published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

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Tyrimo metu apibendrinti ir išanalizuoti 74 knarkiančiųjų bei lengvu ir vidutinio sunkumo obstrukcinės miego apnėjos hipopnėjos sindromu (OMAHS) sergančių pacientų klinikiniai duomenys, ir įvertinta 38 jų miego partnerių emocinė būklė prieš pacientų gydymą ir praėjus 2–4 mėn. po pacientams taikyto knarkimo ir OMAHS gydymo – radiodažnuminės termoabliacijos (RDTA). Šio darbo uždaviniai: 1. Ištirti ir palyginti knarkiančiųjų bei sergančių lengvu ir vidutinio sunkumo OMAHS pacientų viršutinių kvėpavimo takų anatomines ir funkcines savybes, apnėjų hipopnėjų indeksą, nusiskundimus sveikata ir emocinę būklę. 2. Įvertinti knarkiančiųjų bei sergančių lengvu ir vidutinio sunkumo OMAHS pacientų gyvenimo kokybę prieš pradedant gydymą ir po gydymo RDTA. 3. Įvertinti su RDTA operacijomis susijusių pacientų nusiskundimų intensyvumą ir pooperacinių komplikacijų dažnį. 4. Ištirti ir įvertinti knarkiančiųjų bei sergančių lengvu ir vidutinio sun¬kumo OMAHS pacientų nusiskundimus ir apnėjų hipopnėjų indeksą po gydymo RDTA. 5. Ištirti ir įvertinti knarkiančiųjų bei sergančių lengvu ir vidutinio sunkumo OMAHS pacientų emocinę būklę po gydymo RDTA. 6. Ištirti ir įvertinti knarkiančiųjų bei sergančių lengvu ir vidutinio sunkumo OMAHS miego partnerių emocinę būklę ir jos pokyčius po pacientų gydymo RDTA. Po pacientų gydymo RDTA nustatytas pacientų nusiskundimų intensyvumo ir apnėjų hipopnėjų indekso sumažėjimas bei emocinės būklės pagerėjimas, ir pacientų miego part¬ne¬rių depresiškumo sumažėjimas... [toliau žr. visą tekstą] / A total of 74 snoring and mild to moderate obstructive sleep apnea hypopnea syndrome (OSAHS) patients underwent complete full night polysomnography (PSG) and clinical examination and were treated with two sessions of radiofrequency tissue ablation (RFTA). The emotional state of 38 bed partners of snoring and mild to moderate OSAHS patients were evaluated at the baseline and 2–4 months after the patients completed the treatment. Objectives of the study: 1. To examine and evaluate the relationship between complaints, anatomical features, PSG results, and emotional state of snoring and mild to moderate OSAHS patients. 2. To assess the quality of life among snoring and mild to moderate OSAHS patients before and after the RFTA treatment. 3. To analyze the morbidity and the rate of postoperative compli¬ca¬tions of RFTA. 4. To evaluate the influence of RFTA on the objective (PSG results) and subjective (complaints) outcomes in snoring and mild to moderate OSAHS patients. 5. To evaluate the influence of RFTA on the outcomes of anxiety and depression in snoring and mild to moderate OSAHS patients. 6. To examine the emotional state and to evaluate the effect of RFTA on anxiety and depression in bed partners of snoring and mild to moderate OSAHS patients. A remarkable improvement in patients’ complaints, PSG results and emotional state after RFTA was observed. RFTA therapy resulted in improved depression scores for the bed partners of snoring and mild to moderate OSAHS patients.

Objective: We aim to improve our understanding of sleep physiology by describing the changes in mandibular position during sleep in normal subjects. Methods: We developed a novel method for mapping mandibular position simultaneously in three dimensions (anteroposterior, vertical and lateral) using magneto-resistive sensors strategically placed around 3 different moving joints on an external apparatus attached to the head and mandible. Spherical coordinates derived from these sensors provided information of jaw position in each of the three measurement planes. We assessed changes in jaw position in twelve healthy subjects (6 male, 6 female) aged (mean ± SD) 23 ± 7 years, Body Mass Index 22.5 ± 3.4 kg/m2, and with nasal resistance 3.24 ± 0.67 cmH2O/L/s by recording mandibular position simultaneously with overnight sleep polysomnography. Results: Jaw position was significantly influenced by sleep stage (p<0.001). The transition from wake to light sleep (stage one) was accompanied by significant jaw closure and jaw protrusion (p<0.05). As non-rapid-eye-movement (NREM) sleep deepened from stages 1 through slow wave sleep (SWS), vertical jaw opening (p<0.05) and posterior jaw movement progressively increased (p<0.05). REM sleep was associated with the greatest degree of jaw opening of all sleep stages (p<0.05). Lateral jaw position was not significantly different between sleep stages. Conclusion: This study describes, for the first time, an accurate method of measuring changes in mandibular position during sleep in all three dimensions. The observed changes during sleep in healthy subjects suggest a simultaneous modulation of upper airway muscular tone, which may be important in the understanding of upper airway occlusion in Obstructive Sleep Apnea. / Thesis (Master, Physiology) -- Queen's University, 2008-08-29 14:27:57.726

This thesis draws from music technology to create novel sonifications of heart rate information that may be of clinical utility to physicians. Current visually-based methods of analysis involve filtering the data, so that by definition some aspects are illuminated at the expense of others, which are decimated. However, earlier research has demonstrated the suitability of the auditory system for following multiple streams of information. With this in mind, sonification may offer a means to display a potentially unlimited number of signal processing operations simultaneously, allowing correlations among various analytical techniques to be observed. This study proposes a flexible listening environment in which a cardiologist or researcher may adjust the rate of playback and relative levels of several parallel sonifications that represent different processing operations. Each sonification "track" is meant to remain perceptually segregated so that the listener may create an optimal audio mix. A distinction is made between parameters that are suited for illustrating information and parameters that carry less perceptual weight, which are employed as stream separators. The proposed sonification model is assessed with a perception test in which participants are asked to identify four different cardiological conditions by auditory and visual displays. The results show a higher degree of accuracy in the identification of obstructive sleep apnea by the auditory displays than by visual displays. The sonification model is then fine-tuned to reflect unambiguously the oscillatory characteristics of sleep apnea that may not be evident from a visual representation. Since the identification of sleep apnea through the heart rate is a current priority in cardiology, it is thus feasible that sonification could become a valuable component in apnea diagnosis.

Snoring is a highly prevalent disorder affecting 20-40% of adult population. Snoring is also a major indicative of obstructive sleep apnea (OSA). Despite the magnitude of effort, the acoustical properties of snoring in relation to physiological states are not yet known. This thesis explores statistical properties of snoring sounds and their association with OSA. First, an unsupervised technique was developed to automatically extract the snoring sound segments from the lengthy recordings of respiratory sounds. This technique was tested over 5665 snoring sound segments of 30 participants and the detection accuracy of 98.6% was obtained. Second, the relationship between anthropometric parameters of snorers with different degrees of obstruction and their snoring sounds’ statistical characteristics was investigated. Snoring sounds are non-Gaussian in nature; thus second order statistical methods such as power spectral analysis would be inadequate to extract information from snoring sounds. Therefore, higher order statistical features, in addition to the second order ones, were extracted. Third, the variability of snoring sound segments within and between 57 snorers with and without OSA was investigated. It was found that the sound characteristics of non-apneic (when there is no apneic event), hypopneic (when there is hypopnea), and post-apneic (after apnea) snoring events were significantly different. Then, this variability of snoring sounds was used as a signature to discriminate the non-OSA snorers from OSA snorers. The accuracy was found to be 96.4%. Finally, it was observed that some snorers formed distinct clusters of snoring sounds in a multidimensional feature space. Hence, using Polysomnography (PSG) information, the dependency of snoring sounds on body position, sleep stage, and blood oxygen level was investigated. It was found that all the three variables affected snoring sounds. However, body position was found to have the highest effect on the characteristics of snoring sounds. In conclusion, snoring sounds analysis offers valuable information on the upper airway physiological state and pathology. Thus, snoring sound analysis may further find its use in determining the exact state and location of obstruction.

Objectif: Le syndrome d'apnée obstructive du sommeil (SAOS) est de plus en plus présent en Amérique du Nord et a été associé avec certaines maladies chroniques, particulièrement les maladies cardiaques. En première ligne, là où la prévalence de cooccurrence de maladies chroniques est très élevée, l'association potentielle avec l'apnée du sommeil est inconnue. L'objectif de cette étude était d'explorer l'association entre l'apnée obstructive du sommeil et 1) la présence et la gravité de la multimorbidité (cooccurrence de plusieurs maladies chroniques), et 2) des sous-catégories de multimorbidité. Méthode La technique d'échantillonnage en grappe a été utilisée pour recruter 120 patients atteints de SAOS à différents niveaux de gravité et ce, à partir de la base de données d'un laboratoire de sommeil. La gravité de la maladie a été établie grâce aux résultats de la polysomnographie. Les patients, qui furent invités à participer, ont reçu, par la poste, un questionnaire de renseignements sociodémographiques et le questionnaire auto-rapporté Disease Burden Morbidity Assessment (DBMA). L'envoi incluait un formulaire de consentement permettant l'accès au dossier médical afin d'obtenir plusieurs autres informations essentielles. Le DBMA a été utilisé pour avoir un score global de multimorbidité et des sous-scores de maladies qui affectent divers systèmes. Résultats Les analyses bivariées n'ont pas permis de démontrer une association entre l'apnée obstructive du sommeil et la multimorbidité (r = 0,117; p = 0,205). Par contre, le SAOS grave a été associé à la multimorbidité (odds ratio ajustés = 7,3 [1,7-32,2] ; p = 0,05). Le SAOS est modérément corrélé avec des sous-scores de multimorbidité vasculaire (r = 0,26 ; p = 0,01) et de syndrome métabolique (r = 0,26 ; p = 0,01). Conclusion Cette étude démontre que la gravité du SAOS est associée à la gravité de la multimorbidité et à des sous-scores de multimorbidité. Cette recherche ne permet pas d'établir un lien de causalité, d'autres recherches s'imposent pour confirmer ces associations. Toutefois, les intervenants de santé en première ligne devraient être au fait de cette association potentielle et devraient investiguer la présence de l'apnée du sommeil quand cela leur semble approprié.

Snoring is a highly prevalent disorder affecting 20-40% of adult population. Snoring is also a major indicative of obstructive sleep apnea (OSA). Despite the magnitude of effort, the acoustical properties of snoring in relation to physiological states are not yet known. This thesis explores statistical properties of snoring sounds and their association with OSA. First, an unsupervised technique was developed to automatically extract the snoring sound segments from the lengthy recordings of respiratory sounds. This technique was tested over 5665 snoring sound segments of 30 participants and the detection accuracy of 98.6% was obtained. Second, the relationship between anthropometric parameters of snorers with different degrees of obstruction and their snoring sounds’ statistical characteristics was investigated. Snoring sounds are non-Gaussian in nature; thus second order statistical methods such as power spectral analysis would be inadequate to extract information from snoring sounds. Therefore, higher order statistical features, in addition to the second order ones, were extracted. Third, the variability of snoring sound segments within and between 57 snorers with and without OSA was investigated. It was found that the sound characteristics of non-apneic (when there is no apneic event), hypopneic (when there is hypopnea), and post-apneic (after apnea) snoring events were significantly different. Then, this variability of snoring sounds was used as a signature to discriminate the non-OSA snorers from OSA snorers. The accuracy was found to be 96.4%. Finally, it was observed that some snorers formed distinct clusters of snoring sounds in a multidimensional feature space. Hence, using Polysomnography (PSG) information, the dependency of snoring sounds on body position, sleep stage, and blood oxygen level was investigated. It was found that all the three variables affected snoring sounds. However, body position was found to have the highest effect on the characteristics of snoring sounds. In conclusion, snoring sounds analysis offers valuable information on the upper airway physiological state and pathology. Thus, snoring sound analysis may further find its use in determining the exact state and location of obstruction.

BACKGROUND: In children, sleep-related airway obstruction by large tonsils and adenoids can cause obstructive sleep apnea (OSA). OSA may lead to poor growth, developmental delay, behaviour or learning problems. Recent evidence also suggests that children with OSA may develop cardiovascular complications, the mechanisms perhaps involving hypoxemia, the autonomic nervous system, apneas, and arousals. Surgical removal of tonsils and adenoids (adenotonsillectomy (T&A)) usually cures pediatric OSA. To diagnose OSA at all levels of severity, polysomnography is currently the best approach. The McGill Oximetry Score (MOS) is a validated measure based on nocturnal pulse oximetry. An abnormal MOS has a 97% positive predictive value at detecting moderate-severe OSA. Because the MOS was devised by measuring frequency of desaturations (&lt;90%) and numbers of clusters of desaturations, it is not accurate at detecting OSA in children who do not have such drops in oxygen saturation. Accordingly, other measures applicable to a wider spectrum of children should be assessed. These measures should be simpler, less cumbersome, cheaper, and more accessible than polysomnography. / OBJECTIVES: To study alternative approaches that may be used to identify moderate-severe OSA in children, two studies were conducted. We examined one subjective measure - the OSA-18 parent questionnaire - and two objective measures - pulse rate and pulse rate variability. For the OSA-18 study, the goal was to determine whether it would accurately detect children with moderate-severe OSA as indicated by an abnormal MOS. For the pulse rate and pulse rate variability study, the goal was to determine if either or both would decrease after treatment with T&A for children with moderate-severe OSA. / METHODS: For the OSA-18 study, we used a cross-sectional design that included children 1-18 years old referred to a pediatric sleep laboratory for evaluation of suspected OSA. Alongside data from the OSA-18, we analyzed demographic and medical data (from a parent questionnaire) and information regarding adenotonsillar hypertrophy. We estimated sensitivity, specificity, positive and negative predictive values as well as receiver operating curves of the OSA-18 in detecting an abnormal MOS. We also conducted univariate and multivariate logistic regression analyses, using the MOS as the dependent variable and the OSA-18 score and others (age, gender, comorbidities, race) as independent variables. For the second study, we used a retrospective before-after design to compare pulse rate and pulse rate variability as measured by nocturnal pulse oximetry pre- and post-T&A of otherwise healthy children 1-18 years old with moderate-to-severe OSA. / RESULTS: For the OSA-18 study, we studied 334 children (58% male, mean age 4.6 +/- 2.2 years). The OSA-18 had a sensitivity of 40% and a negative predictive value of 73% for detecting an abnormal MOS. In addition, the area under the receiver operating curve was 0.611. While controlling for other independent variables in the logistic regression model, for each unit increase in the OSA-18 Score, the odds of having an abnormal MOS were increased by 2%. However, for each increase in age of 1 year, the odds of having an abnormal MOS were decreased by 17%. In the pulse rate and pulse rate variability study, 25 subjects (88% male; mean age 4.3 +/- 3.6 years) were enrolled. Following T&A, pulse rate and pulse rate variability decreased in 21 of 25 and 23 of 25 children, respectively. Mean pulse rate dropped from 99.7+/-11.2 to 90.1+/-10.7 bpm, p&lt;0.001; age-standardized pulse rate (z-score) from 0.8 (0.4, 1.5) to 0.4 (0, 0.9), p=0.04). Pulse rate variability, as measured by the standard deviation of the pulse rate decreased from 10.3 +/- 2.1 to 8.2 +/- 1.6 bpm, p&lt;0.001. As well, OSA symptomatology, parental concern about breathing during sleep and the MOS all improved. / CONCLUSIONS: Based on the first study we conclude that among children referred to a sleep laboratory, the OSA-18 does not accurately detect which children will have an abnormal MOS. The OSA-18 should not be used in place of objective testing to identify moderate-severe OSA in children. However, from the second study we conclude that measures of the autonomic nervous system such as pulse rate and pulse rate variability, as measured by pulse oximetry, decreased following surgical treatment of moderate-severe OSA. The results of this study potentially serve as important data for further work that would determine the accuracy of pulse rate and pulse rate variability measures and their diagnostic usefulness for OSA at all levels of severity.

The role of dopamine in directly modulating somatic motoneuron excitability and hence muscle tone is unknown. We investigated whether dopamine influences the trigeminal motor pool (MoV) that innervates the masseter and tensor palatini muscles, both of which function to maintain upper airway patency. We hypothesized that dopamine facilitates motor outflow at the MoV. We focally applied apomorphine (nonspecific dopamine receptor agonist) at the MoV in anaesthetized rats. We also applied receptor-specific agonists and antagonists to determine the receptor subtype mediating dopaminergic mechanisms of action. We demonstrated that dopaminergic transmission at the MoV potently increased motor outflow via the D1-like receptor and facilitated masseter and tensor palatini muscle tone. It is unknown whether endogenous dopamine release on to airway motoneurons influences their activity to regulate muscle tone in natural sleep-wake behaviours. This issue warrants investigation because the neurochemical basis of upper airway motor dysfunction (e.g. obstructive sleep apnea) remains poorly characterized.