Functional aspects of the Eustachian tube by means of 3D-modeling.

The extent of dysfunction of the Eustachian tube (ET) is relevant in understanding the pathogenesis of secondary otological diseases such as acute or chronic otitis media. The underlying mechanism of ET dysfunction remains poorly understood except for an apparent genesis such as a nasopharyngeal tumor or cleft palate. To better describe the ET, its functional anatomy, and the biomechanical valve mechanism and subsequent development of diagnostic and interventional tools, a three-dimensional model based on thin-layer histology was created from an ET in this study. Blackface sheep was chosen as a donor. The 3-D model was generated by the coherent alignment of the sections. It was then compared with the cone-beam computed tomography dataset of the complete embedded specimen taken before slicing. The model shows the topographic relation of the individual components, such as the bone and cartilage, the muscles and connective tissue, as well as the lining epithelium with the lumen. It indicates a limited spiraling rotation of the cartilaginous tube over its length and relevant positional relationships of the tensor and levator veli palatine muscles.

Isolated Ear Clicks with Partial Voluntary Control.

BACKGROUND: Ear click is a rare type of objective tinnitus, classically described with associated palatal tremor/myoclonus (PT). CASE REPORT: A 15-year-old boy reported a constant bilateral ear clicking for 4 years, that could be stopped at will for a few seconds. Clinically, the ear clicks were audible without visible eardrum or palatal movement, and could be entrained by the examiner. Brain MRI was normal. DISCUSSION: We propose to classify this as isolated ear clicks with partial voluntary control, putting it into context with other subcategories of "essential" or "isolated" PT.

Functional characterization of extrinsic tongue muscles in the Pink1-/- rat model of Parkinson disease.

Parkinson disease (PD) is associated with speech and swallowing difficulties likely due to pathology in widespread brain and nervous system regions. In post-mortem studies of PD, pathology has been reported in pharyngeal and laryngeal nerves and muscles. However, it is unknown whether PD is associated with neuromuscular changes in the tongue. Prior work in a rat model of PD (Pink1-/-) showed oromotor and swallowing deficits in the premanifest stage which suggested sensorimotor impairments of these functions. The present study tested the hypothesis that Pink1-/- rats show altered tongue function coinciding with neuromuscular differences within tongue muscles compared to wildtype (WT). Male Pink1-/- and WT rats underwent behavioral tongue function assays at 4 and 6 months of age (n = 7-8 rats per group), which are time points early in the disease. At 6 months, genioglossus (GG) and styloglossus (SG) muscles were analyzed for myosin heavy chain isoforms (MyHC), α-synuclein levels, myofiber size, centrally nucleated myofibers, and neuromuscular junction (NMJ) innervation. Pink1-/- showed greater tongue press force variability, and greater tongue press forces and rates as compared to WT. Additionally, Pink1-/- showed relative increases of MyHC 2a in SG, but typical MyHC profiles in GG. Western blots revealed Pink1-/- had more α-synuclein protein than WT in GG, but not in SG. There were no differences between Pink1-/- and WT in myofiber size, centrally-nucleated myofibers, or NMJ innervation. α-synuclein protein was observed in nerves, NMJ, and vessels in both genotypes. Findings at these early disease stages suggest small changes or no changes in several peripheral biological measures, and intact motor innervation of tongue muscles. Future work should evaluate these measures at later disease stages to determine when robust pathological peripheral change contributes to functional change, and what CNS deficits cause behavioral changes. Understanding how PD affects central and peripheral mechanisms will help determine therapy targets for speech and swallowing disorders.

Palatal Tremor - Pathophysiology, Clinical Features, Investigations, Management and Future Challenges.

Background: Palatal tremor is involuntary, rhythmic and oscillatory movement of the soft palate. Palatal tremor can be classified into three subtypes; essential, symptomatic and palatal tremor associated with progressive ataxia. Methods: A thorough Pubmed search was conducted to look for the original articles, reviews, letters to editor, case reports, and teaching neuroimages, with the keywords "essential", "symptomatic palatal tremor", "myoclonus", "ataxia", "hypertrophic", "olivary" and "degeneration". Results: Essential palatal tremor is due to contraction of the tensor veli palatini muscle, supplied by the 5th cranial nerve. Symptomatic palatal tremor occurs due to the contraction of the levator veli palatini muscle, supplied by the 9%th and 10%th cranial nerves. Essential palatal tremor is idiopathic, while symptomatic palatal tremor occurs due to infarction, bleed or tumor within the Guillain-Mollaret triangle. Progressive ataxia and palatal tremor can be familial or idiopathic. Symptomatic palatal tremor and sporadic progressive ataxia with palatal tremor show signal changes in inferior olive of medulla in magnetic resonance imaging. The treatment options available for essential palatal tremor are clonazepam, lamotrigine, sodium valproate, flunarizine and botulinum toxin. The treatment of symptomatic palatal tremor involves the treatment of the underlying cause. Discussion: Further studies are required to understand the cause and pathophysiology of Essential palatal tremor and progressive ataxia and palatal tremor. Similarly, the link between tauopathy and palatal tremor associated progressive ataxia needs to be explored further. Oscillopsia and progressive ataxia are more debilitating than palatal tremor and needs new treatment approaches.

A Case of Paraneoplastic Myoclonus Attributed to Non-Small Cell Lung Cancer.

Background: It is well known that myoclonus can be a paraneoplastic manifestation of underlying malignancy. Case Report: A 78-year-old male diagnosed with papillary variant non-small cell lung cancer (NSCLC) presented with tremulousness that rapidly evolved into severe, diffuse myoclonus with prominent palatal involvement requiring intubation. The generalized myoclonus resolved with on levetiracetam, chemotherapy and immune modulation. While low titer positive P/Q type calcium channel autoantibodies were detected, it's etiologic relevance is unclear. Discussion: This case highlights a rare neurologic paraneoplastic presentation of papillary NSCLC. It also illustrates the importance of monitoring airway safety when myoclonus is generalized. Highlights: A new, rare paraneoplastic presentation of papillary variant non-small cell lung adenocarcinoma is described. The patient presented with severe diffuse myoclonus with prominent palatal involvement without encephalitis that responded to a combination of chemotherapy, immune modulation, and levetiracetam. No clear causal antibody was found.

Electrophysiological Evidence for Functional (Psychogenic) Essential Palatal Tremor.

Background: There is little published work describing the electrophysiological characteristics of essential palatal tremor, a condition now believed by many to be a functional (psychogenic) movement disorder. Case Report: Here we combine electroencephalography and electromyography with time-locked video recordings to document two cases of essential palatal tremor in which a definitive diagnosis is achieved using these electrophysiological tools. Discussion: We believe that sharing how these objective tools can be used to diagnose a functional movement disorder, as well as providing more published evidence to support the functional origin of essential palatal myoclonus, will help to diagnose this condition in the future.

Management of palatal myoclonic tinnitus based on clinical characteristics: a large case series study.

Background: Palatal myoclonic tinnitus (PMT) is a rare otological condition caused by rhythmic contractions of soft palate muscles. Due to its rarity, only a few case series studies have been reported in the literature at the present time.Aims: This large case series study reviews treatment outcomes of PMT patients over the past 15 years based on clinical characteristics.Materials and methods: Between the year 2003 and 2018, 54 patients with a diagnosis of PMT were assessed. Clinical characteristics, audiological findings, psychological status, and other relevant medical history were thoroughly reviewed. Response to various treatment modalities were retrospectively analyzed.Results: The mean age of enrolled patients was 29.0 ± 16.4 years, with female gender predominance. All of the patients complained of 'clicky' sounding tinnitus. Twenty-nine patients had comorbid tinnitus of other type. Reassurance and behavior therapy was sufficient for young patients. Medication was effective in 44.4% of the patients. Botulinum toxin injection in the palate led to complete resolution of symptoms in a majority of intractable PMT patients.Conclusions and significance: Management of PMT should be customized according to the individual clinical characteristics of the patients. This study may provide insightful information to establish optimal treatment modalities for PMT.

Intravelar and Extravelar Portions of Soft Palate Muscles in Velic Constrictions: A Three-Dimensional Modeling Study.

Purpose This study predicts and simulates the function and relative contributions of the intravelar and extravelar portions of the levator veli palatini (LVP) and palatoglossus (PG) muscles in velic constrictions. Method A finite element-based model of the 3-dimensional upper airway structures (palate, pharynx, tongue, jaw, maxilla) was implemented, with LVP and PG divided into intravelar and extravelar portions. Simulations were run to investigate the contributions of these muscles in velopharyngeal port (VPP) closure and constriction of the oropharyngeal isthmus (OPI). Results Simulations reveal that the extravelar portion of LVP, though crucial for lifting the palate, is not sufficient to effect VPP closure. Specifically, the characteristic "bulge" appearing in the posterior soft palate during VPP closure ( Pigott, 1969 ; Serrurier & Badin, 2008 ) is found to result from activation of the intravelar portion of LVP. Likewise, the intravelar portion of posterior PG is crucial in bending the "veil" or "traverse" ( Gick, Francis, Klenin, Mizrahi, & Tom, 2013 ) of the velum anteriorly to produce uvular constrictions of the OPI ( Gick et al., 2014 ). Conclusions Simulations support the view that intravelar LVP and PG play significant roles in VPP and OPI constrictions.

Soft palate muscle activation: a modeling approach for improved understanding of obstructive sleep apnea.

A Hill model-based phenomenological method for muscle activation was used to investigate defectiveness of the palatal muscle tone during sleep for obstructive sleep apnea (OSA) patients. Based on the stretch-stress characteristic of muscle activation when the eccentric contraction is considered, a specifically defined phenomenological strain-energy function was used, as well as the Holzapfel-type strain-energy function for the passive part. A continuum mechanical framework, including the stress tensor and elasticity tensor, was obtained, based on the defined strain-energy function. The model parameters were obtained by fitting the constitutive model to experimental test data. Three-dimensional patient-specific geometry was modeled, accounting for the muscle tissue layer and based on the quantitative histology study of the soft palate. Anatomically representative boundary conditions for the finite element calculation were also considered. Palatal muscle activation level (electromyographic data) versus the negative pressure was defined in the simulations, and the patients' activation level was set to be lower than for the healthy people. The simulation results showed that reduced in activation level for the patients causes a less negative closing pressure, and this makes the soft palate more prone to collapse. In addition, if we account for the passive-active transfer displayed as the muscle contraction corresponding to the neurogenic reflex in the soft palate, the collapse is prevented. This numerical representation of the reduced activation for the OSA patients may provide increased understanding of OSA physiology.

Does drug-induced sleep endoscopy predict surgical success of limited palatal muscle resection in patients with obstructive sleep apnea?

OBJECTIVE: The aims of this study were to determine the associated factors affecting the success rate of limited palatal muscle resection (LPMR), and to investigate whether drug-induced sleep endoscopy (DISE) could predict the therapeutic response to LPMR in patients with obstructive sleep apnea obstructive sleep apnea (OSA). METHODS: Twenty-one consecutive OSA patients underwent LPMR were enrolled. All patients received routine ENT examination, preoperative DISE, and polysomnography (PSG). Clinical, polysomnographic, cephalometric variables, and DISE findings were evaluated. The measurements were related to the success or failure of LPMR based on the results of preoperative and postoperative PSG. RESULTS: The overall success rate of LPMR was 66.6%. Postoperative AHI and minimal oxygen saturation were significantly decreased after LPMR (p<0.001). Comparison between success and failure groups revealed no significant differences in BMI, Friedman stage, preoperative AHI, minimal oxygen saturation, and all cephalometric parameters. However, the success of LPMR was significantly correlated with site, degree, and configuration of obstruction in DISE. In the velopharynx, complete obstruction (p=0.006) with anterolateral or concentric pattern (p=0.044) had significantly better success rate than partial obstruction with lateral pattern. CONCLUSION: DISE was only predictive method for identifying the success in OSA patients undergoing LPMR. Patients with anteroposterior or concentric total obstruction in the velopharynx might be suitable candidate for LPMR.

Differences in the Tensor Veli Palatini Between Adults With and Without Cleft Palate Using High-Resolution 3-Dimensional Magnetic Resonance Imaging.

OBJECTIVE: To investigate the dimensions of the tensor veli palatini (TVP) muscle in adults with and without cleft palate. DESIGN: Prospective study. PARTICIPANTS: There were a total of 14 adult participants, 8 noncleft and 6 with cleft palate. METHODS: Analysis and comparison of the TVP muscle and surrounding structures was completed using 3D MRI data and Amira 5.5 Visualization Modeling software. TVP muscle volume, hamular process distance, mucosal thickness, TVP muscle length, and TVP muscle diameter were used for comparison between participant groups based upon previous research methods. RESULTS: Mann-Whitney U tests revealed a significantly smaller ( U < .001, P = .002) TVP muscle volume in the cleft palate group (median = 536.22 mm3) compared to individuals in the non-cleft palate group (median = 895.19 mm3). The TVP muscle was also significantly shorter ( U = 1.00, P = .003) in the cleft palate group (median = 18.04 mm) versus the non-cleft palate (median = 21.18 mm). No significant differences were noted for the other measured parameters. CONCLUSION: Significant differences in the TVP muscle volume and length among the noncleft participants found in this study may insights into the reported increased incidence of otitis media with effusion (OME) seen in the cleft population. Results from this study contribute to our understanding of the underlying anatomic differences among individuals with cleft palate.

Respiratory difficulty with palatal, laryngeal and respiratory muscle tremor in adult-onset Alexander's disease.

Sleep apnoea and respiratory difficulties are reported in adult-onset Alexander's disease (AOAD), an autosomal-dominant leukodystrophy that presents mainly with progressive ataxia. We demonstrate for the first time that the respiratory symptoms can result from association of palatal tremor with a similar tremor of laryngeal and respiratory muscles that interrupts normal inspiration and expiration.A 60-year-old woman presented with progressive ataxia, palatal tremor and breathlessness. MRI revealed medullary atrophy, bilateral T2 hyperintensities in the dentate nuclei and hypertrophic olivary degeneration (HOD). AOAD was confirmed genetically with a positive glial fibrillary acidic protein (GFAP) mutation. Electrophysiological study revealed 1.5 Hz rhythmic laryngeal and respiratory muscle activity. Her respiratory symptoms were significantly improved at night with variable positive pressure ventilation.This case illustrates that palatal tremor in AOAD, and potentially in other conditions, may be associated with treatable breathlessness due to a similar tremor of respiratory muscles.

Palatoglossus coupling in selective upper airway stimulation.

OBJECTIVES/HYPOTHESIS: Selective upper airway stimulation (sUAS) of the hypoglossal nerve is a useful therapy to treat patients with obstructive sleep apnea. Is it known that multiple obstructions can be solved by this stimulation technique, even at the retropalatal region. The aim of this study was to verify the palatoglossus coupling at the soft palate during stimulation. STUDY DESIGN: Single-center, prospective clinical trail. METHODS: Twenty patients who received an sUAS implant from April 2015 to April 2016 were included. A drug-induced sedated endoscopy (DISE) was performed before surgery. Six to 12 months after activation of the system, patients' tongue motions were recorded, an awake transnasal endoscopy was performed with stimulation turned on, and a DISE with stimulation off and on was done. RESULTS: Patients with a bilateral protrusion of the tongue base showed a significantly increased opening at the retropalatal level compared to ipsilateral protrusions. Furthermore, patients with a clear activation of the geniohyoid muscle showed a better reduction in apnea-hypopnea index. CONCLUSIONS: A bilateral protrusion of the tongue base during sUAS seems to be accompanied with a better opening of the soft palate. This effect can be explained by the palatoglossal coupling, due to its linkage of the muscles within the soft palate to those of the lateral tongue body. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:E378-E383, 2017.