Dilation of the oropharynx via selective stimulation of the hypoglossal nerve

Obstructive sleep apnea (OSA) is caused by the retraction of the tongue to occlude the upper airway (UAW). Electrical stimulation of the tongue protrudor and retractor muscle has been demonstrated as an effective technique to alleviate UAW obstructions and is considered to be a potential treatment for OSA. Recent studies have shown that selective stimulation of the hypoglossal nerve (HG) to activate tongue muscles using a single implantable device presents an attractive approach for treating OSA. In this study, the functional outcome of selective hypoglossal nerve stimulation with a multi-contact peripheral nerve electrode was studied by imaging the airway in anesthetized beagles. A pulse train of varying amplitude was applied through each one of the tripolar contact sets of the nerve electrode while the pharyngeal images were acquired via a video grabber into a computer. For the open mouth positions, the tongue activation patterns were also viewed and videotaped with a digital camcorder through the mouth. The percent dilation of the pharyngeal opening for each contact was calculated. The images show that stimulations delivered through the electrode contacts placed around the HG nerve trunk can generate several different activation patterns of the tongue muscles. Some of these patterns translate into a substantial increase in the oropharyngeal size, while others do not have any effect on the pharynx. The activation patterns vary as a function of the head position and the lower jaw. These results suggest that selective nerve stimulation can be a useful technique to maximize the effects of HG nerve stimulation in removing the obstructions in sleep apnea patients

Correlation between Apnea Severity and Sagittal Cephalometric Features in a Population of Patients with Polysomnographically Diagnosed Obstructive Sleep Apnea

Background and Objective: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder featuring a repeated closure of the upper airway during sleep. Craniofacial anatomy is a potential risk and worsening factor for OSA. This study aims to assess the relationship between cephalometric features of craniofacial morphology and OSA severity in a population of patients with OSA. Material and Methods: A sample of forty-two patients (n = 42, M = 76%, mean age = 57.8 ± 10.8) with a polysomnographically (PSG) confirmed diagnosis of OSA were recruited and underwent cephalometric evaluation of 16 cephalometric variables. In addition, the apnea–hypopnea index (AHI), oxygen desaturation (SatMin), Epworth sleepiness scale (ESS), and body mass index (BMI) were assessed. Then t-tests were performed to compare the values of all cephalometric variables between two AHI severity-based groups (mild-to-moderate = AHI ≤ 30; severe = AHI > 30). Single- and multiple-variable regression analyses were performed to assess the associations between AHI scores and cephalometric features. Results: Mean AHI, SatMin, and BMI were 31.4 ev/h, 78.7%, and 28.1, respectively. The cephalometric variables were not significantly different between the two OSA-severity groups (p > 0.05). Multiple-variable regression analyses showed that gonial angle and nasopharynx space were negatively associated with AHI, explaining 24.6% of the total variance. Conclusion: This investigation reported that severity of AHI scores in patients with OSA showed a negative correlation with gonial angle and nasopharynx space. As a general remark, although maxillofacial anatomy can be a predisposing factor for OSA, disease severity depends mainly upon other variables

Awareness and Sources of Knowledge about Obstructive Sleep Apnea: A Cross Sectional Survey Study

Obstructive sleep apnea (OSA) is a multifactorial sleep breathing disorder, seriously impacting quality of life and involving approximately 1 billion of the world’s population. It is characterized by episodes of total cessation of breathing or decreases in airflow during sleep. Available data suggest that most cases of OSA remain undiagnosed even in developed countries. This is due to a lack of widespread knowledge about this pathology and the medical morbidities and mortality it brings about, among both laypeople and physicians. Moreover, despite receiving indications about the need to undergo specific evaluations for OSA signs and symptoms, sometimes patients do not pay sufficient attention to the problem. This is probably due to a lack of correct information on these issues. The present investigation analyzed the level of knowledge about OSA pathology and the sources through which a group of OSA patients gained information on their condition. A survey of 92 patients diagnosed with OSA (mean age 60.55 ± 10.10) and referred to the Unit of Orthodontics and Dental Sleep Medicine of the University of Bologna was conducted by means of a questionnaire investigating sociodemographic characteristics, the level of general knowledge on OSA pathology and its possible medical consequences. Despite about two third (67.38%) of the population demonstrating extensive knowledge, remarkably, a group of subjects (20.65%) had poor awareness of the OSA condition. A statistically significant correlation emerged between the level of knowledge about OSA and the level of education (p = 0.002). A great effort should be made to improve the quality of information and the communication modalities for OSA to enable a fully appropriate awareness of the condition among patients

Mechanisms and pathophysiology of obstructive sleep apnea

Istotą obturacyjnego bezdechu podczas snu jest zapadanie się ścian gardła, przerywające przepływ powietrza do i z płuc [...

Sex, stress and sleep apnoea: decreased susceptibility to upper airway muscle dysfunction following intermittent hypoxia in females

Obstructive sleep apnoea syndrome (OSAS) is a devastating respiratory control disorder more common in men than women. The reasons for the sex difference in prevalence are multifactorial, but are partly attributable to protective effects of oestrogen. Indeed, OSAS prevalence increases in post-menopausal women. OSAS is characterized by repeated occlusions of the pharyngeal airway during sleep. Dysfunction of the upper airway muscles controlling airway calibre and collapsibility is implicated in the pathophysiology of OSAS, and sex differences in the neuro-mechanical control of upper airway patency are described. It is widely recognized that chronic intermittent hypoxia (CIH), a cardinal feature of OSAS due to recurrent apnoea, drives many of the morbid consequences characteristic of the disorder. In rodents, exposure to CIH-related redox stress causes upper airway muscle weakness and fatigue, associated with mitochondrial dysfunction. Of interest, in adults, there is female resilience to CIH-induced muscle dysfunction. Conversely, exposure to CIH in early life, results in upper airway muscle weakness equivalent between the two sexes at 3 and 6 weeks of age. Ovariectomy exacerbates the deleterious effects of exposure to CIH in adult female upper airway muscle, an effect partially restored by oestrogen replacement therapy. Intriguingly, female advantage intrinsic to upper airway muscle exists with evidence of substantially greater loss of performance in male muscle during acute exposure to severe hypoxic stress. Sex differences in upper airway muscle physiology may have relevance to human OSAS. The oestrogen–oestrogen receptor α axis represents a potential therapeutic target in OSAS, particularly in post-menopausal women

Dynamic MR Imaging of the upper airway during Muller’s manoeuvre Versus during sleep: A Comparative study

OSA is characterized by repetitive partial or complete upper airway collapse duringsleep, resulting in disrupted normal sleep architecture and associated with arterial desaturations. The diagnosis of obstructive sleep apnoea is confirmed by overnight polysomnography (PSG). Sleep MRI is a new emerging non invasive modality in the preoperative evaluation of patients with obstructive sleep apnoea. It was observed that Muller’s maneuver could depict the airway pathologies accurately at par with the images acquired during slee

МЕСТО АНЕСТЕЗИОЛОГИЧЕСКОГО ОБЕСПЕЧЕНИЯ В ДИАГНОСТИЧЕСКОМ АЛГОРИТМЕ СИНДРОМА ОБСТРУКТИВНОГО АПНОЭ – ГИПОПНОЭ СНА

Drug-induced sleep endoscopy occupies the important place in the diagnostic procedure of obstructive sleep apnea – sleep hypopnea and often defines the further treatment tactics. The review presents the main aspects of this manipulation and its anesthetic provision. Despite the long term experience of using drug-induced sleep endoscopy, the phenomenon of the increased and individual sensitivity of the inspiratory center to the hypnotic agent in those suffering from obstructive sleep apnea – sleep hypopnea has not been interpreted yet from research point of view. The issue of defining individual pharmacological threshold for induced apnea and personal level of sedation depth still remains important. Слип-эндоскопия занимает важное место в диагностическом алгоритме синдрома обструктивного апноэ – гипопноэ сна (СОАГС) и зачастую определяет дальнейшую тактику лечения. В обзоре рассмотрены основные моменты этой процедуры и ее анестезиологическое обеспечение. Несмотря на многолетний опыт использования слип-эндоскопии, феномен повышенной и индивидуальной чувствительности к гипнотическим препаратам дыхательного центра у пациентов с СОАГС до сих пор не получил научной интерпретации. Остается актуальным вопрос индивидуального определения фармакологического порога для индуцированного апноэ и персонифицированного уровня глубины седации.

Influence of treatment with continuous positive airway pressure on respiratory muscle function and physical fitness in patients with obstructive sleep apnoea and overlap syndrome

Wstęp: Celem badania była ocena wpływu leczenia dodatnim ciśnieniem w drogach oddechowych (CPAP) na czynność mięśni oddechowych oraz wydolność fizyczną u chorych na obturacyjny bezdech senny (OBS) i zespół nakładania (ZN) (OBS i POChP). Materiał i metody: Zbadano 9 chorych z OBS oraz 9 pacjentów z ZN. Przed zastosowaniem leczenia za pomocą CPAP oraz po 6 miesiącach terapii wykonywano badania maksymalnych ciśnień oddechowych, badania czynnościowe układu oddechowego oraz oceniano wydolność fizyczną pacjentów. Wyniki: W grupie OBS nie stwierdzono poprawy tolerancji wysiłku pod wpływem terapii. Dystans w 6MWD wynosił 571,8 &#177; 76,6 m przed i 554,0 &#177; 125,5 m po leczeniu, a Wmax 142 &#177; 41 W i 139 &#177; 38 W odpowiednio przed i po leczeniu. Maksymalne ciśnienie wdechowe (PImax) w grupie OBS nie zmieniło się istotnie: 140,4 &#177; 32,0 cm H2O przed i 155,9 &#177; 31,5 po leczeniu (p = 0,14). Maksymalne ciśnienie wydechowe (PEmax) wynosiło 170,5 &#177; 49,2 cm H2O przed i 199,9 &#177; 27,6 cm H2O po terapii (p = 0,067). Siła uścisku mięśni rąk u chorych z grupy OBS wzrosła z 50,5 &#177; 16,5 kg przed do 61,0 &#177; 17,0 kg po leczeniu (lewa ręka) (p = 0,05) i z 53,3 &#177; 14,2 do 58,9 &#177; 15,9 (prawa ręka) (p < 0,05). W grupie ZN leczenie poprawiło tolerancję wysiłku o 17%. Wmax zwiększyło się z 81 &#177; 33 W przed do 95 &#177; 38 W po leczeniu. Nie zmienił się natomiast dystans w 6MWD (504 &#177; 144 m przed i 492 &#177; 108 m po leczeniu). Siła mięśni oddechowych u chorych z grupy ZN po leczeniu CPAP wykazywała tendencję do poprawy. PImax wzrosło z 89,2 &#177; 35,7 cm H2O przed do 106,3 &#177; 31,4 cm H2O po terapii (p < 0,05). PEmax wynosiło 159,9 &#177; 45,8 cm H2O przed i 184,2 &#177; 45,0 cm H2O po leczeniu (NS). Siła uścisku prawej ręki w grupie ZN wynosiła 44,5 &#177; 17,7 kg przed i 47,9 &#177; 10,4 kg po leczeniu (NS), natomiast lewej - 38,1 &#177; 15,9 kg przed i 46,9 &#177; 11,1 kg po terapii (p < 0,05). W łącznej analizie obu grup wykazano tendencję do poprawy siły mięśni oddechowych po leczeniu CPAP (wzrost PImax z 123 do 133 cm H2O; p = 0,006 i PEmax z 168,1 do 192 cm H2O). Wnioski: Wyniki te wskazują, że leczenie za pomocą CPAP poprawia siłę mięśni oddechowych i szkieletowych u chorych z OBS i ZN oraz poprawia wytrzymałość i tolerancję wysiłku u chorych z ZN.Introduction: The aim of this study was to evaluate the effect of CPAP treatment on respiratory muscle strength and exercise tolerance in patients with obstructive sleep apnoea (OSA) and overlap syndrome (OS). Material and methods: 9 patients with OSA and 9 patients with OS were studied. Respiratory muscle assessment, 6 minute walking distance (6MWD) and cycloergometry exercise test were performed before and after six month period of CPAP treatment. Results: In OSA group exercise tolerance did not change after the treatment. Mean 6MWD was 571.8 &#177; 76.6 m before and 554.0 &#177; 125.5 m after treatment, mean Wmax was 142 &#177; 41 W before and 139 &#177; 38 W after treatment. PImax in OSA group did not change significantly, 140.4 &#177; 32.0 cm H2O before and 155.9 &#177; 31.5 after treatment (p = 0.14). PEmax improved from 170.5 &#177; 49.2 cm H2O, to 199.9 &#177; 27.6 cm H2O (p = 0.067). Handgrip force in OSA group improved from 50.5 &#177; 16.5 kg to 61.0 &#177; 17.0 kg (left hand) (p = 0.05) and from 53.3 &#177; 14.2 to 58.9 &#177; 15.9 (right hand) (p < 0.05). In OS group exercise tolerance improved by 17% after CPAP treatment from Wmax = 81 &#177; 33 W before to 95 &#177; 38 W after. Mean 6MWD was at the same level before (504 &#177; 144 m) and after treatment (492 &#177; 108 m). PImax in OS group improved from 89.2 &#177; 35.7 cm H2O to 106.3 &#177; 31.4 cm H2O (p < 0.05). PEmax in OS group did not change significantly, 159.9 &#177; 45.8 cm H2O before and 184.2 &#177; 45.0 cm H2O after treatment (NS). Handgrip force in OS group improved from 38.1 &#177; 15.9 kg to 46.9 &#177; 11.1 kg (left hand) (p < 0.05) and did not change in right hand (44.5 &#177; 17.7 kg vs. 47.9 &#177; 10.4 kg) (NS). Data analysis of the whole group (18 pts) showed clear tendency to improve strength of respiratory muscles in patients treated with CPAP. Mean PImax improved from 123 to 133 cm H2O (p = 0.006) and PEmax improved from 168.1 to 192 cm H2O (p = 0.02). Conclusions: CPAP treatment improved strentgh of respiratory and skeletal muscles in patients with OSA and OS and improved exercise tolerance in patients with OS

A Novel mHealth Approach for the Monitoring and Assisted Therapeutics of Obstructive Sleep Apnea

Obstructive sleep apnea is a respiratory problem that has serious consequences for physical and mental health, but also in monetary terms, since traffic accidents and poor work performance, among other direct consequences, are attributed to it. It is estimated that between 9% and 38% of the world’s population has this disease. This is a multifactorial disease, therefore, there are several methods of detection and treatment; however, all of them cause discomfort to the patient, or to those around them. In this article we propose a system for the detection and control of obstructive sleep apnea that promises to overcome the drawbacks of the existing therapies, therefore, potentially making it a practical and effective solution for this disease. The proof of concept presented in this paper makes use of an electromyography sensor to collect the myoelectric signal produced by the genioglossus muscle. Surface electrodes provide the electromyography signals to an ESP32 microcontroller, which has the function of analyzing and comparing the data obtained with a predefined value of the apnea threshold. After the detection of an apnea, the circuit is able to create a stimulus signal that is applied directly to the muscle, so that airway occlusion does not occur, and the user does not wake up. The data from each use are automatically sent to a database to be viewed and analyzed at a later point.info:eu-repo/semantics/publishedVersio

The effects of mild hypoxia on hypoglossal motoneurones in neonates

The patency of the upper airway is dependent on the activity of the genioglossus muscle, the main protrusor muscle of the tongue. The force generated by this muscle opposes the negative intraluminal pressure produced by the contraction of the diaphragm during inspiration. Recent studies suggest that there is an immaturity in genioglossus muscle control in neonates and obstructive apnoea may occur when the activity of this muscle is reduced or absent without a corresponding decrease in the activity of the diaphragm. However, little is known of the processes mediating and influencing the activity of the hypoglossal nerve, the motor nerve of the genioglossus muscle, at this stage in development. In newborn babies, central apnoea (when there is no inspiratory effort) is usually followed by obstructive apnoea (when although there is inspiratory effort there is no inspiratory flow). It is therefore possible that hypoxia which develops during central apnoea, inhibits the activity of the genioglossus muscle and as a consequence the airway becomes obstructed. The aim of this study was therefore to determine whether hypoglossal motoneurones are inhibited during hypoxia in neonates. This study has investigated the effect of mild levels of hypoxaemia (PaO2 47.2 ± 3.8mmHg) on the activity of hypoglossal motoneurones in anaesthetized neonatal kittens (27 days old). The results showed that the majority of hypoglossal motoneurones increased in discharge frequency during hypoxia but for a substantial proportion the increase was only transient. Furthermore, some motoneurones showed a decrease in discharge frequency. Intracellular recordings showed that during similar levels of hypoxia, although a large proportion of the motoneurones were depolarized, at least some of these repolarized despite the continuing hypoxia. In addition, some hypoglossal motoneurones were hyperpolarized. This is the clearest evidence that inhibitory mechanisms, in addition to excitatory mechanisms, mediate the effects of hypoxia on hypoglossal output in neonates. Furthermore, the results suggest that hypoxia has an effect on the hypoglossal motoneurones independently of, or in addition to, its effect through respiratory rhythm. In some preliminary studies, the transmembrane input resistance increased during the hyperpolarization in response to hypoxia. One possibility is that the inhibition is mediated by the removal of an excitatory input. If the inhibition found in this study occurs in human babies it may be a compounding factor in apnoeas of the newborn