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.

[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.

[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.

[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.

[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.·

[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.

[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.

[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.

[First language acquisition research and theories of language acquisition]. / Erstspracherwerbsforschung und Spracherwerbstheorien.

BACKGROUND: In principle, a child can seemingly easily acquire any given language. First language acquisition follows a certain pattern which to some extent is found to be language independent. Since time immemorial, it has been of interest why children are able to acquire language so easily. Different disciplinary and methodological orientations addressing this question can be identified. METHODS: A selective literature search in PubMed and Scopus was carried out and relevant monographies were considered. RESULTS: Different, partially overlapping phases can be distinguished in language acquisition research: whereas in ancient times, deprivation experiments were carried out to discover the "original human language", the era of diary studies began in the mid-19th century. From the mid-1920s onwards, behaviouristic paradigms dominated this field of research; interests were focussed on the determination of normal, average language acquisition. The subsequent linguistic period was strongly influenced by the nativist view of Chomsky and the constructivist concepts of Piaget. Speech comprehension, the role of speech input and the relevance of genetic disposition became the centre of attention. The interactionist concept led to a revival of the convergence theory according to Stern. DISCUSSION: Each of these four major theories--behaviourism, cognitivism, interactionism and nativism--have given valuable and unique impulses, but no single theory is universally accepted to provide an explanation of all aspects of language acquisition. Moreover, it can be critically questioned whether clinicians consciously refer to one of these theories in daily routine work and whether therapies are then based on this concept. It remains to be seen whether or not new theories of grammar, such as the so-called construction grammar (CxG), will eventually change the general concept of language acquisition.

[Anatomy of the upper esophageal sphincter]. / Anatomie des oberen Ösophagussphinkters.

The upper esophageal sphincter (UES) forms a barrier between the pharynx and the esophagus. When closed, the barrier function serves to prevent reflux and aerophagia; when open, swallowing, belching and vomiting are possible. The closing muscles include caudal parts of the inferior pharyngeal sphincter and cranial parts of the upper esophagus musculature. Sphincter opening is achieved by muscles that insert from the outside to connect to the larynx and pharynx in the sphincter region. The closing muscles are innervated by branches of the glossopharyngeal and vagal nerves, and central control is probably mediated by several reflexes. This article presents an overview of the current understanding of the complex UES anatomy.

[Infantile swallowing]. / Frühkindliches Schlucken.

BACKGROUND: Increasing numbers of preterm infants 1 and ever-improving potentials in neonatal medicine will lead to a rising incidence in infantile feeding problems. Profound knowledge regarding the development and anatomy of pre- and postnatal swallowing functions is essential for the assessment and therapy of infantile feeding and swallowing problems. METHOD: For this systematic review a selective literature research in PubMed has been carried out. RESULTS: Oropharyngeal structures and oral-motor skills for sucking and swallowing develop during embryonic and foetal stages and enable postnatal oral feeding. Knowledge of pre- and postnatal developmental stages of oral-motor development and swallowing serves as a base for the assessment of preterm infants' abilities and tolerance for feeding. A direct comparison of the swallowing process between infants, children and adults is not possible due to different anatomical characteristics. Developmental processes and neurologically triggered coordination procedures of early feeding skills are complex and very susceptible to faults. Disruption can cause severe disorders of swallowing coordination. Feeding problems are a common problem in preterm infants. Differentiated assessments on the basis of these results and early intervention facilitating oral-motor skills can accelerate the transition from tube to oral feeding and prevent further feeding issues.

[Guideline-conform diagnostics in language impairments]. / Leitliniengerechte Diagnostik bei Spracherwerbsstörungen.

In order to distinguish more accurately and easily between language difficulties in need of therapy or special support versus language impairments a S2K guideline was developed by interdisciplinary teams of different (medical) societies and professional associations. This guideline was published in 2011 and has replaced all existing monodisciplinary guidelines. According to the new S2K guideline standardised measures of language testing are mandatory. Apart from reviewing the S2K guidelines, this article aims to suggest how these guidelines can be established in clinical practice. By closely following this new guideline, testing and diagnosing children with language difficulties is believed to be enhanced considerably, and also comply with quality management standards.

[Prosody, speech input and language acquisition]. / Prosodie, Inputsprache und Spracherwerb.

BACKGROUND: In order to acquire language, children require speech input. The prosody of the speech input plays an important role. In most cultures adults modify their code when communicating with children. Compared to normal speech this code differs especially with regard to prosody. METHOD: For this review a selective literature search in PubMed and Scopus was performed. RESULTS: Prosodic characteristics are a key feature of spoken language. By analysing prosodic features, children gain knowledge about underlying grammatical structures. Child-directed speech (CDS) is modified in a way that meaningful sequences are highlighted acoustically so that important information can be extracted from the continuous speech flow more easily. CDS is said to enhance the representation of linguistic signs. DISCUSSION: Taking into consideration what has previously been described in the literature regarding the perception of suprasegmentals, CDS seems to be able to support language acquisition due to the correspondence of prosodic and syntactic units. However, no findings have been reported, stating that the linguistically reduced CDS could hinder first language acquisition.

[Phonation onset and simultaneous activation of non-larynx related muscles]. / Beeinflussung des Stimmlippeneinschwingvorganges durch Aktivierung kehlkopfferner Muskeln.

BACKGROUND: Various voice therapy techniques include not only phonation exercises but also measure to regulate tonus of non-larynx related muscles. This is based on the belief that the use of non-laryngeal muscles may affect laryngeal muscle action during phonation onset und phonation. Here we raised the question if indeed a well defined activation of muscles distant to the larynx may effect phonation onset time and the vibratory cycles following thereafter. METHOD: Prospective partly randomized single center pilot study with 8 healthy volunteers. Analysed variables were time of phonation onset and closed quotient (Qx) derived via electroglottgraphy. According to a randomization protocol volunteers had to press a training device ( + condition) or to keep the hand quiet ( - condition). RESULTS: Comparism of both conditions did not reveal any significant difference, however Qx tended to be higher in the + condition. DISCUSSION: The data presented here does not confirm that activation of hand muscles influences phonation onset time. However the preceding vibratory cycles may be altered towards a higher tone of intralaryngeal muscles regulating vocal fold tension. Further studies including more volunteers or patients with functional voice disorders and protocols employing the activation of other muscle groups are warranted in order to shed more light into the interrelationship between larynx and other muscle activation during phonation.

[Neuromuscular electric stimulation therapy in otorhinolaryngology]. / Neuromuskuläre Elektrostimulationsverfahren in der HNO-Heilkunde.

BACKGROUND: Animal experiments have shown that after specific nerve traumatization, neuromuscular electrostimulation (NMES) can promote nerve regeneration and reduce synkinesia without negatively interfering with normal regeneration processes. NMES is used routinely in physical rehabilitation medicine. METHODS: This systematic literature search in the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, the DAHTA database, the Health Technology Assessment Database and MEDLINE or PubMed considered studies on the use of NMES in otorhinolaryngology that have been published in German or English. RESULTS: The search identified 180 studies. These were evaluated and relevant studies were included in the further evaluation. DISCUSSION: In the fields of otorhinolaryngology and phoniatry/paediatric audiology, clinical studies investigating the effects of NMES on facial and laryngeal paresis, as well as dysphonia and dysphagia have been carried out. The evidence collected to date is encouraging; particularly for the treatment of certain forms of dysphagia and laryngeal paresis.

[Clicking larynx syndrome : a literature review and multiple-case report]. / Das Clicking-Larynx-Syndrom : Literaturübersicht und Fallberichte.

BACKGROUND: A clicking noise in the larynx can probably be provoked in many adults. However, these clicks are not usually associated with pain and physicians are not consulted. The combination of a clicking larynx and pain may severely reduce an individual's quality of life. Up until now, the so-called clicking larynx syndrome (CLS) has not been defined in German teaching literature. Therefore, this article reviews the international literature on CLS and also presents three case reports. METHODS: A selective literature search using PubMed and Google was conducted. The Google search resulted in the identification of several patient forums. Three case reports are also presented (multiple-case report). RESULTS: A total of 4 studies were identified in which different kinds of clicking sounds in the larynx were described. These sounds were typically provoked by movements of the head and/or neck, swallowing or circumlaryngeal manipulation. In forums patients reported many different types of laryngeal clicking sounds, which were often described as extremely irritating. Three patients have recently presented with such symptoms at our department. DISCUSSION: The literature published on CLS suggests (although does not strictly prove) that laryngeal clicking sounds are caused by friction between the superior cornu or the top edge of the thyroid cartilage and the hyoid, or alternatively due to contact of these structure with the cervical spine. Seldom do patients report a former laryngeal trauma. The causes of the associated pain remain unclear. The treatment of choice seems to be resection of the structures associated with the clicking noise by thyroplastic surgery or reduction of the hyoid bone greater horn. It is therefore important to inform patients with mild CLS that these clicking sounds are harmless and to advise CLS patients suffering from pain of the appropriate treatment options.