Superior Laryngeal Nerve Paresis Research Articles

A Case of Nervus Laryngeus Superior Paresis Treated With Novafon Local Vibration Voice Therapy

The aim of the study is to present a case of chronic idiopathic superior laryngeal nerve paresis (SLNp) treated with a novel voice therapy approach called Novafon Local Vibration Voice Therapy (NLVVT). Outcome measurements including acoustics, aerodynamics, and self-perception of voice handicap were acquired before intervention (i.e., NLVVT) and after intervention (i.e.,follow-up). The use of NLVVT was modified from previous reports of use in functional voice disorders for application to a neurological voice disorder (SLNp). The results showed that NLVVT had meaningful improvements in Voice Range Profile boundaries, an increase in speaking fundamental frequency, and improved acoustic indices of voice quality in a case of SLNp. The follow-up after NLVVT intervention revealed maintenance of the post-treatment improvements at a 1-month measurement interval. The NLVVT program may have potential to improve voice quality and vocal function in a case of SLNp. Further research is necessary to test a potential effectiveness for NLVVT applied to vocal fold immobility due to paresis in both larger numbers of patients and more well-designed, controlled experiments.

Difficulty producing high-pitched sounds in singing: correlations with laryngostroboscopy and electromyographic findings

IntroductionDifficulties or limitations in producing high-pitched sounds while singing may be due to the vocal technique used or organic factor. The observation of such difficulty or limitation by singing teachers is one of the main reasons affected individuals are referred to otolaryngologists. ObjectiveTo evaluate the laryngostroboscopic and electromyographic changes in the cricothyroid muscles of singers with difficulties or limitations producing high-pitched sounds. MethodsThis is a cross-sectional study. Ten singers with difficulty producing high-pitched sounds underwent voice, laryngostroboscopic, and electromyographic evaluations. ResultsNone of the evaluated singers presented signs of impairment of the superior laryngeal nerve on laryngostroboscopy. The electromyographic findings for the cricothyroid muscle were normal for all singers. Six singers presented vocal fold lesions, seven had signs suggestive of laryngopharyngeal reflux, and two presented vascular changes. ConclusionNo signs suggestive of superior laryngeal nerve paresis or paralysis were observed on laryngostroboscopy and electromyography of the cricothyroid muscle in singers with difficulties or limitations producing high-pitched sounds. The presence of vocal fold lesions should be investigated in this population.

Effects of Voice Therapy on Laryngeal Motor Units During Phonation in Chronic Superior Laryngeal Nerve Paresis Dysphonia

Injury to the superior laryngeal nerve can result in dysphonia, and in particular, loss of vocal range. It can be an especially difficult problem to address with either voice therapy or surgical intervention. Some clinicians and scientists suggest that combining vocal exercises with adjunctive neuromuscular electrical stimulation may enhance the positive effects of voice therapy for superior laryngeal nerve paresis (SLNP). However, the effects of voice therapy without neuromuscular electrical stimulation are unknown. The purpose of this retrospective study was to demonstrate the clinical effectiveness of voice therapy for rehabilitating chronic SLNP dysphonia in two subjects, using interspike interval (ISI) variability of laryngeal motor units by laryngeal electromyography (LEMG). Both patients underwent LEMG and were diagnosed with having 70% recruitment of the cricothyroid muscle, and 70% recruitment of the cricothyroid and thyroarytenoid muscles, respectively. Both patients received voice therapy for 3 months. Grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, stroboscopic examination, aerodynamic assessment, acoustic analysis, and Voice Handicap Index-10 were performed before and after voice therapy. Mean ISI variability during steady phonation was also assessed. After voice therapy, both patients showed improvement in vocal assessments by acoustic, aerodynamic, GRBAS, and Voice Handicap Index-10 analysis. LEMG indicated shortened ISIs in both cases. This study suggests that voice therapy for chronic SLNP dysphonia can be useful for improving SLNP and voice quality.

Laryngeal Electromyographic findings in patients with vocal fold motion asymmetry.

Vocal fold motion asymmetry (VFMA) is often attributed to vocal fold paresis or an anatomical variant. Although laryngeal electromyography (LEMG) may be used to evaluate patients with vocal fold paresis, electrodiagnostic findings in VFMA have not been well defined. Review of a case series Twenty-five symptomatic patients with VFMA were examined by LEMG, and the findings were analyzed. Although all were thought to have unilateral recurrent laryngeal nerve paresis, LEMG showed only nine to have unilateral recurrent nerve paresis. There were nine with both ipsilateral recurrent laryngeal nerve and superior laryngeal nerve paresis, four with bilateral paresis, and three were normal. Reduced total number of units, reduced recruitment, motor units firing fast, and polyphasic units were more common, whereas fibrillation potentials, fasciculation, positive sharp waves, and complex repetitive discharges were uncommon. The LEMG findings are most consistent with old, healed neuropathy. McNemar's test for the acute versus chronic denervation potentials showed significant differences. VFMA has a high incidence of vocal fold paresis that can be better defined by LEMG. The site and side of paresis is often wrong based on laryngoscopy findings alone. The LEMG findings of VFMA appear to be consistent with old, healed neuropathy 4 Laryngoscope, 126:E273-E277, 2016.

Superior laryngeal nerve injury: effects, clinical findings, prognosis, and management options.

The superior laryngeal nerve (SLN) provides motor innervation to the cricothyroid muscle. However, the functions of this muscle and the anatomic variations of the nerve that supplies it are not fully understood. SLN paresis and paralysis (SLNp) is difficult to diagnose because of a lack of consistent laryngeal findings, and its effects on the voice likely go beyond simple pitch elevation control. Although SLNp has traditionally been thought to lead to voice pitch limitation, recent research findings reveal multiple roles for this nerve in voice and speech. Cricothyroid muscles are the primary controls of fundamental frequency of voice. SLNp can lead to significant contraction of pitch range, vocal fold vibratory phase asymmetry, and acoustic aperiodicity, thus leading to an overall poor vocal quality. In addition, cricothyroid muscles may also play a role in pitch lowering and shifting from voiced to unvoiced sounds during speech. Subtle signs, symptoms, and diagnostic findings associated with SLNp make this disorder difficult to characterize clinically. Lack of treatment methodologies to restore the dynamic action of the cricothyroid muscles poses difficulties in treating patients with this condition. A more thorough understanding of the effects of SLNp will improve diagnosis and treatment.

Sjögren's syndrome with paresis of the internal branch of the superior laryngeal nerve

AbstractA 46‐year‐old woman developed painful dysesthesia in her extremities and ataxic gait. She was diagnosed with Sjögren's syndrome, and her condition was diagnosed as sensory ataxic and painful neuropathy. Intravenous immunoglobulin therapy alleviated the ataxia and severe pain in her extremities. When she was 61‐years‐old, she developed dysphagia and dyspnea. Laryngoscopy showed tactile anesthesia on the epiglottis, indicating paresis of the superior laryngeal nerve. We considered that the primary cause of dysphagia was paresis of the internal branch of the superior laryngeal nerve, and carried out tracheostomy and high‐dose intravenous methylprednisolone therapy (1 g/day × 3 days). Her dysphagia and aspiration gradually improved without following oral steroid therapy. Our case is the first report of the internal branch of superior laryngeal nerve paresis as a possible cause of dysphagia and aspiration in a patient with Sjögren's syndrome. Additional cases of Sjögren's syndrome with dysphagia should be investigated to confirm our findings.

Effects of asymmetric superior laryngeal nerve stimulation on glottic posture, acoustics, vibration

Evaluate the effects of asymmetric superior laryngeal nerve stimulation on the vibratory phase, laryngeal posture, and acoustics. Basic science study using an in vivo canine model. The superior laryngeal nerves were symmetrically and asymmetrically stimulated over eight activation levels to mimic laryngeal asymmetries representing various levels of superior laryngeal nerve paresis and paralysis conditions. Glottal posture change, vocal fold speed, and vibration of these 64 distinct laryngeal-activation conditions were evaluated by high speed video and concurrent acoustic and aerodynamic recordings. Assessments were made at phonation onset. Vibratory phase was symmetric in all symmetric activation conditions, but consistent phase asymmetry toward the vocal fold with higher superior laryngeal-nerve activation was observed. Superior laryngeal nerve paresis and paralysis conditions had reduced vocal fold strain and fundamental frequency. Superior laryngeal nerve activation increased vocal fold closure speed, but this effect was more pronounced for the ipsilateral vocal fold. Increasing asymmetry led to aperiodic and chaotic vibration. This study directly links vocal-fold tension asymmetry with vibratory phase asymmetry, in particular the side with greater tension leads in the opening phase. The clinical observations of vocal fold lag, reduced vocal range, and aperiodic voice in superior laryngeal paresis and paralysis is also supported.

Hyoid advancement to the mandible (hyo-mandibular advancement)

Hyoid advancement to the mandible was first described in 1984, but was later abandoned by most surgeons for the easier to perform advancement to the laryngeal cartilage. New modifications of the hyo-mandibular advancement technique has made this approach easier to perform and are described in this paper. The hyo-mandibular advancement technique has a higher success rate for the treatment of sleep apnea, especially in women.

Laryngeal Granulomas Associated with Superior Laryngeal Nerve Paresis

The association between superior laryngeal nerve (SLN) paresis and laryngeal granuloma formation has not been described earlier. The aim of this study was to present a series of patients with isolated unilateral SLN paresis who developed contralateral vocal process granulomas. The study design was a retrospective chart review including all patients presenting to Indiana University from February 2006 to August 2007 with laryngeal electromyography (LEMG)-documented unilateral SLN paresis and evidence of laryngeal granuloma on videostroboscopy. Patient history, examination, LEMG findings, and response to treatment were recorded. Three cases of unilateral SLN paresis associated with contralateral vocal process granulomas were identified. In all patients, videostroboscopy examination demonstrated shortening of the ipsilateral vocal fold on adduction and asymmetric contact of the vocal processes at the site of granuloma formation. All patients failed to respond to aggressive antireflux therapy. One patient had spontaneous recovery of the SLN paresis, with subsequent resolution of the granuloma. Two patients were successfully treated with surgical laser excision of the granulomas and injection of botulinum toxin into the normal cricothyroid muscle to alter the vocal process contact points. Vocal process granulomas can be associated with unilateral SLN paresis, potentially related to altered contact points between the vocal processes of the arytenoids.

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Videostroboscopic findings in unilateral superior laryngeal nerve paralysis and paresis

Our aim was to present laryngovideostroboscopic findings in unilateral superior laryngeal nerve paresis and paralysis. Retrospective case review, academic voice clinic. Blinded retrospective review of videostroboscopic recordings from cases confirmed by laryngeal electromyography. Three cases of unilateral superior laryngeal nerve paresis and paralysis were identified. At rest, there were no common abnormal laryngeal findings. Upon phonation, common findings were ipsilateral vocal fold bowing and shortening, vocal process height asymmetry with the ipsilateral vocal process overriding the normal, and ipsilateral hyperadduction of the false vocal fold. The common features noted in these cases of laryngeal electromyography-proved uSLNp could be used to make a presumptive diagnosis of this disorder.

Objective Voice Measures in Nonsinging Patients With Unilateral Superior Laryngeal Nerve Paresis

The clinical value of objective voice measures in nonsinging patients with superior laryngeal nerve dysfunction is unknown. In this study, patients with symptomatic unilateral superior nerve paresis were evaluated for maximum phonation time, frequency range of phonation, and mean flow rate. Patients with coexisting pathology, bilateral superior nerve paresis, and those with recurrent laryngeal nerve paresis were excluded from this analysis. A total of 35 nonsinging patients, 14 men and 21 women, with unilateral superior laryngeal nerve paresis were examined between 1999 and 2002. The severity of superior laryngeal nerve paresis ranged from 25% to 85% of normal recruitment with a mean of 70% superior laryngeal nerve recruitment in men and 65% in women by electromyography. In both men and women with superior laryngeal nerve paresis, the maximum phonation time and frequency range of phonation were decreased and the mean air flow rate was increased when compared with normal population values. The jitter percent, shimmer percent, and noise-to-harmonic ratio were also increased in patients when compared with normative data. Selected objective voice measures are abnormal in voice patients with superior laryngeal nerve paresis, which suggests that the measures may be useful as outcomes measures after therapy. More research is encouraged.

Voice range in superior laryngealnerve paresis and paralysis

Evaluation of Physiologic Frequency Range (PFR) and Musical Frequency Range (MRP) of Phonation was performed on 56 adults (singers and nonsingers) presenting with superior laryngeal nerve (SLN) paresis or paralysis confirmed by laryngeal electromyography. The most common etiology was neuritis (69.7%), followed by iatrogenic and unknown causes,each accounting for 10.2% of cases, and finally trauma (8.9%). Both female and male singers with SLN paresis or paralysis had significantly higher PFR and MPR than nonsingers. Female classical singers presented PFR and MPR of up to 10 semitones (ST) higher than nonclassical singers and nonsingers. The lowest PFR and musical ranges were found in patients with SLN paresis associated with recurrent laryngeal nerve paresis or paralysis. The authors suggest that voice range measurement is a useful parameter for analyzing the effects of SLN paresis or paralysis on voice and that it may also assist in measuring outcome following voice therapy.

Superior laryngeal nerve paresis and paralysis.

Superior laryngeal nerve paresis and paralysis are relatively common but often difficult to diagnose with certainty. They are most commonly caused by viral infections, though other etiologies must be considered. A thorough history and physical examination, including strobovideolaryngoscopy and laryngeal electromyography, are needed for definitive diagnosis. It is essential to establish the diagnosis accurately to differentiate an apparent superior laryngeal nerve paresis from other conditions, such as myasthenia gravis. Laryngeal electromyography is used to confirm clinical impressions, as a guide for therapy, and as one measure of recovery. In our experience, accurate and early diagnosis assure the best phonatory outcome by directing therapy that will prevent or eliminate compensatory vocal abuses, which may themselves lead to even more serious vocal injury.

Partial superior laryngeal nerve (SLN) lesions before and after thyroid surgery.

AbstractThe incidence of superior laryngeal nerve (SLN) lesions and their consequences in terms of voice quality was studied in 20 patients undergoing thyroid surgery, performed by surgeons who were not specialists in endocrine surgery. The SLN function was examined by electromyography (EMG) of the cricothyroid muscles before and after surgery. Voice analysis was performed through the registration of the average pitch and range of the speaking voice and the upper pitch limit. The perceptual voice quality was judged by a panel of listeners. Voice problems were registered through a questionnaire. The larynx status was examined by indirect laryngoscopy before and after surgery. Three patients who had not previously been operated on in the neck had partial SLN lesions before surgery. According to the EMG, no SLN at risk developed a complete lesion, but 58% of the SLN's developed partial lesions which persisted 1 year after surgery in all but 1 of the examined patients. Seven of 10 patients with isolated SLN lesions had postoperative voice problems, which had disappeared after 1 year in 4 of them. Standard indirect laryngoscopy failed to diagnose an isolated partial SLN paresis. A significant correlation was found between SLN lesion and a reduction in the average pitch of the speaking voice (p < 0.05). Partial SLN lesions cannot be diagnosed exclusively on voice symptoms and standard indirect laryngoscopy. EMG registrations make a definite diagnosis possible. Measurements of the average pitch of the voice could be used as a noninvasive screening procedure.