Demographics, Management, and Outcomes Associated With Idiopathic Vocal Fold Paralysis: A Systematic Review

OBJECTIVE

Idiopathic vocal fold paralysis (IVFP) is an enigmatic disease that results in voice, breathing, and swallowing impairments. This systematic review provides a comprehensive discussion of the demographics, management, and outcomes of IVFP.

DATA SOURCES

PubMed and Embase databases.

REVIEW METHODS

The PubMed and Embase databases were queried with the keywords "((vocal fold paralysis) OR (vocal cord paralysis)) AND (idiopathic)." Articles were selected if published between 1990 and 2023 and reported data related to patients aged ≥18 years with IVFP. Case studies and reviews were excluded. Participant demographics, presenting symptoms, and spontaneous recovery data were extracted.

RESULTS

The database query identified 509 relevant abstracts, of which 29 studies met the inclusion criteria. A total of 1238 patients with IVFP were identified with a mean age of 55.8 years (range: 40.0-70.2). Patients experienced unilateral IVFP in 97.0% of cases with 67.5% affecting the left side. The most common presenting symptoms were dysphonia (n = 78), dysphagia (n = 41), sore throat (n = 16), and cough (n = 13). Five studies reported time to presentation with a mean of 114.5 days (range: 28-341). Eleven studies found a mean spontaneous recovery rate of 31.6% (range: 11.8%-87.5%) over a mean of 139.4 days (range: 68-180). Only 4.3% of patients were documented to have a viral upper respiratory infection (URI) before developing IVFP. No specific treatments were linked to spontaneous recovery.

CONCLUSION

There is a paucity of research describing the presentation and outcomes of patients with IVFP. Viral URI may be a potential contributing factor to IVFP development; however, more research is necessary.

A Single Centre's Experience of Non-Iatrogenic Neonatal Bilateral Vocal Cord Paralysis

OBJECTIVES

To review our institutional experience with bilateral vocal cord paralysis (BVCP) of non-iatrogenic origin in neonates, with a particular focus on diagnostic methods and the changing role of tracheostomy and non-invasive ventilation.

STUDY DESIGN

Retrospective, single-centre study at a tertiary paediatric hospital.

METHODS

Our BVCP population was reviewed (2003-2020). We extracted demographics, diagnostic methods (endoscopy and imaging), methods of respiratory/ventilatory support, and functional outcomes.

RESULTS

60 neonates with BVCP were included. All underwent endoscopic assessment, revealing synchronous airway lesions in 20% of the cases. Brain MRIs were obtained in 55/60 patients and showed anomalies in 30% of the cases, particularly intracranial haemorrhages, with only one structural anomaly of the brain. Approximately two-thirds of the children required respiratory/ventilatory support, and 16/60 children received tracheostomies. We observed a progressive reduction in the use of tracheostomies over the study period, with in parallel a longer length of respiratory or ventilator support. 4/16 children remained tracheostomy dependent at last follow-up, all of them with associated comorbidities. The only significant feature associated with the need for tracheostomy was previous intubation. Overall, almost 40% of the children needed nutritional support at discharge. No deaths related to BVCP occurred.

CONCLUSION

We observed a significant decrease in the use of tracheostomies within the study period. The need for intubation and existence of comorbidities seems to be the most relevant outcome factors. Incomplete recovery and swallowing impairment are common, thus warranting long-term follow-up.

The properties of laryngeal electromyography in the non-paralyzed sides of patients with idiopathic vocal cord paralysis

OBJECTIVE

To evaluate the injuries of the recurrent laryngeal nerve (RLN), superior laryngeal nerve (SLN), and their innervated laryngeal muscles on the non-paralyzed sides in patients with idiopathic vocal cord paralysis (IVCP).

METHODS

Eighty-four cases of patients with IVCP were evaluated using stroboscopic laryngoscopy, voice analysis, and laryngeal electromyography(LEMG). Concurrently, twenty-eight cases involving healthy volunteers without vocal cord paralysis were enrolled and examined using LEMG during the same period. Subsequently, comparisons of LEMG results were conducted between the paralyzed and non-paralyzed sides, and among the non-paralyzed sides.Furthermore, a comparison was conducted between the LEMG results of the non-paralyzed sides in patients with IVCP and the corresponding ipsilateral sides in healthy volunteers.These comparisons were stratified based on the side of paralysis and the duration of the disease course (less than 3 months versus more than 3 months) for IVCP patients.

RESULTS

Initially, the amplitude of the RLN, the action potential durations (APDs) and amplitude of the thyroarytenoid muscle (TM), and the amplitude of the posterior cricoarytenoid muscle (PCM) on the paralyzed side were significantly lower than those on the non-paralyzed side. Conversely, the latency of the RLN on the paralyzed side was significantly longer compared to the non-paralyzed side (P < 0.05). However, there were no significant differences in the latency and amplitude of the SLN, nor in the APD and amplitude of the CM between the paralyzed and non-paralyzed sides (P > 0.05). Furthermore, no significant differences were observed in the LEMG results of the non-paralyzed sides in IVCP patients, irrespective of the paralyzed side or the duration of the disease course (P > 0.05), and no significant differences of the LEMG results were observed when comparing the non-paralyzed sides of patients with IVCP to the ipsilateral sides of healthy volunteers (P > 0.05). However, when the disease course is less than 3 months, the amplitudes of the SLN and CM in the non-paralyzed side (right side) of left-sided IVCP patients are significantly lower than those in the non-paralyzed side (left side) of right-sided IVCP patients (SLN, 6.23 ± 4.42 mv vs. 10.21 ± 7.56 mv, t=-2.296, P = 0.028; CM, 0.49 ± 0.17 mv vs. 0.60 ± 0.19 mv, t=-2.207, P = 0.032), of which the amplitude of the CM is significantly reduced compared to the right side of healthy controls (0.49 ± 0.17 mv vs. 0.61 ± 0.21 mv, t=-2.423, P = 0.019), indicating that the SLN and CM on the non-paralyzed side are vulnerable to damage. Moreover, in patients with right-sided IVCP persisting for more than 3 months, there was a significant reduction in the amplitudes of the SLN and RLN, as well as the TM and PCM on the non-paralyzed side (left side), compared to the corresponding ipsilateral sides in healthy volunteers (P < 0.05). This observation indicates that the LEMG results for the non-paralyzed side in IVCP patients are not entirely normal, particularly in cases of right-sided IVCP with a disease duration exceeding three months.

CONCLUSION

In patients with IVCP, it is imperative to conduct a simultaneous analysis of LEMG results from both the paralyzed and non-paralyzed sides after determining the affected side and the progression of the paralysis. This thorough examination is crucial for accurately evaluating the condition and prognosis of individuals with IVCP.

LEVEL OF EVIDENCE: 4

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.

Screening for Vocal Fold Movement Impairment in Children Undergoing Esophageal and Airway Surgery

INTRODUCTION

Children undergoing cervical and/or thoracic operations are at risk for recurrent laryngeal nerve injury, resulting in vocal fold movement impairment (VFMI). Screening for VFMI is often reserved for symptomatic patients.

OBJECTIVE

Identify the prevalence of VFMI in screened preoperative patients prior to an at-risk operation to evaluate the value of screening all patients at-risk for VFMI, regardless of symptoms.

METHODS

A single center, retrospective review of all patients undergoing a preoperative flexible nasolaryngoscopy between 2017 and 2021, examining the presence of VFMI and associated symptoms.

RESULTS

We evaluated 297 patients with a median (IQR) age of 18 (7.8, 56.3) months and a weight of 11.3 (7.8, 17.7) kilograms. Most had a history of esophageal atresia (EA, 60%), and a prior at-risk cervical or thoracic operation (73%). Overall, 72 (24%) patients presented with VFMI (51% left, 26% right, and 22% bilateral). Of patients with VFMI, 47% did not exhibit the classic symptoms (stridor, dysphonia, and aspiration) of VFMI. Dysphonia was the most prevalent classic VFMI symptom, yet only present in 18 (25%) patients. Patients presenting with a history of at-risk surgery (OR 2.3, 95%CI 1.1, 4.8, p = 0.03), presence of a tracheostomy (OR 3.1, 95%CI 1.0, 10.0, p = 0.04), or presence of a surgical feeding tube (OR 3.1, 95%CI 1.6, 6.2, p = 0.001) were more likely to present with VFMI.

CONCLUSION

Routine screening for VFMI should be considered in all at-risk patients, regardless of symptoms or prior operations, particularly in those with a history of an at-risk surgery, presence of tracheostomy, or a surgical feeding tube.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3564-3570, 2023.

Increased 18F-FDG Uptake in the Posterior Region of Contralateral Vocal Folds in Beagle Dogs With Unilateral Vocal Fold Immobility Disorders

OBJECTIVE

To explore the glycolytic metabolism of contralateral vocal fold compensation by examining the glycolytic metabolism of the posterior region of vocal folds in beagles with unilateral vocal fold immobility disorders and its correlation with acoustic parameters.

STUDY DESIGN

Prospective animal study.

SETTING

Department of Voice METHODS: Ten adult beagles were divided randomly into three groups: a unilateral cricoarytenoid joint dislocation (UCAJD) group (n = 4), a unilateral vocal fold paralysis (UVFP) group (n = 4), and a control group (n = 2). Positron emission tomography-computed tomography (PET/CT) scans of larynx and recordings of vocalizations were collected 4 months after the operations. The maximum standardized uptake values (SUVmax) of 18F-FDG within each posterior region of the vocal folds were obtained from PET/CT and voice recordings were analyzed for acoustic parameters F0, jitter, shimmer, and loudness using PRAAT.

RESULTS

In both UCAJD and UVFP groups, a significant increase of SUVmax was observed in the contralateral vocal fold relative to the impaired fold (P < 0.05). The SUVmax values of the contralateral vocal folds and the SUVmax values of the impaired vocal folds in the UCAJD, UVFP, and control groups were both found to be significantly different (P < 0.05). The SUVmax of the contralateral vocal fold may exhibit a potentially negative correlation with jitter and shimmer, with R2 values of 0.42 and 0.26 and P values of 0.03 and 0.11, respectively.

CONCLUSION

UCAJD and UVFP can cause enhanced glycolytic metabolism of the contralateral vocal fold relative to the impaired vocal fold. The SUVmax of the contralateral vocal fold may be positively correlated with acoustic quality.

Patterns of Recurrence of Phonotraumatic Vocal Fold Lesions Suggest Distinct Mechanisms of Injury

OBJECTIVES/HYPOTHESIS

To examine patterns of recurrence of benign phonotraumatic vocal fold lesions over time for insights into pathophysiology.

STUDY DESIGN

Case series with mathematical modeling.

METHODS

Medical records and stroboscopic exams of adults who underwent microlaryngoscopic resection of phonotraumatic vocal fold lesions over a 13-year period were reviewed for time to recurrence after surgery. Uniform and log-normal probability distributions were fitted to the time to recurrence curves for vocal fold polyps, midfold masses, and pseudocysts. Model fits were compared using the Akaike information criterion corrected, a standard measure of the goodness of fit. Stochastic simulations were used to verify that the mechanistic hypotheses were concordant with the selected probability distributions and empiric data.

RESULTS

Of 567 patients who underwent microlaryngoscopic resection, 65 had a recurrence (16 polyps, 14 midfold masses, and 35 pseudocysts). Midfold mass and pseudocyst recurrences were predominantly seen in younger women. Polyps were best fit by a uniform distribution rather than log-normal, whereas midfold masses and pseudocysts were better fit by log-normal rather than uniform. Stochastic simulations suggest that polyps recur sporadically according to a paroxysmal-developmental model, whereas midfold mass and pseudocyst recurrences follow a force-multiplication, damage-accumulation process.

CONCLUSIONS

Vocal fold polyps are acute lesions evenly distributed by age and gender that recur uniformly over time, suggesting they arise from sudden tissue reactions to phonotraumatic stress. Pseudocysts and midfold fibrous masses are chronic lesions predominantly found in young women that recur with log-normal distribution over time, suggesting gradual damage accumulation in larynges predisposed to enhanced phonotrauma.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.