The natural history of idiopathic unilateral vocal fold paralysis: evidence and problems

Long-Term Outcomes and Revision Rates in Laryngeal Reinnervation

OBJECTIVES

Nonselective laryngeal reinnervation is an effective procedure to improve voice quality after unilateral vocal fold paralysis. Few studies have captured long-term outcome data, and the revision rate for this operation is currently unknown. The objective of this study is to describe the long-term outcomes and revision rates of unilateral, nonselective reinnervation in pediatric and adult patients.

METHODS

Patients who underwent laryngeal reinnervation from 2000 to 2022 with a single surgeon were identified for inclusion. Patients who underwent bilateral, super selective, deinnervation and reinnervation, and/or concurrent arytenoid adduction procedures were excluded. Outcome measures included maximum phonation time [MPT], voice handicap index score [VHI], patient-reported percent normal voice, revision procedures, and complications. Data were compiled and analyzed using paired t-tests, repeated measures analysis of covariance, and binary logistic regression analysis.

RESULTS

One hundred thirty-two patients underwent unilateral, nonselective ansa-recurrent laryngeal nerve [RLN] laryngeal reinnervation. Reinnervation significantly improved MPT and patient-reported percentage of normal voice and significantly decreased VHI. Eleven patients underwent revision procedures, corresponding to a revision rate of 8.3%. Additional procedures included medialization laryngoplasty [n = 3], medialization laryngoplasty with arytenoid adduction [n = 3] and injection augmentation greater than 1 year after reinnervation [n = 5]. The only factor associated with the need for additional surgery was time lapse from nerve injury to reinnervation. The overall complication rate was 6.8%; no patient required reintubation or tracheostomy.

CONCLUSION

Unilateral, nonselective laryngeal reinnervation can provide reliable improvement in vocal symptoms after recurrent laryngeal nerve injury. The revision rate after laryngeal reinnervation is favorable and comparable to framework surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3187-3192, 2024.

A comparative analysis of laryngeal nerve damage in patients with idiopathic vocal cord paralysis exhibiting different paralytic sides

Objective

To assess the extent of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) damage in patients with idiopathic vocal cord paralysis (IVCP) exhibiting different paralytic sides.

Methods

A total of 84 IVCP cases were evaluated using stroboscopic laryngoscopy, voice analysis, and laryngeal electromyography (LEMG). The results were compared between patients with left-sided paralysis and right-sided paralysis based on different disease courses (less than or more than 3 months).

Results

Initially, the average age and disease progression of IVCP patients were found to be similar regardless of the side of paralysis (p > .05). Additionally, there were no significant variations in voice indicators, such as MPT, DSI, and VHI, between IVCP patients with left and right vocal cord paralysis (p > .05). Furthermore, no disparities were detected in the latencies and amplitudes of the paralyzed RLN and SLN, as well as the durations and amplitudes of the action potentials in the paralyzed TM and PCM, among IVCP patients with left and right vocal cord paralysis (p > .05). Notably, the amplitudes of the left paralytic CM were significantly lower than those of the right paralytic CM (0.45 vs. 0.53, Z = -2.013, p = .044). In addition, no disparities were observed in APDs and amplitudes between the ipsilateral PCM and TM, either for patients with left or right vocal fold paralysis (p > .05). Finally, all the IVCP patients were subdivided into two subgroups according to different disease course (less than or more than 3 months), and in each subgroup, the comparison of voice indicators and LEMG results in IVCP patients with left or right vocal fold paralysis were similar with the above findings (p > .05).

Conclusion

Overall, the degree of RLN and SLN damage appeared to be similar in IVCP patients with left and right vocal cord paralysis, provided that the disease course was comparable.

Level of Evidence

4.

Immediate effect of recurrent laryngeal nerve stimulation in patients with idiopathic unilateral vocal fold paralysis

BACKGROUND

There is a lack of effective treatment for idiopathic unilateral vocal fold paralysis (IUVFP). A better phonation was reported by patients after laryngeal nerve stimulation during our clinical examination.

OBJECTIVES

This study aims to investigate immediate effect of recurrent laryngeal nerve (RLN) stimulation on phonation in patients with IUVFP.

MATERIAL AND METHODS

Sixty-two patients with clinically identified IUVFP underwent RLN stimulation with needle electrodes. Laryngoscopy, acoustic analysis, and voice perception assessment were performed for quantitative comparison of vocal function and voice quality before and after the intervention.

RESULTS

Laryngoscopic images showed a larger motion range of the paralyzed vocal fold (p < .01) and better glottal closure (p < .01) after RLN stimulation. Acoustic analysis revealed that the dysphonia severity index increased significantly (p < .01) while the jitter and shimmer decreased after the intervention (p < .05). According to perceptual evaluation, RLN stimulation significantly increased RBH grades in patients with IUVFP (p < .01). Furthermore, the improvement in voice perception had a moderate positive correlation with the decrease in the glottal closure.

CONCLUSIONS AND SIGNIFICANCE

This study shows a short-term improvement of phonation in IUVFP patients after RLN stimulation, which provides proof-of-concept for trialing a controlled delivery of RLN stimulation and assessing durability of any observed responses.

Subject-Specific Modeling of Implant Placement for Type I Thyroplasty Surgery

Type I thyroplasty is widely used to improve voice production in patients affected by unilateral vocal fold paralysis. Almost two-thirds of laryngologists report using Silastic® implants to medialize the vocal fold, with implant size, shape, and location determined experientially. However, post-surgical complications arising from this procedure (extrusion, migration, resizing) necessitate revision in 4.5-16% of patients. To improve initial surgical outcomes, we have developed a subject-specific modeling tool, PhonoSim, which uses model reconstruction from MRI scans to predict the optimal implantation location. Eleven vocal fold sample sides from eight larynges of New Zealand white rabbits were randomized to two groups: PhonoSim informed (n = 6), and control (no model guidance, n = 5). Larynges were scanned ex vivo in the abducted configuration using a vertical-bore 11.7 T microimaging system, and images were used for subject-specific modeling. The PhonoSim tool simulated vocal fold adduction for multiple implant location placements to evaluate vocal fold adduction at the medial surface. The best implant placement coordinates were output for the 6 samples in the PhonoSim group. Control placements were determined by the same surgeon based on anatomical landmarks. Post-surgical MRI scans were performed for all samples to evaluate medialization in implanted vocal folds. Results show that PhonoSim-guided implantation achieved higher vocal fold medialization relative to controls (28 to 55% vs. - 29 to 39% respectively, in the glottal area reduction), suggesting that this tool has the potential to improve outcomes and revision rates for type I thyroplasty.

Type I Thyroplasty or Fat Injection Laryngoplasty Versus Arytenoid Adduction: Effects of Surgery on Voice Recovery in Patients With Unilateral Vocal Fold Paralysis

Objective: Type I (medialization) thyroplasty (MT), fat injection laryngoplasty (FIL), and arytenoid adduction (AA) are the 3 most common surgical treatments for unilateral vocal fold paralysis (UVFP). While MT and FIL involve medialization of the paralyzed vocal fold, the goal of AA is to reduce the glottal-level difference. The current study compared the effects of these surgical treatments on voice quality in patients with UVFP. Methods: This retrospective study included 87 patients with UVFP who underwent MT (n = 12), FIL (n = 31), AA (n = 6), or AA with MT (n = 38). Patients who underwent the former 2 surgical treatments were included in the thyroplasty (TP) group, while those who underwent the latter 2 were included in the AA group. Maximum phonation time (MPT), pitch period perturbation quotient (PPQ), amplitude perturbation quotient, and harmonic-to-noise ratio (HNR) were evaluated in all patients before and 1 month after surgery. Results: The TP group exhibited significant improvements in MPT (P < .001) and PPQ (P = .012), while the AA group exhibited significant improvements in all parameters (P < .001). Before surgery, voice quality was significantly worse in the AA group than in the TP group for all measures. However, there were no significant differences between the groups after treatment. Conclusion: Surgeries in both groups were effective for voice recovery in patients with UVFP under the appropriate surgical selection. Our results also highlight the importance of preoperative evaluation and the potential value of etiology for selecting the appropriate procedure.

Extracellular matrix deformations of the porcine recurrent laryngeal nerve in response to hydrostatic pressure

Damage to the recurrent laryngeal nerve (RLN) caused by supraphysiological compression or tension imposed by adjacent tissue structures, such as the aorta, may contribute to onset of idiopathic unilateral vocal fold paralysis (iUVP) resulting in difficulty speaking, breathing, and swallowing. We previously demonstrated in adolescent pigs that the right RLN epineurium exhibits uniform composition of adipose tissue, with larger quantities along its length within the neck region in contrast to the left RLN that shows greater collagen composition in the thoracic region and greater quantities of adipose tissue in the neck region. In contrast, the epineurium in piglets was primarily composed of collagen tissue that remained uniform along the length of the left and right RLNs. Tensile testing of the left and right RLN in piglets and pigs showed associated differences in strain by RLN side and segment by age. The goal of this study was to investigate how external hydrostatic compression of the RLN affects the nerve's connective tissue and microstructure. RLN segments were harvested from the distal (cervical/neck) regions and proximal (subclavian for the right RLN, thoracic for the left RLN) regions from eight adolescent pigs and nine piglets. RLN segments were isolated and assessed under fluid compression to test hypotheses regarding epineurium composition and response to applied forces. Second harmonic generation (SHG) imaging of epineurial collagen was conducted at 0, 40, and 80 mmHg of compression. The cartesian strain tensor, principal strain (Eps1), and principal direction of the RLN collagen fibers were determined at each pressure step. Significantly larger values of the 1st principal strain occurred in the proximal segments of the pig left RLN when compared to the same segment in piglets (p = 0.001, pig = 0.0287 [IQR = 0.0161 - 0.0428], piglet = 0.0061 [IQR = 0.0033 - 0.0156]). Additionally, the median transverse strain Eyy) for the second pressure increment was larger in the right proximal segment of pigs compared to piglets (p < 0.001, pig = 0.0122 [IQR = 0.0033 - 0.0171], piglet = 0.0013 [IQR = 0.00001 - 0.0028]). Eyy values were significantly larger in the right proximal RLN versus the left proximal RLNs in pigs but not in piglets (p < 0.001). In contrast to piglets, histological analysis of pig RLN demonstrated increased axial alignment of epineurial and endoneurial collagen in response to compressive pressure. These findings support the hypothesis that the biomechanical response of the RLN to compressive pressure changed from being similar to being different between the right and left RLNs during development in the porcine model. Further investigation of these findings associated with age-related onset of idiopathic UVP may illuminate underlying etiologic mechanisms. STATEMENT OF SIGNIFICANCE: Damage to the recurrent laryngeal nerve (RLN) caused by compression imposed by the aorta may contribute to the onset of left-sided idiopathic unilateral vocal fold paralysis resulting in difficulty speaking, breathing, and swallowing. The goal of this study was to investigate how compression affects the connective tissue and microstructure of the RLN. We quantified the pressure induced deformation of the RLN using multiphoton imaging as a function of both location (proximal versus distal) and age (piglets, adolescent pigs). Our results demonstrate that the biomechanical response of the RLN to compression changes in the right versus left RLN throughout development, providing further evidence that the the left RLN is exposed to increasing dynamic loads with age.

Brain adaptation following various unilateral vocal fold paralysis treatments: A magnetic resonance imaging based longitudinal case series

Aim

Examination of central compensatory mechanisms following peripheral vocal nerve injury and recovery is essential to build knowledge about plasticity of the neural network underlying phonation. The objective of this prospective multiple-cases longitudinal study is to describe brain activity in response to unilateral vocal fold paralysis (UVFP) management and to follow central nervous system adaptation over time in three patients with different nervous and vocal recovery profiles.

Materials and methods

Participants were enrolled within 3 months of the onset of UVFP. Within 1 year of the injury, the first patient did not recover voice or vocal fold mobility despite voice therapy, the second patient recovered voice and mobility in absence of treatment and the third patient recovered voice and vocal fold mobility following an injection augmentation with hyaluronic acid in the paralyzed vocal fold. These different evolutions allowed comparison of individual outcomes according to nervous and vocal recovery. All three patients underwent functional magnetic resonance imaging (fMRI task and resting-state) scans at three (patient 1) or four (patients 2 and 3) time points. The fMRI task included three conditions: a condition of phonation and audition of the sustained [a:] vowel for 3 s, an audition condition of this vowel and a resting condition. Acoustic and aerodynamic measures as well as laryngostroboscopic images and laryngeal electromyographic data were collected.

Results and conclusion

This study highlighted for the first time two key findings. First, hyperactivation during the fMRI phonation task was observed at the first time point following the onset of UVFP and this hyperactivation was related to an increase in resting-state connectivity between previoulsy described phonatory regions of interest. Second, for the patient who received an augmentation injection in the paralyzed vocal fold, we subsequently observed a bilateral activation of the voice-related nuclei in the brainstem. This new observation, along with the fact that for this patient the resting-state connectivity between the voice motor/sensory brainstem nuclei and other brain regions of interest correlated with an aerodynamic measure of voice, support the idea that there is a need to investigate whether the neural recovery process can be enhanced by promoting the restoration of proprioceptive feedback.

Long-term voice outcomes of laryngeal framework surgery for unilateral vocal fold paralysis

OBJECTIVE

To evaluate the short- and long-term voice outcomes after unilateral medialization thyroplasty (MT) and unilateral medialization thyroplasty with arytenoid adduction (MT + AA) in patients with unilateral vocal fold paralysis.

METHODS

Voice outcomes were assessed preoperatively, and postoperatively at 3 and 12 months according to a standardized protocol. Voice assessment was performed using Voice Handicap Index (VHI), GRBAS Grade, Maximum Phonation Time (MPT), s/z-ratio and subjective numeric rating scales on voice quality, effort, performance and influence on life.

RESULTS

Sixty-one patients were included (34 MT and 27 MT + AA). Significant pre- to postoperative improvements were seen in all voice outcome parameters. No significant differences in post-operative values were identified between the groups.

CONCLUSION

Based on our findings, we conclude that patients with unilateral vocal fold paralysis who undergo MT and MT + AA achieve comparable and significant long time voice improvement, although voices do not completely normalize. We also conclude that this does not mean that AA is a superfluous procedure, but can indicate the accurate identification of patients in need of the additional AA procedure based on clinical parameters.

Care and Management of Voice Change for Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline

Voice change is a common complaint after thyroid surgery and has significant impacts on quality of life. The Korean Society of Laryngology, Phoniatrics, and Logopedics set up a task force team to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations include preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, including in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQ) in three categories: preoperative (KQ1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. Detailed evidence profiles are presented for each recommendation. The level of evidence for each recommendation is classified into high, moderate, and low-quality. The recommendation's strengths are adjusted to consider the level of evidence resulting in the recommendation and are divided into strong and weak. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Characteristics, natural evolution and surgical treatment outcomes of unilateral laryngeal paralysis versus ankylosis: A longitudinal cohort study

AIMS

Although unilateral laryngeal immobility (ULI) can results from paralysis or ankylosis of the cricoarytenoid joint, no comparative study exists to date. Aim of this study was to compare clinical features, aetiologies, spontaneous recovery and evolution after surgical treatment of ULI according to its mechanism.

METHODOLOGY

Longitudinal observational cohort study between 1992 and 2017 in a tertiary care referral centre and university teaching hospital. All adult patients with isolated ULI were included. Presenting symptoms and demographic data were recorded at baseline. During follow-up, natural recovery and, if a surgical treatment was performed, treatment failure rate were noted.

RESULTS

994 patients were included, 56.4% of male and with a mean age of 58 years. Overall, 91% had paralysis and 9% had ankylosis. Dysphonia was the main symptom in both groups (>96%). Dyspnoea was more frequent in patients with ankylosis (26.1% vs 4.2% in those with paralysis) whereas dysphagia was more frequent in those with paralysis (31.1% vs 20% in those with ankylosis). With a mean follow-up of 2.3 years (±5.1), spontaneous recovery did not differ according to ULI's aetiology (hazard ratio 1.43, 95% confidence interval 0.85-2.40). Overall, 37.1% underwent a surgical treatment, and paralysis was associated with a lower odd of treatment failure (hazard ratio 0.27, 95% confidence interval 0.10-0.70) over a mean follow-up of 3.1 years (±4.1).

CONCLUSION

ULI resulting from paralysis or ankylosis differ in their symptoms and responses to surgical treatment, whereas natural evolution was similar.

Unilateral Vocal Cord Paresis During Sleep Endoscopy

Abnormalities of vocal cord motion in children with obstructive sleep apnea (OSA) who undergo drug-induced sleep endoscopy (DISE) are not frequently described. A 17-year-old female with a history of asthma, reflux, and bipolar disorder had a history of poor sleep. Polysomnography (PSG) showed apnea-hypopnea index (AHI) of 13.9/hr, obstructive AHI 10.3/hr, and oxygen saturation nadir 87%. Physical exam showed BMI 34 and 3+ tonsils. She underwent DISE with propofol infusion, which showed partial obstruction at the palatine and lingual tonsil levels, a posteriorly displaced epiglottis along with immobility of the left vocal cord. Tonsillectomy was performed as planned. At her post-op visit, laryngoscopy showed normal vocal cord motion bilaterally. Post-operative PSG was improved.

Numerical and experimental investigations on vocal fold approximation in healthy and simulated unilateral vocal fold paralysis

We have developed a novel surgical/computational model for the investigation of unilateral vocal fold paralysis (UVFP) which will be used to inform future in silico approaches to improve surgical outcomes in type I thyroplasty. Healthy phonation (HP) was achieved using cricothyroid suture approximation on both sides of the larynx to generate symmetrical vocal fold closure. Following high-speed videoendoscopy (HSV) capture, sutures on the right side of the larynx were removed, partially releasing tension unilaterally and generating asymmetric vocal fold closure characteristic of UVFP (sUVFP condition). HSV revealed symmetric vibration in HP, while in sUVFP the sutured side demonstrated a higher frequency (10 - 11%). For the computational model, ex vivo magnetic resonance imaging (MRI) scans were captured at three configurations: non-approximated (NA), HP, and sUVFP. A finite-element method (FEM) model was built, in which cartilage displacements from the MRI images were used to prescribe the adduction and the vocal fold deformation was simulated before the eigenmode calculation. The results showed that the frequency comparison between the two sides were consistent with observations from HSV. This alignment between the surgical and computational models supports the future application of these methods for the investigation of treatment for UVFP.

Natural Course of Unilateral Vocal Fold Paralysis and Optimal Timing of Permanent Treatment

Importance

Permanent surgical treatment for unilateral vocal fold paralysis (UVFP) should be performed when further neural recovery is improbable. Conservative delay of the surgical procedure may cause unnecessary deterioration of the patient's quality of life. Knowledge of the natural course of UVFP is important for better management and counseling.

Objective

To evaluate the natural course of UVFP, focusing on the recovery time according to the injury level to assess the optimal timing for permanent surgical intervention.

Design, Setting, and Participants

This retrospective case series enrolled 1264 patients with UVFP who visited the voice clinic of Seoul National University Hospital, Seoul, Korea, from November 1, 2005, through December 31, 2016. Medical records and stroboscopic video images were reviewed to obtain data on demographic characteristics, vocal fold movement, onset and recovery time, follow-up duration, and cause. Cases of UVFP were classified into 5 groups based on the location of injury: distal to the thyroid level, thyroid level, esophagus and mediastinum level, heart and lung level, and proximal to the thorax level. Data analysis was performed from January 23, 2018, to May 21, 2018.

Main Outcomes and Measures

Recovery of vocal fold movement defined as more than vocal fold twitching confirmed by stroboscopy video images, estimated injury level, and start time of recovery. The recovery time was analyzed according to age, sex, paralytic side, and 5 injury levels.

Results

Of 1264 eligible patients with UVFP (655 [51.8%] male; median age, 56 years [range, 1-90 years]), 208 had evidence of recovery with the recovery time relatively accurate. The maximum recovery time for the group with distal to the thyroid-level injury was 120 days; the group with thyroid-level injury, 157 days; the group with esophagus and mediastinum-level injury, 244 days; the group with heart and lung-level injury, 328 days; and the group with proximal to the thorax-level injury, 333 days with the exception of 1 outlier value (482 days). Recovery time did not differ according to age, sex, or paralytic side. As distance between the vocal fold and injury level increased, the maximum recovery time increased, plateauing at 1 year. Among the patients who showed recovery of the vocal fold movement, most patients with injuries distal to or at the level of the thyroid recovered within 6 months, whereas those with injury more distant from the vocal fold recovered within approximately 1 year.

Conclusions and Relevance

A linear association between injury level and maximum recovery time was observed. The findings suggest that the decision to proceed with permanent phonosurgical treatment should be based on the level of injury associated with UVFP.

Experience with laryngeal reinnervation using nerve-muscle pedicle in pediatric patients

OBJECTIVE

Vocal fold paralysis (VFP) in adducted position remains a challenge for airway surgeons. Alternatives to tracheostomies such as lateralization, cordectomy, and posterior rib grafting disrupt the laryngeal tissue or framework and carry an increased risk of aspiration. Laryngeal reinnervation using nerve-muscle pedicle (NMP), carries the distinct advantage of preserving the larynx, sparing the recurrent laryngeal nerve, and obtaining an active VF abduction. The aim of this study was to evaluate the success and complications of laryngeal reinnervation using nerve-muscle pedicle (NMP) in pediatric patients presenting with dyspnea related to VFP in adducted position.

METHODS

In this case series performed at a tertiary care referral center, review of medical records on all pediatric patients with VFP in adduction treated with laryngeal reinnervation using NMP between 1999 and 2017. Data were collected on the preoperative flexible laryngoscopy, suspension micro-laryngoscopy, and laryngeal electromyography as well as post-operative clinical assessment of the voice and airway. All patients underwent surgery consisting of the transfer of an innervated omohyoid muscle pedicle onto the paralyzed posterior cricoarytenoid muscle. The main outcomes measured were the clinical and fiberoptic laryngoscopic airway assessment monthly for the first 6 months, then at 12 months and annually thereafter. Clinical assessment included dyspnea evaluation based on a visual analog scale and voice assessment using the GRBAS scores. Complications from the treatment were also noted. These outcomes were determined before collection of data.

RESULTS

16 cases were identified, with a mean age of 4 years. The recurrent laryngeal nerve paralysis was bilateral in 3 cases and unilateral in 13 cases. There were no peri or postoperative complications. After a mean follow-up of 7 years, vocal fold abduction was observed in 10 out of 16 cases and disappearance of paradoxical inspiratory adduction in 3 cases. Persistent dyspnea was noted in 7 cases (44%), and moderate dysphonia was present in 11 cases (69%). Finally, additional procedures were necessary in 2 patients (13%) to achieve the outcomes.

CONCLUSIONS

Laryngeal reinnervation using NMP may be used in pediatric patients. This procedure, is safe and allows us to spare the recurrent laryngeal nerve while obtaining an active VF abduction in the majority of cases, and an improvement in breathing in most cases.

QUALITY OF EVIDENCE

4.

Yield of Imaging to Evaluate Unilateral Vocal Fold Paralysis of Unknown Etiology

OBJECTIVES/HYPOTHESIS

To identify the incidence and nature of positive findings on imaging studies ordered for evaluation of unilateral vocal fold paralysis (UVFP) of unknown etiology, to analyze these findings based on laterality, and to examine the use of the expanded-field computed tomography (CT) neck protocol in this evaluation.

STUDY DESIGN

Retrospective review.

METHODS

A total of 145 patients from 2000 to 2018 with UVFP of unknown etiology were studied. Data on imaging studies ordered, laterality of paralysis, and significant positive results were studied. An expanded-field CT neck protocol that included the entire course of the vagus and recurrent laryngeal nerves was instituted during the study period.

RESULTS

A total of 20.7% of patients had an etiology for paralysis identified on imaging. Malignancies comprised the majority of findings overall (19/30), whether in the chest (12/18) or the neck (7/12). Etiology was more often found in the chest for left-sided paralysis (15/21) and in the neck for right-sided paralysis (6/9). In 26 patients who underwent both expanded-field CT neck and CT chest, no findings related to the UVFP were seen on CT chest that were not captured by expanded-field CT neck.

CONCLUSIONS

This is one of the largest retrospective studies examining the incidence of positive findings on imaging studies for evaluation of UVFP of unknown etiology. Imaging in one of five patients with UVFP of unknown etiology will reveal a causative lesion, most often malignant. Left-sided paralysis tends to localize to the chest, and right-sided paralysis to the neck. Expanded-field CT neck may allow practitioners to forego dedicated CT chest in evaluation of UVFP.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1840-1844, 2021.

Surgical effects of type-I thyroplasty and fat injection laryngoplasty on voice recovery

OBJECTIVE

Type-I thryroplasty, also known as medialization thyroplasty (MT) and autologous fat injection laryngoplasty (FIL) are one of the main surgical treatments for unilateral vocal fold paralysis (UVFP). Both procedures have the same concept of completing the glottal closure by medializing the vocal fold, although the surgical approaches are quite different. In order to assess these surgical effects, we examined the treatment outcomes and benefits of the two surgeries.

METHODS

We collected data from the 135 phonosurgeries that we performed out of 375 patients with UVFP at Osaka Voice Center, Osaka Kaisei Hospital from January 2009 to February 2013. After excluding cases with glottal level differences on phonation, either MT or FIL were performed on 80 cases. The inclusion criteria for the present study were: (1) patients had no history of previous phonosurgery, and (2) functional evaluations were available before/after surgery. Consequently, 43 participants (12 for MT and 31 for FIL) were enrolled in this study. Surgical effects were evaluated by means of the maximum phonation time (MPT), pitch period perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and harmonic to noise ratio (HNR) just before, one month, and 6 months after surgery.

RESULTS

Both MT and FIL showed significant improvement in MPT (MT, p = 0.005; FIL, p < 0.001) and PPQ (MT, p = 0.047; FIL, p = 0.041) at 1 month postoperation. We also compared the variation of each variable between the two procedures, but there were no significant differences in these parameters. However, MPT, APQ, and HNR at the post-MT after 6 months worsened compared to those at 1 month posttreatment, whereas MPT showed only a slight decrease from the 1st month to the 6th month in those with FIL.

CONCLUSION

Both MT and FIL were effective for the voice recovery in patients with UVFP. Our findings suggest that surgical results in FIL might be better than those in MT 6 months after surgery, although there were no significant differences between these two procedures 1 month postoperation.

Guidelines for the Management of Unilateral Vocal Fold Paralysis From the Korean Society of Laryngology, Phoniatrics and Logopedics

The Korean Society of Laryngology, Phoniatrics and Logopedics appointed a task force to establish clinical practice guidelines for the management of unilateral vocal fold paralysis (UVFP). These guidelines cover a comprehensive range of management-related factors, including the diagnosis and treatment of UVFP, and provide in-depth information based on current, up-to-date knowledge. Detailed evidence profiles are provided for each recommendation. The CORE databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers, using a predefined search strategy. When insufficient evidence existed, expert opinions and Delphi questionnaires were used to fill the evidence gap. The committee developed 16 evidence-based recommendations in six categories: initial evaluation (R1–4), spontaneous recovery (R5), medical treatment (R6), surgical treatment (R7–14), voice therapy (R15), and aspiration prevention (R16). The goal of these guidelines is to assist general otolaryngologists and speech-language pathologists who are primarily responsible for treating patients with UVFP. These guidelines are also intended to facilitate understanding of the condition among other health-care providers, including primary care physicians, nurses, and policy-makers.

Efficacy of speech language therapy intervention in unilateral vocal fold paralysis - a systematic review and a meta-analysis of visual-perceptual outcome measures

OBJECTIVE

Unilateral vocal folds paralysis is a disorder that affects a patient's quality-of-life by disturbing their phonation, breathing, and swallowing activities. This systematic review aimed to estimate the efficacy of voice treatment on the vocal fold motility in adult patients with unilateral vocal folds paralysis.

METHODS

PubMed, CINAHL, CENTRAL, and Web of Science were searched for retrospective and prospective cohort, case-control, and cross-sectional with comparative studies with adults that were published between 1 January 2008 to 31 December 2018. After applying the inclusion and exclusion criteria a total of 10 studies containing morpho-functional evaluation results were included in the analysis. Pooled data analysis of the motility of the vocal folds before and after voice therapy allowed inferring about the efficacy of voice therapy intervention in patients with unilateral vocal folds paralysis. A random-effect model was used to estimate the effect size. Publication bias was considered.

RESULTS

The pooled data analysis of the visual-perceptual measures revealed that vocal fold motility improved in 72% (95% CI: 64.0-80.0) of all patients after the therapeutic interventions. The inconsistency index (I² = 18.35%) of the studies included in this meta-analysis revealed an extremely low heterogeneity. Funnel plot and Cochran's Q test showed no publication bias. The systematic review was limited to only English language articles.

CONCLUSION

This meta-analysis supports the evidence that voice therapy intervention can have a positive effect on the vocal fold motility, that is, they can improve the glottal gap closure, irrespective of the exercises and techniques used.

[Update on vocal fold augmentation]

Unilateral vocal fold palsy is a frequent cause of hoarseness. In the presence of glottis closure insufficiency, the effectiveness of conservative voice therapy is often limited and phonosurgery may be indicated. Injection laryngoplasty is effective for correction of insufficiency. Early intervention during the first 6 months after diagnosis is desired to avoid subsequent insufficient endogenous compensation. Particularly patients with glottic closure insufficiency ≤2 mm in stroboscopy may benefit from this procedure. With appropriate patient selection, duration of the effect exceeding 12 months has been described for hyaluronic acid, calcium hydroxylapatite, and autologous fat. Due to rare complications such as allergic swelling at the injection site, regular laryngoscopic monitoring and observation for two nights after injection are recommended. The voice must only be rested for a few hours.

Vocal cord paralysis following general anesthesia with endotracheal intubation: a clinical review on 43 cases

Background

Vocal cord paralysis (VCP) is one of the most stressful experiences for patients undergoing general anesthesia. Moreover, it is a risk factor for aspiration pneumonia and may increase morbidity and mortality. We examined several clinical features of the condition by reviewing the medical records of patients who experienced VCP following general anesthesia.

Methods

We reviewed the medical records of 321 patients who consulted an otolaryngologist owing to hoarseness, sore throat, throat discomfort, or dysphagia after general anesthesia. Among these, we included in the present study 43 patients who were diagnosed with VCP by laryngoscopy, who did not have symptoms of suspected VCP before surgery, who had no past history of VCP, and for whom endotracheal intubation was not continued after surgery.

Results

The mean age of patients with VCP was 51.3 years. With respect to surgical site, the most common was upper limb surgery, performed in 12 cases (9 cases were performed in sitting posture. With respect to surgical duration, only 11 cases lasted less than 3 h, whereas 32 cases required a surgical duration longer than 3 h. The most common symptom of VCP was hoarseness. Nine of the patients with VCP recovered spontaneously, but VCP persisted in 13 cases until the final follow-up examination.

Conclusions

We hope that this study might call attention to the occurrence of VCP following general anesthesia. Moreover, it is necessary to further evaluate the reasons for the higher incidence of VCP in upper limb surgery performed in sitting posture.

Hemi-laryngopharyngeal Spasm (HeLPS): Defining a New Clinical Entity

OBJECTIVE

Hemi-laryngopharyngeal spasm (HeLPS) has recently been described in the neurosurgical literature as a cause of intermittent laryngopharyngeal spasm and cough due to vascular compression of the vagus nerve at the cerebellopontine angle. We present the diagnostic criteria for this syndrome.

METHODS

A retrospective chart review of six patients with HeLPS and three patients misdiagnosed with this condition are presented. All patients were diagnosed and treated at a tertiary care academic centre from July 2013 to July 2017.

RESULTS

Patients with HeLPS had five defining characteristics: 1) All patients had symptoms of episodic laryngopharyngeal spasm and coughing. Patients were asymptomatic between episodes and were refractory to speech therapy and reflux management. 2) Laryngoscopy showed hyperactive twitching of the ipsilateral vocal fold in two of the six patients. No other inter-episodic abnormalities were seen. 3) Botulinum toxin A injections into the thyroarytenoid muscle on the affected ipsilateral side reduced laryngopharyngeal spasms. Botulinum toxin injection in the contralateral thyroarytenoid muscle did not improve laryngopharyngeal spasm. 4) Magnetic resonance imaging revealed ipsilateral neurovascular compression of the vagus nerve rootlets by the posterior inferior cerebellar artery. 5) Microvascular decompression (MVD) surgery of the ipsilateral vagus nerve resolved all symptoms (follow-up 2-4 years).

CONCLUSION

The diagnostic criteria for hemi-laryngopharyngeal spasm (HeLPS) are proposed. Otolaryngology recognition of this new clinical entity may lead to a surgical cure and avoid the unnecessary therapies associated with misdiagnosis.

LEVEL OF EVIDENCE

4.

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.

Study protocol to develop a patient-reported outcome measuring disability associated with unilateral vocal fold paralysis: a mixed-methods approach with the CoPE collaborative

INTRODUCTION

Patient-reported outcome (PRO) measures are increasingly developed with multisite, representative patient populations so that they can serve as a primary endpoint in clinical trials and longitudinal studies. Creating multisite infrastructure during PRO measure development can facilitate future comparative effectiveness trials. We describe our protocol to simultaneously develop a PRO measure and create a collaborative of tertiary care centres to address the needs of patients with unilateral vocal fold paralysis (UVFP). We describe the stakeholder engagement, information technology and regulatory foundations for PRO measure development and how the process enables plans for multisite trials comparing treatments for this largely iatrogenic condition.

METHODS AND ANALYSIS

The study has three phases: systematic review, measure development and measure validation. Systematic reviews and qualitative interviews (n=75) will inform the development of a conceptual framework. Qualitative interviews with patients with UVFP will characterise the lived experience of the condition. Candidate PRO measure items will be derived verbatim from patient interviews and refined using cognitive interviews and expert input. The PRO measure will be administered to a large, multisite cohort of adult patients with UVFP via the CoPE (vocal Cord Paralysis Experience) Collaborative. We will establish CoPE to facilitate measure development and to create preliminary infrastructure for future trials, including online data capture, stakeholder engagement, and the identification of barriers and facilitators to participation. Classical test theory psychometrics and grounded theory characterise our approach, and validation includes assessment of latent structure, reliability and validity.

ETHICS AND DISSEMINATION

Our study is approved by the University of Wisconsin Health Sciences Institutional Review Board. Findings from this project will be published in open-access journals and presented at international conferences. Subsequent use of the PRO measure will include comparative effectiveness trials of treatments for UVFP at CoPE Collaborative sites.

Early Injection Laryngoplasty With a Long-Lasting Material in Patients With Potentially Recoverable Unilateral Vocal Fold Paralysis

Objectives.

Injection laryngoplasty (IL) is one of the major options for treatment of unilateral vocal fold paralysis (UVFP). Early IL in patients with abrupt-onset UVFP can reduce hoarseness and aspiration-related discomfort and complications. Temporary or short-lasting materials are recommended for the early IL since permanent or long-lasting materials may negatively affect the voice quality when vocal fold motion is spontaneously recovered.

Methods.

Patients who received IL with a long-lasting material (ArteSense) within 1 month following development of postoperative UVFP were enrolled for this study. They were categorized into a spontaneously recovered group (n=30) and unrecovered group (n=276) from UVFP. The subjective and objective voice parameters were collected before and 6 months after IL. Patients’ demographics and collected voice parameters were compared between the two groups.

Results.

Age and sex distributions were not different between the two groups. Aspiration symptom, maximum phonation time (MPT), jitter, shimmer, noise to harmonic ratio (NHR), overall grade (G) and breathiness (B) of GRBAS (grade of dysphonia, roughness, breathiness, asthenia, strain) scale score, and voice handicap index (VHI) were significantly improved after IL in both groups. The amounts of improvement in MPT, jitter, shimmer, NHR and VHI were significantly greater in the recovered group. There was no IL-related complication including granuloma formation, hypersensitivity to injection material, or worsening of hoarseness.

Conclusion.

Early IL with a long-lasting material can be safely performed to improve voice quality and to reduce aspiration episode for the patients with postoperative UVFP, regardless of recovery from the paralysis. The amounts of improvement in the subjective and objective voice parameters were significantly greater in patients who showed spontaneous recovery from UVFP when compared with those in patients who did not.

Long-term quality of voice is usually acceptable after initial hoarseness caused by a thyroidectomy or a parathyroidectomy

Background

Vocal cord (VC) palsy following a thyroidectomy or parathyroidectomy can result in significant morbidity for the patient. We aimed to investigate the incidence of VC palsy in a tertiary referral Institution, track the management of these cases and record the long-term outcomes and VC recovery rates.

Methods

Retrospective review of all thyroidectomy/parathyroidectomy operations performed over 11 years. Patients with an unequivocal hoarse voice postoperatively were included. We analysed the patient's clinical characteristics and voice outcomes, operative, pathology and laryngoscopy reports during their follow-up.

Results

Ten patients fitted the inclusion criteria and were analysed. Median age at date of operation was 47.5 years (range, 16-81 years) and the M:F ratio was 1:2.3 (M:3, F:7). The median FU was 62.5 months (range, 12-144 months). The median hospital stay was 1.5 days (range, 1-87 days). There were 7 recurrent laryngeal nerve (RLN) injuries by manipulation, 1 case of RLN resection, 1 inadvertent division (with primary nerve repair) and 1 RLN was shaved off the thyroid. Long-term voice outcomes for the 7 patients with an RLN manipulation injury were: 3/7 patients had normal voice, 3/7 had moderate hoarseness and 1/7 had long-term hoarseness. The long-term voice outcome of the patient with RLN shaving off the thyroid gland was excellent while the 2 remaining patients (RLN resection and inadvertent division) needed 12 and 18 months respectively to achieve a normal quality of voice. Four out of the 10 patients had permanent VC palsy in the long-term and their voice outcomes varied: 1 patient had a normal voice, 2 patients had moderate hoarseness and 1 patient had persistent hoarseness. Only 1/10 patients did not show any voice improvement after 12 months.

Conclusions

In the vast majority of cases post-operative hoarseness due to RLN palsy improves in the long-term, albeit voice may not return completely to normal.

Medical and Surgical Advances in the Treatment of Unilateral Vocal Fold Paralysis

Purpose

In this chapter, unilateral vocal fold paralysis is described, and treatment options are discussed with emphasis on recent developments in treatment.

Conclusion

Unilateral vocal fold paralysis is a disorder commonly encountered by otolaryngologists and speech-language pathologists alike and is caused by dysfunction of one of the recurrent laryngeal nerves leading to dysphonia and dysphagia. The etiology of this disorder can include malignancy, iatrogenic injury, or traumatic injury or may be due to idiopathic causes, and evidence has suggested that the rates of different etiologies have changed over time. Treatment options include a variety of approaches and range from expectant management, voice therapy, as well as surgical and procedural approaches. Surgical approaches generally aim to augment the affected vocal fold to medialize its position, thereby reducing glottic insufficiency, and can include injection laryngoplasty and laryngeal framework surgery. Recurrent laryngeal nerve reinnervation is also an option for certain patients and can improve vocal fold bulk by restoring basal neurologic stimulation. Though it is a well-described phenomenon, with new developments in procedural interventions, unilateral vocal fold paralysis remains a dynamic entity in the field.

The incidence and recovery rate of idiopathic vocal fold paralysis: a population-based study

PURPOSE

To determine the incidence and spontaneous recovery rate of idiopathic vocal fold paralysis (IVFP) and paresis (IVFp), and the impact of steroid treatment on rates of recovery.

METHODS

This retrospective cohort study included all patients with IVFP or IVFp within a large integrated health-care system between January 1, 2008 and December 31, 2014. Patient demographics and clinical characteristics, including time to diagnosis, spontaneous recovery status, time to recovery, and treatment, were examined.

RESULTS

A total of 264 patients were identified, 183 (69.3%) with IVFP and 81 (30.7%) with IVFp. Nearly all cases (96.6%) were unilateral and 89.8% of patients were over the age of 45. The combined (IVFP and IVFp) 7-year mean incidence was 1.04 cases per 100,000 persons each year with the highest 7-year mean annual incidence in white patients (1.60 per 100,000). The total rate of spontaneous recovery was 29.5%, where 21.2% had endoscopic evidence of resolution and 8.3% had clinical improvement in their voice without endoscopic confirmation. The median time to symptom resolution was 4.0 months. Use of steroids was not linked with spontaneous recovery in multivariable analyses.

CONCLUSION

The annual incidence of VFP (IVFP and IVFp) was 1.04 cases per 100,000 persons, with spontaneous recovery occurring in nearly a third of patients, regardless of steroid use.

Idiopathic Unilateral Vocal Fold Paralysis in Older Patients: Characteristics in the Disease Course and Implication of Computed Tomography for Evaluation of Etiology

OBJECTIVES

This study aimed to compare the characteristics of idiopathic unilateral vocal fold paralysis (IUVFP) in elderly versus younger patients, including the diagnostic yield of computed tomography (CT) scans for identifying the structural causes of IUVFP.

METHODS

We retrospectively analyzed medical records of the patients initially diagnosed with IUVFP in a single referral tertiary hospital. We compared patients' baseline characteristics, initial symptoms, laryngoscopic findings, and prevalence of structural causes on CT scans with respect to age (younger, <65 years vs older, ⩾65 years).

RESULTS

One hundred forty-two patients were enrolled (90 younger, 52 older). Evident structural causes were more frequently found on CT in older patients than younger patients (40.4% vs 22.2%, P = .034). Among truly idiopathic cases (70 younger, 31 older), recovered vocal fold mobility was identified in 48.6% younger and 41.9% older patients ( P = .666). There was no statistically significant difference in the characteristics between unrecovered and recovered subjects of the older patients with true IUVFP (all P > .05).

CONCLUSIONS

The CT scans provided significantly higher diagnostic yields in older patients than younger patients. The degrees of symptoms and complications and likelihood of natural recovery did not significantly differ between younger and older patients with IUVFP.

Association between Upper Respiratory Infection and Idiopathic Unilateral Vocal Fold Paralysis

INTRODUCTION

Unilateral vocal fold paralysis (UVFP) without an identifiable cause is termed idiopathic unilateral vocal fold paralysis (IUVFP). Some authors have postulated that select cases of IUVFP have a viral etiology, but the causality has not been established. We set out to review institutional cases of IUVFP and determine if there is a correlation between upper respiratory infection symptoms and presentation of IUVFP.

METHODS

Cases of IUVFP were reviewed over a 10-year period (2002-2012). The history was investigated to review presenting symptoms. We specifically reviewed for symptoms of upper respiratory infection at the onset of UVFP and tallied the frequency. Symptoms included sore throat, laryngitis, cough, influenza, bronchitis, pneumonia, otalgia, and sinusitis. The seasonal onset (if possible) was determined based on the history provided from the initial consultation.

STUDY DESIGN

Case series.

RESULTS

Overall, 107 patients presented with IUVFP; 35.5% of patients reported symptoms of upper respiratory infection at the onset of UVFP. Among these individuals, pharyngitis/laryngitis was the most common presenting symptom; 34.2% reported cough. In total, 40.0% of patients with IUVFP reported an onset of symptoms between December and February.

CONCLUSIONS

This study suggests that symptoms of upper respiratory infection frequently occur with the presentation of IUVFP. The onset of symptoms tended to occur between December and February. The mechanism of viral-mediated UVFP has not been established. Future studies to explore this pathophysiology are needed.

Injection medialization laryngoplasty improves dysphagia in patients with unilateral vocal fold immobility

Objective

To assess patient reported swallowing outcomes before and after injection medialization laryngoplasty in patients with unilateral vocal fold immobility (UVFI).

Methods

Case series with chart review of patients with UVFI who underwent injection medialization laryngoplasty at a community laryngology practice by a single clinician between October 2015 and December 2017. Patient-reported validated surveys of swallowing impairment, Eating Assessment Tool (EAT-10), demographics, etiology and duration of symptoms were recorded before and after injection. A paired t test was done on EAT-10 surveys before and after IML to assess for statistical significance.

Results

Twenty-one patients with UVFI and glottic insufficiency underwent IML between October 2015 and December 2017. Nineteen of 21 patients (90%) presented with dysphagia (EAT-10 ≥ 3). 76% of patients with dysphagia reported improvement in swallowing function after IML. The EAT-10 scores of UVFI patients with dysphagia before and after IML were 17.0 ± 14.0 and 4.2 ± 9.6, respectively (p = 0.004).

Conclusions

Nearly all patients with UVFI and glottic insufficiency report associated dysphagia. Three fourths of these patients perceive improvement in their swallowing function after injection medialization laryngoplasty. Patients with idiopathic UVFI may have a more sustained improvement and those with severe preop dysphagia may not benefit. Further research is necessary to refine patient selection and to assess duration of improved swallowing function.

An unusual cause of hoarseness and recurrent laryngeal nerve palsy

Recurrent laryngeal nerve palsy and thyroid disease suggest locally invasive thyroid malignancy. In contrast, recurrent laryngeal nerve palsy caused by benign multinodular goiters or ectopic thyroid tissue accounts for only 1% of cases. This article describes an unusual case of recurrent laryngeal nerve palsy secondary to a benign ectopic retrosternal thyroid tissue mass. Recurrent laryngeal nerve palsy should be considered in the differential diagnosis of patients presenting with progressive voice weakness and hoarseness.

Clinical Practice Guideline: Hoarseness (Dysphonia) (Update)

Objective

This guideline provides evidence-based recommendations on treating patients who present with dysphonia, which is characterized by altered vocal quality, pitch, loudness, or vocal effort that impairs communication and/or quality of life. Dysphonia affects nearly one-third of the population at some point in its life. This guideline applies to all age groups evaluated in a setting where dysphonia would be identified or managed. It is intended for all clinicians who are likely to diagnose and treat patients with dysphonia.

Purpose

The primary purpose of this guideline is to improve the quality of care for patients with dysphonia, based on current best evidence. Expert consensus to fill evidence gaps, when used, is explicitly stated and supported with a detailed evidence profile for transparency. Specific objectives of the guideline are to reduce inappropriate variations in care, produce optimal health outcomes, and minimize harm. For this guideline update, the American Academy of Otolaryngology—Head and Neck Surgery Foundation selected a panel representing the fields of advanced practice nursing, bronchoesophagology, consumer advocacy, family medicine, geriatric medicine, internal medicine, laryngology, neurology, otolaryngology–head and neck surgery, pediatrics, professional voice, pulmonology, and speech-language pathology.

Action Statements

The guideline update group made strong recommendations for the following key action statements (KASs): (1) Clinicians should assess the patient with dysphonia by history and physical examination to identify factors where expedited laryngeal evaluation is indicated. These include, but are not limited to, recent surgical procedures involving the head, neck, or chest; recent endotracheal intubation; presence of concomitant neck mass; respiratory distress or stridor; history of tobacco abuse; and whether the patient is a professional voice user. (2) Clinicians should advocate voice therapy for patients with dysphonia from a cause amenable to voice therapy. The guideline update group made recommendations for the following KASs: (1) Clinicians should identify dysphonia in a patient with altered voice quality, pitch, loudness, or vocal effort that impairs communication or reduces quality of life (QOL). (2) Clinicians should assess the patient with dysphonia by history and physical examination for underlying causes of dysphonia and factors that modify management. (3) Clinicians should perform laryngoscopy, or refer to a clinician who can perform laryngoscopy, when dysphonia fails to resolve or improve within 4 weeks or irrespective of duration if a serious underlying cause is suspected. (4) Clinicians should perform diagnostic laryngoscopy, or refer to a clinician who can perform diagnostic laryngoscopy, before prescribing voice therapy and document/communicate the results to the speech-language pathologist (SLP). (5) Clinicians should advocate for surgery as a therapeutic option for patients with dysphonia with conditions amenable to surgical intervention, such as suspected malignancy, symptomatic benign vocal fold lesions that do not respond to conservative management, or glottic insufficiency. (6) Clinicians should offer, or refer to a clinician who can offer, botulinum toxin injections for the treatment of dysphonia caused by spasmodic dysphonia and other types of laryngeal dystonia. (7) Clinicians should inform patients with dysphonia about control/preventive measures. (8) Clinicians should document resolution, improvement or worsened symptoms of dysphonia, or change in QOL of patients with dysphonia after treatment or observation. The guideline update group made a strong recommendation against 1 action: (1) Clinicians should not routinely prescribe antibiotics to treat dysphonia. The guideline update group made recommendations against other actions: (1) Clinicians should not obtain computed tomography (CT) or magnetic resonance imaging (MRI) for patients with a primary voice complaint prior to visualization of the larynx. (2) Clinicians should not prescribe antireflux medications to treat isolated dysphonia, based on symptoms alone attributed to suspected gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR), without visualization of the larynx. (3) Clinicians should not routinely prescribe corticosteroids for patients with dysphonia prior to visualization of the larynx. The policy level for the following recommendation about laryngoscopy at any time was an option: (1) Clinicians may perform diagnostic laryngoscopy at any time in a patient with dysphonia.

Disclaimer

This clinical practice guideline is not intended as an exhaustive source of guidance for managing dysphonia (hoarseness). Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgment or establish a protocol for all individuals with this condition, and it may not provide the only appropriate approach to diagnosing and managing this problem. Differences from Prior Guideline (1) Incorporation of new evidence profiles to include the role of patient preferences, confidence in the evidence, differences of opinion, quality improvement opportunities, and any exclusion to which the action statement does not apply (2) Inclusion of 3 new guidelines, 16 new systematic reviews, and 4 new randomized controlled trials (3) Inclusion of a consumer advocate on the guideline update group (4) Changes to 9 KASs from the original guideline (5) New KAS 3 (escalation of care) and KAS 13 (outcomes) (6) Addition of an algorithm outlining KASs for patients with dysphonia

Selective recurrent laryngeal nerve stimulation using a penetrating electrode array in the feline model

OBJECTIVES/HYPOTHESIS

Laryngeal muscles (LMs) are controlled by the recurrent laryngeal nerve (RLN), injury of which can result in vocal fold (VF) paralysis (VFP). We aimed to introduce a bioelectric approach to selective stimulation of LMs and graded muscle contraction responses.

STUDY DESIGN

Acute experiments in cats.

METHODS

The study included six anesthetized cats. In four cats, a multichannel penetrating microelectrode array (MEA) was placed into an uninjured RLN. For RLN injury experiments, one cat received a standardized hemostat-crush injury, and one cat received a transection-reapproximation injury 4 months prior to testing. In each experiment, three LMs (thyroarytenoid, posterior cricoarytenoid, and cricothyroid muscles) were monitored with an electromyographic (EMG) nerve integrity monitoring system. Electrical current pulses were delivered to each stimulating channel individually. Elicited EMG voltage outputs were recorded for each muscle. Direct videolaryngoscopy was performed for visualization of VF movement.

RESULTS

Stimulation through individual channels led to selective activation of restricted nerve populations, resulting in selective contraction of individual LMs. Increasing current levels resulted in rising EMG voltage responses. Typically, activation of individual muscles was successfully achieved via single placement of the MEA by selection of appropriate stimulation channels. VF abduction was predominantly observed on videolaryngoscopy. Nerve histology confirmed injury in cases of RLN crush and transection experiments.

CONCLUSIONS

We demonstrated the ability of a penetrating MEA to selectively stimulate restricted fiber populations within the feline RLN and selectively elicit contractions of discrete LMs in both acute and injury-model experiments, suggesting a potential role for intraneural MEA implantation in VFP management.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:1606-1614, 2018.

Time course of recovery of idiopathic vocal fold paralysis

OBJECTIVES/HYPOTHESIS

To clarify the time course of recovery in patients with idiopathic vocal fold paralysis.

STUDY DESIGN

Retrospective chart review.

METHODS

Medical records for all patients with idiopathic vocal fold paralysis over a 10-year period were reviewed to obtain demographic and clinical information, including onset of disease and recovery of vocal function. Stroboscopic exams of patients who recovered voice were reviewed blindly to assess return of vocal fold motion.

RESULTS

Thirty-eight of 55 patients (69%) recovered vocal function. Time course of recovery could be assessed in 34 patients who did not undergo injection augmentation. The mean time to recovery was 152.8 ± 109.3 days (left, 179.8 ± 111.3 days; right, 105.3 ± 93.7 days; P = .088). Two-thirds of patients recovered within 6 months. Probability of recovery declined over time. Five of 22 patients who recovered voice had return of vocal fold motion; 17 did not. The mean time to recovery did not differ between these groups (return of motion, 127.4 ± 132.3 days; no return of motion, 160.1 ± 105.1 days; P = .290).

CONCLUSIONS

Sixty-nine percent of patients with idiopathic vocal fold paralysis recovered vocal function, two-thirds doing so within 6 months of onset. Age, gender, laterality, use of injection augmentation did not influence recovery rate. Declining probability of recovery over time leads us to consider framework surgery after 6 months in patients with idiopathic paralysis.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:148-152, 2018.

Medialization Laryngoplasty After Injection Augmentation

OBJECTIVES

This study aims to assess the effect of vocal fold injection augmentation (IA) on subsequent medialization laryngoplasty (ML).

STUDY DESIGN

A retrospective cohort study with follow-up telephone survey was carried out.

METHODS

Clinical records of patients with unilateral vocal fold paralysis or paresis (VFP) who underwent ML between April 2006 and March 2015 were reviewed. Patients who underwent IA before ML were compared with patients who did not, with respect to demographic information, symptoms, Voice Handicap Index-10 (VHI-10), etiology of VFP, and revision rate. Among patients undergoing IA, the effects of injection material and of interval from IA to ML on revision rate were assessed. Follow-up telephone surveys were conducted to evaluate long-term outcomes using VHI-10 and a condition-specific questionnaire.

RESULTS

One hundred thirty-five patients (70 male:65 female) with vocal fold paralysis (125) or paresis (10) underwent ML (96 left:39 right). Sixty-six (48.9%) patients underwent concurrent arytenoid adduction. Fourteen (10.4%) patients required revision. Fifty-six (41.5%) patients had prior IA; five (8.9%) patients underwent revision. Seventy-nine (58.5%) patients did not have IA; nine (11.4%) patients required revision (P = 0.78). Neither augmentation material nor length of interval between last IA and ML affected the revision rate (P = 1.00; P ≥ 0.11 for all tested intervals, respectively). No difference in follow-up VHI-10 score was found between patients who had IA before ML and patients who had not (P = 0.73).

CONCLUSIONS

IA does not appear to affect the revision rate or long-term outcome of subsequent ML.

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

OBJECTIVES/HYPOTHESIS

Patients with unilateral vocal fold paralysis (UVFP) are commonly told to wait 12 months for spontaneous recovery. This study aims to 1) determine the time to vocal recovery in UVFP, 2) use that data to develop a neurophysiologically plausible model for recovery, and 3) use the model to generate meaningful predictions for patient counseling.

STUDY DESIGN

Case series with de novo mathematical modeling.

METHODS

Patients with UVFP who could pinpoint a discrete onset of vocal improvement were identified. The time-to-recovery data were modeled by assuming an "early" recovery group with neuropraxia and a "late" recovery group with more severe nerve injury. For the late group, a two-stage model was developed to explain the time to recovery: regenerating axons must cross the site of injury in stage 1 (probabilistic), followed by unimpeded regrowth to the larynx in stage 2 (deterministic).

RESULTS

Of 727 cases of UVFP over a 7-year period, 44 reported spontaneous recovery with a discrete onset of vocal improvement. A hybrid distribution incorporating the two stages (exponentially modified Gaussian) accurately modeled the time-to-recovery data (R² = 0.918). The model predicts 86% of patients with recoverable UVFP will recover within 6 months, with 96% recovering within 9 months. Earlier vocal recovery is associated with recovery of vocal fold motion and younger age.

CONCLUSIONS

Waiting 12 months for spontaneous recovery is probably too conservative. Repair across the site of injury, and not regrowth to larynx, is likely the rate-determining step in reinnervation, consistent with other works on peripheral nerve regeneration.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2585-2590, 2017.

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.

Unilateral Vocal Fold Paralysis: A Systematic Review of Speech-Language Pathology Management

OBJECTIVES

Dysphonia due to unilateral vocal fold paralysis (UVFP) can be characterized by hoarseness and weakness, resulting in a significant impact on patients' activity and participation. Voice therapy provided by a speech-language pathologist is designed to maximize vocal function and improve quality of life. The purpose of this paper is to systematically review literature surrounding the effectiveness of speech-language pathology intervention for the management of UVFP in adults.

STUDY DESIGN

This is a systematic review.

METHODS

Electronic databases were searched using a range of key terms including dysphonia, vocal fold paralysis, and speech-language pathology. Eligible articles were extracted and reviewed by the authors for risk of bias, methodology, treatment efficacy, and clinical outcomes.

RESULTS

Of the 3311 articles identified, 12 met the inclusion criteria: seven case series and five comparative studies. All 12 studies subjectively reported positive effects following the implementation of voice therapy for UVFP; however, the heterogeneity of participant characteristics, voice therapy, and voice outcome resulted in a low level of evidence.

CONCLUSIONS

There is presently a lack of methodological rigor and clinical efficacy in the speech-language pathology management of dysphonia arising from UVFP in adults. Reasons for this reduced efficacy can be attributed to the following: (1) no standardized speech-language pathology intervention; (2) no consistency of assessment battery; (3) the variable etiology and clinical presentation of UVFP; and (4) inconsistent timing, frequency, and intensity of treatment. Further research is required to develop the evidence for the management of UVFP incorporating controlled treatment protocols and more rigorous clinical methodology.