Acoustic and perceptual evaluation of laryngeal reinnervation by ansa cervicalis transfer

Systematic review and meta-analysis of laryngeal reinnervation techniques in adults with unilateral and bilateral vocal fold palsies

OBJECTIVE

To evaluate the outcomes of reinnervation techniques for the treatment of adult unilateral vocal fold paralysis and bilateral vocal fold paralysis.

METHODS

A literature review was conducted in the Embase and Medline databases in English, with no limitations on the publication date. The outcome parameters of interest included visual, subjective perceptual, acoustic, aerodynamic analysis and electromyography. A meta-analysis with a random-effects model and inverse variance was calculated.

RESULTS

The systematic Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach resulted in 27 studies, totalling 803 patients (747 unilateral cases and 56 bilateral cases). Thyroid cancer and/or surgery had caused unilateral vocal fold paralysis in 74.8 per cent of cases and bilateral vocal fold paralysis in 69.6 per cent of cases. Statistically significant improvements in patients were observed for voice, deglutition and decannulation (bilateral vocal fold paralysis). Meta-analysis of 10 reinnervation techniques was calculated for the maximum phonation time of 184 patients.

CONCLUSION

Reinnervation was shown to improve voice, swallowing and decannulation, but studies lacked control groups, limiting generalisability. Larger studies with controls are needed.

Effect of Aging on Vocal Outcomes After Laryngeal Reinnervation Combined With Arytenoid Adduction

OBJECTIVE

To evaluate the impact of aging on vocal function following laryngeal reinnervation combined with arytenoid adduction (AA) in the treatment of paralytic dysphonia.

METHODS

Sixty-eight patients with unilateral vocal fold paralysis who underwent refined nerve-muscle pedicle flap (NMP) implantation and AA were classified into four groups according to age: under 50 years (-50), in their 50s, 60s, and 70 years and older (70+). These groups consisted of 15, 14, 22, and 17 patients, respectively. Their vocal function was followed periodically for 24 months after surgery.

RESULTS

Vocal function in all groups showed significant improvement after surgery. Significant improvements in vocal function were observed during a 24-month follow-up period: maximum phonation time in the -50 and 50 seconds groups; pitch range and voice handicap index-10 in the -50, 50s, and 60s groups; "Grade" in the -50, 50s, and 70+ groups; and "Breathiness" and voice-related quality of life in all groups. There were no significant differences in vocal function among the four groups, except for pitch range, at the 24-month postoperative assessment.

CONCLUSIONS

Although the younger groups tended to exhibit better vocal function compared to the older groups 24 months postoperatively, the refined NMP+AA proved effective in the treatment of breathy dysphonia resulting from unilateral vocal fold paralysis, not only in the younger population but also in the older population.

Selective ansa cervicalis nerve transfer to the marginal mandibular nerve for lower lip reanimation: An anatomical study in cadavers and a case report

BACKGROUND

Donor nerve options for lower lip reanimation are limited in patients undergoing oncological resection of the facial nerve. The ansa cervicalis nerve (ACN) is an advantageously situated donor with great potential but has not been examined in detail. In the current study, the anatomical technical feasibility of selective ACN to marginal mandibular nerve (MMN) transfer for restoration of lower lip tone and symmetry was explored. A clinical case is presented.

METHODS

Dissections were conducted in 21 hemifaces in non-embalmed human cadavers. The maximal harvestable length of ACN was measured and transfer to MMN was simulated. A 28-year-old male underwent ACN-MMN transfer after parotidectomy (carcinoma) and was evaluated 12 months post-operatively (modified Terzis' Lower Lip Grading Scale [25 observers] and photogrammetry).

RESULTS

The harvestable length of ACN was 100 ± 12 mm. A clinically significant anatomical variant ("short ansa") was present in 33% of cases (length: 37 ± 12 mm). Tensionless coaptation was possible in all cases only when using a modification of the surgical technique in "short ansa" cases (using an infrahyoid muscle nerve branch as an extension). The post-operative course of the clinical case was uneventful without complications, with improvement in tone, symmetry, and function at the lower lip at 12-month post-operative follow-up.

CONCLUSIONS

Selective ACN-MMN nerve transfer is anatomically feasible in facial paralysis following oncological ablative procedures. It allows direct nerve coaptation without significant donor site morbidity. The clinical case showed good outcomes 12 months post-operatively. A strategy when encountering the "short ansa" anatomical variant in clinical cases is proposed.

Investigating the cepstral acoustic characteristics of voice in healthy children

OBJECTIVES

This study aimed to determine the cepstral acoustic parameters that vary depending on age and gender in vocally healthy children, and to establish normative data for cepstral analysis.

BACKGROUND

Cepstral measurements are among the strongest predictors of auditory-perceptual evaluation of voice and differentiate between healthy and dysphonic voices. More spesificially, ceptral peak prominence is accepted to be as a strong acoustic predictor of breathiness and overall severity of dysphonia. Cepstral measures determine voice quality reliably not only in sustained vowel samples but also in running speech samples. Determining the parameters related to the acoustic profile of children with normal voices can lead us to a better understanding of the effect of changes in the larynx and vocal fold structure during growth and development. There is a limited number of norm studies examining the cepstral acoustic properties of pediatric voice. Determining norm-specific values and clinical guidelines of cepstral acoustics according to the age and gender in vocally healthy children are utmost important.

METHODS

A total of 160 vocally healthy children were divided into the following four age groups: Group-I included children within the age range of 4-7 years, Group-II included 7-11 years, Group-III 11-14 years, and Group-IV included children within the age range of 14-18 years. An equal number of male and female participants were assigned to each group. PENTAX Medical CSL Model 4500 was used for recording all tasks. For acoustic analysis, Multi-Dimensional Voice Program and Analysis of Dysphonia in Speech and Voice were used.

RESULTS

Cepstral Peak Prominence (CPP), Cepstral Peak Prominence Standard Deviation (CPP SD), and Low-To-High Spectral Ratio (L/H Ratio) increased with age. It is found that the CPP parameter of all-voiced sentences and nasal-weighted sentences increased with age in boys, while no significant pattern was observed in any sample for girls. For L/H ratio, it can be said that there is a general increase with age in all speech samples, except for the vowel-weighted and voiceless plosive sentence samples, evident especially in the group above the age of 15 years. This study concluded that the CPP SD parameter in the vowel-weighted sentences increased with age in boys. It was also noticed in this study that CPP F0 standard deviation (SD) intervals were narrower in vowel-weighted, easy onset, and voiceless plosive sentence samples than in all-voiced, hard glottal attack and nasal-weighted sentence samples.

CONCLUSION

This study established cepstral acoustic normative values for a wide age range of the pediatric population. It is thought that age and gender specific cepstral acoustic findings presented in this study contributed to the related literature. In addition, to our knowledge, this is the first study that provides a normative cepstral acoustic database of the CAPE-V/Turkish sentences in the pediatric population.

Role of reinnervation in the management of recurrent laryngeal nerve injury: current state and advances

PURPOSE OF REVIEW

To present the current state of knowledge concerning different laryngeal reinnervation procedures for unilateral and bilateral vocal palsy.

RECENT FINDINGS

Recent reports show positive outcomes on both unilateral and bilateral reinnervations. The phrenic nerve is the most commonly used donor for bilateral vocal palsy, but use of the superior laryngeal nerve has also been suggested.

SUMMARY

Reinnervation of the larynx is a complex undertaking that can be performed by ENT surgeons with skills in microsurgery. Advances in this this field represent a paradigm shift in laryngeal rehabilitation and a prerequisite for laryngeal transplantation. Advances in basic understanding of nerve regeneration and in particular the need to surgically manage competitive reinnervation make the results of laryngeal reinnervation more predictable.

Results of ansa to recurrent laryngeal nerve reinnervation

Objective

We sought to describe the results of ansa cervicalis to recurrent laryngeal nerve (ansa-RLN) reinnervation for unilateral vocal fold paralysis.

Study Design

A chart review was performed on patients undergoing ansa-RLN reinnervation for unilateral vocal cord paralysis at a tertiary care center. Patient perceptions of preoperative and postoperative voice quality was surveyed. Acoustic and visual parameters were assessed from videostroboscopy.

Results

From a total of 25 study patients, 15 patients underwent both preoperative and postoperativ video stroboscopies. In stroboscopies within 6 months, the average improvement in overall severity, roughness, and breathiness was 69, 79, and 100 percent, respectively. In stroboscopies after 6 months, the average improvement in overall severity, roughness, and breathiness was 63, 66, and 100 percent, respectively. Postoperatively, all patients had reinnervation of the vocal fold.

Conclusions

Voice outcomes were improved in patients with preoperative and postoperative stroboscopies.

Significance

Ansa-RLN reinnervation should be considered as a treatment for unilateral vocal fold paralysis.

Outcomes of Laryngeal Reinnervation for Unilateral Vocal Fold Paralysis in Children

Objective:

Outcomes of laryngeal reinnervation with ansa-cervicalis for unilateral vocal fold paralysis (UVFP) may be influenced by age of the patient and time interval between laryngeal nerve injury and reinnervation, suggesting less favorable outcomes in older patients and greater than 2-year time interval after injury. This study examines these issues in the pediatric population.

Method:

Review of prospectively collected data set of 35 children and adolescents (1-21 years) that underwent ansa-recurrent laryngeal nerve (RLN) laryngeal reinnervation for UVFP.

Results:

The time from RLN injury to reinnervation averaged 5.0 years (range, 0.8-15.2 years). No correlation was found between age at reinnervation ( r = 0.15) and patient- or parent-reported global percentage voice outcome or perceptual ratings. There was slight negative correlation in duration between RLN injury and reinnervation and voice outcomes ( r = −0.31). Postoperative voice self/surrogate global percentage rating average was 80.5% (range, 50%-100%), and perceptual rating GRBAS sum score average was 2.9 (range, 0-7).

Conclusion:

In pediatric ansa-RLN reinnervation for UVFP, no correlation between age at surgery and postoperative outcome was found. Denervation duration showed slight negative correlation, similar to what has been reported in adults, though voice improvement was seen in all patients.

Diagnosis and management with botulinum toxin in 11 cases of laryngeal synkinesis

Laryngeal synkinesis is a vocal fold movement disorder produced by a misdirected reinnervation after a recurrent laryngeal nerve injury. Its symptoms differ greatly between patients, requiring diverse therapeutical approaches. We aim to describe our experience in the diagnosis and treatment of different laryngeal synkinesis presentations. 11 patients diagnosed between 2011 and 2014 in a tertiary referral center with laryngeal synkinesis confirmed by laryngeal electromyography were included in our study. All medical records and laryngoscopic and electromyographic data were reviewed retrospectively. Four patients had previous unilateral vocal fold palsy and seven had a bilateral palsy with different degrees of clinical involvement. All of them showed paradoxical movements during inhalation in videofibrolaryngoscopic examination. Laryngeal electromyography confirmed the diagnosis of laryngeal synkinesis. Dyspnea was the main presentation symptom. Three patients with mild symptoms were not treated. Patients with unilateral vocal fold immobility were successfully treated with periodic botulinum toxin injections. Patients with bilateral immobility had a good initial response to botulinum toxin, although in some of them, a posterior cordectomy had to be finally performed. In conclusion, laryngeal synkinesis is a heterogeneous clinic entity that appears in patients with unilateral or bilateral vocal fold paralysis. Videofibrolaryngoscopy and laryngeal electromyography are essential to a correct diagnosis. Botulinum toxin injections are the main treatment for symptomatic cases, even if in bilateral palsy cases more aggressive treatments are often required.

Laryngeal adductor function in experimental models of recurrent laryngeal nerve injury

OBJECTIVES/HYPOTHESIS

Most patients with unilateral vocal fold paralysis experience some degree of spontaneous reinnervation, which depends upon the type and severity of recurrent laryngeal nerve (RLN) injury. After partial recovery, the paretic vocal fold may or may not adduct adequately to allow glottic closure, which in turn affects phonatory and swallowing outcomes. This process was studied in a series of canine laryngeal nerve injury models.

STUDY DESIGN

Animal (canine) experiments.

METHODS

Maximum stimulable laryngeal adductor pressure (LAP) was measured pretreatment (baseline) and at 6 months following experimental RLN injuries (total n = 59). The nine study groups were designed to simulate a range of severities of RLN injury.

RESULTS

The greatest LAP recovery, at 108% of original baseline, was seen in a 50% transection model; the least recovery was seen when the RLN underwent complete transection with repair, at 56% with precise alignment and 50% with alignment reversed. Intermediate models (partial RLN injuries) gave intermediate results. Crush models recovered 105% of LAP, whereas a half-transection, half-crush injury recovered 72%, and cautery injuries recovered 61%. Controls (complete transection without repair) had no measurable recovery.

CONCLUSIONS

The injured RLN has a strong tendency to recover. Restoration of adductor strength, as determined by the LAP, was predictably related to the severity of RLN injury. The model RLN injuries studied provide a range of expected outcomes that can be used for future experiments exploring interventions that may improve postinjury adductor function.

LEVEL OF EVIDENCE

NA.

The impact of nimodipine administration combined with nerve-muscle pedicle implantation on long-term denervated rat thyroarytenoid muscle

OBJECTIVES/HYPOTHESIS

To evaluate the impact of nimodipineon reinnervation of the long-term denervated rat thyroarytenoid (TA) muscle following nerve-muscle pedicle flap (NMP) implantation.

STUDY DESIGN

Quantitative histologic and physiologic assessments.

METHODS

Using 120 Wistar rats, we performed NMP implantation at different times after transection of the left recurrent laryngeal nerve (RLN). Sixty animals received nimodipine treatment (NIMO [+] group), and the remaining 60 animals received no nimodipine treatment (NIMO [-] group). As a control, an additional 28 animals were subjected only to transection of the left RLN (DNV group). Subgroups were assigned based on the period after RLN transection (0 [immediate], 8, 16, and 32 weeks). In the DNV group, we assessed histologically the muscle area, axons, neuromuscular junctions (NMJs), and myosin heavy chains (MyHC) type IIA and IIB in the TA muscle. In the NIMO (-) and NIMO (+) groups, histologic assessments and evoked electromyography were performed on the TA muscle at 10 weeks post-NMP implantation.

RESULTS

In 8-week interval subgroups, the muscle fiber area and the number of NMJs in the NIMO (+) group were significantly greater than in the NIMO (-) group (P < 0.05, each). In the 0-week and 32-week interval subgroups, the muscle fiber subtype changed significantly, from IIA to IIB (P < 0.01 and P < 0.05, respectively); and, at all time-points the muscle fiber area, number of NMJs, and action potentials in the TA muscle tended to be greater in the NIMO (+) group than in the NIMO (-) group.

CONCLUSIONS

Nimodipine expedited the effects of NMP implantation on reinnervation of the long-term denervated TA muscle. Laryngoscope, 2012.

Medialization versus reinnervation for unilateral vocal fold paralysis: a multicenter randomized clinical trial

PURPOSE

Vocal fold medialization laryngoplasty (ML) and laryngeal reinnervation (LR) as treatments for unilateral vocal fold paralysis (UVFP) were compared in a multicenter, prospective, randomized clinical trial.

METHODS

Previously untreated patients with UVFP were randomized to undergo either ML or LR. Voice results were compared pretreatment and at 6 and 12 months posttreatment using perceptual ratings by untrained listeners (RUL), blinded speech pathologist GRBAS scores, and voice-related quality of life (VRQOL) scores. Other secondary data included maximum phonation time (MPT), cepstral analysis, and electromyography (EMG) findings.

RESULTS

Twenty-four patients from nine sites completed the study, 12 in each group. There were no significant intergroup differences in pretreatment variables. At 12 months, both study groups showed significant improvement in RUL, total GRBAS (grade, roughness, breathiness, asthenia, and strain) scores, and VRQOL scores, but no significant differences were found between the two groups. However, patient age significantly affected the LR, but not the ML, group results. The age less than 52 LR subgroup had significantly (P < .05) better scores than the age more than 52 LR subgroup, and had better RUL and GRBAS scores than the age less than 52 ML subgroup. The age more than 52 ML subgroup results were significantly better than the age more than 52 LR subgroup. The secondary data generally followed the primary data, except that the MPTs for the ML patients were significantly longer than for the LR patients.

CONCLUSIONS

ML and LR are both effective surgical options for patients with UVFP. Laryngeal reinnervation should be considered in younger patients, whereas medialization laryngoplasty should be favored in older patients.

Laryngeal reinnervation using ansa cervicalis for thyroid surgery-related unilateral vocal fold paralysis: a long-term outcome analysis of 237 cases

Objective

To evaluate the long-term efficacy of delayed laryngeal reinnervation using the main branch of the ansa cervicalis in treatment of unilateral vocal fold paralysis (UVFP) caused by thyroid surgery.

Summary of Background Data

UVFP remains a serious complication of thyroid surgery. Up to now, a completely satisfactory surgical treatment of UVFP has been elusive.

Methods

From Jan. 1996 to Jan. 2008, a total of 237 UVFP patients who underwent ansa cervicalis main branch-to-recurrent laryngeal nerve (RLN) anastomosis were enrolled as UVFP group; another 237 age- and gender-matched normal subjects served as control group. Videostroboscopy, vocal function assessment (acoustic analysis, perceptual evaluation and maximum phonation time), and electromyography were performed preoperatively and postoperatively. The mean follow-up period was 5.2±2.7 years, ranging from 2 to 12 years.

Results

Analysis of videostroboscopic findings indicated that the glottic closure, vocal fold edge, vocal fold position, phase symmetry and regularity were significantly improved in the UVFP group (P<0.001, postoperative vs. preoperative). The postoperative parameters of vocal function were also significantly improved in the UVFP group (P<0.001) and showed no statistical differences compared to the control group (P>0.05, respectively). Postoperative laryngeal electromyography confirmed successful reinnervation of laryngeal muscle.

Conclusions

Delayed laryngeal reinnervation with the main branch of ansa cervicalis is a feasible and effective approach for treatment of thyroid surgery-related UVFP; it can restore the physiological laryngeal phonatory function to the normal or a nearly normal voice quality.

Systematic review of laryngeal reinnervation techniques

OBJECTIVE: To systematically review outcomes of reinnervation techniques for the management of unilateral vocal fold paralysis (UVFP).

DATA SOURCES: Medline and Cochrane databases for English-language studies published between 1966 and 2009 on the surgical management of UVFP.

REVIEW METHODS: Studies were excluded if they reported on bilateral vocal fold paralysis, used nonhuman subjects, or did not assess clinical outcomes. Outcomes of interest were visual analysis, acoustic analysis, perceptual analysis, and electromyography.

RESULTS: Of 686 initial studies, 14 studies encompassing 329 patients were eligible for analysis. All studies had a case-series design. Of reported patients, 60.2 percent were men, with mean age of 51 years (range, 12-79 years). The most common reinnervation technique was ansa cervicalis-to-recurrent laryngeal nerve (RLN), which was most commonly performed after thyroidectomy (43.5%). Other techniques with reportable outcomes included primary RLN anastomosis, ansa-to-RLN combined with cricothyroid muscle-nerve-muscle pedicle, ansa-to-thyroarytenoid neural implantation, ansa-to-thyroarytenoid neuromuscular pedicle, and hypoglossal-to-RLN. Median postsurgical follow-up was 12 months, and mean time to first signs of reinnervation was 4.5 months (SD 2.9 months). Visual analysis of glottic gap showed the greatest mean improvement with ansa-to-RLN, from 2.25 (SD 0.886) to 0.75 (SD 0.886) mm ( P < 0.01). Acoustic analysis showed greatest improvement with neural implantation, with a change in mean phonation time from seven (SD 1.22) to 16 (SD 5.52) seconds ( P < 0.01). Perceptual analysis and electromyography demonstrated improvement in all studies.

CONCLUSION: Reinnervation is effective in the management of UVFP, although the specific method may be dictated by anatomical limitations. Prospective studies utilizing uniform and consistent outcome parameters are necessary.

Transaxillary totally endoscopic robot-assisted ansa cervicalis to recurrent laryngeal nerve reinnervation for repair of unilateral vocal fold paralysis

Pediatric unilateral vocal-fold paralysis represents a source of significant morbidity, for which treatment options are quite limited. Conventional management strategies suitable for adults are not appropriate for the developing larynx. In this study, we report the first experience with minimally invasive laryngeal reinnervation. While open techniques for pediatric recurrent laryngeal nerve reinnervation have been performed, these require large, visible incisions, which limit the appeal of this technique. The transaxillary endoscopic approach to the neck significantly reduces pain and recovery time from cervical surgery. In this study, we report the feasibility of transaxillary totally endoscopic robot-assisted laryngeal reinnervation for unilateral vocal-fold paralysis. Operative time was less than 3 hours, and patients were discharged the day of surgery. No postoperative narcotics were required. Initial results are favorable.

Improvement in phonation after reconstruction of the recurrent laryngeal nerve in patients with thyroid cancer invading the nerve

BACKGROUND

We report vocal improvement after reconstruction of the recurrent laryngeal nerve (RLN) in patients with nerve resection, although vocal cord movement was not restored. These methods are not widely recognized.

METHODS

Direct anastomosis, free nerve grafting, or anastomosis to the ansa cervicalis or the vagus nerves with the RLN were performed in 7, 14, 65, and 2 patients with thyroid cancer invading the RLN, respectively. A total of 51 patients had vocal cord paralysis (VCP) pre-operatively. Maximum phonation time (MPT) and vital capacity (VC) were measured before and 1 year after reconstruction. A total of 34 normal subjects and 27 patients with VCP served as controls.

RESULTS

Patients with VCP had significantly shorter MPT values than normal subjects. At 1 year after operation, patients with reconstruction had values of MPT similar to those of normal subjects. Men had significantly longer MPT values than women, but the phonation efficiency index (PEI), defined as the MPT/VC ratio, did not differ by sex. The PEI was significantly less in VCP patients than in normal subjects. Patients with reconstruction achieved PEI values similar to those in normal subjects. Phonation efficiency index values at 1 year after operation was significantly greater than pre-operative PEI and was not affected by the presence or absence of VCP pre-operatively, age, reconstruction method, thickness of suture thread, or use of magnification during the operation.

CONCLUSION

In patients with thyroid cancer requiring RLN resection, RLN reconstruction achieved recovery in phonatory function.

Ansa-RLN reinnervation for unilateral vocal fold paralysis in adolescents and young adults

OBJECTIVE/HYPOTHESIS

To assess the outcomes of management of unilateral vocal fold paralysis by ansa-RLN reinnervation in a series of patients ages 12-21.

STUDY DESIGN

Clinical outcomes study.

METHODS

Six consecutive adolescents and young adults (ages 12-21 years) seeking treatment for unilateral vocal fold paralysis and glottal incompetence underwent ansa-RLN neurorraphy. Pre- and post-operative voice recordings acquired at least 1 year following surgery were submitted to acoustic and perceptual analysis. Patient-based measures were also taken.

RESULTS

Mean perceptual visual analogue scale rating of dysphonia severity (0mm=profoundly abnormal voice, 100mm=completely normal voice) improved from 50mm pre-operatively to 82mm post-operatively. Mean maximum phonation time improved from 6.5s to 13.2s. Pitch and dynamic range were also observed to improve. Global self-ratings of voice function (0-100%) increased from 31.2% to 81.6% of normal.

CONCLUSIONS

Ansa-RLN reinnervation is an effective treatment option for adolescents and young adults with unilateral vocal fold paralysis. The procedure has the potential to improve vocal function substantially, especially in those with isolated paralysis of the recurrent laryngeal nerve. The procedure alleviates the disadvantages associated with other surgical options for this age group.

Ansa Cervicalis-to-Recurrent Laryngeal Nerve Anastomosis for Unilateral Vocal Fold Paralysis: Experience of a Single Institution

Objectives:

One treatment option for unilateral vocal fold paralysis (UVFP) is ansa cervicalis-to-recurrent laryngeal nerve (ansa-RLN) anastomosis to provide reinnervation to the affected vocal fold. The advantages of this treatment approach are that it 1) provides vocal fold tone, bulk, and tension, 2) is technically simple, and 3) does not preclude other medialization procedures. We present all patients who have undergone ansa-RLN anastomosis for UVFP at our institution.

Methods:

An Institutional Review Board-approved retrospective chart review was performed to include all patients who had undergone an ansa-RLN anastomosis procedure for UVFP at our institution. Data from clinical and endoscopic laryngoscopy with stroboscopy were recorded. Statistical analysis was performed on visual and perceptual vocal data.

Results:

A total of 46 patients were included in the study. Stroboscopic analysis and perceptual vocal evaluation was performed in a blinded fashion on the 21 patients who had preoperative and postoperative stroboscopy. Severity, roughness, breathiness, and strain all improved significantly over time. Glottic closure, vocal fold edge, and supraglottic effort all significantly improved after operation. Of the 38 patients with at least 3 months of follow-up, all except 1 demonstrated evidence of reinnervation.

Conclusions:

This technique for treating UVFP results in significant improvements in patients' voice and on visual examination.

Injection Versus Medialization Laryngoplasty for the Treatment of Unilateral Vocal Fold Paralysis

OBJECTIVE/HYPOTHESIS

To determine whether injection laryngoplasty or medialization laryngoplasty is more effective in the treatment of unilateral vocal fold paralysis.

STUDY DESIGN

A retrospective study of patients with unilateral vocal fold paralysis who underwent either injection or medialization laryngoplasty at the University of Arkansas for Medical Sciences between July 29, 2003 and March 8, 2005.

METHODS

The data analyzed included patient characteristics and type of intervention, along with the pretreatment and posttreatment voice parameters of videostrobolaryngoscopy, perceptual analysis, and patients' subjective voice assessment.

RESULTS

Nineteen patients were evaluated. The average time from intervention to posttreatment evaluation was 3 (range, 1-9) months. Improvements were demonstrated in all three voice parameters in both the injection and the medialization groups. No significant differences were found in the degree of improvement between the two groups. Videostrobolaryngoscopy and the perceptual analysis, both rated by the authors, correlated well with each other, but they both correlated poorly with the patients' subjective voice analysis.

CONCLUSIONS

Injection and medialization laryngoplasty were comparable in their improvement of subjective and objective voice outcomes. Both treatment modalities should be included in the otolaryngologist's armamentarium for managing unilateral vocal fold paralysis.

Perceptual ratings of vocal characteristics and voicing features in untreated patients with unilateral vocal fold paralysis

This study used visual analog scales to obtain perceptual ratings of features of voice production in subjects with unilateral vocal fold paralysis (UVFP), including clarity of laryngeal articulation, consistency of loudness across the utterance and the voiced/voiceless distinction. Recordings of repeated /i/, /isi/, and /izi/ from subjects diagnosed with UVFP and control subjects were randomly re-recorded, and then rated by five listeners. Significant differences in ratings (Smirnov test, p < 0.01) were found between groups for "aphonia", "severity", "clarity of articulation", "overall loudness", "consistency of loudness" and "amount of effort". Four of five raters agreed on the accuracy of /s/ or /z/ productions for only 54% of the samples from the subjects with UVFP. Voiceless and voiced cognates were equally likely to be rated as inaccurate. Results suggested that these variables were sensitive to changes in voice production resulting from paralysis, and may be useful in measuring treatment outcomes and spontaneous recovery of function.

LEARNING OUTCOMES

As a result of reading this manuscript the reader will (1) gain an understanding of types of perceptual scales and how to develop the set of vocal characteristics to be used in distinguishing patients with UVFP and those without, (2) learn which vocal characteristics listeners are able to use to successfully distinguish between patients with UVFP and those without and (3) understand the possible role for perceptual ratings in tracking changes in vocal characteristics in subjects over time following treatment or spontaneous recovery of function.

Laryngeal reinnervation

Laryngeal reinnervation refers to any of a number of surgical procedures intended to restore neural connections to the larynx, which have usually been lost from some type of trauma (eg, surgical). The nerve function(s) to be restored may be those of the recurrent laryngeal nerve or its subdivisions, those of the superior laryngeal nerve, or both, and they may be motor or sensory. Several different donor nerves are available and have been described. The technique used may be direct end-to-end anastomosis (neurorrhaphy), direct implantation of a nerve ending into a muscle, the nerve-muscle pedicle technique, or muscle-nerve-muscle methods. These nerves and techniques may be combined in many ways. A number of new techniques have been reported in animal studies; however, the animal studies do not always predict the results of analogous surgeries in human patients. The historical and current perspectives on these techniques are discussed in this article.

Neurophysiology of vocal fold paralysis

Although a tremendous volume of energy and literature has been devoted to laryngeal paralysis in the past decade, there are still substantial gaps in our understanding of fundamental issues. Oddly enough, controversy remains regarding the actual innervation pathways of the larynx and whether the paralyzed larynx is truly denervated or dysfunctionally reinnervated. An appreciation of these basic issues is prerequisite to making prudent decisions regarding the most appropriate type of intervention. The purpose of this article is to provide a brief overview of basic laryngeal anatomy and neurophysiology to prepare the reader for a subsequent discussion of futuristic research for treatment of laryngeal paralysis.A novel approach is described, which can induce selective reinnervation of individual laryngeal muscles by their original motor fibers within the recurrent laryngeal nerve.

Evidence-based treatment of paralytic dysphonia: making sense of outcomes and efficacy data

The criteria used to determine the success or failure of a given treatment for vocal fold paralysis are fundamental components of routine clinical practice and treatment outcomes research for the surgeon and voice therapist. The purpose of this article is to offer a guide to the critical interpretation of available measures of out-come and efficacy for this patient population. Such data form the basis for the practice of evidence-based medicine and voice therapy,essential if the standard of care is to evolve to the benefit of the patient. A better understanding of the potentials and limitations of each measure is important for treatment planning and patient counseling and, ultimately, for the conception of future well-designed clinical research. The complex issues regarding outcomes measurement are addressed here within the context of current treatment literature on vocal fold paralysis. Particular emphasis is placed on realistic data gathering within clinical practice.

Electromyographic findings in recurrent laryngeal nerve reinnervation

Abductor, adductor, and combined reinnervation procedures have been explored with variable success rates. We describe the experience of a tertiary care center with adductor reinnervation procedures, including preoperative and postoperative videostroboscopy and electromyography (EMG) findings. A retrospective chart review was performed from 1997 to 2001 that included 9 patients. Preoperative and postoperative voice comparison was performed by 3 blinded speech pathologists. Clinical comparisons of videostroboscopy findings for vocal fold bulk, tone, position, presence of gap, and movement are elucidated. The preoperative and postoperative EMG findings are described. In all patients, preoperative EMG revealed a dense, complete denervation of the affected recurrent laryngeal nerve. No movement was noted on videostroboscopy with persistent glottic gap. Reinnervation involved a nerve-muscle pedicle or a direct neurorrhaphy of the ansa cervicalis to the recurrent laryngeal nerve. Voice improvement was noted between 60 days and 3 months after reinnervation. Four postoperative EMG studies were performed. An early postoperative EMG study at 5 months revealed activation of the lateral cricoarytenoid muscle and thyroarytenoid muscle with head-lift. Videostroboscopy showed excellent near-midline static positioning of the vocal fold. Late EMG studies, performed 12 to 16 months after reinnervation, revealed "learning" of these muscles, with new activation on "eee" phonation. We conclude that recurrent laryngeal nerve reinnervation procedures belong in the armamentarium of the laryngologist for the treatment of vocal fold paralysis. The EMG findings reported in this study suggest that ongoing reinnervation allows for activation with phonation in matured neuronal anastomoses. Overall, this procedure results in excellent patient acceptance and near-normal vocal quality.

Results of fascial augmentation in unilateral vocal fold paralysis

The objective of this study was to evaluate the effects on voice quality of augmentation by injection of minced fascia in patients with unilateral vocal fold paralysis. Preoperative and postoperative voice samples from 14 patients (6 men and 8 women; mean age, 59 years) were analyzed by computerized acoustic analysis and blinded perceptual evaluation. Statistically significant improvements were seen in perturbation measurements (jitter and shimmer), noise-to-harmonics ratio, and maximum phonation time. A panel of evaluators rated 10 of the 14 postoperative voices as normal or near-normal. Injection laryngoplasty with minced fascia offers a new, effective, well-tolerated, and inexpensive method to medialize a paralyzed vocal fold. The graft seems to survive well, as indicated by good vocal results with a follow-up ranging from 5 to 32 months.

Management of common voice problems: Committee report

OBJECTIVE

This report provides the reader with a state-of-the-art update on a number of common voice problems that require phonosurgical intervention.

STUDY DESIGN AND SETTING

This multiauthor review is not a position statement of the American Academy of Otolaryngology-Head and Neck Surgery (AAOHNS) and may reflect institutional preference and/or bias. It arose from a panel discussion at the AAOHNS meeting in 2000.

RESULTS

We provide a review of the genesis and management of papillomatosis, dysplastic glottal epithelium, arytenoid granulomas, Reinke's edema, and vocal-fold paralysis.

CONCLUSIONS AND SIGNIFICANCE

In the past decade, there has been a dramatic expansion of knowledge regarding a variety of voice disorders and associated treatment. There has been a convergence of basic science investigations in anatomy, physiology, and pathology with clinical trials of treatment, both surgical and nonsurgical. This information should provide the reader with current insight into critical management issues of the aforementioned disorders.

The relationship between cepstral peak prominence and selected parameters of dysphonia

Traditional measures of dysphonia vary in their reliability and in their correlations with perceptions of grade. Measurements of cepstral peak prominence (CPP) have been shown to correlate well with perceptions of breathiness. Because it is a measure of periodicity, CPP should also predict roughness. The ability of CPP and other acoustic measures to predict overall dysphonia and the subcategories of breathiness and roughness in pathological voice samples is explored. Preoperative and postoperative speech samples from 19 patients with unilateral recurrent laryngeal nerve paralysis who underwent operative intervention were analyzed by trained listeners and by measures of smoothed CPP (CPPS), noise-to-harmonic ratio (NHR), amplitude perturbation quotient (APQ), relative average perturbation (RAP), and smoothed pitch perturbation quotient (sPPQ). The data were analyzed with bivariate Pearson correlation statistics. Grade of dysphonia and breathiness ratings correlated better with measurements of CPPS than with the other measures. CPPS from samples of connected speech (CPPS-s) best predicted overall dysphonia. None of the measures were useful in predicting roughness.

Objective voice quality analysis before and after onset of unilateral vocal fold paralysis

This study was designed to investigate objective voice quality measurements in unilateral vocal fold paralysis (UVFP) by eliminating intersubject variability. To our knowledge this is the first report objectively analyzing paralytic dysphonia as compared to the same voice before onset of UVFP. The voices of two male subjects were prospectively recorded before and after the onset of iatrogenic UVFP (thoracic surgery). The following acoustic measurements of the vowel /a/ were performed using the CSL and MDVP (Kay Elemetrics): jitter, shimmer, harmonics-to-noise ratio, cepstral peak prominence, the relative energy levels of the first harmonic, the first formant and the third formant, the spectral slope in the low-frequency zone (0-1 kHz and 0-2 kHz), and the relative level of energy above 6 kHz. Distribution of spectral energy was analyzed from a long-term average spectrum of 40 seconds of text. Laryngeal aerodynamic measurements were obtained for one patient before and after onset of paralysis using the Aerophone II (Kay Elemetrics). Pitch and amplitude perturbation increased secondary to UVFP, while the harmonics-to-noise ratio and the cepstral peak prominence decreased. A relative increase in the mid-frequency and high-frequency ranges and a decrease in the low-frequency spectral slope were observed. Mean airflow rate and intraoral pressure increased, and glottal resistance and vocal efficiency decreased secondary to UVFP. The findings of this self-paired study confirm some but not all the results of previous studies. Measures involving the fundamental and the formants did not corroborate previous findings. Further investigation with vocal tract modeling is warranted.

Motion-specific laryngeal reinnervation using muscle-nerve-muscle neurotization

There is no current treatment method that can reliably restore physiologic movement to a paralyzed vocal fold. The purposes of this study were to test the hypotheses that 1) muscle-nerve-muscle (M-N-M) neurotization can be induced in feline laryngeal muscles and 2) M-N-M neurotization can restore movement to a paralyzed vocal fold. Muscle-nerve-muscle neurotization can be defined as the reinnervation of a denervated muscle via axons that are induced to sprout from nerves within an innervated muscle and that then traverse a nerve graft interposed between it and the target denervated muscle. A paralyzed laryngeal muscle could be reinnervated by axons from its contralateral paired muscle, thus achieving motion-specific reinnervation. Eighteen adult cats were divided into sham, hemilaryngeal-denervated, and M-N-M-reinnervated thyroarytenoid muscle groups. Five of the 6 reinnervated animals had histologic evidence of axons in the nerve graft, 4 of the 6 had evoked electromyographic evidence of crossed reinnervation, and 1 of the 6 had a return of appropriately phased adduction. This technique has great potential and should be further investigated.

Objective voice analysis after autologous fat injection for unilateral vocal fold paralysis

This study was designed to objectively compare a patient's voice after onset of unilateral vocal fold paralysis (UVFP) to his or her own normal voice, and to compare the results after treatment by intrafold injection of autologous fat. Acoustic recordings were obtained for 2 male patients before thoracic surgery and after the onset of iatrogenic left UVFP. Vocal fold augmentation was performed 10 days after UVFP. The acoustic recordings were repeated within 3 days and at 1 month. The phonation quotient, pitch perturbation quotient, amplitude perturbation quotient, harmonics-to-noise ratio, cepstral peak prominence, and long-term average spectrum were analyzed. All parameters improved after treatment, with a return to preparalytic values for most. During the first month, some deterioration was noted. This is the first study comparing a subject's own normal voice to his or her voice after vocal fold augmentation. We recommend overinjection of fat if vocal fold atrophy is expected.

Laryngeal reinnervation with the hypoglossal nerve: II. Clinical evaluation and early patient experience

OBJECTIVES/HYPOTHESIS

To determine whether the hypoglossal nerve (XII) can serve as a suitable donor for human laryngeal reinnervation.

STUDY DESIGN

Prospective, nonrandomized.

METHODS

Measurements were made on patients undergoing open neck procedures to determine the length of XII available and that required to perform XII-recurrent laryngeal nerve (RLN) anastomosis. The morbidity of combined XII and RLN injuries was studied using temporary lidocaine block of the ipsilateral XII in patients with unilateral vocal fold paralysis (UVFP). A pilot series of patients with UVFP who underwent XII-RLN reinnervation was evaluated for morbidity of the procedure, and for improvement in voice and swallowing.

RESULTS

In 89 necks the average available length of XII was 2 cm less than that needed to reach the larynx, indicating the RLN stump must be at least 3 cm to allow tension-free anastomosis. Twenty-five patients with untreated UVFP underwent temporary lidocaine block of XII; 8 had slight changes in their speech, none had increased aspiration. Nine patients underwent XII-RLN reinnervation. Postoperative speech analysis correlated well with the findings of the temporary lidocaine block of XII. One-year follow-up of five patients showed excellent voice quality, resolution of any preoperative aspiration, and minimal morbidity. Slight adductory movement of the reinnervated vocal fold was seen during tongue thrust. Electromyography confirmed substantial polyphasic action potentials in the thyroarytenoid muscle.

CONCLUSIONS

The hypoglossal nerve is a very suitable donor for reinnervation of patients with UVFP. There should be enough length for primary XII-RLN anastomosis in most patients. Donor site morbidity is acceptable. Preoperative lidocaine block of XII is a good predictor of actual donor site morbidity and could be used to assess patients undergoing facial-hypoglossal anastomosis as well.

Laryngeal synkinesis revisited

First described in 1982, laryngeal synkinesis continues to play an important diagnostic and therapeutic role following recurrent laryngeal nerve (RLN) injury. Vocal fold motion impairment (formerly called "vocal cord paralysis"), hyperadducted and hyperabducted vocal folds, and certain laryngeal spasmodic and tremor disorders are often best explained by synkinesis. A closer look at these mechanisms confirms that following RLN injury, immobile vocal folds may be nearly normally functional (favorable), or spastic, hyperadducted, or hyperabducted (unfavorable). This has resulted in a functional classification of laryngeal synkinesis as follows: type I laryngeal synkinesis, with satisfactory voice and airway (vocal fold poorly mobile, or immobile); type II synkinesis, with spasmodic vocal folds and an unsatisfactory voice and/or airway; type III synkinesis, with hyperadducted vocal folds and airway compromise; and type IV synkinesis, with hyperabducted vocal folds, poor voice, and possible aspiration. This classification facilitates the understanding of laryngeal pathophysiology following RLN injuries and promotes a more scientific basis for management.