with arytenoid abduction (AAb), a procedure that enlarges the glottis by external rotation of the arytenoid cartilage and thus moves the vocal process laterally and rostrally, but does not preclude adduction for phonation. Therefore, AAb has the potential to preserve voice in patients with bilateral abductor laryngeal paralysis. METHODS: I performed a retrospective review of AAb in 11 patients with bilateral laryngeal paralysis and 3 patients with other neurologic causes of glottal airway compromise, ie, adductor breathing dystonia, frequent laryngospasm, and progressive laryngeal breathing dysfunction. RESULTS: Seven of the 11 patients with bilateral paralysis had dramatic airway improvement. One patient required a tracheotomy after AAb, and 3 patients with an existing tracheotomy could not be decannulated. Arytenoid abduction relieved airway obstruction in the patient with recurrent laryngospasm and in the child with progressive laryngeal breathing dysfunction, but the patient with adductor breathing dystonia has persistent stridor. The factors associated with a poor airway outcome included prolonged tracheotomy, electromyographic evidence of inspiratory activity of adductor muscles, chronic obstructive pulmonary disease, sleep apnea, and prior cordotomy or arytenoidectomy. CONCLUSIONS: Arytenoid abduction is most effective in patients with bilateral laryngeal paralysis of less than 1 year's duration who do not have unfavorable laryngeal adductor activity.

Immediate and partial neural dysfunction after thyroid and parathyroid surgery: Need for recognition, laryngeal exam, and early treatment.

BACKGROUND: Laryngeal dysfunction after thyroid and parathyroid surgery requires early recognition and a standardized approach for patients that present with voice, swallowing, and breathing issues. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to define the terms "immediate vocal fold paralysis" and "partial neural dysfunction" and to provide clinical consensus statements based on review of the literature, integrated with expert opinion of the group. METHODS: A multidisciplinary expert panel constructed the manuscript and recommendations for laryngeal dysfunction after thyroid and parathyroid surgery. A meta-analysis was performed using the literature and published guidelines. Consensus was achieved using polling and a modified Delphi approach. RESULTS: Twenty-two panelists achieved consensus on five statements regarding the role of early identification and standardization of evaluation for patients with "immediate vocal fold paralysis" and "partial neural dysfunction" after thyroid and parathyroid surgery. CONCLUSION: After endorsement by the AHNS Endocrine Section and Quality of Care Committee, it received final approval from the AHNS Council.

Recommendations of the Neurolaryngology Study Group on laryngeal electromyography.

The Neurolaryngology Study Group convened a multidisciplinary panel of experts in neuromuscular physiology, electromyography, physical medicine and rehabilitation, neurology, and laryngology to meet with interested members from the American Academy of Otolaryngology Head and Neck Surgery, the Neurolaryngology Subcommittee and the Neurolaryngology Study Group to address the use of laryngeal electromyography (LEMG) for electrodiagnosis of laryngeal disorders. The panel addressed the use of LEMG for: 1) diagnosis of vocal fold paresis, 2) best practice application of equipment and techniques for LEMG, 3) estimation of time of injury and prediction of recovery of neural injuries, 4) diagnosis of neuromuscular diseases of the laryngeal muscles, and, 5) differentiation between central nervous system and behaviorally based laryngeal disorders. The panel also addressed establishing standardized techniques and methods for future assessment of LEMG sensitivity, specificity and reliability for identification, assessment and prognosis of neurolaryngeal disorders. Previously an evidence-based review of the clinical utility of LEMG published in 2004 only found evidence supported that LEMG was possibly useful for guiding injections of botulinum toxin into the laryngeal muscles. An updated traditional/narrative literature review and expert opinions were used to direct discussion and format conclusions. In current clinical practice, LEMG is a qualitative and not a quantitative examination. Specific recommendations were made to standardize electrode types, muscles to be sampled, sampling techniques, and reporting requirements. Prospective studies are needed to determine the clinical utility of LEMG. Use of the standardized methods and reporting will support future studies correlating electro-diagnostic findings with voice and upper airway function.

Research priorities in spasmodic dysphonia.

OBJECTIVE: To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia. STUDY DESIGN AND SETTING: A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities. RESULTS: Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. CONCLUSIONS: The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. SIGNIFICANCE: This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.

Management of neurologic disorders of the larynx.

OBJECTIVES: I review the literature on management of neurologic disorders of the larynx. METHODS: I reviewed the literature on laryngeal physiology, clinical evaluation of laryngeal function, and the clinical presentation and treatment of neurologic disorders that frequently affect the larynx. RESULTS: Laryngeal function is complex, as this organ is important in breathing, speech, and swallowing. Coordination of these roles is very susceptible to disruption by neurologic disorders. Diagnosis of neurologic disease is primarily based on history and physical examination; however, the diagnosis of laryngeal dysfunction is frequently overlooked, because the larynx is not easily accessible to examination by non-otolaryngologists. Evaluation of laryngeal function includes listening to the voice, systematic observation of the larynx during speech and nonspeech tasks, and, sometimes, ancillary tests. Neurologic disorders that affect laryngeal function include Parkinson's disease, essential tremor, stroke, amyotrophic lateral sclerosis, multiple sclerosis, and dystonia. The otolaryngologist can sometimes provide treatment to specifically improve symptoms of laryngeal involvement. CONCLUSIONS: Otolaryngology consultation is important in the diagnosis and treatment of neurologic disorders that affect laryngeal function. The otolaryngologist should be able to perform a systematic evaluation of laryngeal and pharyngeal function, and should be aware of the clinical presentation of neurologic disorders that affect the larynx.

Otolaryngology in Low-Resource Settings: Practical and Ethical Considerations.

Providing otolaryngology care in low-resource settings requires careful preparation to ensure good outcomes. The level of care that can be provided is dictated by available resources and the supplementary equipment, supplies, and personnel brought in. Other challenges include personal health and safety risks as well as cultural and language differences. Studying outcomes will inform future missions. Educating and developing ongoing partnerships with local physicians can lead to sustained improvements in the local health care system.

Indications for Surgical Repair of Type 1 Laryngeal Cleft.

OBJECTIVES: Type 1 laryngeal cleft (T1LC) is a congenital deficiency in the posterior glottis, resulting in a communication between the hypopharynx and glottis. No consensus treatment paradigm exists for timing and criteria for patient selection for surgical repair. Our goal is to assess whether patient characteristics can help predict improvement after surgery. METHODS: After Institutional Review Board exemption, a retrospective chart review was performed for patients undergoing surgery to diagnose a T1LC. Charts were examined for age, presenting symptoms, comorbidities, pre/postoperative videoflouroscopic swallow study reports, and outcomes. RESULTS: Ninety-seven patients with clinical suspicion for T1LC underwent direct laryngoscopy and bronchoscopy, and 63 (64%) were diagnosed with a T1LC. Twenty-two patients (63%) undergoing surgery achieved clinical or radiographic improvement. There was no difference in average age, aspiration, or penetration between clinical improvement and no improvement groups. Of 13 patients with comorbidities that increase their risk of aspiration, 12 were significantly improved. There were 5 complications, which were managed conservatively. CONCLUSIONS: Our experience supports the repair of T1LC repair at time of diagnostic laryngoscopy if satisfactory improvement is not noted with conservative treatment. This should be performed without segregation for age, comorbidities, or degree of dysphagia. Our technique is performed with minimal complications and achieves satisfactory results.

International neuromonitoring study group guidelines 2018: Part II: Optimal recurrent laryngeal nerve management for invasive thyroid cancer-incorporation of surgical, laryngeal, and neural electrophysiologic data.

The purpose of this publication was to inform surgeons as to the modern state-of-the-art evidence-based guidelines for management of the recurrent laryngeal nerve invaded by malignancy through blending the domains of 1) surgical intraoperative information, 2) preoperative glottic function, and 3) intraoperative real-time electrophysiologic information. These guidelines generated by the International Neural Monitoring Study Group (INMSG) are envisioned to assist the clinical decision-making process involved in recurrent laryngeal nerve management during thyroid surgery by incorporating the important information domains of not only gross surgical findings but also intraoperative recurrent laryngeal nerve functional status and preoperative laryngoscopy findings. These guidelines are presented mainly through algorithmic workflow diagrams for convenience and the ease of application. These guidelines are published in conjunction with the INMSG Guidelines Part I: Staging Bilateral Thyroid Surgery With Monitoring Loss of Signal. Level of Evidence: 5 Laryngoscope, 128:S18-S27, 2018.

International neural monitoring study group guideline 2018 part I: Staging bilateral thyroid surgery with monitoring loss of signal.

This publication offers modern, state-of-the-art International Neural Monitoring Study Group (INMSG) guidelines based on a detailed review of the recent monitoring literature. The guidelines outline evidence-based definitions of adverse electrophysiologic events, especially loss of signal, and their incorporation in surgical strategy. These recommendations are designed to reduce technique variations, enhance the quality of neural monitoring, and assist surgeons in the clinical decision-making process involved in surgical management of recurrent laryngeal nerve. The guidelines are published in conjunction with the INMSG Guidelines Part II, Optimal Recurrent Laryngeal Nerve Management for Invasive Thyroid Cancer-Incorporation of Surgical, Laryngeal, and Neural Electrophysiologic Data. Laryngoscope, 128:S1-S17, 2018.

Spontaneous laryngeal reinnervation after recurrent laryngeal or vagus nerve injury.

OBJECTIVES: The status of innervation in patients with laryngeal paralysis is somewhat controversial. Electromyographic activity has been frequently documented in the laryngeal muscles of patients with laryngeal paralysis, and animal experiments report a strong propensity for reinnervation after laryngeal nerve injury. However, a study of intraoperative electromyography performed in patients during reinnervation surgery failed to document activity with stimulation of the recurrent laryngeal nerve (RLN). Noting the long-observed differences in the symptoms of patients with vagus nerve injury and those with RLN injury, I hypothesized that reinnervation is influenced by the site of nerve injury. METHODS: Cats were sacrificed at various intervals after resection of 1 cm of either the RLN or the vagus nerve, without any attempt to repair the nerve. RESULTS: Four months after RLN resection, distal nerve biopsy revealed unmyelinated axons scattered through fibrous tissue. By 6 months, myelinated axons were organized, and electromyographic and histologic examination showed preferential reinnervation of the thyroarytenoid muscle. After vagotomy, the RLN was fibrotic and no axons were present. Both the thyroarytenoid and posterior cricoarytenoid muscles were fibrotic and had no electromyographic activity. CONCLUSIONS: The results confirm the strong propensity for laryngeal reinnervation after RLN injury, but not after vagus nerve injury. Preferential reinnervation of adductor muscles may account for a medial position of the paralyzed vocal fold.

Arytenoid abduction for dynamic rehabilitation of bilateral laryngeal paralysis.

OBJECTIVES: Bilateral laryngeal paralysis results in airway obstruction, but the voice is often nearly normal. Tracheotomy provides an airway and preserves voice. Surgical procedures to statically enlarge the glottis can permit decannulation, but do so at the expense of the voice. Motion analysis in cadaver larynges has demonstrated that adductor and abductor muscles rotate the arytenoid cartilage around different axes. We sought to determine whether external rotation of the arytenoid cartilage could enlarge the airway without abolishing residual phonatory adduction. METHODS: We performed arytenoid abduction in 6 patients with obstructing laryngeal paralysis. A suture was placed in the muscular process and posterior-inferior traction was applied, anchoring the suture to the inferior cornu of the thyroid cartilage. Outcomes were evaluated by assessing airway symptoms, by assessing the voice, and by documentation of laryngeal motion via videolaryngoscopy. RESULTS: Three patients with severe stridor had marked relief of symptoms, and 2 of the 3 tracheotomy-dependent patients were decannulated. Three patients had good voices, 2 had mild breathiness, and 1 was very breathy. CONCLUSIONS: Arytenoid abduction is a promising treatment for relieving airway obstruction in patients with laryngeal paralysis. It has the potential to preserve voice in patients with residual phonatory adduction.

Aortic arch compliance and idiopathic unilateral vocal fold paralysis.

Unilateral vocal fold paralysis (UVP) occurs related to recurrent laryngeal nerve (RLN) impairment associated with impaired swallowing, voice production, and breathing functions. The majority of UVP cases occur subsequent to surgical intervention with approximately 12-42% having no known cause for the disease (i.e., idiopathic). Approximately two-thirds of those with UVP exhibit left-sided injury with the average onset at ≥50 yr of age in those diagnosed as idiopathic. Given the association between the RLN and the subclavian and aortic arch vessels, we hypothesized that changes in vascular tissues would result in increased aortic compliance in patients with idiopathic left-sided UVP compared with those without UVP. Gated MRI data enabled aortic arch diameter measures normalized to blood pressure across the cardiac cycles to derive aortic arch compliance. Compliance was compared between individuals with left-sided idiopathic UVP and age- and sex-matched normal controls. Three-way factorial ANOVA test showed that aortic arch compliance (P = 0.02) and aortic arch diameter change in one cardiac cycle (P = 0.04) are significantly higher in patients with idiopathic left-sided UVP compared with the controls. As previously demonstrated by other literature, our finding confirmed that compliance decreases with age (P < 0.0001) in both healthy individuals and patients with idiopathic UVP. Future studies will investigate parameters of aortic compliance change as a potential contributor to the onset of left-sided UVP.NEW & NOTEWORTHY Unilateral vocal fold paralysis results from impaired function of the recurrent laryngeal nerve (RLN) impacting breathing, swallowing, and voice production. A large proportion of adults suffering from this disorder have an idiopathic etiology (i.e., unknown cause). The current study determined that individuals diagnosed with left-sided idiopathic vocal fold paralysis exhibited significantly greater compliance than age- and sex-matched controls. These seminal findings suggest a link between aortic arch compliance levels and RLN function.

Botulinum toxin therapy for abductor spasmodic dysphonia.

Botulinum toxin has been widely accepted as an effective therapy for controlling the symptoms of adductor spasmodic dysphonia (ADSD). Reported experience with botulinum treatment for abductor spasmodic dysphonia (ABSD) has been less impressive. Factors that may impair outcomes for ABSD include differences in the pathophysiology of ADSD and ABSD and limitation of maximal dose from airway restriction with posterior cricoarytenoid muscle (PCA) weakness. We report our experience with botulinum injection of the PCA with an asymmetric dose escalation protocol, based on clinical observations that in ABSD, abductor spasms are often stronger on one side, usually the left. The nondominant side was injected with 1.25 units. Dominant side dose began at 5 units, with step-wise increments of 5 units per week until one of three endpoints was reached: Elimination of breathy voice breaks, complete abductor paralysis of the dominant side, or airway compromise. Fourteen of 17 patients achieved good or fair voice, with dominant-side doses ranging from 10 to 25 units. Exercise intolerance limited PCA dose in two patients. One patient had persisting breathiness that improved with medialization thyroplasty. Asymmetric botulinum toxin injection into PCA muscles can suppress abductor spasm in patients with ABSD, but breathiness may persist, because of inadequate glottal closure.

Laryngeal examination in thyroid and parathyroid surgery: An American Head and Neck Society consensus statement: AHNS Consensus Statement.

This American Head and Neck Society (AHNS) consensus statement discusses the techniques of laryngeal examination for patients undergoing thyroidectomy and parathyroidectomy. It is intended to help guide all clinicians who diagnose or manage adult patients with thyroid disease for whom surgery is indicated, contemplated, or has been performed. This consensus statement concludes that flexible transnasal laryngoscopy is the optimal laryngeal examination technique, with other techniques including laryngeal ultrasound and stroboscopy being useful in selected scenarios. © 2016 Wiley Periodicals, Inc. Head Neck 38: 811-819, 2016.

The magnanimous professional life and tragic demise of J. H. Douglas, MD.

OBJECTIVES/HYPOTHESIS: Many of the hallmarks of a very successful medical career, such as recognition as a leader in a field of medicine, making important contributions to medical knowledge of the day, and a steadfast dedication to patient care, had already been achieved by Dr. John Hancock Douglas. Therefore, the mystery surrounding his dismissal from membership of the newly formed American Laryngology Society (now the ALA) and his tragic demise stand in stark contrast. We discuss the model professional life and mysterious but tragic final days of this very important laryngologist of the 19th century. STUDY DESIGN/METHODS: A historical vignette. RESULTS: Dr. Douglas's professional qualities of leadership of the American Sanitary Commission, his various contributions to the advancement of medical knowledge during that era, and his steadfast dedication to the care of his patients represent highlights of a very honorable professional career. His final demise, bankrupt, in an ill state of health, and stripped of his professional appointment to the ALA, seems an unjust end to the life of this notable and magnanimous laryngologist. CONCLUSIONS: We offer this historical review of the life and demise of Dr. John H. Douglas as a tribute to this important figure in our profession's history.

Voice handicap index results for older patients with adductor spasmodic dysphonia.

Adductor spasmodic dysphonia (ADSD) adversely affects a speaker's ability to effectively communicate. For many individuals suffering with ADSD, botulinum toxin (Botox) is the chosen treatment to remediate the symptoms. Although Botox's effects on symptom remediation have been examined before, patient perception of improvement post-Botox has been examined less frequently. Further, no studies have addressed the symptomatic changes in older adults that occur after Botox treatment. The Voice Handicap Index (VHI) was used as the instrument to assess older patient's (>65 years) perception of how ADSD impacts certain areas of their life pre- and post-Botox injection. The outcome of the VHI was related to a clinical judgment of voice severity. Participants also completed the Social Readjustment Rating Scale (SRRS) to examine overall stress level, and the outcome of the SRRS was correlated to postinjection VHI scores. Results indicated no significant correlation between VHI scores and voice severity or SRRS ratings. The current study suggests further study of voice outcomes with older adults with ADSD is needed.

Thyroidectomy in the professional singer-neural monitored surgical outcomes.

BACKGROUND: Voice changes commonly occur from thyroidectomy and may be due to neural or nonneural causes. Such changes can be a source of significant morbidity for any patient, but thyroidectomy in the professional singer carries special significance. We test the hypothesis that the career of singers and professional voice users is not impaired after neural monitored thyroid surgery. METHODS: A quantitative analysis of pre- and postoperative neural monitored thyroid surgery voice outcomes utilizing three validated vocal instruments-Voice Handicap Index (VHI), Singing Voice Handicap Index (SVHI), and Evaluation of Ability to Sing Easily (EASE)-in a unique series of professional singers/voice users was performed. Additional quantitative analysis related to final intraoperative electromyography (EMG) amplitude, the time to return to performance, and vocal parameters affected during this interval was performed. RESULTS: Twenty-seven vocal professionals undergoing thyroidectomy were identified, of whom 60% had surgery for thyroid cancer. Pre- and postsurgery flexible fiberoptic laryngeal exams were normal in all patients. Return to performance rate was 100%, and mean time to performance was 2.26 months (±1.61). All three vocal instrument mean scores, pre-op vs. post-op, were unchanged: VHI, 4.15 (±5.22) vs. 4.04 (±3.85), p=0.9301; SVHI, 11.26 (±14.41) vs.12.07 (±13.09), p=0.8297; and EASE, 6.19 (±9.19) vs. 6.00 (±7.72), p=0.9348. The vocal parameters most affected from surgery until first performances were vocal fatigue (89%), high range (89%), pitch control and modulation (74%), and strength (81%). Final mean intraoperative EMG amplitude was within normal limits for intraoperative stimulation and had no relationship with time to first professional performance (p=0.7199). CONCLUSIONS: Neural monitored thyroidectomy, including for thyroid malignancy, in professional voice users is safe without any changes in three different voice/singing instruments, with 100% return to performance. Intraoperative EMG data at the conclusion of surgery and postoperative laryngeal exam were normal in all patients. Specific vocal parameters are transiently affected during the postoperative recovery phase, which is important to outline in the consent process of this unique patient population and may provide insight into the physiologic state of the larynx subsequent to thyroid surgery.

Perceptual analyses of spasmodic dysphonia before and after treatment.

OBJECTIVE: To evaluate expert listeners' perceptions of voice and fluency in persons with adductor spasmodic dysphonia (ADSD) before and after treatment with botulinum toxin type A (Botox), as a function of initial severity of the disorder (while controlling for patients' age at injection). DESIGN: Simple before-and-after trial with blinded randomized listener judgments. SETTING: Ambulatory care clinic at a single medical center. PARTICIPANTS: Forty-two consecutive patients with ADSD who underwent examination, with a 3- to 6-week follow-up, after initial botulinum toxin type A injection. There were also 42 age- and sex-matched healthy control subjects. INTERVENTIONS: Injections of botulinum toxin type A into the thyroarytenoid muscle(s). MAIN OUTCOME MEASURES: Computer-implemented visual analog scaling judgments of voice quality and speech fluency made by expert listeners under psychoacoustically controlled conditions. RESULTS: Response to botulinum toxin type A varied markedly as a function of pretreatment severity of ADSD. More severe initial symptoms exhibited greater magnitudes of improvement. Patients with mild dysphonia did not exhibit pretreatment to posttreatment change. Following treatment, voice and fluency remained significantly (P<.05) poorer in ADSD than in healthy speakers. Older patients exhibited less improvement than younger patients when the effect of initial severity was statistically controlled. CONCLUSIONS: Voice quality and fluency improved for most patients following treatment, but older patients and those with milder dysphonia exhibited the least optimal responses to the procedure. Patients who were profoundly impaired demonstrated the greatest amount of improvement. Computer-implemented visual analog scaling provided a reliable clinical tool for determining treatment-related changes in those with ADSD.

Speech intelligibility in severe adductor spasmodic dysphonia.

This study compared speech intelligibility in nondisabled speakers and speakers with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (Botox) injection. Standard speech samples were obtained from 10 speakers diagnosed with severe ADSD prior to and 1 month following Botox injection, as well as from 10 age- and gender-matched healthy adults. This yielded 3 speaking conditions: pre-Botox injection, post-Botox injection, and normal control. Thirty phrases were extracted from the speech samples and arranged in a counterbalanced listening experiment. Thirty students, reporting little experience with distorted speech, served as listeners. Each listener's response was scored for words correctly identified using a liberal scoring criterion yielding a percentage of words correctly identified for each speaker. The results indicated that the speakers with ADSD were significantly more intelligible in the post-Botox condition than in the pre-Botox condition. The results also indicated that healthy speakers were significantly more intelligible than the speakers in both the pre- and post-Botox conditions. In general, these results indicated that intelligibility is affected in severe ADSD and that the use of Botox injection in ADSD improves intelligibility scores. However, the results also indicated that the use of Botox injection does not result in speech intelligibility similar to that of normal, non-ADSD speakers.