Droplet applicator module for reproducible and controlled endoscopic laryngeal adductor reflex stimulation.

This work presents a droplet applicator module to generate stable droplets with different muzzle energies for the reproducible endoscopic stimulation of the laryngeal adductor reflex (LAR). The LAR is a protective reflex of the human larynx; an abnormal LAR performance may cause aspiration pneumonia. A pathological LAR can be detected by evaluating its onset latency. The reflex can be triggered by shooting a droplet onto the laryngeal mucosa, which is referred to as Microdroplet Impulse Testing of the LAR (MIT-LAR). Stimulation intensity variation is desired as the reflex threshold may vary inter-individually. The kinetic energy of a droplet after detachment from the nozzle, i.e., its muzzle energy, is considered an appropriate metric for the LAR stimulation intensity. In this work, a suitable nozzle channel geometry is identified based on the experimental evaluation of droplet formation using three different nozzle channel geometries. Two nontoxic additives are evaluated regarding their effect on fluid properties and droplet formation. The range of achievable droplet muzzle energies is determined by high-speed cinematography in association with a physically motivated model of the macroscopic droplet motion. The experimental results show that sodium chloride is a suitable additive to enhance droplet stability in the studied parameter range with the proposed system. Droplet muzzle energy variation from 0.02 µ J to 1.37 µ J was achieved while preserving the formation of a single stimulation droplet. These results are an important prerequisite for a safe and reproducible LAR stimulation by MIT-LAR, which could also help to further elucidate the physiological mechanisms underlying this laryngeal reflex.

[Guideline: Auditory Processing and Perception Disorders: Diagnostics : S1-Guideline of The German Society of Phoniatrics and Pediatric Audiology]. / Leitlinie: "Auditive Verarbeitungs- und Wahrnehmungsstörungen": Diagnostik : S1-Leitlinie der Deutschen Gesellschaft für Phoniatrie und Pädaudiologie.

In accordance with international consensus papers, auditory processing disorders (APD) are defined as disorders of central processes of hearing. Following the establishment of a commission of experts from the German Society for Phoniatrics and Pediatric Audiology, the existing S1 guideline was revised and updated. In this chapter, a position is taken on the clinical diagnostics of APD as well as on the delimitation of similar disorders.

[Guideline: Auditive Processing and Perception Disorders: Definition : Guideline of the German Society of Phoniatrics and Pediatric Audiology]. / Leitlinie "Auditive Verarbeitungs- und Wahrnehmungsstörungen": Definition : S1-Leitlinie der Deutschen Gesellschaft für Phoniatrie und Pädaudiologie.

In accordance with international consensus papers, Auditory Processing Disorders are defined here as disorders of central processes of hearing, which enable, among other things, the pre-conscious and conscious analysis, differentiation, and identification of changes in time, frequency, and intensity of acoustic or auditory speech signals as well as processes of binaural interaction (e. g., for localization, lateralization, noise clearance, and summation) and dichotic processing. Following the establishment of a commission of experts from the German Society for Phoniatrics and Pediatric Audiology, the existing S1 guideline was revised and updated. In this chapter, a position is taken on the definition of this clinical disorder as well as on the delimitation of similar disorders.

[High-resolution manometry of pharyngeal swallowing dynamics]. / Hochauflösungsmanometrie der pharyngealen Schluckdynamik.

BACKGROUND: To transport a bolus from the mouth into the stomach, regular contraction of the pharyngeal muscles and a coordinated function of the upper esophageal sphincter (UES) are necessary. The muscle contraction generates intraluminal pressure, which pushes the bolus continuously forward. In contrast to imaging studies, manometric methods enable assessment of intraluminal pressure buildup and the function of the muscles involved. These methods were initially established for the esophagus and have been used increasingly in the pharynx for 7-8 years. Pharyngeal high-resolution manometry (pHRM) allows pressure measurements in high spatial and temporal resolution, and assessment of pharyngeal swallowing dynamics. OBJECTIVE: An overview is given of the implementation, evaluation, and interpretation of the pHRM data, as well as of the current state of research. MATERIALS AND METHODS: PubMed and Scopus were searched for the keywords "high-resolution manometry" and "pharynx" or "upper esophageal sphincter". Original articles, reviews, and book chapters on the subject pHRM were included. RESULTS: Swallowing pressure conditions in the pharynx and the UES can be assessed by pHRM. The spatiotemporal pressure plot gives an overview of changes in pharyngeal motor function. Determination of swallowing parameters enables a sophisticated evaluation of swallowing; a comparison with normal values permits delimitation of pathologies. CONCLUSION: Although several swallowing parameters still need to be further evaluated for clinical routine, a pHRM study should nowadays always be carried out for a comprehensive evaluation of the swallowing process.

[Laryngeal and larynx-associated reflexes]. / Larynxreflexe und larynxassoziierte Reflexe.

The laryngeal adductor reflex and the pharyngoglottal closure reflex protect the trachea and lower respiratory tract against the entrance of foreign material. The laryngeal expiration reflex and the cough reflex serve to propel foreign material, which has penetrated in the cranial direction. The inspiration reflex, the sniff reflex, and the swallowing reflex are further larynx-associated reflexes. In patients with dysphagia the laryngeal adductor reflex can be clinically tested with air pulses. The water swallow test serves to show the integrity of the cough reflex. The sniff reflex is useful to test the abduction function of the vocal folds. Future studies should address laryngeal reflexes more specifically, both for a better understanding of these life-supporting mechanisms and to improve diagnostic procedures in patients with impaired laryngeal function.

[Diagnosis of auditory processing disorders in children]. / Diagnostik auditiver Verarbeitungs- und Wahrnehmungsstörungen bei Kindern.

Despite normal hearing thresholds in pure tone audiometry, 0.5-1 % of children have difficulty understanding what they hear. An auditory processing disorder (APD) can be assumed, which should be clarified and treated. Based on a selective literature search in the PubMed and Scopus databases using the term "auditory processing disorder", several consensus papers are discussed. Numerous studies on APD have revealed partially contradicting results, thus fueling critical discussion regarding validity and reliability-of specific audiometric APD methods and the APD construct in particular. In order to correctly advise parents and, where necessary, treat affected children, otorhinolaryngologists, phoniatrists, and pediatric audiologists must understand the psychometric properties of applied tests and have knowledge of current discussion. Diagnosis is generally a multistep interdisciplinary process.

[Deliberate release of the laryngeal adductor reflex via microdroplet impulses: Development of a device]. / Gezielte Auslösung des laryngealen Adduktionsreflexes per Mikrotröpfchenabgabe: Entwicklung einer Vorrichtung.

BACKGROUND: The laryngeal adductor reflex (LAR), a reflexive vocal fold closing mechanism, includes an early, probably di- or oligosynaptic ipsilateral LAR1- and a late ipsilateral and contralateral LAR2 polysynaptic component. In a clinical evaluation of dysphagia the LAR can be triggered by air pulses or tactile stimuli and typically assessed only qualitatively. METHODOLOGY: The development and construction of a device that can selectively shoot very small water droplets (microdroplet impulse testing MIT). RESULTS: The MIT device has a water reservoir with an infinitely adjustable pressure. The opening period of the piezo-electrically operated valve determines the droplet size. With a high-speed camera system, the change in the airspeed of the drop can be determined, depending on the set water reservoir pressure. With the knowledge of the droplet size, the shooting speed and the estimation of the distance between the valve and laryngeal mucosa or airspeed can be determined the muzzle energy. By mounting the MIT device to a high speed glottography system, the time between the impact of the droplet on the laryngeal mucosa and the start of the laryngeal adduction, the LAR latency can be determined using an image by image evaluation. DISCUSSION: In dysphagia with penetration or aspiration it is presumed that the protective function of the larynx is no longer adequately ensured. The MIT-LAR device provides a valid and reliable method to assess LAR quantitatively. Furthermore, it holds the promise of being a simple to handle method that can be used clinically for routine diagnostics.

[Characterization of the Laryngeal Adductor Reflex by Stimulation with Microdroplets Impulses (Microdroplet Impulse Testing)]. / Charakterisierung des laryngealen Adduktionsreflexes durch Stimulation mit Mikrotröpfchen-Impulsen (microdroplet impulse testing).

BACKGROUND: The larynx is considered a crossing point between breathing and swallowing pathways. During swallowing, the airway below the glottis must be protected against food components by an appropriate laryngeal closure mechanism. The laryngeal adductor reflex (LAR) with an early, probably di- or oligosynaptic interconnected ipsilateral LAR1- and a late ipsilateral and contralateral LAR2 polysynaptic component is believed to serve as such a mechanism. Here we aimed to measure and characterize the LAR in healthy volunteers and to compare the data obtained with previously published data. METHODS: We designed a prospective pilot study. 10 healthy volunteers (22-57 years) participated. To elicit the LAR we used a newly designed microdroplet impulse testing (MIT) device: very small waterdroplets were shot onto the endolaryngeal mucosa. By simultaneously observing the anatomical structures with a high speed glottography system, the time between impact of the microdroplet on the mucosa and the beginning of the adduction movement and thus an approximate value for the reflex latency could be determined. RESULTS: An early adduction movement corresponding to LAR1 could not be detected. The measured LAR2 latency time was higher than the EMG LAR2 data. No significant latency difference between right and left stimulation was found. DISCUSSION: Since we were unable to demonstrate any LAR1 component it may be that muscle activity observable by EMG may not be sufficient to lead to a visible medial vocal cord movement. The longer LAR2 latency compared to EMG data may be explained by the fact that the visually vocal cord movement occurs after a delay although muscle activity already started as evidenced by EMG.Further studies on LAR are warranted, especially since our results also raise questions about the clinical significance of the LAR.

[High resolution manometry study of pharyngeal function in patients with myotonic dystrophy]. / Hochauflösungsmanometrische Untersuchung der pharyngealen Funktion bei myotoner Dystrophie.

BACKGROUND: Patients with myotonic dystrophy (MD) are known to suffer from oropharyngeal dysphagia and esophageal motility disorders, which are often the cause of aspiration pneumonia. So far only little is known about the pharyngeal contractility and the function of the upper esophageal sphincter in these patients, in particular only few data are available for manometric investigations allowing assessment of the pharyngeal pressure build-up during swallowing. The aim of this study was to collect such data in patients with MD using high resolution manometry. METHOD: In two patients with MD high resolution manometry studies were performed during swallowing and phonation to determine pressure-dependent parameters. The results were compared with normal values from healthy subjects. RESULTS: In both patients a reduced pressure in the entire pharynx during swallowing was determined. The duration of the contraction in the velopharynx and tongue base region was shortened. The structural course of the swallowing process and the opening and closing functions of the upper esophageal sphincter were regular. During realization of closed vowels a reduced pressure build-up in the velopharyngeal region was observed. CONCLUSION: The force of contraction and the associated pharyngeal pressure build-up during swallowing were reduced resulting in an incomplete clearing of the pharynx. Beside myopathic disorders, neuromuscular disorders also have to be considered. The functional course of the swallowing process and the swallowing pattern was retained. The reduced pressure build-up in the velopharyngeal region can be considered as the cause for rhinophonia. To evaluate the pharyngeal function in patients with MD, high resolution manometry is a useful tool for assessing the pharyngeal function besides the basic diagnostics.

[Medication-induced dysphagia : A review]. / Medikamenteninduzierte Dysphagien : Ein Überblick.

As a highly differentiated physiological process, swallowing may be affected by a variety of confounding factors. Primarily described are swallowing disorders caused by mechanical anatomic changes (e. g., alteration of the cervical spine, goiter), surgery for head and neck tumors, thyroid abnormalities, and neuromuscular disorders. Age-related cerebral neurological and blood vessel-associated changes can also cause dysphagia (so-called presbyphagia) or worsen the condition.Medication-associated dysphagia is recognized far less frequently, not paid due attention, or accepted in silence; particularly in older patients. Furthermore, pharmacological interference of different medications is frequently inadequately considered, particularly in the case of polypharmacy.Initial treatment of medication-induced dysphagia includes a critical review of medication status, with the aim of reducing/discontinuing the causative medication by giving precise instructions regarding its administration; as well as antacid medication, diet, and professional oral stimulation or swallowing training.To date, medication-induced dysphagia has not occupied the focus of physicians and therapists. This is despite the fact that many active agents can have a negative effect on swallowing and medication-induced dysphagia caused by polypharmacy is not uncommon, particularly in old age. This article presents an overview of the different classes of drugs in terms of their direct or indirect negative effects on the swallowing function.

[Auditory processing and perception disorders (APPD): summary and updated overview]. / Auditive Verarbeitungs- und Wahrnehmungsstörungen (AVWS): Zusammenfassung und aktualisierter Überblick.

The APD guideline of 2009 was supplemented by the statements listed here. The addition is based on current knowledge and findings. Otherwise, the Guideline 2009 remains valid. Here, a summary of the updated APD guideline is given, thus proving an overview of the definition of APD, diagnosis, differential diagnosis and recommended for APD management.

[Normative Data of Pharyngeal and Upper Esophageal Sphincter High Resolution Manometry]. / Normwerte für die Hochauflösungsmanometrie von Pharynx und oberem Ösophagussphinkter.

BACKGROUND: High resolution manometry (HRM) can provide information about the muscular contraction of the pharynx and the upper esophageal sphincter (UES) and represents an important tool in the diagnostics of dysphagia. To compare the results of swallowing studies interindividually and to identify pathological swallows, normative data are necessary. Normative data for the use of an HRM-probe with a large diameter has already been published. As previously has been shown these probes can influence the normal contraction of the pharynx and the UES. In this study comprehensive normal values are presented for small HRM-probes in diameter (2 mm), that only minimally affect pharyngeal and UES contractions. METHOD: 29 healthy volunteers underwent pharyngeal and upper esophageal HRM. All subjects performed 10 water swallows of 2 ml in an upright position. Pressure and time dependent parameters of the velopharyngeal region, the tongue base and the UES have been evaluated. Mean and median values and different percentile ranges were calculated. RESULTS: The normative values for the key parameters were (mean±SD): maximum velopharyngeal pressure 269.9±113.1 mmHg, maximum tongue base pressure 278±93.6 mmHg, maximum UES pressure 205.8±64.0 mmHg, UES resting pressure 42.5±18.7 mmHg and relaxation time of the UES 681.6±86.8 ms. Further parameters have been measured. CONCLUSION: Time dependent values are comparable to those already published. Especially in the UES lower pressures can be measured when a small HRM-probe is used. The normative data established in this study might help to distinguish pathological from physiological swallows using HRM.

[Subjective audiometric procedures in children]. / Subjektive audiometrische Verfahren bei Kindern.

BACKGROUND: Before the era of objective audiometric procedures, the primary aim of subjective audiometric procedures was determination of the hearing threshold, e.g. to assess hearing aid indications. Nowadays, the results of objective audiometric procedures play a major role in hearing threshold determination in children. Contrastingly, subjective audiometric procedures are also employed in order to verify, or acquire an objective picture of, social hearing abnormalities evident from the children's anamneses. METHODS: A selective literature search was conducted in the PubMed and Scopus databases and current textbooks were also considered. RESULTS: Subjective audiometric procedures for children employ both nonlinguistic and linguistic stimuli. Procedures can differ in many ways and it can be differentiated between, for example, observational or behavioural audiometry and procedures in which the children are explicitly instructed on how to react to signals. DISCUSSION: Several subjective audiometric procedures have been developed to examine the hearing and listening skills of children. Some of these tests differ significantly in terms of their intended application, test construction and test quality criteria. Only a detailed understanding of the particular subjective audiometric procedure being applied enables formulation of the"correct" questions; which, providing the child is willing to cooperate, can also be specifically answered using the test.

[Fall prevention counselling for patients with hearing and balance disorders]. / Sturzprävention im Rahmen des HNO-ärztlichen Counsellings bei älteren Patienten mit Hör- und Gleichgewichtsstörungen.

BACKGROUND: Otolaryngologists caring for patients with hearing and balance disorders are also responsible for advising patients about their increased risk of falling and informing them of fall prevention measures. This review will give a brief overview of appropriate programs. METHODS: This systematic review is based on a selective literature search. RESULTS: Intrinsic and extrinsic fall risk factors can be distinguished. The former include not only hearing and balance disorders, but also increasing age, nocturia, dementia, limited mobility and poor nutritional status. Extrinsic factors include, for example, unfixed carpet edges, poor lighting and poor footwear. Fall prevention can be achieved through appropriate counselling about risk factors and fall prevention courses. DISCUSSION: The frequency of falls--with potentially very adverse consequences--increases continuously beyond the age of 60 years. Furthermore, the risk of falling is significantly increased in patients with hearing and balance disorders. Otolaryngologists caring for this patient group should inform them about their fall risk and advise appropriate countermeasures during counselling. A basal knowledge of fall prevention measures is therefore helpful.

[How reliable are non-instrumental assessment tools for dysphagia?]. / Welche Aussagekraft haben nichtinstrumentelle Diagnoseverfahren bei Dysphagie?

BACKGROUND: The requirement for otorhinolaryngologists and phoniatricians to diagnose dysphagia and evaluate its extent is on the rise, particularly in light of demographic changes. The gold standards in confirmatory diagnostics are fiberoptic endoscopic evaluation of swallowing (FEES) and the videofluoroscopic swallowing examination (VFS). Standardized assessments, such as questionnaires or assessments involving probatory swallows are often applied as screening or supportive measures. This article aims to give a critical overview of the assessment tools frequently used in clinical routine. Test quality is assessed, particularly compared to FEES and VFS. METHODS: A selective literature search using PubMed has been conducted. RESULTS: On the basis of this lierature search, 48 assessment tools were identified. These can be classified into screening tools, instrument-based tools (implementation standards and evaluation protocols) and questionnaire-based assessment inventories. DISCUSSION: In order to diagnose and evaluate dysphagia on the basis of assessment critieria, clinicians should be aware of indications for, as well as the advantages, disadvantages and test quality of the assessment tools. Considering the different assessment tools for anamnesis and probatory swallowing, rather low sensitivities and specificities for possible penetration and aspiration are evident. In cases where these symptoms of dysphagia are not evident and reliably assessable, confirmatory assessment via FEES or VFS is essential.

[Inducible laryngeal obstruction vs. bronchial asthma]. / Belastungsinduzierte laryngeale Obstruktion in Abgrenzung zum Asthma bronchiale.

UNLABELLED: Inducible Laryngeal Obstruction vs. Bronchial -Asthma Background: Inducible laryngeal obstructions (ILO) represent paroxysmal and sometimes severe dyspnea caused by different factors. Symptomatically ILO resembles bronchial asthma and is therefore often misdiagnosed. In the following 3 cases regarding a special type of ILO, the exercise induced laryngeal obstruction (EILO) will be presented. It will also be demonstrated, how EILO can be diagnosed and differentiated from bronchial asthma. METHOD: Laryngeal symptoms were provoked by spiroergometry (treadmill or bicycle) and inspected by laryngoscopy. RESULTS: Symptoms could be provoked in all of the 3 patients by either treadmill or bicycle spiroergometry. When a stridor occurred, usually 1.5-2 min after the anaerobe threshold had been exceeded, spiroergometry showed a decline or plateau of carbon dioxide emission and oxygen intake. Laryngoscopy revealed adduction of the vocal cords during inspiration occa-sionally with a collapse of supraglottic structures towards the endolarynx. DISCUSSION: This article is the first to report that EILO can be distinctly depicted by spiroergometry. The decline or plateau in oxygen and carbon dioxide curves in coordination with the onset of stridor, approximately 1.5-2 min after the anaerobe threshold had been exceeded, was found to be reproducible in all cases. Furthermore, endoscopy immediately following peak exhaustion represents a practical tool for the identification of EILO.·

[Swallowing and dysphagia in the elderly]. / Schlucken und Schluckstörungen im Alter.

Disturbances of the swallowing process can occur at any age and might lead to choking. However, the risk of dysphagia increases with advanced age. This is not only due to a higher incidence of diseases that cause dysphagia, but also to age-related changes in the mechanisms of swallowing. Aging affects all of the anatomic structures involved in the swallowing process. Important changes include limitations to mastication, delayed triggering of the swallowing reflex, expansion of pharyngeal structures, prolonged pharyngeal propulsion, loss of pharyngeal sensitivity, increased rigidity of the esophageal wall and reduced esophageal contractility. Changes in swallowing function caused by aging alone are termed presbyphagia. If these changes are so severe that their compensation is no longer possible, presbydysphagia occurs. For diagnostic and therapeutic purposes it is mandatory to evaluate presbyphagic and presbydysphagic changes in the swallowing process, and to distinguish these from other non-age-related causes of dysphagia.

[Laryngeal adduction reflex]. / Der laryngeale Adduktionsreflex.

BACKGROUND: Laryngeal Adductor Reflex Background: A rapid closure of the vocal folds is necessary, whenever foreign materials or food particles penetrate into the larynx. Otherwise a passage of these particles into the trachea or the lower respiratory tract would be imminent. An aspiration could mechanically block the respiratory tract and cause severe dyspnoea or cause aspiration pneumonia. METHOD: For this systematic review a selective literature research in PubMed and Scopus using the keywords "laryngeal adductor reflex" and "vocal fold closure" has been carried out. RESULTS: Apart from the oesophago-glottal and pharyngo-glottal closure reflexes, the laryngeal adductor reflex (LAR) has been investigated in particular. The LAR qualifies as a reflectory laryngeal adductor mechanism and involves early, presumably di- or oligosynaptic ipsilateral LAR1 as well as late polysynaptic ipsi- and contralateral LAR2 components. In clinical routine diagnostic settings of dysphagia, LAR is only assessed qualitatively and usually triggered by air pulses or tactile stimulation. DISCUSSION: Dysphagiologists often find that not only the laryngeal sensibility in general is impaired, but especially the protective laryngeal adduction mechanism, which results in a higher risk of aspiration. Thus, it appears mandatory to test the LAR not only qualitatively but also quantitatively. Unfortunately a valid and reliable method that can be employed in clinical practice has not yet been put forward.

[Physiology of the upper esophageal sphincter]. / Physiologie des oberen Ösophagussphinkters.

The upper esophageal sphincter (UES) forms a barrier between the pharynx and the esophagus. When opened, the UES allows the food bolus to pass into the esophagus, as well as permitting emesis and eructation. The basal sphincter tone constitutes a barrier function which serves to prevent reflux and passive aerophagia in the case of deep breathing. Basal sphincter tone is dependent on several influencing factors; during swallowing, sphincter opening and closure follow a complex multiphase pattern. This article presents an overview of the current understanding of UES physiology.