Laryngeal Electromyography for Prognosis of Vocal Fold Paralysis

Application of Ultrasound-Guided Cervical Plexus Block in Type I Thyroid Cartilage Laryngoplasty and Vocal Cord Medialization Surgery

BACKGROUND

Under the background that cervical plexus block (CPB) is often adopted for type I thyroid cartilage laryngoplasty (TCL) and vocal cord medialization (VCM), the present study sought to investigate whether ultrasound-guided CPB (USCPB) could improve the efficiency of type I TCL and VCM.

METHODS

Patients with TCL were enrolled and subjected to deep and superficial USCPBs. Intravenous dexmedetomidine pumping was used to assist the painless sedation and ensure the patients to be awake for phonation during surgery. Blood pressure, electrocardiogram, heart rate (HR), and blood oxygen saturation (SpO2) of patients were recorded. The complications, like local anesthetic toxicity and total spinal anesthesia, were monitored.

RESULTS

All patients underwent CPB without infiltration anesthesia and complication. The use of Sufentanil at the dose of 5-10 μg was reported in 2 of 15 patients. No Horner syndrome was discovered in patients after anesthesia, and total intravenous anesthesia with intravenous pumping of dexmedetomidine was effective. During surgery, HR, diastolic blood pressure and mean blood pressure were barely changed, but systolic blood pressure was decreased.

CONCLUSION

Ultrasound-guided CPB with the intravenous dexmedetomidine pumping is a safe anesthesia method for patients during TCL.

Prospective Quantitative Laryngeal Electromyography Changes in Patients With Iatrogenic Unilateral Vocal Fold Paralysis

OBJECTIVE

To track quantitative laryngeal electromyography (LEMG) and voice outcome survey (VOS) changes over 12 months postiatrogenic unilateral vocal fold paralysis (UVFP). To explore the factors influencing these changes.

STUDY DESIGN

Historical cohort study.

SETTING

Tertiary medical center.

METHODS

Patients who developed UVFP after surgery underwent a series of assessments, including quantitative LEMG, videolaryngostroboscopy, voice acoustic analysis, and completion of the VOS at diagnosis and at the 12-month follow-up. The subsequent data from these assessments were then compared for analysis. Bivariate analysis examined predictors of changes in VOS and LEMG data respectively, with significant factors further included in a multivariate regression model.

RESULTS

The study enrolled 99 patients. LEMG data were prospectively collected within 3.9 months (±SD: 0.2) postsurgery, followed by an average 13.2-month (±SD: 0.2) follow-up. A worse initial turn ratio of thyroarytenoid-lateral cricoarytenoid muscle correlated with more significant subsequent improvement in LEMG findings, reflecting a similar trend observed in the change of VOS scores.

CONCLUSION

This study contributes valuable insights into the temporal change of quantitative LEMG and VOS in patients with iatrogenic UVFP. It suggests that poor initial LEMG and VOS results do not necessarily determine a worse prognosis in terms of electrical activity.

Clinical Effects of Voice Therapy on Vocal Outcomes in Unilateral Vocal Fold Paralysis: Proof-of-Concept Study for Two SOVT-Based Treatment Protocols

BACKGROUND

Studies on treatment efficacy in unilateral vocal fold paralysis (UVFP) often lack a predetermined treatment protocol, and little is known about the effects of specific vocal techniques on vocal outcomes and quality of life in UVFP patients. The purpose of this preliminary proof-of-concept study is to investigate the effects and feasibility of two intensive treatment protocols based on water-resistance therapy (WRT) and vocal function exercises (VFE).

METHODS

Ten participants with acute or chronic UVFP/paresis were recruited in the study and randomly assigned to the WRT or VFE group. Three of these participants presented with aphonia and could not complete the program as prescribed. The remaining participants completed an intensive therapy program with the assigned vocal technique. Before, during, and after the program, a multidimensional voice assessment was performed. Maximum phonation time, acoustic, perceptual, and patient-reported outcome measures (PROMs) were obtained.

RESULTS

WRT and VFE had positive clinical effects on instrumental and auditory-perceptual voice quality, glottal closure, and PROMs, but interindividual variability was high. Studies with larger sample sizes are necessary to confirm or refute these findings.

CONCLUSION

The WRT- and VFE-based therapy programs are both feasible and seem to elicit positive clinical changes in UVFP patients. Suggestions on how to improve the programs are provided, as well as considerations for implementation in clinical practice. Follow-up research is needed to examine the efficacy of both programs on group level.

Clinical Experiences of Speech-Language Pathologists in the Rehabilitation of Unilateral Vocal Fold Paralysis

PURPOSE

Unilateral vocal fold paralysis (UVFP) is a neurological voice disorder that is often first treated by a speech-language pathologist (SLP). In literature, little consensus is found regarding voice therapy onset, duration, frequency, and content. The aim of the current study is to investigate the clinical practice of SLPs for treatment of UVFP regarding diagnostics and treatment characteristics. Additionally, the study examined the personal experiences of SLPs regarding UVFP care.

METHOD

An online survey was completed by 37 respondents, all SLPs with experience in treating UVFP. Demographic characteristics, experiences with voice assessments and treatment modalities were examined. Lastly, experiences and opinions of SLPs on evidence-based practice and their own clinical practice were surveyed.

RESULTS

Almost all respondents used a multidimensional voice assessment with findings from laryngovideostroboscopy to assess UVFP. Laryngeal electromyography is not yet integrated in regular clinical practices. The most commonly used vocal techniques were resonant voice exercises, laryngeal manipulation, semioccluded vocal tract exercises (SOVTEs), vocal hygiene, and Vocal Function Exercises, with SOVTEs most often considered effective. A total of 75% of the respondents feel confident treating UVFP, and 87.6% believe it is important to stay updated on evidence-based practice. Variation in therapy timing and dosage was observed, and 48.4% of SLPs usually started early voice therapy within 4 weeks after UVFP onset.

CONCLUSION

Flemish SLPs generally feel confident treating UVFP patients and show interest in improving evidence-based practice. Initiatives to train clinicians further in UVFP care and encouraging SLPs to provide practice-based evidence will enhance the knowledge base for evidence-based practice in UFVP.

Laryngeal electromyography, a useful tool in difficult cases of pediatric laryngeal mobility disorders

INTRODUCTION

Pediatric laryngeal mobility disorders constitute a challenge in terms of diagnosis and treatment, especially in small children and those complex patients with prior history of prolonged intubation or surgery. Laryngeal electromyography (L-EMG) may help to distinguish vocal fold paralysis from fixation.

MATERIAL AND METHODS

Ten children with laryngeal mobility disorders (including bilateral vocal fold immobility (BVFI) or unilateral vocal fold immobility (UVFI) with contralateral hypomobility) underwent suspension laryngoscopy and L-EMG between July 2019 and March 2021. The EMG data were acquired simultaneously in both thyroarytenoid muscles. Anesthesia was lightened until volitional activity appeared like cough, cry or spontaneous Valsalva maneuver.

RESULTS

We found secondary airway lesions in 2 patients and 3 vocal fold fixation. L-EMG recordings were pathologic in 4 patients (3 moderate and 1 severe nerve lesion). No recurrent laryngeal nerve injury was found in congenital BVFI cases. The data from both suspension laryngoscopy and L-EMG recordings influenced clinical decision-making.

CONCLUSIONS

L-EMG adds value to suspension laryngoscopy in the management of pediatric patients with laryngeal mobility disorders. Selected cases such as patients with iatrogenic BVFI, UVFI with associated contralateral hypomobility or patients with combined pathologies may obtain the greatest benefit.

Laryngeal Electromyography in the Therapeutic Process of Patients with Vocal Fold Immobility or Dysmobility

(1) Background: Laryngeal electromyography (LEMG) plays a key role in classifying the severity of nerve damage and determining the prognosis of the nerve recovery. LEMG is primarily a qualitative study, without a standardized approach to interpretation. The development of qualitative and quantitative analysis would situate LEMG in the gold standard of modern neurolaryngologic diagnostics. The aim of this study was to quantitatively evaluate laryngeal electromyography recorded in patients with vocal fold immobility or dysmobility. (2) Methods: The electromyographic material comprised 84 thyroarytenoid muscles recordings of 42 patients. (3) Results: In our study, we observed significant differences between EMG characteristics of healthy and paralyzed VF. Our study showed that recording laryngeal muscle activity during successive phases of breathing provides additional valuable information. We noticed that the frequency and amplitude of motor unit potentials correlates with the return of vocal fold functionality. (4) Conclusions: Laryngeal EMG guides the clinician on the best course of treatment for the patient. It is therefore important to develop an effective methodology and consensus on the quantitative interpretation of the record. Amplitude and frequency parameters are valuable in predicting neural recovery and in the return of vocal fold mobility.

Quantitative laryngeal electromyography (LEMG) in unilateral vocal fold paralysis: Developing normative values using the opposite normal mobile vocal fold

OBJECTIVE

Laryngeal electromyography (LEMG) is used to confirm neuropathy; traditionally, it is evaluated qualitatively. This study aimed to develop normative values for the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex by determining the mean turns (MT) and mean amplitudes (MA) using the opposite normal mobile vocal fold in unilateral vocal fold paralysis (VFP). This study also compared the MT and MA of the paralyzed vocal fold with that of the normal side and analyzed their correlations.

METHODS

This is a cross-sectional study in which 77 patients (18 males, 59 females, mean age of 48) with unilateral VFP with an opposite normal mobile vocal fold underwent LEMG with a standardized protocol. Koufman gradings and MT and MA were used for the qualitative and quantitative evaluations. Mann-Whitney U test was performed to compare the median of the turns and amplitudes between the opposite normal mobile vocal fold and the paralyzed side. A linear-scale graphical "cloud" of the normal TA-LCA muscle complex was generated using logarithmic regression analysis. The qualitative and quantitative parameters were analyzed using multiple analysis of variance and Kruskall-Wallis test. Post-hoc analysis was performed to further determine the differences of the significance between both parameters. The correlation between the qualitative and quantitative parameters was analyzed using Spearman correlation.

RESULTS

The MT and MA were significantly higher for the normal TA-LCA muscle complex than the paralyzed side (582 vs. 336; 412 vs. 296, respectively) and the median of the turns and amplitudes were significantly lower in the paralyzed side with p-values <0.001. A significant difference was observed between the Koufman grading and the combination of MT and MA [F (8,144) = 73.254] and between the Koufman grading and MT and MA individually [H (4, 72) = 18.3 and H (4, 72) =33.4], in which both had p-values <0.001. A moderate negative linear relationship was seen between the Koufman grading and MT and MA. On further analysis, it was revealed that only certain pairs of Koufman grading were statistical significant.

CONCLUSIONS

This study was the first to present the quantitative normative values and "cloud" of the TA-LCA muscle complex using the opposite normal mobile vocal fold in patients with unilateral VFP in which it is comparable to healthy controls. We concluded that quantitative LEMG supports the qualitative Koufman grading method however it cannot be used independently to determine the severity of neuropathy.

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.

Successful Use of High-Flow Nasal Cannula for Concurrent Vocal Cord Electromyography and Tubeless Microlaryngeal Surgery in a Spontaneously Breathing Adult Patient: A Case Report

Ventilation during microlaryngoscopy previously included jet ventilation, microlaryngeal endotracheal tubes, and extended apnea. Historically, apneic oxygenation provided a tubeless field but limited operative time. Increased utilization of high-flow nasal cannula in intensive care units and operating rooms has created new opportunities to expand tubeless microlaryngoscopy. Although few studies have described high-flow nasal cannula for microlaryngoscopy, there remains much to be explored. In this case report, we describe the unique setting of utilizing high-flow nasal cannula in a spontaneously breathing patient to create an optimal tubeless surgical field for both microlaryngoscopy and vocal cord electromyography.

[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.

The surgical treatment of unilateral vocal cord paralysis (UVCP): qualitative review analysis and meta-analysis study

PURPOSE

The objectives of this meta-analysis were to summarize the key surgical procedures for UVCP and to evaluate which of these is associated with better results in terms of vocal improvement.

METHODS

A systematic review of the literature was conducted in search of articles focused on the comparison of voice outcome between different techniques for the UVCP treatment. Then, a quantitative analysis was carried out for papers published from 2013 onwards, reporting only adult patients with unilateral paralysis for each study, and each surgical technique was evaluated for its capability of achieving good functional outcomes in terms of GRBAS-I scale and maximum phonation time in seconds (MPT).

RESULTS

The search identified 1853 publications. A total of 159 articles were stratified and included according to our selection criteria. 21 out of 159 articles were selected for quantitative synthesis. For trans-oral techniques: the mean GRBAS-I scale were 2.33 before injection and 0.41 after injection. The mean MPT before injection were 4.78 and 12.50 after injection. For open techniques the mean GRBAS-I scale were 2.43 before surgery and 0.68 after surgery. For open technique, the mean MPT were 3.50 before surgery and 12.40 after surgery.

CONCLUSIONS

The two types of techniques lead to an improvement in terms of vocal outcomes emphasizing that from the examined literature an indication emerges to perform an early injection because this could reduce the possible need for a more invasive intervention of permanent medialization in the future.

Perspectives on voice treatment for unilateral vocal fold paralysis

PURPOSE OF REVIEW

Unilateral vocal fold paralysis (UVFP) is a common cause of neurogenic dysphonia resulting in glottal insufficiency. To restore glottal sufficiency and reduce the presenting dysphonia, treatment involving either surgical intervention, voice therapy or a combination of the two is typically provided. Currently, there is no consensus for the most effective voice treatment for UVFP. This results in an inability to compare current studies, and a lack of treatment effectiveness for the management of UVFP. This study aims to review the most recent literature for the management of dysphonia due to UVFP to establish the current evidence base for voice treatment options.

RECENT FINDINGS

There was found to be a lack of consistency in the rationale, selection and timing of the surgical intervention and/or voice therapy being provided for patients with UVFP.

SUMMARY

Further consensus is required for the rationale and selection of voice treatment prescriptions for the management of UVFP in order to improve treatment effectiveness and voice outcomes in patients with UVFP.

Vocal fold paresis: Medical specialists' opinions on standard diagnostics and laryngeal findings

PURPOSE

There is still no clear consensus on the diagnostic value of specific laryngeal findings in patients with suspected vocal fold paresis (VFP). The aim of the study was to establish expert opinion on criteria for the diagnosis of VFP in Europe.

METHODS

A cross-sectional survey using the questionnaire introduced by Wu and Sulica for US American experts was addressed to laryngeal experts in Germany, Austria, and Switzerland and in a second survey wave to members of the European Laryngological Society.

RESULTS

100 respondents returned survey 1 (response rate 47.2%). 26% worked at a university department. 28% regularly used laryngeal electromyography (LEMG). A pathologic test results in LEMG was considered to have the strongest positive predictive value for VFP (79 ± 23%), followed by a decreased vocal fold abduction (70 ± 29%), decreased vocal fold adduction (61 ± 34%), and atrophy of the hemilarynx (61 ± 31%). The multivariate analysis showed the predictive value of LEMG was estimated lower by respondents from non-university hospital (β = - 16.33; confidence interval (CI) = - 25.63 to - 7.02; p = 0.001) and higher in hospitals with higher frequency of VFP patients per months (β = 1.57; CI = - 0.98 to 2.16; p < 0.0001). 30 ELS members returned survey 2 (response rate, 8.4%). Their answers were not significantly different to survey 1.

CONCLUSIONS

The laryngology experts in Europe rely on LEMG for diagnosis of VFP like the US American experts, but paradoxically only a minority uses LEMG frequently. Next to LEMG, motion abnormities were considered to have the best predictive value for the diagnosis of VFP.

[Vocal cord paralysis after endotracheal intubation: an uncommon complication of general anesthesia]

BACKGROUND

General anesthesia is a safe, frequent procedure in clinical practice. Although it is very unusual in procedures not related to head and or neck surgery, vocal cord paralysis is a serious and important complication. Incidence has been associated with patient age and comorbidities, as well as the position of the endotracheal tube and cuff. It can become a dangerous scenario because it predisposes aspiration.

OBJECTIVES

To present a case and analyze the risk factors associated with increased risk of vocal cord paralysis described in the literature.

CASE REPORT

53 year-old diabetic man, who developed hoarseness in the postoperative period after receiving general anesthesia for an elective abdominal laparoscopic surgery. Otolaryngological evaluation showed left vocal cord paralysis.

CONCLUSIONS

Vocal cord paralysis can be a serious complication of general anesthesia because of important voice dysfunction and risk of aspiration. The management is not yet fully established, so prevention and early diagnosis is essential.

Comparison of Clinical Characteristics Between Patients With Different Causes of Vocal Cord Immobility

Objective

To analyze the clinical characteristics between neurogenic and non-neurogenic cause of vocal cord immobility (VCI).

Methods

The researchers retrospectively reviewed clinical data of patients who underwent laryngeal electromyography (LEMG). LEMG was performed in the bilateral cricothyroid and thyroarytenoid muscles. A total of 137 patients were enrolled from 2011 to 2016, and they were assigned to either the neurogenic or non-neurogenic VCI group, according to the LEMG results. The clinical characteristics were compared between the two groups and a subgroup analysis was done in the neurogenic group.

Results

Among the 137 subjects, 94 patients had nerve injury. There were no differences between the neurogenic and non-neurogenic group in terms of demographic data, underlying disease except cancer, and premorbid events. In general characteristics, cancer was significantly higher in the neurogenic group than non-neurogenic group (p=0.001). In the clinical findings, the impaired high pitched 'e' sound and aspiration symptoms were significantly higher in neurogenic group (p=0.039 for impaired high pitched 'e' sound; p=0.021 for aspiration symptoms), and sore throat was more common in the non-neurogenic group (p=0.014). In the subgroup analysis of neurogenic group, hoarseness was more common in recurrent laryngeal neuropathy group than superior laryngeal neuropathy group (p=0.018).

Conclusion

In patients with suspected vocal cord palsy, impaired high pitched 'e' sound and aspiration symptoms were more common in group with neurogenic cause of VCI. Hoarseness was more frequent in subjects with recurrent laryngeal neuropathy. Thorough clinical evaluation and LEMG are important to differentiate underlying cause of VCI.

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.