The undervalued potential of positional therapy in position-dependent snoring and obstructive sleep apnea—a review of the literature

PURPOSE: Research during the past 10–20 years shows that positional therapy (PT) has a significant influence on the apnea–hypopnea index. These studies are predominantly performed as case series on a comparably small number of patients. Still, results have not found their way into the daily diagnostic and treatment routine. An average of 56 % of patients with obstructive sleep apnea (OSA) have position-dependent OSA (POSA), commonly defined as a difference of 50 % or more in apnea index between supine and non-supine positions. A great deal could be gained in treating patients with POSA with PT. The aim of this paper was to perform a thorough review of the literature on positional sleep apnea and its therapy. METHODS: A broad search strategy was run electronically in the MEDLINE and EMBASE databases using synonyms for position and sleep apnea. RESULTS: Sixteen studies were found which examined the effect of PT on OSA. In this literature review, we discuss the various techniques, results, and compliance rates. CONCLUSION: Long-term compliance for PT remains an issue, and although remarkable results have been shown using innovative treatment concepts for PT, there is room for both technical improvement of the devices and for further research

Prevalence of obstructive sleep apnoea in REM behaviour disorder:response to continuous positive airway pressure therapy

Objectives: Rapid eye movement behaviour disorder (RBD) is a parasomnia in which there is loss of muscle atonia during rapid eye movement (REM) sleep, resulting in dream enactment. The aims of this study were to determine the prevalence of obstructive sleep apnoea (OSA) in RBD patients and determine whether continuous positive airway pressure (CPAP) therapy improved RBD symptoms in patients with concomitant RBD and OSA.Methods: A questionnaire was mailed to 120 patients identified from a tertiary sleep centre with RBD meeting full International Classification for Sleep Disorders-3 (ICSD-3) criteria. Patients were diagnosed as having OSA if they had an apnoea-hypopnea index (AHI) ≥ 5. The questionnaire focused on CPAP-use, compliance and complications. Standard statistical analysis was undertaken using SPSS (v.21, IBM).Results: One hundred and seven of the potential participants (89.2%) had an OSA diagnosis. Out of 72 who responded to the questionnaire, (60%) 27 patients were using CPAP therapy. CPAP therapy improved RBD symptoms in 45.8% of this group. Despite this positive response to treatment in nearly half of CPAP-users, there was no significant difference in subjective or objective CPAP compliance between those who reported RBD improvement and those who did not. Subjective compliance with CPAP was over-reported, with mean usage being 7.17 ± 1.7 h per night compared to objective mean compliance of 5.71 ± 1.7.Conclusions: OSA is a very common co-morbidity of RBD. CPAP therapy might improve self-reported RBD symptoms further, in addition to standard RBD treatment. However, further research into its topic is necessary.</p

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave)

Pharyngeal airway dimensions: a cephalometric, growth-study-based analysis of physiological variations in children aged 6-17

SummaryOBJECTIVE: The aim was to assess pharyngeal airway dimensions and physiological changes based on lateral cephalometric radiographs from healthy untreated children aged 6-17 years. MATERIALS/METHODS: The sample consisted of 880 lateral cephalograms (412 females and 468 males) of the Zurich Craniofacial Growth Study. Statistical analyses on cephalometric measurements of airway dimensions (distances ‘p': shortest distance between soft palate and posterior pharyngeal wall and ‘t': shortest distance between tongue and posterior pharyngeal wall) and craniofacial parameters were performed. To disclose differences between different age groups, a Kruskal-Wallis test was applied. The influence of gender on ‘p' and ‘t' was analysed by a Mann-Whitney U-test for each age group separately. The Spearman correlation was computed in order to investigate associations between craniofacial parameters. Variables associated with ‘p' and ‘t' were chosen for multiple regression model investigation. RESULTS: The results demonstrated high interindividual variations. A slight influence of age on ‘p' (P = 0.034) could be attested (+1.03mm) but not on ‘t' (P = 0.208). With the exception of the 9-year age group, no significant differences between the genders were found. Correlation analysis revealed several statistically significant correlations between ‘t' or ‘p' and antero-posterior cephalometric variables. All correlation coefficients were, however, very low and the adjusted coefficient of determination also revealed the regression model to be very weak. CONCLUSIONS: The high interindividual variations of ‘p' and ‘t' render the use of reference values problematic. Contrary to other craniofacial structures, neither age-related changes nor sexual dimorphism were found for ‘p' and ‘t'. Any associations to antero-posterior cephalometric characteristics seem lo

Effects of SIDS risk factors and hypoxia on cardiovascular control in infants

Background and aims. Sudden infant death syndrome (SIDS) is a rare lethal event occurring in 0.1 to 0.3 of infants. In Finland, 10 to 20 infants die from SIDS annually. Research has defined many risk factors for SIDS, but the cascade leading to death remains unexplained. Cardiovascular recordings of infants succumbing to SIDS, as well as animal models, suggest that the final sequelae involve cardiovascular collapse resembling hypotensive shock. There is also evidence of previous hypoxia in SIDS infants. In animal studies, vestibulo-mediated cardiovascular control has been shown to be important in hypotensive shock. Hence, we hypothetized that SIDS victims may have impaired vestibulo-mediated cardiovascular control, possibly due to previous hypoxic episodes. In this thesis, we studied cardiovascular control, and especially vestibulo-mediated cardiovascular control in infants with known risk factors for SIDS at 2 to 4 months of age when the risk for SIDS is highest. Study subjects. A full polysomnographic recording with continuous blood pressure (BP) measurement was performed in 50 infants at 2-4 months of age: 20 control infants, nine infants with univentricular heart (UVH) suffering from chronic hypoxia, 10 infants with bronchopulmonary dysplasia (BPD) with intermittent postnatal hypoxic events, and 11 infants whose mothers had smoked during pregnancy, and thus had been exposed to intrauterine hypoxia and nicotine, were studied. In addition, 20 preterm infants were studied at the gestational age of 34-39 weeks to evaluate developmental aspects of cardiovascular control during head-up tilt test and vestibular stimulus. Methods. Linear side motion and 45° head-up tilt tests were performed in quiet non-rapid eye movement sleep (NREM). Heart rate (HR) and BP responses were analysed from the tests without signs of subcortical or cortical arousal. In addition, HR variability during NREM sleep was assessed. As a general marker of cardiovascular reactivity, HR response to spontaneous arousal from NREM sleep was also evaluated. Results.Side motion test. In the side motion test, control infants presented a biphasic response. First, there was a transient increase in HR and BP. This was followed by a decrease in BP to below baseline, and a return to baseline in HR. All other infant groups showed altered responses. UVH infants and preterm infants near term age had markedly reduced responses. Infants with BPD presented with variable responses: some responded similarly to controls, whereas others showed no initial increase in BP, and the following BP decrease was more prominent. Infants with intrauterine exposure to cigarette smoke showed flat initial BP responses, and the following decrease was more prominent, similarly to a subgroup of BPD infants. Tilt test. Control infants presented with a large variability in BP responses to head-up tilting. On average, systolic BP remained, at first, close to baseline, and diastolic BP increased, after which both decreased and remained below baseline even at the end of the tilt test. On average, HR showed a biphasic response with an initial increase followed by a decrease to below and, finally, a return to baseline. UVH infants showed a similar BP response, but their HR response was tachycardic. Preterm infants with BPD presented with an even greater variability in their BP responses to head-up tilts than control infants, but the overall response as a group did not differ from that of the controls. The tilt response of infants exposed to maternal cigarette smoking during pregnancy did not markedly differ from the control response. Preterm infants near term age showed attenuated responses in both cardiovascular measures, together with greater inter-subject variability compared to the control infants. Discussion. In conclusion, the studied infants with SIDS risk factors showed altered vestibulo-mediated cardiovascular control during the linear side motion test and head-up tilt test. The findings support our initial hypothesis that some infants with SIDS risk factors have defective vestibulo-mediated cardiovascular control, which may lead to death in life-threatening situations.Kätkytkuolemat ovat harvinaisia, mutta ne ovat edelleen suurin yksittäinen syy täysiaikaisena syntyneiden imeväisten kuolemaan. Suomessa kätkytkuolemaan menehtyy vuosittain 10-20 lasta. Kätkytkuoleman syytä ei tiedetä. Epidemiologisten tutkimusten avulla kätkytkuoleman riskitekijät tunnetaan hyvin; näitä ovat mm. vatsallaan nukkuminen, äidin raskaudenaikainen tupakointi ja keskosuus. Selällään nukuttamisen yleistymisen myötä kätkytkuolemien määrä on vähentynyt olennaisesti. Koe-eläintöissä ja muutamassa kätkytkuoleman aikaisessa seurantanauhoituksessa on viitteitä siitä, että kätkytkuoleman mekanismi todennäköisesti muistuttaa verenvuotosokin loppuvaiheen kaltaista verenkiertoelimistön toiminnan romahtamista. Koe-eläintöiden perusteella tällaisessa sokkitilanteessa tasapainotumakevälitteinen verenkierron säätely on tärkeää. Tämän tutkimuskokonaisuuden pääolettaman mukaan kätkytkuolleilla on puutteellinen tasapainotumakevälitteinen sykkeen ja verenpaineen säätely. Koska kätkytkuolleilla on myös todettu merkkejä hapenpuutteesta ennen kuolemaa, voi poikkeavan tasapainotumakevälitteisen verenkierron säätelyn syynä olla edeltänyt hapenpuute: riskiryhmistä esimerkiksi keskosilla lyhytkestoiset hapenpuutejaksot ja äidin raskaudenaikaiselle tupakoinnille altistuneilla lapsilla pitkäaikainen lievä hapenpuute sikiöaikana. Myös pitkäaikaisesta syntymän jälkeisestä hapenpuutteesta kärsivillä yksikammiosydämisillä imeväisillä on todettu äkillisiä, kätkytkuoleman kaltaisia kuolemia. Tutkimme imeväisen verenkierron säätelyä unen aikana rekisteröimällä verenkiertovasteita sivuttaissiirto- ja kippilavatestille täysiaikaisilla imeväisillä sekä imeväisillä, joilla on yllämainittuja kätkytkuoleman riskitekijöitä tai hapenpuutetta. Unirekisteröinti tehtiin yhteensä 70 imeväiselle. 2-4 kuukauden korjatussa iässä tutkittiin 20 täysiaikaista verrokkia, 10 bronkopulmonaalisesta dysplasiasta kärsivää keskosta, 9 yksikammiosydämistä imeväistä sekä 11 imeväistä, joiden äidit tupakoivat raskauden aikana. Lisäksi tutkimme 20 keskosta 34-39 raskausviikon iässä sykkeen ja verenpaineen säätelyn kehityksen kartoittamiseksi. Sivuttaissiirtotesti sekä 45° kippilavatesti pää ylöspäin tehtiin rauhallisessa ei-REM-unessa. Terveiden täysiaikaisten verrokkien verenpaine- ja sykevasteita käytettiin vertailukohtana muiden ryhmien vasteita arvioitaessa. Syke- ja verenpainevasteet arvioitiin testeistä, joissa ei ollut viitettä havahtumisesta tai heräämisestä. Sydämen sykkeen vaihtelevuutta ja spontaanin heräämisen aiheuttamaa sykevastetta käytettiin kuvaamaan yleistä verenkiertoelimistön säätelyn herkkyyttä. Sivuttaissiirtotestissä verrokit reagoivat kaksivaiheisella syke- ja verenpainevasteella. Sekä verenpaine että syke nousivat aluksi, jonka jälkeen verenpaine laski alle lähtötason ennen paluuta lähtötasoon, ja syke palasi lähtötasoon. Muissa tutkituissa ryhmissä vasteet poikkesivat normaalivasteista. Yksikammiosydänlapsilla sekä lähellä laskettua aikaa tutkituilla keskosilla syke- ja verenpainevasteet sivuttaissiirrolle olivat hyvin vaimeat. Puolet bronkopulmonaalisesta dysplasiasta kärsivistä imeväisistä reagoi samoin kuin verrokit, mutta puolella verenpaineen nousu puuttui ja sitä seurannut verenpaineen lasku oli selvästi normaalia syvempi. Myös imeväisillä, joiden äidit olivat tupakoineet raskauden aikana, verenpaineen alkunousu puuttui ja sitä seurannut verenpaineen lasku oli verrokkeja syvempi. Kippilavatestissä täysiaikaisten verrokkien verenpainevasteet olivat hyvin vaihtelevat. Keskimäärin testin alussa systolinen verenpaine pysyi ennallaan ja diastolinen nousi. Testin jatkuessa molemmat laskivat alle lähtötason, jossa ne pysyivät vielä testin lopettamisen jälkeenkin. Verrokkien sykevasteet olivat selkeästi yhtenevämmät ja vaste oli kaksivaiheinen: alun sykkeen nousua seurasi sykkeen lasku alle lähtötason ja paluu takaisin lähtötasoon. Yksikammiosydänlasten verenpainevasteet olivat verrokkien kaltaiset, mutta heidän sykkeensä pysyi korkeana koko testin ajan. Bronkopulmonaalisesta dysplasiasta kärsivien imeväisten verenpainevasteissa oli vielä voimakkaampaa vaihtelua kuin verrokkien vasteissa, mutta ryhmänä heidän vasteensa ei eronnut verrokeista. Raskaudenaikaiselle tupakoinnille altistuneiden imeväisten verenkiertovasteet eivät eronneet verrokeista. Lähellä laskettua aikaa tutkittujen keskosten syke- ja verenpainevasteissa oli suurta vaihtelua verrattuna täysiaikaisiin verrokkeihin, mutta ryhmänä verenkiertovasteet olivat vaimeammat kuin verrokeilla. Tässä tutkimuksessa todettiin poikkeava tasapainotumakevälitteinen verenkierron säätely imeväisillä, joilla on yllämainittuja kätkytkuoleman riskitekijöitä ja edeltäneitä hapenpuutejaksoja. Tutkimustulokset tukevat etukäteisolettamustamme, että heikentynyt tasapainotumakevälitteinen verenkierron säätely imeväisillä voi olla osaltaan johtamassa kätkytkuolemaan henkeä uhkaavassa tilanteessa

Insomnia and sleep-disordered breathing in FKRP-related limb-girdle muscular dystrophy R9. The Norwegian LGMDR9 cohort study (2020)

Limb-girdle muscular dystrophy R9 (LGMDR9) is a progressive and disabling genetic muscle disease. Sleep is relevant in the patient care as it impacts on health, functioning, and well-being. LGMDR9 may potentially afect sleep by physical or emotional symptoms, myalgia, or sleep-disordered breathing (SDB) through cardiorespiratory involvement. The objective was to investigate the occurrence of insomnia and unrecognized or untreated SDB in LGMDR9, associated factors, and relationships with fatigue and health-related quality of life (HRQoL). All 90 adults in a Norwegian LGMDR9 cohort received questionnaires on sleep, fatigue, and HRQoL. Forty-nine of them underwent clinical assessments and 26 without mask-based therapy for respiration disorders additionally underwent polysomnography (PSG) and capnometry. Among 77 questionnaire respondents, 31% received mask-based therapy. The prevalence of insomnia was 32% of both those with and without such therapy but was signifcantly increased in fatigued respondents (54% vs 21%). Insomnia levels correlated inversely with mental HRQoL. Among 26 PSG candidates, an apnea–hypopnea index (AHI)≥5/h was observed in 16/26 subjects (≥15/h in 8/26) with median 6.8 obstructive apneas and 0.2 central apneas per hour of sleep. The AHI was related to advancing age and an ejection fraction<50%. Sleep-related hypoventilation was detected in one subject. Fatigue severity did not correlate with motor function or nocturnal metrics of respiration or sleep but with Maximal Inspiratory Pressure (r=− 0.46). The results indicate that insomnia and SDB are underrecognized comorbidities in LGMDR9 and associated with HRQoL impairment and heart failure, respectively. We propose an increased attention to insomnia and SDB in the interdisciplinary care of LGMDR9. Insomnia and pulmonary function should be examined in fatigued patients

Das Blutdruckverhalten unter Hypoxie bei Patienten mit obstruktiver Schlafapnoe

Diese Arbeit befaßt sich mit dem Blutdruck und Atemverhalten unter Hypoxie bei Patienten mit obstruktiver Schlafapnoe und oder Hypertonie und Gesunden Vergleichspersonen. Zusätzlich wurde überprüft ob eine während der Messung eingenommene unterschiedliche Körperposition (sitzend/liegend) Einfluß auf die jeweilige Blutdruck bzw. Atem-Reaktion bei den Patienten hatte. Als Ergebnis erbrachten die Messungen das es keinen signifikanten Unterschied zwischen der Blutdruck sowie Atemreaktion zwischen Gesunden und Patienten mit obstruktiver Schlafapnoe, sowie zwischen den unterschiedlichen Messpositionen gib

The role of upper airway morphology in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a highly prevalent sleep-related breathing disorder, characterized by repetitive complete and/or partial obstructions of the upper airway during sleep. It is suggested that impaired upper airway morphology is a fundamental pathophysiological trait of OSA. However, the exact role of the upper airway morphology in the pathogenesis and treatment of OSA is still not well known. Therefore, the general aim of this thesis was to evaluate the role of upper airway morphology in the pathogenesis of different OSA phenotypes and in the effects of mandibular advancement device (MAD) therapy. Upper airway morphology was investigated by cone beam computed tomography (CBCT). No significant differences in the upper airway morphology between positional and non-positional OSA (chapter 2), nor between Dutch and Chinese patients with mild to moderate OSA (chapter 3) were found. Further, miniscrew-assisted orthodontic treatment with premolar extractions increased upper airway dimensions in young adults with Class II malocclusion (chapter 4). Finally, no significant differences in the changes in upper airway dimensions between two types of MADs in situ (chapter 5), nor between responders and non-responders (chapter 6) with mild to moderate OSA were found. Therefore, it was concluded that the upper airway morphology does not play a significant role in the pathogenesis of different OSA phenotypes and in the treatment effects of MADs. Future research involving both anatomical and non-anatomical factors is needed to better understand the pathogenesis and treatment outcomes of OSA