Laryngeal Region Research Articles

The neural mechanisms underlying swallowing

Swallowing is regarded as the first step in nutrition; it transports food boluses and liquid from the mouth to the stomach and is a defensive response to prevent aspiration. Swallowing movements are produced by a central pattern generator (CPG) located in the lower brainstem. The swallowing CPG includes two main groups of neurons: one is located within the nucleus tractus solitarii and contains the generator neurons involved in triggering, shaping, and timing the sequential or rhythmic swallowing pattern and the other is located in the ventrolateral medulla and contains switching neurons that distribute the swallowing drive to various pools of related motoneurons. Swallowing movements can be triggered by either central inputs or peripheral inputs from pharyngeal and laryngeal regions, but the precise neural mechanisms of the swallowing CPG remain to be fully elucidated. This review discusses the fundamental knowledge of ingestion behaviors, with a focus on swallowing.

CO2 Modulates the Central Neural Processing of Sucrose Perception

The five universally accepted tastes, sweet, salty, sour, bitter, and umami (a savory sensation elicited by monosodium glutamate) have specific receptors in oral, pharyngeal and laryngeal regions [1]. The most credited candidates to the function of human primary taste cortex are the frontal operculum and the anterior insula; while the opercular cortex and the orbitofrontal cortex are thought to code for secondary gustatory functions, while the amygdale and the dorsolateral prefrontal cortex are involved as hierarchically superior processing units [2]. Conversely, more is known on the peripheral pathway of taste, including the molecular dynamics of many receptors [3].

Larinksin Bazaloid Skuamöz Hücreli Karsinomu

Basaloid squamous cell carcinoma (BSCC), which is a high-grade and rare variant of squamous cell carcinoma, is often located in the head and neck region. It is usually localized in the oropharynx (base of the tongue), hypopharynx (pyriform sinus), and supraglottic laryngeal regions of the upper aerodigestive tract. It is characterized as clinically aggressive and usually diagnosed in its advanced stage as distant metastases. Therefore, aggressive surgical intervention is essential. A 55-year-old patient with a diagnosis of laryngeal squamous cell carcinoma underwent total laryngectomy and bilateral neck dissection because of disease recurrence after radiotherapy. Histological examination revealed the presence of a basaloid squamous cell carcinoma of the larynx. Chemotherapy was planned because of laryngeal recurrence. In our case report, a rare variant (poorly differentiated BSCC of the larynx) is presented with a review of the relevant literature.

Prospective observer and software-based assessment of magnetic resonance imaging quality in head and neck cancer: Should standard positioning and immobilization be required for radiation therapy applications?

PurposeThe purpose of this study was to investigate the potential of a head and neck magnetic resonance simulation and immobilization protocol on reducing motion-induced artifacts and improving positional variance for radiation therapy applications. Methods and materialsTwo groups (group 1, 17 patients; group 2, 14 patients) of patients with head and neck cancer were included under a prospective, institutional review board–approved protocol and signed informed consent. A 3.0-T magnetic resonance imaging (MRI) scanner was used for anatomic and dynamic contrast-enhanced acquisitions with standard diagnostic MRI setup for group 1 and radiation therapy immobilization devices for group 2 patients. The impact of magnetic resonance simulation/immobilization was evaluated qualitatively by 2 observers in terms of motion artifacts and positional reproducibility and quantitatively using 3-dimensional deformable registration to track intrascan maximum motion displacement of voxels inside 7 manually segmented regions of interest. ResultsThe image quality of group 2 (29 examinations) was significantly better than that of group 1 (50 examinations) as rated by both observers in terms of motion minimization and imaging reproducibility (P < .0001). The greatest average maximum displacement was at the region of the larynx in the posterior direction for patients in group 1 (17 mm; standard deviation, 8.6 mm), whereas the smallest average maximum displacement was at the region of the posterior fossa in the superior direction for patients in group 2 (0.4 mm; standard deviation, 0.18 mm). Compared with group 1, maximum regional motion was reduced in group 2 patients in the oral cavity, floor of mouth, oropharynx, and larynx regions; however, the motion reduction reached statistical significance only in the regions of the oral cavity and floor of mouth (P < .0001). ConclusionsThe image quality of head and neck MRI in terms of motion-related artifacts and positional reproducibility was greatly improved by use of radiation therapy immobilization devices. Consequently, immobilization with external and intraoral fixation in MRI examinations is required for radiation therapy application.

A hybrid approach to the computational aeroacoustics of human voice production.

The aeroacoustic mechanisms in human voice production are complex coupled processes that are still not fully understood. In this article, a hybrid numerical approach to analyzing sound generation in human voice production is presented. First, the fluid flow problem is solved using a parallel finite-volume computational fluid dynamics (CFD) solver on a fine computational mesh covering the larynx. The CFD simulations are run for four geometrical configurations: both with and without false vocal folds, and with fixed convergent or convergent-divergent motion of the medial vocal fold surface. Then the aeroacoustic sources and propagation of sound waves are calculated using Lighthill's analogy or acoustic perturbation equations on a coarse mesh covering the larynx, vocal tract, and radiation region near the mouth. Aeroacoustic sound sources are investigated in the time and frequency domains to determine their precise origin and correlation with the flow field. The problem of acoustic wave propagation from the larynx and vocal tract into the free field is solved using the finite-element method. Two different vocal-tract shapes are considered and modeled according to MRI vocal-tract data of the vowels /i/ and /u/. The spectra of the radiated sound evaluated from acoustic simulations show good agreement with formant frequencies known from human subjects.

Verrucous Carcinoma of Esophagus: A Diagnostic Challenge

Introduction: Verrucous carcinoma of esophagus (VCE) is a rare variant of squamous cell carcinoma; so far less than 23 cases have been reported in literature. VCE is a well-differentiated carcinoma that is slow growing, irregular and wart like in appearance and has a tendency for local invasion. Verrucous squamous cell carcinoma has been reported in the oral cavity, larynx, urogenital and anorectal regions. We present a case of VCE to highlight that high index of suspicion and evaluation with EUS are crucial steps in making an early diagnosis and management of disease. A 64-year-old man referred to our institution for further evaluation of dysphagia and esophageal mass on EGD. He presented with dysphagia to solids and 60 lb. weight loss over a period of 10 months. There was no history of alcohol or tobacco use or ingestion of caustic substances. He had hypertension, diabetes mellitus, and end stage renal disease requiring hemodialysis. Multiple endoscopic evaluations at outside facilities revealed an esophageal mass with inconclusive pathology; squamous atypia without definitive evidence for malignancy was reported. At our institution, EGD and EUS were performed; conventional upper endoscopy revealed a 9cm long near circumferential obstructing mass with a warty/verrucous appearance. On endosonographic evaluation, diffuse thickening of the mucosa and sub-mucosa was noted with invasion through the muscularis propria, without any invasion of surrounding organs and no pathological lymph nodes were noted. Endoscopically obtained biopsy specimens using a jumbo forceps showed abnormally thick hyperplastic squamous mucosa with marked hyperkeratosis, cellular atypia, focal ulceration with heavy inflammatory cells and exhibiting verrucous growth pattern; suggestive of verrucous carcinoma. CT scan of thorax, abdomen and pelvis showed multiple hepatic lesions and lytic lesions in axial and appendicular skeleton suggestive of metastatic disease. EGD was repeated for new onset hematemesis, previously described long circumferential tumor was visualized; given the sub-optimal surgical candidature for palliation and the advanced metastatic disease, a partially covered self-expanding metallic stent was placed for palliation. Diagnosis of VCE is very elusive as is suggested by the current case as well as those described in the literature. A high index of suspicion on the basis of endoscopic features and EUS findings is helpful. Large biopsy specimens to include the sub-mucosa, such as those can be obtained by use of a jumbo forceps, are important for accurate diagnosis. The role of fine-needle aspiration (FNA) during EUS needs to be evaluated in cases with non-diagnostic pathology even with jumbo biopsy forceps.

Numerical Simulation Study on Airflow Structural Characteristics and Vortex Evolution in Human Mouth-Throat Model

Large eddy simulation was used to simulate the airflow movement and vortex evolution in human mouth-throat model in the conditions of the low intensive respiratory patterns, and the airflow structural characteristic and vortex evolution in mouth-throat model was discussed. The results show that two velocity growth points generated in pharyngeal and laryngeal region; the airflow separates in region near the pharynx and the separation zone appears near the anterior wall of pharynx; A turbulence jet appears in the glottal region and the airflow; the jets formatting in pharynx and laryngeal lead to two vorticity growth regions; flat vortex appeared in the throat; a curved vortex like the trachea wall appeared in the anterior wall of trachea, and nearly symmetric reverse vortex pairs appeared in the trachea.

Systemic Amyloidosis: An Otorhinolaryngology Case

Introduction: Amyloidosis is a disease of extracellular deposition of insoluble protein light chain forming amyloid fibrils sheet configuration with B pregueada pentraxin serum amyloid (APS). These substances can be deposited in any organ or tissue. When this occurs in the nasopharyngeal and laryngeal regions, it is an extremely rare event, especially if associated with systemic amyloidosis. Generally, the disease presents localized and not systemic, causing lumiais obstructions in the affected organs. The diagnosis is confirmed by pathological examination with Congo red staining.

Tranexamic acid as maintenance treatment for non-histaminergic angioedema: analysis of efficacy and safety in 37 patients.

Angioedema (AE) is a clinical syndrome characterized by localised swelling lasting several hours. The swelling is often recurring and can be lethal if it is located in the laryngeal region. Much progress has been made recently in the treatment of acute episodes, but no consensus has been reached on maintenance treatment. We have performed a national retrospective observational study to assess the use of tranexamic acid (TA) as maintenance treatment for non-histaminergic AE [hereditary AE (HAE) or idiopathic non-histaminergic AE]. Records for 64 cases were collected from 1 October 2012 to 31 August 2013; 37 of these were included (12 HAE with C1-inhibitor deficiency, six with HAE with normal C1-inhibitor and 19 idiopathic non-histaminergic AE). When treated with TA over six months, the number of attacks was reduced by 75% in 17 patients, 10 patients showed a lower level of reduction and 10 had the same number of attacks. In no instances were symptoms increased. No thromboembolic events were observed, and the main side effects were digestive in nature. Thus, TA, which is well tolerated and inexpensive, appears to be an effective maintenance treatment for some patients with HAE or idiopathic non-histaminergic AE.

English

The variations in the distribution pattern of superior thyroid artery are of great importance for head and neck surgeons because of its vital relationship to the external laryngeal nerve. In this case an unusual unilateral variation in the arterial supply of thyroid gland was found during routine dissection of an elderly male cadaver in the Department of Anatomy, GGS Medical College, Faridkot, Punjab. The left superior thyroid artery took origin from the anterior aspect of left common carotid artery and it exhibited a usual relationship with the left external laryngeal nerve. The inferior thyroid arteries did not show any unusual distribution. Knowledge of such arterial variations related to the thyroid gland is immensely helpful for surgeons in order to put ligature on anomalous artery and to avoid damage to vital structures in this area. It is also helpful to the INTRODUCTION: The Superior Thyroid Artery (STA) is the main source of arterial blood to the thyroid gland, upper part of the larynx and neck region. It is a branch of external carotid artery (ECA) and arises from its anterior surface, just below the level of greater cornu of the hyoid bone. It runs downwards from its origin and gives a branch i.e. superior laryngeal artery (SLA) which pierces the thyrohyoid membrane along with the internal laryngeal nerve. It also gives an infrahyoid branch, a branch to the sternocleidomastoid muscle and a crico-thyroid branch. 1 The relationship of the superior thyroid artery to the external laryngeal nerve is important to the surgeon during thyroid surgery. The artery and nerve are close to each other higher up but diverge near the gland. Thus in order to avoid injury to the external laryngeal nerve, the superior thyroid artery is ligated as near to the gland as possible. The STA is frequently used as a recipient vessel for microvascular free tissue transfer in head and neck surgery, for selective embolization of thyroid and head and neck tumors, and as a landmark for identifying the external laryngeal nerve in thyroid surgery. 2 Surgical procedures involving the thyroid gland require a thorough knowledge not only of the normal gross anatomy of the structures within the region but also of the anatomical variations of the structures located within it. Thyroid surgery being a major surgery and quite often performed, a thorough knowledge of variations in arterial supply is very essential for surgeons to prevent alarming number of table deaths in patients with thyroid disease due to excessive and uncontrollable bleeding. It is also of help to the radiologists and physicians for proper physical examination and treatment of the patient and to the anatomists for learning the variant patterns.

Worst-case scenario intubation of laryngeal granuloma: a case report

BackgroundIntubation of patients with laryngeal granulomas on the vocal folds are sometimes difficult to manage because of potential airway obstruction. Laryngeal granulomas usually have flexible stalks where they attach to the vocal folds. We report a worst-case scenario of dislocation of the laryngeal granuloma during induction of anaesthesia.Case presentationWe present a case of laryngeal granulomas on the posterior vocal fold. A 20-year-old woman had an approximately 10-mm tumour in the laryngeal arytenoid region. Manual ventilation resulted in the tumour lodging in the subglottis and the inflated cuff of the intubation tube successfully returned it to its original position during tube withdrawal. Images were obtained using an Airway Scope® (Hoya-Pentax, Tokyo, Japan) and a video laryngoscope.ConclusionIn our case, the tumour was benign and relatively small in size; therefore, we did not select tracheotomy as an airway management strategy. The case had a granulomatous tumour arising from the posterior vocal folds on the right side, and the tumour was very flexible. To promptly gain control of the airway in such a case using direct laryngoscopy, thus avoiding tracheotomy, other strategies are suggested, such as bronchoscopic visualization with awake or semi-awake intubation.

THE VOCALIZATION MECHANISM OF THE FLORIDA MANATEE (&lt;i&gt;TRICHECHUS MANATUS LATIROSTRIS&lt;/i&gt;)

The mechanism by which Florida manatees produce vocalizations is unknown. Anatomically, the laryngeal region in manatees lacks clearly defined vocal folds. Initially we developed a method to visualize the entire manatee upper respiratory system. We then forced air through fresh necropsied manatee larynxes and generated artificial vocalizations which closely duplicated the normal vocalizations produced by live manatees, both in fundamental frequency and structure of harmonics. Here we report that sound is generated in the larynx when air vibrates bilateral strips of tissue embedded in the lateral laryngeal walls which are in close approximation anteriorly but which diverge posteriorly. We propose that these strips of tissue are the modified vocal folds containing ligaments and we support this through histological stained sections and because they are connected anteriorly to the posterior side of the thyroid cartilage and posteriorly with the arytenoidal cartilages. We also suggest that these vocalizations are then modified within the resonance cavities in the frontal area of the head and the air used to generate these vocalizations also causes a transient deformation of this region before being conserved and returned to the lungs.

Case Report: Recurrent Respiratory Papillomatosis: A Report of two cases and review of literature

Background: Recurrent Respiratory Papillomatosis (RRP) is a non-cancerous tumour of the upper airway caused by the human papilloma virus, presenting as “wart-like” growth, which could be anywhere from the nose to the lungs commonly in the larynx.Design and Setting: Review of two cases at the National Hospital Abuja (NHA).Objectives: To highlight the challenges in the management of RRP.Subjects: Two patients diagnosed with RRP were referred to the paediatric respiratory clinic between 2009 and 2012. Case one is a four year old female who presented with persistent hoarseness of voice, breathing difficulty and noisy breathing of one year duration. She was born at term by spontaneous vertex delivery to a mother who had vaginal warty lesion excised during pregnancy. A neck X-ray showed opacities around the laryngeal region with total obliteration of air column with histological confirmation of squamous papilloma. She had eight excision surgeries within a two years period with treatment with oral acyclovir, interferon, and methotrexate and tracheotomy tube in situ. Case two, a six year old female presented with persistent hoarseness of voice that progressed to loss of voice, noisy and difficulty in breathing, snoring and frequent arousal from sleep of 1½ years. Histology was diagnostic of laryngeal Papillomatosis and she had two excisions surgeries and treatment with oral acyclovir and tracheotomy tube in place.Conclusion: RRP though a slow growing tumour, presently has no definitive cure. Excision surgeries provide temporal relief and antiviral agents adjuvant therapies. Prevention with vaccination is desirable.Keyword: Recurrent respiratory Papillomatosis, Human papilloma virus.

Visualization of the laryngeal muscles with high-quality magnetic resonance imaging

The larynx is the organ to adjust voice in speech important for controlling voice phonation, and the tensions of the vocal folds cord is controlled by the relative positions among the thyroid, arytenoid, and cricoid cartilages. Magnetic resonance images (MRI) have been employed to observe the positions of those cartilages, while however, visualizing the laryngeal muscles for activating moving those cartilages is still difficult with the conventional MRI. This study aims to visualize and identify the laryngeal muscles based on the composition of the three different sets of gray-scale MRI data into red, green, and blue channels, namely RGB-MRI. The types of imaging parameters image variations are field-echo opposed-phase (FE(op)), spin-echo proton density weighted (SE(PDw)), and spin-echo T1 weighted (SE(T1w)). This method for image composition helps usidentifying could reveal the location of the muscles in the laryngeal region in vivo. We have successfully identified the sternohyoid muscle, thyrohyoid muscle, lateral thyroarytenoid muscle, cricothyroid muscle, stenrocleidmustoid muscle, omohyoid muscle, and inferior constrictor muscles. The RGB-MRI could give further provide anatomical information of the larynx, especially about the muscle location and its deformation involved in on speech mechanisms, which will be useful for both research experts and beginners.

Laryngeal anomalies: Pitfalls in adult forensic autopsies

This is the first paper to group together most of adult laryngeal anomalies or malformations which may be misinterpreted by the forensic pathologist and taken for a proof of violence. A review of the literature, to list the main pitfalls, to explain their nature and their origins. We found two main categories, the congenital defects and the acquired anomalies. The laryngeal region is complex. The pathologist must keep in mind anatomical variations or malformations, but also sequelae of old injuries and iatrogenic lesions. The survey, the patient's clinical history, the findings of the whole autopsy and, if necessary, histology may help to interpret a laryngeal anomaly.

Anatomical education and surgical simulation based on the Chinese Visible Human: a three-dimensional virtual model of the larynx region

Anatomical knowledge of the larynx region is critical for understanding laryngeal disease and performing required interventions. Virtual reality is a useful method for surgical education and simulation. Here, we assembled segmented cross-section slices of the larynx region from the Chinese Visible Human dataset. The laryngeal structures were precisely segmented manually as 2D images, then reconstructed and displayed as 3D images in the virtual reality Dextrobeam system. Using visualization and interaction with the virtual reality modeling language model, a digital laryngeal anatomy instruction was constructed using HTML and JavaScript languages. The volume larynx models can thus display an arbitrary section of the model and provide a virtual dissection function. This networked teaching system of the digital laryngeal anatomy can be read remotely, displayed locally, and manipulated interactively.

COMPUTED TOMOGRAPHIC FEATURES OF BASIHYOID ECTOPIC THYROID CARCINOMA IN DOGS

Eight dogs with a firm, nonpainful swelling in the ventral laryngeal region and with a final diagnosis of ectopic thyroid carcinoma were investigated by Computed Tomography (CT) at six different institutions. Computed Tomography findings were reviewed, focusing on lesion volume, shape, margins, relationship with surrounding structures and adjacent vessels, attenuation characteristics, and presence of metastases. Ectopic thyroid carcinomas were seen as oval-to-bilobed masses centered on the basihyoid bone with associated bone lysis, highly vascularized capsules with central poorly contrast enhancing areas. In all cases there was laryngeal wall infiltration, in two dogs invasion of the laryngeal lumen and in one case invasion of the ventral muscular and subcutaneous plane. Metastases were found in retropharyngeal lymph nodes (three cases) and in the lung (two cases). Ectopic thyroid carcinoma should be considered in the differential diagnosis when a mass in the basihyoid region is present. Described CT features may be typical for ectopic thyroid neoplasia and could be used to help decide the therapeutic plan.

Helicobacter pylori infection in laryngeal diseases

Clinical studies have shown that Helicobacter pylori can be found not only in the mucosa of the stomach, but in the pharyngeal and laryngeal regions as well. The aim of this prospective case-control study was to identify H. pylori infection in the biopsy material from the larynx of the patients suffering from benign laryngeal diseases (vocal fold polyps, laryngitis) and laryngeal cancer and to investigate the possible relationships between the laryngeal H. pylori and patients' socio-demographic data and laryngopharyngeal reflux. The results of the biopsy material from 67 adult patients treated for benign laryngeal diseases and laryngeal cancer and 11 individuals of the control group revealed that H. pylori infection could be identified in more than one-third of the patients. In the majority of cases H. pylori was found in the patients with chronic laryngitis (45.5%) and laryngeal cancer (46.2%). The findings of these sub-groups significantly differed from those of the control group (9.1%) (p < 0.05). No significant relationships between H. pylori infection found in the laryngeal region and patients' demographic data, their unhealthy habits and reflux-related symptoms or signs were obtained. It could be concluded that H. pylori can colonize in the larynx of patients with benign laryngeal diseases and laryngeal cancer. To clarify the role of H. pylori as a risk factor for laryngeal diseases further research is needed.

Thoracic Fraction of Inhaled Fiber Aerosol

Size-selective sampling is a health-related method to collect airborne particles based on penetration of inhaled particles into different regions of the human respiratory tract; thus, it is the most relevant sampling method to correlate health risks with occupational exposure. The current practice of sampling asbestos and other fibers is not a size-selective method. The thoracic size fraction, defined as the portion of inhaled particles that can penetrate through the larynx, has been suggested as the most relevant size-selective sampling method for fiber aerosol. The thoracic fraction is based on 1-deposition of inhaled spherical particles in the human extrathoracic airways for mouth breathing and corrected for the particle inhalability. There is no comparable information for fiber aerosols; therefore, there is no technical basis to ascertain whether the current thoracic fraction definition is suitable for fiber aerosols. No human data are available from controlled experiments of inhaled fiber aerosols for the obvious reason that most fiber materials are potentially hazardous when inhaled. Our approach was to measure penetration of fiber aerosol in realistic human oropharyngeal airway replicas and to compare that with data from spherical particles. We showed that realistic human oral airway replicas (including the oral cavity, pharynx, and larynx regions) provided useful spherical and fiber particle deposition in the human head airway. These data could be used to test the thoracic fraction curves. The spherical penetration is in agreement with human in vivo data used to establish the thoracic fraction curve. Fiber penetrations through the larynx of two human oral airway replicas were higher than those for spherical particles for the same aerodynamic diameter using the same replicas. The thoracic curve as defined for spherical particles, therefore, may not include some fibers that could penetrate to the thoracic region.

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