Evaluation and management of bilateral vocal cord immobility

Impact of BMI on Dyspnea and Need for Surgical Intervention in Bilateral Vocal Fold Immobility

OBJECTIVE

Bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS) are causes of bilateral vocal fold immobility (BVFI) and may cause shortness of breath, stridor, and need for surgical intervention. Although increased body mass index (BMI) is associated with restrictive breathing patterns in patients with normal upper airways, it is unclear how BMI impacts dyspnea and need for surgical intervention in BVFI patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Three tertiary academic centers in the United States.

METHODS

Demographics, BMI, Dyspnea Index (DI), etiology, presence of tracheostomy and surgical intervention (dilation, tracheostomy, cordotomy, arytenoidectomy, open reconstruction) were collected. Primary outcomes included dyspnea measured by DI and need for surgery to improve airway. Linear regressions were performed to assess continuous outcomes. Mann-Whitney U-test was utilized to assess categorical outcomes.

RESULTS

Among 121 patients, 52 presented with BVFP and 69 with PGS. Previous neck surgery was the most common cause of BVFI (40.2%). 44.3% of patients received a tracheostomy. Through multivariate linear regression, increased BMI was significantly associated with increased DI in the entire cohort (β = .43, P = .016). Increased BMI was also associated with need for any surgical intervention (odds ratio [OR] = 1.07, 95% confidence interval [CI] = [1.01-1.13]) in the overall cohort. When stratifying our data, BMI was only significantly associated with DI in BVFP (β = .496) and need for surgical intervention in PGS (OR = 1.11, 95% CI = [1.01-1.21]), although a positive trend was seen in all analyses.

CONCLUSION

Increased BMI may correlate with worsening dyspnea symptoms and need for surgical intervention in patients with BVFI. Weight-loss-related counseling may benefit symptom management.

Endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis using radiofrequency versus coblation

PURPOSE

To assess the outcomes of endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis (BAVFP) using radiofrequency versus coblation.

METHODS

This was a randomized prospective cohort study that carried out on 40 patients with BAVFP who were subjected to endoscopic/assisted microscopic posterior cordotomy. The patients were randomly allocated into two groups: group (A) patients were operated with radiofrequency, and group (B) patients were operated with coblation. Glottic chink, grade of dyspnea, voice handicap index 10 (VHI10), and aspiration were evaluated pre-operatively and 2 weeks and 3 months post-operatively.

RESULTS

There was a significant improvement in the glottic chink and VHI10 scores postoperatively with a non-significant difference between both groups regarding the degree of improvement. In addition, there was a significant improvement of the grade of dyspnea with a non-significant impact on the degree of aspiration in both groups post operatively. There was a lower incidence of oedema and granulation formation in the coblation group but without a statistical significance.

CONCLUSION

Both techniques are effective alternatives for performing posterior transverse cordotomy in cases of BAVFP.

Partial arytenoidectomy with transoral vocal fold lateralisation in treating airway obstruction secondary to bilateral vocal fold immobility

OBJECTIVE

To report the outcome of 18 patients with a tracheostomy secondary to bilateral vocal fold immobility, who were managed using reconstructive transoral laser microsurgical techniques.

METHODS

A retrospective review was conducted of the surgical outcome of 18 patients with bilateral vocal fold immobility and a tracheostomy resulting from different aetiologies. Follow-up duration ranged from one to five years.

RESULTS

A total of 18 patients had a tracheostomy at presentation because of bilateral true vocal fold immobility and stridor. All cases were treated using reconstructive transoral laser microsurgery with arytenoidectomy and vocal fold lateralisation. All patients were successfully decannulated by eight weeks after surgery.

CONCLUSION

Reconstructive transoral laser microsurgery using partial arytenoidectomy with vocal fold lateralisation is minimally invasive, feasible, safe and effective for airway reconstruction in patients who present with stridor due to bilateral true vocal fold immobility.

Interventions and Outcomes in Glottic Versus Multi-level Airway Stenosis: A Multi-institutional Review

OBJECTIVE

Airway stenosis-particularly multi-level-presents complex management challenges. This study assessed rates of tracheostomy, decannulation, and the number of surgeries required in patients with posterior glottic stenosis (PGS), multi-level airway stenosis (MLAS), and bilateral vocal fold paralysis (BVFP).

METHODS

Airway stenosis patients treated between 2016 and 2021 at three tertiary medical centers were identified. Demographics, etiology of stenosis, medical comorbidities, and patient-reported outcome measures (PROMs) were collected.

RESULTS

158 patients (84 women, mean age 56.98 ± 15.5 years) were identified (54 PGS, 38 MLAS, and 66 BVFP). 72.3% required tracheostomy, including 72.2%, 86.8%, and 63.6% in these groups, respectively. Decannulation rates were 43.6%, 21.2%, and 32.5% in these groups, respectively. Patients with MLAS had higher rates of tracheostomy than BVFP (p < 0.05). However, decannulation rates were not different between groups (p > 0.05). MLAS required more surgeries (mean 4.0 ± 3.9) than PGS (2.4 ± 2.2, p = 0.02) or BVFP (1.0 ± 1.8, p < 0.0001). Mean PROMs scores at the latest follow-up were abnormal: 15.4 ± 12.2 (Dyspnea Index), 19.9 ± 12.2 (Voice Handicap Index-10), and 9.67 ± 11.1 (Eating Assessment Tool-10). Co-morbidities present included body mass index >30 (41.4%), diabetes (31.8%), pulmonary disease (50.7%), gastroesophageal reflux disease (39.4%), autoimmune disease (22.9%), and tobacco use history (55.2%).

CONCLUSIONS

Airway stenosis is a challenging clinical problem that negatively impacts patients' quality of life and often requires numerous surgeries. PGS more frequently requires tracheostomy compared to BVFP, but patients can often decannulate successfully. Patients with multi-level stenosis have lower decannulation rates and require more surgeries than glottic stenosis alone; these patients may benefit from earlier and/or more aggressive intervention.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:528-534, 2023.

Longitudinal Vocal Outcomes and Voice-Related Quality of Life After Selective Bilateral Laryngeal Reinnervation: A Case Study

PURPOSE

Bilateral vocal fold paralysis (BVFP) is a severe disorder that can result in respiratory, swallowing, and voice-related problems. Most surgical treatments do not restore laryngeal function and often need to compromise voice quality to preserve respiratory function. Laryngeal reinnervation (LR) may offer a solution to this problem, but literature on longitudinal outcomes of this procedure is scarce. This study aims to report the longitudinal vocal outcomes of BVFP after LR and subsequent voice therapy.

METHOD

The case of a 23-year-old man with BVFP after a traumatic dissection of both recurrent laryngeal nerves is described. Selective bilateral LR of both adductors and abductors was performed 5 months after the onset of BVFP. Voice therapy was provided after the LR procedure. Multidimensional voice assessments, including acoustic, perceptual, and patient-reported outcome measures (PROMs), were conducted 2, 5, 6.5, 8, and 31 months after LR.

RESULTS

An improvement of vocal capabilities and voice quality was noticed 6.5 months after LR, after 4.5 months of voice therapy, with normative values after 2.5 years. PROMs showed an improvement of voice-related quality of life, but some limitations to activities of daily living were still present. Inspiratory arytenoid abduction was not observed on laryngeal videostroboscopic findings in this patient, but tracheostomy was not required.

CONCLUSIONS

Voice therapy after LR helps establish healthy and efficient voice use without increasing compensatory hyperfunctional behavior. More research is needed to examine potential merits of voice therapy in the rehabilitation of vocal and respiratory functions after LR.

Etiology and presenting features of vocal cord paralysis: changing trends over the last two decades

Background

The study was performed to evaluate the changing trends in etiology and presenting features of vocal cord paralysis (VCP) from March 1998 to March 2020.

Methods

Patient’s record collected from hospital database and divided into two groups, from March 1998 to March 2009 and from April 2009 to March 2020, to evaluate the changing trends in etiology and presenting features.

Results

Total of 711 VCP patients, 80.3% with unilateral (UVCP) and 19.7% with bilateral vocal cord paralysis (BVCP) included. The commonest etiology was non-surgical (57.1%) for UVCP and surgical (55.7%) for BVCP. The commonest surgical etiology was thyroid and parathyroid surgery for both UVCP (16.6%) and BVCP (38.5%). The commonest non-surgical etiology was idiopathic for UVCP (23.1%) and malignancies for BVCP (13.6%). There was increase in surgical etiology for both UVCP (39.3 to 45.3%) and BVCP (51.2 to 57.7%), and decrease in non-surgical etiology for both UVCP (60.7 to 54.6%) and BVCP (48.8 to 42.3%). The change in voice was most common presenting features for both UVCP (69.2%) and BVCP (92.8%). The frequency of the presenting features was comparable, with decrease in the duration of symptom onset over the time period.

Conclusion

The most common etiology for UVCP was idiopathic, and for BVCP was thyroid and parathyroid surgery. For both, UVCP and BVCP there was increasing trend for surgical and decreasing trend for non-surgical etiology. The change in voice was the most common presenting complain, with decrease in duration of symptom onset over time period.

Selective laryngoscopy before thyroidectomy: a risk assessment

BACKGROUND

Patients presenting for thyroidectomy may have an unrecognized pre-existing vocal cord palsy (VCP). This raises the danger of bilateral VCP if a patient sustains an injury to the RLN on the sole functioning side. Part of the rationale for routine preoperative laryngoscopy is to eliminate such a risk. This paper endeavours to quantify the relevant potential risk.

METHODS

Patients who underwent laryngoscopy prior to thyroid or parathyroid surgery in an endocrine surgical unit over a 5 year period were identified. Literature review revealed four papers in which VCP prevalence in patients without risk factors was reported. Using our data, combined with that of these other authors, the background rate of pre-existing VCP was ascertained, and the subsequent risk of bilateral VCP estimated.

RESULTS

Of our 632 patients who underwent preoperative laryngoscopy, there were four patients (0.63%) who were found to have a unilateral VCP, but all had voice symptoms or previous neck surgery. When patients with these risk factors are excluded, our data combined with the published data provides a pre-existing VCP rate of 0.2%. Calculations estimate that if preoperative laryngoscopy is omitted in patients with no risk factors, the risk of bilateral VCP, due to the nerve on the sole functioning side being injured, would be between 1/50000 and 1/150000, depending on an individual surgeon's level of experience.

CONCLUSION

Selective use of laryngoscopy prior to thyroidectomy would result in an acceptably low statistical risk of bilateral VCP. Routine laryngoscopy for all patients is not necessary.

Postoperative Inhaled Steroids Following Glottic Airway Surgery Reduces Granulation Tissue Formation

OBJECTIVES

Transoral laser surgery for glottic stenosis (transverse cordotomy and anteromedial arytenoidectomy (TCAMA)) is often complicated by granulation tissue (GT) formation. GT can cause dyspnea and may require surgical removal to alleviate airway obstruction. Inhaled corticosteroids (ICS) have been shown to reduce benign vocal fold granulomas, however its use to prevent GT formation has not been described. We aimed to analyze the effect of immediate postoperative ICS on GT formation in patients undergoing transoral laser surgery for glottic stenosis.

METHODS

A retrospective analysis of patients that had transoral laser surgery for glottic stenosis from 2000 to 2019 was conducted. Surgical instances were grouped into those that received postoperative ICS and those that did not. Demographics, diagnosis, comorbidities, intraoperative adjuvant therapy, and perioperative medications were collected. Differences in GT formation and need for surgical removal were compared between groups. A multivariate exact logistic regression model was performed.

RESULTS

Forty-four patients were included; 16 required 2 glottic airway surgeries (60 surgical instances). Of the 23 instances where patients received immediate postoperative ICS, 0 patients developed GT; and of the 37 instances that did not receive postoperative ICS, 15 (40.5%) developed GT (P < .0001). Eight (53.3%) of these cases returned to the OR for GT removal. ICS use was solely associated with the absence of GT formation (P = .042) in the multivariate analysis.

CONCLUSIONS

Immediate postoperative use of ICS seems to be a safe and effective method to prevent granulation tissue formation and subsequent surgery in patients following transoral laser airway surgery for glottic stenosis.

Combined Transverse Cordotomy- Anteromedial Arytenoidectomy for Isolated Glottic Stenosis

OBJECTIVES/HYPOTHESIS

Glottic stenosis is a discrete cause of airway compromise. We aimed to determine the surgical outcomes of transverse cordotomy with anteromedial arytenoidectomy (TCAMA), performed in the setting of isolated glottic stenosis resulting from two discrete etiologies: bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS).

STUDY DESIGN

Retrospective, analytic cohort study.

METHODS

Twenty-six patients with isolated glottic stenosis were treated with TCAMA between 2006 and 2019. A retrospective analysis determined decannulation rates and intervals, voice outcomes, swallowing outcomes, and reoperation rates postoperatively. Outcomes between the two etiologic cohorts were compared.

RESULTS

Of the 26 patients, 16/26 patients were diagnosed with PGS and 10/26 with BVFP. Eighteen patients required tracheotomies during their clinical course (11/16 PGS, and 7/10 BVFP), and 100% were ultimately decannulated. The PGS cohort required two-sided interventions more frequently than the BVFP cohort (45.5% vs. 0%, P = .066). Trach-dependent PGS patients required a longer time to achieve decannulation than BVFP patients by a factor of 2.38, although the difference was not statistically significant (102.3 days vs. 42.9 days, respectively, P = .113). Patients demonstrated a significant change in maximum phonation time but no statistically significant differences with preoperative versus postoperative voice outcomes like voice-related quality of life. All patients ultimately returned to their baseline swallow function postoperatively.

CONCLUSION

TCAMA is an effective treatment for surgical rehabilitation of glottic stenosis caused by both BVFP and PGS. Patient-reported outcomes of postoperative vocal function remain consistent following surgical intervention. Additional, prospective studies with greater power are warranted to validate the contrasting outcomes observed when applying this discrete surgical technique across two distinct diagnostic cohorts in this retrospective study.

LEVEL OF EVIDENCE

4. Laryngoscope, 2021.

A Review of Treatment of Bilateral Vocal Fold Movement Impairment

Purpose of Review

Bilateral vocal fold immobility is a challenging life-threatening problem involving multiple treatment options and nuanced clinical decision making. We aim to provide relevant background on the etiology, diagnosis, and management of bilateral vocal fold movement impairment (BVFMI).

Recent Findings

Over the last 20 years, the management of bilateral vocal fold immobility has advanced significantly with the addition of multiple endoscopic approaches as well as procedures with the goal of returning dynamic function to the larynx, among them: selective reinnervation. Chemodenervation has also demonstrated promising results as a temporizing procedure in appropriately selected patients with BVFMI.

Summary

Tracheostomy remains the mainstay of emergent treatment for airway obstruction secondary to bilateral vocal fold immobility. However, recent advances in endoscopic approaches allow for avoidance of tracheostomy in many patients. Developments in dynamic procedures with the aim of restoring laryngeal function allow for adequate airway management while maintaining voice quality and limiting aspiration risk.

Impact of Patient Factors and Management Strategies on Outcomes After Transverse Posterior Cordotomy

OBJECTIVES/HYPOTHESIS

Carbon dioxide laser transverse posterior cordotomy (TPC) aims to improve airway aperture in patients with glottic obstruction. Postoperative complications may worsen airway compromise and necessitate additional interventions. We sought to identify factors impacting outcomes after TPC.

STUDY DESIGN

Retrospective chart review.

METHODS

Medical records of patients who underwent TPC for glottic airway obstruction at a tertiary-care medical center between 2008 and 2018 were reviewed. Demographics, comorbidities, and intra- and postoperative management strategies were analyzed.

RESULTS

Twenty patients who underwent TPC for glottic airway obstruction met inclusion criteria. The mean age was 57 years, and 13 patients were female. Mean follow-up time was 442 days. Seven patients had posterior glottic stenosis, and 13 had bilateral vocal fold paralysis. Twelve patients developed postoperative complications including granuloma formation (four patients), hospital readmission for dyspnea due to glottic edema (five patients), need for revision surgery (nine patients), or failure to decannulate tracheotomy (five patients). Eight patients had an uncomplicated recovery with improved dyspnea, with two patients with tracheotomies decannulated. Patients with a history of smoking tobacco were more likely to experience complications (P = .035). There were no significant differences in outcomes with respect to history of head and neck radiation or gastroesophageal reflux disease. Steroid injection at the surgical site and postoperative medications did not significantly impact outcomes. With respect to granuloma formation, none of the variables analyzed reached significance.

CONCLUSIONS

History of tobacco use increases complication rates after TPC. Other patient comorbidities and intra- and postoperative management strategies do not impact outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1066-1070, 2021.

Outcomes Following Cordotomy by Coblation for Bilateral Vocal Fold Immobility

Importance

Bilateral vocal fold immobility (BVFI) can result in considerable voice and airway impairment. Although the carbon dioxide (CO2) laser is commonly used in transverse cordotomy, the coblator, a minimally invasive, low-thermal technology, has been increasingly used in otolaryngology.

Objective

To investigate outcomes associated with coblation to treat BVFI.

Design, Setting, and Participants

A retrospective case series was conducted between January 2012 and June 2017 including 19 patients with BVFI who underwent cordotomy by coblation in a single tertiary care institution.

Main Outcomes and Measures

Clinical, operative, and health status data for all patients were reviewed. Quality of life was measured by the EuroQol 5-Dimensions (EQ-5D), and the Voice Handicap Index (VHI) was used to measure vocal cord function.

Results

Nineteen patients were eligible for inclusion, 15 of which underwent cordotomy by coblation for BVFI without stenosis. Mean age was 57 years with 13 (68%) women. The etiology of BVFI included thyroidectomy in 8 (42%) patients and prolonged intubation in 7 (37%). Mean length of surgery for BVFI without stenosis was 17 minutes; mean operating room (OR) time was 63 minutes compared with 88 scheduled OR minutes (effect size, 25 minutes; 95% CI, 9 to 40 minutes). During follow-up, 4 (27%) of these patients developed granulation tissue postoperatively. Following surgery, patient-reported shortness of breath significantly improved, with 10 of 14 (71%; 95% CI, 45% to 88%) patients with some level of preoperative breathing difficulty experiencing improvement in their breathing. Stridor also significantly improved, with 10 of 12 (83%; 95% CI, 55% to 95%) patients with some level of preoperative stridor improved after surgery. The EQ-5D results trended toward improvement postoperatively (0.67 to 0.80; effect size, 0.13; 95% CI, -0.10 to 0.34). The functional (22 to 12; effect size, -10; 95% CI, -19 to -2), emotional (23 to 11; effect size, -12; 95% CI, -23 to -3), and total VHI all significantly improved (68 to 39; effect size, -29; 95% CI, -49 to -8).

Conclusions and Relevance

Initial outcomes of cordotomy by coblation revealed that this technique was a safe and efficient approach to treating BVFI. Coblation was associated with significant reduction in OR time compared with scheduled time, and patients experienced significant improvement in shortness of breath, stridor, and vocal cord function.

Computational Fluid Dynamics Analysis of Surgical Approaches to Bilateral Vocal Fold Immobility

OBJECTIVES

Bilateral vocal fold immobility (BVFI) is a rare and life-threatening condition in which both vocal folds are fixed, resulting in airway obstruction associated with life-threatening respiratory compromise. Treatment of BVFI is largely surgical and remains an unsatisfactory compromise between voice, breathing, and swallowing. No comparisons between currently employed techniques currently exist. We sought to employ computational fluid dynamics (CFD) modeling to delineate the optimal surgical approach for BVFI.

METHODS

Utilizing clinical computed tomography of BVFI subjects, coupled with image analytics employing CFD models and subject pulmonary function data, we compared the airflow features in the baseline pathologic states and changes seen between endoscopic cordotomy, endoscopic suture lateralization, and posterior cricoid expansion.

RESULTS

CFD modeling demonstrated that the greatest airflow velocity occurs through the posterior glottis on inspiration and anterior glottis on expiration in both the normal condition and in BVFI. Glottic airflow velocity and resistance were significantly higher in the BVFI condition compared to normal. Geometric indices (cross-sectional area of airway) were lower in posterior cricoid expansion surgery when compared to alternate surgical approaches. CFD measures (airflow velocity and resistance) improved with all surgical approaches but were superior with posterior cricoid expansion.

CONCLUSION

CFD modeling can provide discrete, quantitative assessment of the airflow through the laryngeal inlet, and offers insights into the pathophysiology and changes that occur after surgery for BVFI.

LEVEL OF EVIDENCE

NA. Laryngoscope, 130:E57-E64, 2020.

The Clinical Course of Idiopathic Bilateral Vocal Fold Motion Impairment in Adults: Case Series and Review of the Literature

AIM

Steps for assessment and successful management of bilateral vocal fold motion impairment (VFMI) are (1) recognition of its presence, (2) identifying the etiology and factors restricting vocal fold motion, (3) evaluation of airway patency, and (4) establishing a management plan. No large series documenting the course and outcome of adult idiopathic bilateral VFMI has been published within the past 15 years.

METHODS

Retrospective chart review of adult patients with idiopathic bilateral VFMI at a tertiary academic center. A diagnosis was established if history, physical examination with laryngoscopy, and initial imaging excluded a cause. Records were reviewed for demographics, clinical characteristics, surgical intervention details, and length of follow-up.

RESULTS

Nine adult patients with idiopathic bilateral VFMI were identified. There were five males and four females with a mean age of 59.6 years. The mean follow-up period was 54.4 months (range, 6-111 months). Upon presentation to our laryngology service, three patients were advised observation, three patients were advised to undergo urgent tracheostomy, and three patients were advised to undergo elective surgery for airway management. By the end of the follow-up period, only four patients (4/9, 44.4%) were tracheostomy dependent, one of them was lost to follow-up after tracheostomy tub downsizing for decannulation.

CONCLUSIONS

To our best knowledge, this is the largest series so far of adult patients with idiopathic bilateral VFMI. Conservative treatment can be considered as an alternative to surgery in select cases.

Endoscopic Posterior Cricoid Split With Graft in an Adult With Posterior Cricoid Fracture

A 45-year-old man presented with bilateral vocal fold immobility (BVFI) following a remote history of assault. He was found to have a comminuted, telescoped, and ossified posterior cricoid fracture on imaging. Electromyography revealed normal cricothyroid and thyroarytenoid muscle function, but moderate chronic denervation of bilateral posterior cricoarytenoid muscles. The patient underwent endoscopic posterior cricoid split with rib graft (EPCS/RG), and he regained moderate vocal abduction and full vocal adduction, resolution of dysphonia, and was decannulated. This report describes the only case of an adult with BVFI due to a posterior cricoid fracture that was successfully treated with EPCS/RG. Laryngoscope, 128:2864-2866, 2018.

The First Case of Riboflavin Transporter Deficiency in sub-Saharan Africa

This report describes the first case of a child with genetically confirmed Brown-Vialetto-van Laere syndrome in sub-Saharan Africa. This is an extremely rare clinical condition that presents with an auditory neuropathy, bulbar palsy, stridor, muscle weakness, and respiratory compromise that manifests with diaphragmatic and vocal cord paralysis. It is an autosomal recessive condition for which the genetic mutation has only recently been linked to a riboflavin transporter deficiency. We describe an 11-month-old affected male infant. He has required long-term respiratory support and a gastrostomy tube to support feeding. With high-dose riboflavin supplementation, he had limited recovery of motor function. His respiratory chain enzyme studies were abnormal suggestive of mitochondrial (mt) dysfunction. In the setting of limited resources, recognition of this striking clinical phenotype is important to highlight, specifically regarding the genetic implications of the condition and the potentially remedial response to vitamin supplementation.

Familial impairment of vocal cord mobility in childhood with clubfoot

We report on a family with three siblings, male and female, affected by congenital bilateral limitation of vocal cord abduction, with the additional finding of clubfeet in two. The paternal family history suggests an autosomal dominant inheritance. The siblings and father also have mild craniofacial features, which may be an expression of variability or may be unrelated. The association between congenital vocal cord paralysis and clubfeet has been reported with additional major features or in the context of Charcot-Marie-Tooth disease. However, the two in isolation have only been reported in one other family previously. Genomic analyses of the family, including chromosomal microarray and exome sequencing, showed neither a likely pathogenic variant in a known disease gene nor a compelling candidate gene variant. We propose that the association of these two findings constitutes a novel recognizable phenotype, for which a genetic cause remains undetermined.

Current Treatment Options for Bilateral Vocal Fold Paralysis: A State-of-the-Art Review

Vocal fold paralysis (VFP) refers to neurological causes of reduced or absent movement of one or both vocal folds. Bilateral VFP (BVFP) is characterized by inspiratory dyspnea due to narrowing of the airway at the glottic level with both vocal folds assuming a paramedian position. The primary objective of intervention for BVFP is to relieve patients’ dyspnea. Common clinical options for management include tracheostomy, arytenoidectomy and cordotomy. Other options that have been used with varying success include reinnervation techniques and botulinum toxin (Botox) injections into the vocal fold adductors. More recently, research has focused on neuromodulation, laryngeal pacing, gene therapy, and stem cell therapy. These newer approaches have the potential advantage of avoiding damage to the voicing mechanism of the larynx with an added goal of restoring some physiologic movement of the affected vocal folds. However, clinical data are scarce for these new treatment options (i.e., reinnervation and pacing), so more investigative work is needed. These areas of research are expected to provide dramatic improvements in the treatment of BVFP.

Indications for Direct Laryngoscopic Examination of Vocal Cord Function Prior to Anterior Cervical Surgery

Recurrent laryngeal nerve palsy (RLNP) is among the most common complications in both thyroid surgeries and anterior approaches to the cervical spine, having both a diverse etiology and presentation. Most bilateral paresis, with subsequent devastating impact on patients, are due to failure to recognize unilateral recurrent laryngeal nerve paralysis and, although rare, are entirely preventable with appropriate history and screening. Recurrent laryngeal nerve palsy has been shown to present asymptomatically in as high as 32% of cases, which yields limitations on exclusively screening with physical examination. Based on the available literature, diagnosis of unilateral RLNP is the critical factor in preventing the occurrence of bilateral RLNP as the surgeon may elect to operate on the injured side to prevent bilateral paresis. Analysis of incidence rates shows postoperative development of unilateral RLNP is 13.1 (95% confidence interval [CI]: 6.1-28.1) and 13.90 (95% CI: 6.6-29.3) times more likely in anterior spine and thyroid surgery, respectively, in comparison with intubation. Currently, there is no consensus on when to order a preoperative laryngoscopic examination prior to anterior cervical spine surgery. The importance of patient history should be emphasized, as it is the basis for indications of preoperative laryngoscopy. Efforts to minimize postoperative complications must be made, especially when considering the rising rate of cervical fusion. This study presents a systematic review of the literature defining key causes of RLNP, with a probability-based protocol to indicate direct laryngoscopy prior to anterior cervical surgery as a screening tool in the prevention of bilateral RLNP.

Repeat Imaging in Idiopathic Unilateral Vocal Fold Paralysis

Objective:

Imaging plays a critical role in the evaluation of patients presenting with unilateral vocal fold paresis or paralysis of unknown etiology. In those with idiopathic unilateral vocal fold paralysis (iUVFP), there is no consensus regarding the need or timing of repeat imaging. This study seeks to establish the rate of delayed detection of alternate etiologies for these patients to determine if and when imaging should be repeated.

Methods:

Retrospective chart review was conducted identifying patients at our institution with vocal fold movement impairment between 1998 and 2014. Idiopathic paralysis was diagnosed if physical examination, laryngoscopy, and initial imaging excluded a cause. Demographic data, length of follow-up, and the presence of late lesions were noted. Time to detection was plotted using the Kaplan-Meier method.

Results:

Of 3210 patients reviewed, 207 had a diagnosis of iUVFP. Of these patients, 8 went on to develop alternate diagnoses, including pulmonary disease, skull-base and laryngeal neoplasms, and thyroid malignancy. In Kaplan-Meir analysis, 90% remained “idiopathic” at 5 years of follow-up. The mean time to detection was 27 months.

Conclusions:

Patients initially diagnosed with iUVFP may have an occult cause that later becomes evident. We recommend repeat imaging within 2 years after diagnosis, but this is likely unnecessary beyond 5 years.

Electromyography-Guided Botulinum Toxin Injection Into the Cricothyroid Muscles in Bilateral Vocal Fold Abductor Paralysis

Objectives

Bilateral vocal fold abductor paralysis (BVFAP) both deteriorates quality of life and may cause life-threatening respiratory problems. The aim of this study was to reduce respiratory symptoms in BVFAP patients using cricothyroid (CT) botulinum toxin (BTX) injection.

Methods

Before and 2 weeks and 4 months after bilateral BTX injection into the CT muscles under electromyography; alterations in respiratory, acoustic, aerodynamic and quality of life parameters were evaluated in BVFAP patients with respiratory distress. For the respiratory evaluation modified Borg scale and spirometry, for the voice and aerodynamic evaluations Voice Handicap Index-30 (VHI-30), GRBAS, acoustic analysis (sound pressure level, F0, jitter%, shimmer%, noise-to-harmonic ratio) and maximum phonation time and for the quality of life assessment Short Form-36 (SF-36) form were used.

Results

All patients were female with a mean age of 47±8.1 years. There was a mean time of 11.8±5.5 (minimum 2, maximum 23) months between BVFAP development and BTX injection. In all cases, other than one case with unknown aetiology, the cause of vocal fold paralysis was prior thyroid surgery. In total 18.6±3.1 units of BTX were applied to the CTs. In the preinjection period, and the 2nd week and 4th month after injection, the Borg dyspnea scale was 7.3/5.3/5.0, FIV1 (forced inspiratory volume in one second) was 1.7/1.7/1.8 L, peak expiratory flow (PEF) was 1.4/1.7/2.1 L/sec, maximum phonation time was 7.0/6.4/6.2 seconds and VHI-30 was 63.2/52.2/61.7 respectively. There was no significant alteration in acoustic analysis parameters. Many of the patients reported transient dysphagia within the first week. There were insignificant increases in SF-36 sub-scale values.

Conclusion

After BTX injection, improvements in the mean Borg score, PEF and FIV1 values and SF-36 sub-scale scores showed the restricted success of this approach. This modality may be kept in mind as a transient treatment option for patients refused persistent tracheotomy or ablative airway surgeries.

Laryngoscopy in Bilateral Vocal Fold Immobility: Can You Make a Diagnosis?

Objectives:

This study explores whether videoendoscopic findings and patient history help make the diagnosis in bilateral vocal fold immobility (BVFI).

Methods:

Medical records from 1995 to 2003 were searched to identify patients with posterior glottic stenosis (PGS) and bilateral vocal fold paralysis (BVFP) who also had videoendoscopic examinations. Videoendoscopic examination findings that could help differentiate PGS from BVFP were identified a priori. A weighted scoring index, based on the adjusted odds ratios of significant examination findings on multiple logistic regression, was derived. Associations between the weighted scoring index, patient history, and diagnosis were then evaluated.

Results:

Twenty-six patients with BVFP and 28 patients with PGS were identified. Posterior glottic scar (weight = 2), medial arytenoid erosion with a widened posterior glottis (weight =1), and appropriate vocal fold motion (weight = 1) were significant variables (p ≤ .05, multiple logistic regression) and constituted the weighted scoring index. A weighted scoring index of ≥ 2 and a history of prolonged intubation predicted PGS in 95.2% of cases. A weighted scoring index of ≤ 1 and a history of neck surgery predicted BVFP in 95.0% of cases.

Conclusions:

The weighted scoring index with the patient history provides an objective tool for diagnosing BVFI.

Findings of Multiple Muscle Involvement in a Study of 214 Patients with Laryngeal Dystonia Using Fine-Wire Electromyography

Although perceptual and stroboscopic data help in diagnosing and classifying laryngeal dystonia, these measures do not aid the voice clinician in targeting which specific muscles to treat with botulinum toxin. Most patients achieve smoother, less effortful voicing with standard injection regimens. However, there is a notable failure rate. We performed fine-wire electromyography on 214 consecutive patients with laryngeal dystonia. We correlated voice ratings, stroboscopy data, and fine-wire electromyography data. Videostroboscopy was successful in visually demonstrating most of the audible findings in isolated vocal tremor, but it was much less successful in identifying breaks alone or a combination of breaks and tremor. Fine-wire electromyography revealed that the thyroarytenoid muscle was significantly more likely than the lateral cricoarytenoid muscle to be the predominant muscle associated with adductor spasmodic dysphonia, and that the thyroarytenoid and lateral cricoarytenoid muscles were equally likely to be predominantly involved in tremor spasmodic dysphonia. In addition, several patients in both the adductor spasmodic dysphonia and the tremor spasmodic dysphonia groups presented with interarytenoid muscle predominance. All of the intrinsic laryngeal muscles are capable of being the predominant muscle in laryngeal dystonia, and there are patterns of muscle abnormalities that differ between adductor spasmodic dysphonia and tremor spasmodic dysphonia. Some of the failures in treating adductor spasmodic dysphonia with botulinum toxin, and the greater difficulty with success in treating patients with tremor spasmodic dysphonia, are due to failure to deliver toxin to the appropriate muscles.

Medial Arytenoidectomy versus Transverse Cordotomy as a Treatment for Bilateral Vocal Fold Paralysis

Objectives:

Transverse cordotomy (TC) and medial arytenoidectomy (MA) are procedures performed to enlarge the glottic airway in patients with bilateral vocal fold paralysis (BVFP). Both are less destructive than total arytenoidectomy and have distinct theoretical advantages for voice preservation, but they have never been compared.

Methods:

The records of patients with BVFP treated with TC or MA were reviewed; information regarding the outcome measures of tracheotomy decannulation, dysphagia, Voice Handicap Index score, voice intensity, clinical course, and preoperative and postoperative voice quality was obtained.

Results:

Seventeen patients were available for evaluation (11 with TC, 6 with MA). All 6 patients with a preoperative tracheotomy were decannulated. Four patients in the MA group and 2 in the TC group had an increase in their postoperative Voice Handicap Index score. Two of the patients in the MA group had a decrease in phonatory sound pressure level of 3 dB, and 1 in the TC group had a decrease of 2 dB sound pressure level. Patient self-report of airway status following TC or MA showed that 62.5% (10 of 16) were significantly better and 25% (4 of 16) were somewhat better. Blinded audio perceptual analysis comparing preoperative and postoperative voice quality showed no difference between the MA and TC groups. A swallowing quality-of-life instrument confirmed a lack of swallowing difficulties postoperatively.

Conclusions:

Both TC and MA are good treatment options for BVFP, with a low incidence of complications in postoperative voice or of swallowing difficulties and a consistent improvement of laryngeal airway restriction symptoms.

Sarcoidosis Presenting as Bilateral Vocal Cord Paralysis due to Bilateral Vagal Nerve Involvement

We herein report a rare case of sarcoidosis presenting as bilateral vocal cord paralysis due to bilateral vagal nerve involvement. A 72-year-old woman with uveitis of the left eye complained of hoarseness and aspiration due to bilateral vocal cord paralysis. An endobronchial needle aspiration biopsy specimen of the mediastinal lymph nodes showed non-caseating epithelioid cell granuloma. Total protein and cell concentrations in the cerebrospinal fluid were increased. We diagnosed her to have sarcoidosis with bilateral vagal nerve involvement. Corticosteroid therapy improved her symptoms of hoarseness and aspiration. Sarcoidosis should therefore be taken into consideration as a potential cause of bilateral vocal cord paralysis.

Diagnostic Yield of Computed Tomography in the Evaluation of Idiopathic Vocal Fold Paresis

Objective

To determine the diagnostic yield of computed tomography (CT) in establishing an etiology in patients with idiopathic unilateral vocal fold paresis (IUVFP). To determine the proportion of CT scans yielding incidental findings requiring further patient management.

Study Design

Case series with chart review.

Setting

Tertiary laryngology practice.

Subjects

Laryngology clinic patients under the care of the 2 senior authors.

Methods

All clinic patients were identified who had a diagnosis of IUVFP and underwent CT of the skull base to the upper mediastinum from 2004 to 2014. Demographic, historical, examination, and investigation data were extracted. CT reports and endoscopic recordings were reviewed. Patients were excluded if there were insufficient clinical findings recorded or if there was a known neurologic disorder, complete vocal fold immobility, or bilateral involvement.

Results

A total of 174 patients with IUVFP who had also undergone contrast-enhanced CT were identified. Of the 174 patients, 5 had a cause for their paresis identified on CT. This equated to a diagnostic yield of 2.9% (95% confidence interval, 0.94% to 6.6%). Of the 174 patients, 48 had other incidental lesions identified that required further follow-up, investigation, or treatment. This equated to an incidental yield of 27.6% (95% confidence interval, 21.1% to 34.9%).

Conclusion

This is the second and largest study to evaluate the diagnostic yield of CT in the evaluation of IUVFP. It demonstrates a low diagnostic yield and a high incidental yield. These findings suggest that the routine use of CT in the evaluation of idiopathic vocal fold paresis should be given careful consideration and that a tailored approach to investigation with good otolaryngologic follow-up is warranted.

Acquired Glottic Stenosis-The Ongoing Challenge: A Review of Etiology, Pathogenesis, and Surgical Management

OBJECTIVE

To review the etiology and pathogenesis of acquired glottic stenosis, as well as the workup, patient preparation, interventional options, and their changing trends, as described in the literature since the 19th century until the present day.

METHODS

Literature from the PubMed search engine and the authors' personal experience were used. The search included up to date studies and historical reports covering different aspects of glottic stenosis, such as basic science, pathogenesis, anesthesia, and surgical techniques.

RESULTS

At present, the most common etiology for acquired glottic stenosis is damage to the posterior commissure after intubation. Until less than a century ago, infectious diseases such as diphtheria and syphilis were the most prevalent etiologies. The common pathway of stenosis includes mucosal and cartilaginous ulcers, granulation formation, fibrosis, and tethering scars. Planning of surgical intervention must begin with the matching of expectations with the patient and considering voice versus airway functions. Preoperative tracheotomy should be considered for securing the airway. Anesthesia has to be carefully planned, and both the surgeon and the anesthesiologist have to be familiar with the options for tubeless jet ventilation. Surgical options include a variety of open and endoscopic resection and reconstruction procedures, which are reviewed in this article, followed by images and illustrations based on the authors' experience.

CONCLUSION

Acquired glottic stenosis compromises the breathing, voice production, and airway protection. Reconstructing the stenosed glottis is one of the major challenges facing laryngologists in this era. For this reason, the surgeon must be familiar with the variety of treatment options.

New laryngoscope for endoscopic arytenoidectomies

OBJECTIVE

During an endoscopic arytenoidectomy, an intubation tube must be elevated anteriorly with the laryngoscope to ensure an adequate surgical field. This paper describes a new laryngoscope that has a canal along the outer wall of the body and a ridge which runs along the canal.

METHOD

Ten patients underwent endoscopic total arytenoidectomy using this new laryngoscope and 10 patients underwent the same operation using a regular laryngoscope.

RESULTS

The duration of all operations ranged between 25 and 65 minutes, with a median duration of 42.5 minutes. The median duration with the new laryngoscope was 39 minutes, and that with the regular laryngoscope was 49 minutes; this difference was statistically significant (p < 0.05).

CONCLUSION

This new laryngoscope shortened the duration of the endoscopic arytenoidectomy and facilitated the procedure by enlarging the surgical field. This new laryngoscope may be a beneficial surgical instrument for posterior endoscopic laryngeal operations.

[Neurolaryngology]

The neuroanatomy of voice and speech is complex. An intricate neural network is responsible for ensuring the main functions of the larynx: airway protection, cough and Valsalva production, and providing voice. Coordination of these roles is very susceptible to disruption by neurological disorders. Neurological disorders that affect laryngeal function include Parkinson's disease, stroke, amyotrophic lateral sclerosis, multiple sclerosis, dystonia and essential tremor. A thorough neurological evaluation should be routine for any patient presenting with voice complaints suggestive of neurogenic cause. Endoscopic visualisation of the larynx using a dynamic voice assessment with a flexible laryngoscope is a crucial part of the evaluation and ancillary tests are sometimes performed. Otolaryngologic evaluation is important in the diagnosis and treatment of neurological disorders that affect laryngeal function.

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.

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.

Neurotrophin expression of laryngeal muscles in response to recurrent laryngeal nerve transection

OBJECTIVE/HYPOTHESIS

The recurrent laryngeal nerve (RLN) commonly regenerates after injury; however, functional motion is rarely recovered. Animal experiments have documented aberrant reinnervation after nerve transection, with motor axons reaching inappropriate muscles. More recently, experimental results suggest that lack of vocal fold motion after RLN injury is due to preferential reinnervation of adductor muscles, with inadequate reinnervation of the posterior cricoarytenoid muscle (PCA), the only abductor muscle of the larynx. Information on factors that could influence the receptiveness of these muscles to reinnervation could be useful in developing new therapeutic strategies. It is hypothesized that the thyroarytenoid muscle (TA) and the PCA differ in expression of neurotrophins in response to denervation.

STUDY DESIGN

Laboratory experiment.

METHODS

Rats were sacrificed at 3 days, 6 weeks, or 4 months after unilateral RLN injury measure expression of brain-derived nerve growth factor (BDNF), nerve growth factor (NGF), and neurotrophin 4 (NT-4) in the TA and PCA muscles, using immunohistochemistry. We also assessed nerve regeneration.

RESULTS

NGF was significantly diminished in the denervated TA muscle at 3 days after injury and increased at 6 weeks. BDNF expression was unchanged in the TA, but was diminished in both PCA muscles at 3 days and 6 weeks, returning to near-normal levels at 4 months after injury. Robust nerve regeneration of distal RLN was present at 4 months.

CONCLUSIONS

Results suggest that the TA and PCA muscles respond differently to denervation.

Vocal fold paresis and paralysis: what the thyroid surgeon should know

The thyroid surgeon must have a thorough understanding of laryngeal neuroanatomy and be able to recognize symptoms of vocal fold paresis and paralysis. Neuropraxia may occur even with excellent surgical technique. Patients should be counseled appropriately, particularly if they are professional voice users. Preoperative or early postoperative changes in voice, swallowing, and airway function should prompt immediate referral to an otolaryngologist. Early recognition and treatment may avoid the development of complications and improve patient quality of life.

Vocal fold paresis and paralysis

Diagnosis and treatment of the immobile or hypomobile vocal fold are challenging for the otolaryngologist. True paralysis and paresis result from vocal fold denervation secondary to injury to the laryngeal or vagus nerve. Vocal fold paresis or paralysis may be unilateral or bilateral, central or peripheral, and it may involve the recurrent laryngeal nerve, superior laryngeal nerve, or both. The physician's first responsibility in any case of vocal fold paresis or paralysis is to confirm the diagnosis and be certain that the laryngeal motion impairment is not caused by arytenoid cartilage dislocation or subluxation, cricoarytenoid arthritis or ankylosis, neoplasm, or other mechanical causes. Strobovideolaryngoscopy, endoscopy, radiologic and laboratory studies, and electromyography are all useful diagnostic tools.

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.

Bilateral vocal fold immobility in a patient with overlap syndrome rheumatoid arthritis/systemic sclerosis

Bilateral vocal fold immobility (BVFI) can be the result of a primary disorder or as an iatrogenic complication of surgery or intubation. Laryngeal involvement can be a rare complication of connective tissue disorders and it usually occurs in association with other symptoms and signs that indicate active disease. We present a case of BVFI in a patient with an overlap syndrome rheumatoid arthritis/systemic sclerosis, referred to our division because of dysphonia and dyspnea. The video-laryngostroboscopy showed the presence of BVFI. Physical examination, blood tests, lung and neck high resolution computed tomography scans did not demonstrate significant abnormalities. She was treated with pulses of intravenous methylprednisolone with slow improvement.

Unilateral arytenoid adduction improves voice in a patient with bilateral vocal fold immobility

Bilateral vocal fold immobility (BVFI) due to prolonged endotracheal intubation resulted in aphonia without any airway morbidity and was treated by several reconstructive procedures. Laryngeal reinnervation and silicone implantation failed to medialize one of those two fixed cords. Arytenoid adduction (AA) eventually achieved this goal. To select an optimal reconstructive procedure, a careful perusal of the history and head and neck examination including laryngeal electromyography, are necessary to determine the causes. AA procedure played an essential clinical indication in this study, not just an adjunct to the medialization laryngoplasty as usual. Since both the vocal cords positions were ranked as lateral positions subjectively, the full adduction for one of those two fixed vocal cords was performed without significant airway obstruction. The practice in this study provided an experience in correcting the voice in patients with BVFI. We need further experience to medialize the vocal cord in an appropriate magnitude since its counterpart may position variously and compromise the airway.

[When should tracheotomy be performed in bilateral vocal cord paralysis involving multiple system atrophy?]

OBJECTIVES

Bilateral vocal cord paralysis caused by central nervous system dysfunction results from such diverse causes as cerebrovascular disorder and neurodegenerative disease. Otolaryngologists are often consulted about indications of tracheostomy for such cases, but if their recognition of causative disease is insufficient, it is difficult to judge indications of tracheostomy. We reviewed tracheostomy cases due to bilateral vocal cord paralysis caused by multiple system atrophy (MSA) and considered points to keep in mind in such cases.

MATERIALS AND METHODS

We diagnosed 9 cases of vocal cord midline fixation due to central bilateral vocal cord paralysis caused by MSA and treated by tracheostomy. We reviewed clinical conditions and suitable time for tracheostomy because it presents a specific clinical course.

RESULTS

7 cases were MSA-P and 2 cases were MSA-C. Inspiratory stridor in awaking and dysphasia was aggravated at the almost same time in 7 cases.

DISCUSSION

Vocal cord abductor paralysis in MSA may cause sudden death, but when an otolaryngologist not familiar with this disease is asked for air way evaluation, it is possible to be diagnosed as no vocal cord paralysis because there is no an adductor disorder, so clinical course of MSA should be clarified more. In vocal cord midline fixation, it was expected that intervention by hypermyotony in the progress of Parkinsonism was a main factor, as was vocal cord abductor disorder due to a neurogenic change in the posterior cricoarytenoid muscle in MSA. The aggravation of dysphasia is an important index in judging the indication of tracheostomy.