Neuromuscular compensation mechanisms in vocal fold paralysis and paresis

Dewan, Karuna; Vahabzadeh‐Hagh, Andrew M.; Soofer, Donna; Chhetri, Dinesh K.

doi:10.1002/lary.26409

Cited by 17 publications

(29 citation statements)

References 20 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although neuromuscular compensation is well-recognized as a major cause of voice impairment after thyroid surgery [ 29 , 30 ], the current study yielded several insights: (1) if RLN injury is moderate, nerve recovery may occur immediately after surgery, and compensation may result in almost undetectable subjective and objective voice changes; (2) a severe RLN injury may impair the swallowing function. In addition to choking caused by VFM impairment, changes in neuromuscular function associated with swallowing after RLN injury requires further study.…”

Section: Discussionmentioning

confidence: 91%

How the Severity and Mechanism of Recurrent Laryngeal Nerve Dysfunction during Monitored Thyroidectomy Impact on Postoperative Voice

Huang

Chiang

et al. 2021

Cancers

View full text Add to dashboard Cite

Intraoperative neuromonitoring can qualify and quantify RLN function during thyroid surgery. This study investigated how the severity and mechanism of RLN dysfunction during monitored thyroid surgery affected postoperative voice. This retrospective study analyzed 1021 patients that received standardized monitored thyroidectomy. Patients had post-dissection RLN(R2) signal <50%, 50–90% and >90% decrease from pre-dissection RLN(R1) signal were classified into Group A-no/mild, B-moderate, and C-severe RLN dysfunction, respectively. Demographic characteristics, RLN injury mechanisms(mechanical/thermal) and voice analysis parameters were recorded. More patients in the group with higher severity of RLN dysfunction had malignant pathology results (A/B/C = 35%/48%/55%, p = 0.017), received neck dissection (A/B/C = 17%/31%/55%, p < 0.001), had thermal injury (p = 0.006), and had asymmetric vocal fold motion in long-term postoperative periods (A/B/C = 0%/8%/62%, p < 0.001). In postoperative periods, Group C patients had significantly worse voice outcomes in several voice parameters in comparison to Group A/B. Thermal injury was associated with larger voice impairments compared to mechanical injury. This report is the first to discuss the severity and mechanism of RLN dysfunction and postoperative voice in patients who received monitored thyroidectomy. To optimize voice and swallowing outcomes after thyroidectomy, avoiding thermal injury is mandatory, and mechanical injury must be identified early to avoid a more severe dysfunction.

show abstract

Section: Discussionmentioning

confidence: 91%

How the Severity and Mechanism of Recurrent Laryngeal Nerve Dysfunction during Monitored Thyroidectomy Impact on Postoperative Voice

Huang

Chiang

et al. 2021

Cancers

View full text Add to dashboard Cite

show abstract

“…Accuracy of stimulation was also visually confirmed by reviewing high-speed video recordings for appropriate vocal fold movement, as described previously. 16 Since speakers with vocal fold paresis activate other laryngeal muscles to compensate for weakened ones, 17 we modeled various combinations of neuromuscular compensation for each set of graded RLN stimulation. In one canine (experiment 1), the right RLN and SLN were stimulated at three constant levels (80%, 90%, and 100% of maximum activation), while the left SLN was stimulated at three constant levels (0%, 50%, and 100%).…”

Section: Neuromuscular Conditions Testedmentioning

confidence: 99%

Perceptual Evaluation of Vocal Fold Vibratory Asymmetry

et al. 2021

Self Cite

View full text Add to dashboard Cite

Objectives: Laryngeal vibratory asymmetry occurring with paresis may result in a perceptually normal or abnormal voice. The present study aims to determine the relationships between the degree of vibratory asymmetry, acoustic measures, and perception of sound stimuli.Study Design: Animal Model of Voice Production, Perceptual Analysis of Voice. Methods: In an in vivo canine model of phonation, symmetric and asymmetric laryngeal vibration were obtained via graded unilateral recurrent laryngeal nerve (RLN) stimulation simulating near paralysis to full activation. Phonation was performed at various contralateral RLN and bilateral superior laryngeal nerve stimulation levels. Naïve listeners rated the perceptual quality of 182 unique phonatory samples using a visual sort-and-rate task. Cepstral peak prominence (CPP) was calculated for each phonatory condition. The relationships among vibratory symmetry, CPP, and perceptual ratings were evaluated.Results: A significant relationship emerged between RLN stimulation and perceptual rating, such that sound samples from low RLN levels were preferred to those from high RLN levels. When symmetric vibration was achieved at mid-RLN stimulation, listeners preferred samples from symmetric vibration over those from asymmetric vibration. However, when symmetry was achieved at high RLN levels, a strained voice quality resulted that listeners dispreferred over asymmetric conditions at lower RLN levels. CPP did not have a linear relationship with perceptual ratings.Conclusions: Laryngeal vibratory asymmetry produces variable perceptual differences in phonatory sound quality. Though CPP has been correlated with dysphonia in previous research, its complex relationship with quality limits its usefulness as clinical marker of voice quality perception.

show abstract

“…Left UVFP was modeled as previously described. 10 Unilateral RLN paralysis. Thus, for each UVFP type, 320 unique muscle neuromuscular activation states were studied per animal (64 conditions/ suture × five sutures).…”

Section: Neuromuscular Conditions Testedmentioning

confidence: 99%

“…The color-coded format allows visual interpretation of data trends for a large number of related laryngeal activation conditions, as previously reported. [10][11][12] For consistency and ease of interpretation, comparative suture-position MAP data are presented in figures for RLN paralysis. Data trends were consistent across both RLN and vagal paralysis models, as elaborated in the results section.…”

Section: Data Presentation and Interpretationmentioning

confidence: 99%

“…8,9 The acoustic and aerodynamic effects of suture direction have been studied in cadaveric larynges but not in an in vivo model, where comprehensive assessment of muscular compensation is possible. 8,9 The normal vocal fold adductors and cricothyroid (CT) muscles can compensate in UVFP, 10 but their effectiveness at various AA suture positions is unknown. This study aims to evaluate how AA suture position on the thyroid ala affects voice production and quality using an in vivo model of UVFP.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Arytenoid Adduction Suture Position on Voice Production and Quality

2020

Self Cite

View full text Add to dashboard Cite

Objectives/Hypothesis: Arytenoid adduction (AA) is performed to treat unilateral vocal fold paralysis with a large posterior glottal gap. However, the voice effects of AA suture position remain unclear. This study aimed to evaluate voice production and quality as a function of AA suture position on the thyroid ala in a neuromuscularly intact in vivo larynx. Study Design: Animal model. Methods: Unilateral recurrent laryngeal nerve and vagal paralysis were modeled in two canines. AA suture position was varied across five equidistant positions on the anterior inferior thyroid ala, from a paramedian position anteriorly to the oblique line posteriorly. Phonation was performed over 8 × 8 graded level combinations of recurrent and superior laryngeal nerve stimulation per suture position. The primary outcome was percent successful phonatory conditions. Secondary outcomes included fundamental frequency (F0), phonation onset pressure (PTP), cepstral peak prominence (CPP), and laryngeal posture. Results: Anterior suture positions resulted in a greater percentage of successful phonatory conditions compared to posterior sutures. Suture position 2, located at the anterior inferior thyroid ala, resulted in the highest percentage of successful phonatory conditions, lowest PTP, and lower muscle activation levels to achieve higher CPP. Posterior sutures resulted in wider glottal gap and more effective F0 and vocal fold strain increase with cricothyroid muscle contraction, but with fewer successful phonatory conditions and higher PTP. Trends were consistent across both paralysis types. Conclusions: AA suture placed in the anterior inferior thyroid ala resulted in the best acoustic, aerodynamic, and voice quality outcomes. This study provides scientific evidence for maintaining current clinical practice.

show abstract

Neuromuscular compensation mechanisms in vocal fold paralysis and paresis

Cited by 17 publications

References 20 publications

How the Severity and Mechanism of Recurrent Laryngeal Nerve Dysfunction during Monitored Thyroidectomy Impact on Postoperative Voice

How the Severity and Mechanism of Recurrent Laryngeal Nerve Dysfunction during Monitored Thyroidectomy Impact on Postoperative Voice

Perceptual Evaluation of Vocal Fold Vibratory Asymmetry

Effects of Arytenoid Adduction Suture Position on Voice Production and Quality

Contact Info

Product

Resources

About