Ultrasound-Guided Botulinum Neurotoxin Injection for Alleviating Cricopharyngeus Muscle Spasticity: A Cadaveric Feasibility Study with Nerve Ending Analysis.

Botulinum neurotoxin (BNT) injection into the cricopharyngeus muscle (CPM) under ultrasound (US) guidance is a minimally invasive technique performed to relieve cricopharyngeal dysphagia by reducing CPM spasticity. This technique is basically accessible only to both lateral sides of the CPM. This cadaveric study aimed to evaluate whether US-guided injection could effectively deliver BNT to abundant areas of gross nerve endings within the CPM. We utilized a newly modified Sihler's staining method to identify regions with abundant neural endings within the CPM while preserving the three-dimensional morphology of the muscle in 10 sides of 5 fresh cadavers. A mixture of 0.2 mL dye was injected into the 16 sides of CPM under US guidance in 8 cadavers. Nerve endings were abundant in posterolateral areas of the CPM; the injected dye was identified at the posterolateral area on 12 sides (12/16 side, 75%) without diffusion into the posterior cricoarytenoid muscle. The injection failed on four sides (two sides of the prevertebral fascia and two sides of the esophagus below the CPM). These results suggest that US-guided injection could be a feasible technique as it can deliver BNT to the most abundant nerve distribution areas within the CPM in most cases.

Comparison of Doses to Parotid, Temporomandibular Joint, and Pharyngeal Constrictor Muscles Using Different Techniques in Radiotherapy for Oropharyngeal Cancer.

OBJECTIVE: The purpose of this research was to compare two treatment techniques for oropharyngeal cancers: conventional linac-based static intensity-modulated radiotherapy (sIMRT) and helical tomotherapy (HT). The study examined several parameters, including target coverage, organs at risk, integral dose, and beam on time. Additionally, the study evaluated the doses to the parotid, temporomandibular joint, and pharyngeal constrictor muscles, which are important for swallowing. METHOD: The present study retrospectively analyzed the data of 13 patients with oropharyngeal cancer who underwent radiotherapy between 2019 and 2021. The treatment plans for each patient were regenerated using both sIMRT and HT treatment planning systems with the sequential boost method. The techniques were evaluated and compared based on dose-volume histogram, homogeneity index, and conformity index parameters. The target coverage and organs at risk were statistically compared for two techniques. Additionally, the doses received by the healthy tissue volume were obtained for integral dose evaluation. The beam on time for each technique was assessed. RESULTS: When considering planning target volume evaluation, there was no difference in Dmeans between the two techniques and sIMRT demonstrated higher D2% values compared to the HT. The HT technique had better results for all organs at risk, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle. As for integral dose, it has been shown that the sIMRT technique provides better protection compared to HT. In addition, the beam on time was also longer with the HT technique. CONCLUSION: Both techniques may provide optimal target coverage for patients with oropharyngeal cancer. HT conferred notable advantages, especially with regard to critical structures implicated in swallowing, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle, in comparison to sIMRT.

Magnetic Resonance Imaging of the Velopharynx: Clinical Findings in Patients with Velopharyngeal Insufficiency.

BACKGROUND: Magnetic resonance imaging (MRI) is the only imaging modality capable of directly visualizing the levator veli palatini (LVP) muscles: the primary muscles responsible for velopharyngeal closure during speech. MRI has been used to describe normal anatomy and physiology of the velopharynx in research studies, but there is limited experience with use of MRI in the clinical evaluation of patients with velopharyngeal insufficiency (VPI). METHODS: MRI was used to evaluate the velopharyngeal mechanism in patients presenting for VPI management. The MRI followed a fully awake, nonsedated protocol with phonation sequences. Quantitative and qualitative measures of the velopharynx were obtained and compared with age- and sex-matched individuals with normal speech resonance. RESULTS: MRI was completed successfully in 113 of 118 patients (96%). Compared with controls, patients with VPI after cleft palate repair had a shorter velum (P < 0.001), higher incidence of LVP discontinuity (P < 0.001), and shorter effective velar length (P < 0.001). Among patients with persistent VPI after pharyngeal flap placement, findings included a pharyngeal flap base located inferior to the palatal plane [11 of 15 (73%)], shorter velum (P < 0.001), and higher incidence of LVP discontinuity (P = 0.014). Patients presenting with noncleft VPI had a shorter (P = 0.004) and thinner velum (P < 0.001) and higher incidence of LVP discontinuity (P = 0.014). CONCLUSIONS: MRI provides direct evidence of LVP muscle anomalies and quantitative evaluation of both velar length and velopharyngeal gap. This information is unavailable with traditional VPI imaging tools, suggesting that MRI may be a useful tool for selecting surgical procedures to address patient-specific anatomic differences.

[Clinical effect of the modified pharyngeal flap of bilateral muscular rings in the treatment of moderate and severe velopharyngeal insufficiency].

To introduce the modified pharyngeal flap of bilateral muscular rings (BMR), and to discuss the clinical effect of this operation in the correction of moderate and severe velopharyngeal insufficiency. The clinical data of 18 patients who underwent BMR surgery in the Department of Craniofacial Plastic and Aesthetic Surgery, School of Stomatology, The Fourth Military Medical University from May 2019 to July 2021 were retrospectively analyzed. There were 10 males and 8 females, with a median age of 8.5 years (aged from 5 to 34 years). The patients were diagnosed preoperatively with moderate to severe velopharyngeal insufficiency (velopharyngeal closure ratio<0.7). The results of nasopharyngoscopy and speech assessment were compared and analyzed before operation and at the follow-up 6 months after the operation to evaluate the changes in velopharyngeal function and speech. Eighteen patients underwent BMR, 4 patients had snoring (the symptom disappeared after a few weeks in 3 cases), and 2 patients had local erosion of the wound, which delayed healing. Postoperative nasopharyngoscopy showed that all patients achieved comparatively complete velopharyngeal closure, some patients got enhanced lateral pharyngeal wall motility, and all patients got active motility of posterior pharyngeal wall flap. The postoperative speech assessment was significantly improved compared with that before the operation. The preoperative median score was 9 (range 7-12), and the postoperative median score was 2 (range 0-4). The statistical analysis was performed by paired non-parametric Wilcoxon signed rank test, and the difference was statistically significant (P<0.001). BMR is a reliable method for the treatment of moderate and severe velopharyngeal insufficiency. This technique can achieve functional contraction of the full circumference of the ventilator while preserving the obstructive effect of the posterior pharyngeal wall flap, which is helpful to balance nasal ventilation and velopharyngeal closure and improve the velopharyngeal function of patients.

The palatopharyngeal muscle in otolaryngology practice: an anatomical-based surgical report.

OBJECTIVES: The author discusses current otolaryngological procedures employing the palatopharyngeus muscle, based on the surgical anatomy of the muscle and its neural supply. These techniques should be deeply revised for more conservative, anatomically-based maneuvers. METHODS: Revision of anatomical and surgical research and comments with the provision of a primary concept. RESULTS: The palatopharyngeus muscle is innervated by the pharyngeal plexus (the vagus and the accessory nerves) with additional fibers from the lesser palatine nerves. The innervation enters the muscle mainly through its lateral border. CONCLUSIONS: The palatopharyngeus muscle has a fundamental role in swallowing and speech. The muscle helps other dilators to maintain upper airway patency. Sphincter pharyngoplasty should be revised as regards its role as a sphincter. Palatopharyngeal procedures for OSA employing the palatopharyngeus muscle should follow the conservative, anatomically-based, and non-neural ablation concept.

Zebras in Adult Dysphagia Workup: Where to Look When You Think You Have Looked Everywhere.

While many patients who present with dysphagia have a clinically identifiable cause of dysphagia, the etiology of swallowing difficulty is oftentimes a diagnostic enigma. The aim of this article is to review possible etiologies of dysphagia when objective evidence of dysphagia is lacking. Included in this discussion are cricopharyngeal spasm, retrograde cricopharyngeal dysfunction, muscle tension dysphagia, dysphagia secondary to medications, and functional dysphagia.

Pediatric retrograde cricopharyngeal dysfunction diagnosed by high-resolution impedance manometry.

OBJECTIVES: The inability to burp, known as retrograde cricopharyngeal dysfunction (R-CPD), was initially described in adults. The proposed clinical diagnostic criteria for R-CPD include belching inability, abdominal bloating and discomfort/nausea, postprandial chest pain, and involuntary noises. Botulinum toxin injection to the cricopharyngeal muscle has been reported to be beneficial. High-resolution esophageal impedance-manometry (HRIM) features in adolescent patients with R-CPD have not been described yet.  The aim of our study was to describe the clinical and HRIM findings of pediatric patients with R-CPD. METHODS: Clinical and manometric features of five pediatric patients diagnosed with R-CPD were reviewed. HRIM study protocol was modified to include the consumption of carbonated drink to provoke symptoms and distinctive manometric features. RESULTS: We report five female patients aged 15-20 years who presented with an inability to burp and involuntary throat sounds. HRIM revealed normal upper esophageal sphincter (UES) relaxation during swallowing, but abnormal UES relaxation with concurrent high esophageal impedance reflecting air entrapment and secondary peristalsis following the carbonated drink challenge. Four patients exhibited esophageal motility disorder. All patients reported improvement or resolution of symptoms after botulinum toxin injection to the cricopharyngeus muscle. CONCLUSIONS: Adolescents with an inability to burp, reflux-like symptoms, bloating, and involuntary throat noises should be assessed for R-CPD by pediatric gastroenterologists with HRIM. The relatively recent recognition of this novel condition is the likely reason for its under- and misdiagnosis in children.

BMP signaling to pharyngeal muscle in the C. elegans response to a bacterial pathogen regulates anti-microbial peptide expression and pharyngeal pumping.

Host response to pathogens recruits multiple tissues in part through conserved cell signaling pathways. In Caenorhabditis elegans, the bone morphogenetic protein (BMP) like DBL-1 signaling pathway has a role in the response to infection in addition to other roles in development and postdevelopmental functions. In the regulation of body size, the DBL-1 pathway acts through cell autonomous signal activation in the epidermis (hypodermis). We have now elucidated the tissues that respond to DBL-1 signaling upon exposure to two bacterial pathogens. The receptors and Smad signal transducers for DBL-1 are expressed in pharyngeal muscle, intestine, and epidermis. We demonstrate that expression of receptor-regulated Smad (R-Smad) gene sma-3 in the pharynx is sufficient to improve the impaired survival phenotype of sma-3 mutants and that expression of sma-3 in the intestine has no effect when exposing worms to bacterial infection of the intestine. We also show that two antimicrobial peptide genes - abf-2 and cnc-2 - are regulated by DBL-1 signaling through R-Smad SMA-3 activity in the pharynx. Finally, we show that pharyngeal pumping activity is reduced in sma-3 mutants and that other pharynx-defective mutants also have reduced survival on a bacterial pathogen. Our results identify the pharynx as a tissue that responds to BMP signaling to coordinate a systemic response to bacterial pathogens.

Three-dimensional Analysis of the Muscles Related to the So-Called "Pterygomandibular Raphe": An Anatomical and Histological Study.

The pterygomandibular raphe (PMR) is a tendinous bundle between the bucinator (BM) and the superior constrictor of pharynx (SC) and has been considered essential for swallowing. Despite its functional significance, previous studies reported that the PMR is not always present. Another study reported presence of the connecting fascia between the BM and deep temporalis tendon (dTT). Therefore, the present study analyzed the three-dimensional relationship between the BM, SC, and dTT. We examined 13 halves of 11 heads from adult Japanese and Caucasian cadavers: eight halves macroscopically and five halves histologically. There was no clear border between the BM and SC in any specimens macroscopically. The BM attachment varied depending on its levels. At the level of the superior part of the internal oblique line, the BM fused with the SC with no clear border. At the level of the midpart of the internal oblique line of the mandible, the BM attached to the dTT directly, and the SC attached to the dTT via collagen fibers and the BM. Based on these results, these muscles should be described as the BM/dTT/SC (BTS) complex. The three-dimensional relationship of the BTS complex might result in the so-called "pterygomandibular raphe." The BTS complex could be important as a muscle coordination center in chewing and swallowing.

[Help, I can't burp! A brief overview and case discussion of retrograde cricopharyngeal dysfunction]. / Hilfe, ich kann nicht rülpsen: Falldarstellung und Kurzübersicht zur retrograden krikopharyngealen Dysfunktion.

In this short communication, we discuss the recently described syndrome of retrograde cricopharyngeal dysfunction (R-CPD) with its first description in 2019 by the laryngologist Dr. Bastian. Diagnosis is generally based on typical clinical symptoms, e.g., the inability to belch, a bloated abdomen and retrosternal gurgling noises. We also describe high-resolution esophageal manometry as a new tool to further secure the diagnosis of R­CPD, as well as therapeutic options such as botulinum toxin injections in the cricopharyngeal muscle or cricopharyngeal myotomy and the published data thereon.

Postoperative Care of Zenker Diverticula: Contemporary Perspective from the Prospective OUtcomes Cricopharyngeaus Hypertonicity (POUCH) Collaborative.

OBJECTIVES: The aim of the study was to identify trends in postoperative management of persons undergoing surgery for Zenker diverticula (ZD) by evaluating length of stay (LOS), diet on discharge, and imaging with or without surgical complication. METHODS: Prospectively enrolled adult patients with cricopharyngeal muscle dysfunction with diverticula undergoing surgery from August 1, 2017 to February 1, 2023 were included. Data were extracted from a multi-institutional REDCap database, summarizing means, medians, percentages, and frequencies. Fisher's exact or chi squared analyses were utilized, as appropriate, to compare subsets of data. Descriptive analysis assessed differences in clinical course and the relationship to postoperative management. RESULTS: There were 298 patients with a mean (standard deviation) age of 71.8 (11.2) years and 60% male. Endoscopic surgery was performed in 79.5% (237/298) of patients versus 20.5% (61/298) open surgery. Sixty patients (20.1%) received postoperative imaging, with four leaks identified. Complications were identified in 9.4% of cases (n = 29 complications in 28 patients), more commonly in open surgery. Most (81.2%) patients were discharged within 23 h. About half of patients (49%) were discharged from the hospital on a pureed/liquid diet; 36% had been advanced to a soft diet. In patients without complications, LOS was significantly longer following open cases (p = 0.002); postoperative diet was not different between open and endoscopic (p = 0.26). CONCLUSIONS: Overall, most patients are discharged within 23 h without imaging. However, LOS was affected by surgical approach. Postoperative complications are different in endoscopic versus open surgery. Complications with either approach were associated with prolonged LOS, need for imaging, and diet restriction. LEVEL OF EVIDENCE: Level III Laryngoscope, 134:2678-2683, 2024.

Tongue, palatal, hyoid and pharyngeal muscle activity during chewing, swallowing, and respiration.

OBJECTIVE: Chewing, swallowing, and respiration are synchronized oropharyngeal functions. This study aimed to analyze the dynamics and coordination during natural chewing and swallowing in relation to respiratory phases. DESIGN: Eight oropharyngeal muscles in minipigs were recorded using electromyography, X-ray fluoroscopy, and nasopharyngeal dynamics. Chewing cycles and swallowing episodes were analyzed for timing and activity amplitude along respiratory cycles. Digastric and middle pharyngeal constrictor were used as zero-points for timing analysis in chewing cycles and swallowing episodes, respectively. The beginning of these cycles and episodes were used as the zero-point for timing analysis in respiration during feeding. RESULTS: The timing of jaw closing (57.8%) was longer than opening (42.2%) during chewing. Muscle activity occurred 20% later than digastric onsets and 15% earlier than jaw closing phase. Duration of muscle activity was shorter in ipsilateral than contralateral sides except for palatal muscles. Pharyngeal, palatal, and hyoid muscles showed longer durations than tongue muscles in jaw opening (p < 0.05). Palatal and hyoid muscles showed 2-phased activity in chewing while hyoid muscles showed higher amplitude in chewing and swallowing than other muscles. About 80% of the chewing cycles and swallowing episodes occurred in expiration. Nasopharyngeal airflow velocity increased from jaw opening to swallowing while airflow pressure decreased. CONCLUSION: These findings indicate key activity of palatal and pharyngeal muscles mostly in chewing. The respiratory cycle changes in chewing and swallowing simultaneously with the activation of the tongue, palatal, and pharyngeal muscles. These findings will be useful for further understanding the mechanisms in swallowing and breathing disorders.

Regional associations between inspiratory tongue dilatory movement and genioglossus activity during wakefulness in people with obstructive sleep apnoea.

Inspiratory tongue dilatory movement is believed to be mediated via changes in neural drive to genioglossus. However, this has not been studied during quiet breathing in humans. Therefore, this study investigated this relationship and its potential role in obstructive sleep apnoea (OSA). During awake supine quiet nasal breathing, inspiratory tongue dilatory movement, quantified with tagged magnetic resonance imaging, and inspiratory phasic genioglossus EMG normalised to maximum EMG were measured in nine controls [apnoea-hypopnea index (AHI) ≤5 events/h] and 37 people with untreated OSA (AHI >5 events/h). Measurements were obtained for 156 neuromuscular compartments (85%). Analysis was adjusted for nadir epiglottic pressure during inspiration. Only for 106 compartments (68%) was a larger anterior (dilatory) movement associated with a higher phasic EMG [mixed linear regression, beta = 0.089, 95% CI [0.000, 0.178], t(99) = 1.995, P = 0.049, hereafter EMG↗/mvt↗]. For the remaining 50 (32%) compartments, a larger dilatory movement was associated with a lower phasic EMG [mixed linear regression, beta = -0.123, 95% CI [-0.224, -0.022], t(43) = -2.458, P = 0.018, hereafter EMG↘/mvt↗]. OSA participants had a higher odds of having at least one decoupled EMG↘/mvt↗ compartment (binary logistic regression, odds ratio [95% CI]: 7.53 [1.19, 47.47] (P = 0.032). Dilatory tongue movement was minimal (>1 mm) in nearly all participants with only EMG↗/mvt↗ compartments (86%, 18/21). These results demonstrate that upper airway dilatory mechanics cannot be predicted from genioglossus EMG, particularly in people with OSA. Tongue movement associated with minimal genioglossus activity suggests co-activation of other airway dilator muscles. KEY POINTS: Inspiratory tongue movement is thought to be mediated through changes in genioglossus activity. However, it is unknown if this relationship is altered by obstructive sleep apnoea (OSA). During awake supine quiet nasal breathing, inspiratory tongue movement, quantified with tagged magnetic resonance imaging (MRI), and inspiratory phasic genioglossus EMG normalised to maximum EMG were measured in four tongue compartments of people with and without OSA. Larger tongue anterior (dilatory) movement was associated with higher phasic genioglossus EMG for 68% of compartments. OSA participants had an ∼7-times higher odds of having at least one compartment for which a larger anterior tongue movement was not associated with a higher phasic EMG than controls. Therefore, higher genioglossus phasic EMG does not consistently translate into tongue dilatory movement, particularly in people with OSA. Large dilatory tongue movements can occur despite minimal genioglossus inspiratory activity, suggesting co-activation of other pharyngeal muscles.

Combined laryngeal framework surgery and cricopharyngeal muscle-origin transection: a novel effective surgery for dysphagia with pharyngolaryngeal palsy and cricopharyngeal dysfunction under local anesthesia.

BACKGROUND: Cricopharyngeal myotomy and laryngeal framework surgery can improve swallowing function in patients with severe dysphagia. We developed a novel surgical technique for severe dysphagia associated with pharyngolaryngeal paralysis and cricopharyngeal dysfunction, performed under local anesthesia, and investigated its effectiveness. METHODS: We included nine patients who underwent cricopharyngeal muscle-origin transection with laryngeal framework surgery through a horizontal skin incision under local anesthesia. CONCLUSIONS: All patients demonstrated significant improvement in the Food Intake LEVEL Scale without complications. Thus, this surgical technique may serve as a useful and less invasive treatment option for patients with severe dysphagia.