Polysomnography Research Articles

Real-time observation of nasal cycle during sleep with polysomnography.

To investigate the nasal cycle (NC) during sleep in healthy individuals without nasal obstruction or obstructive sleep apnoea via a flexible wearable respiratory monitoring system in a continuous and real-time manner. NC during sleep was continuously measured in 30 healthy individuals (15 women, 15 men) via long-term sleep respiratory monitoring system, while sleep stage and body position were simultaneously recorded via polysomnography (PSG). The number of NC transitions and positional changes were documented each night. Additionally, time intervals between NC transitions and their closest positional changes during sleep were meticulously recorded to investigate potential correlations between them. A total of 86.7% of the participants displayed the classic NC, with a mean duration of 6.43 ± 2.33h. Nightly observations revealed an average occurrence of 2.19 ± 0.40 NC transitions, predominantly occurring during REM stage (68.4%), and 9.15 ± 7.77 postural changes. Analysis of the intervals between NC transitions and positional changes revealed an average absolute value of 27.72 ± 10.85min, with a substantial 56.4% exceeding 30min, indicating a non-obvious sequence order among them. NC can be measured in a continuous and real-time manner, the transitions occur mainly during the REM stage. However, we have not identified a clear correlation between NC transition and positional change.

Estimating the severity of obstructive sleep apnea during wakefulness using speech: A review

Obstructive sleep apnea (OSA) is a chronic breathing disorder during sleep that affects 10-30% of adults in North America. The gold standard for diagnosing OSA is polysomnography (PSG). However, PSG has several drawbacks, for example, it is a cumbersome and expensive procedure, which can be quite inconvenient for patients. Additionally, patients often have to endure long waitlists before they can undergo PSG. As a result, other alternatives for screening OSA have gained attention. Speech, as an accessible modality, is generated by variations in the pharyngeal airway, vocal tract, and soft tissues in the pharynx, which shares similar anatomical structures that contribute to OSA. Consequently, in this study, we aim to provide a comprehensive review of the existing research on the use of speech for estimating the severity of OSA. In this regard, a total of 851 papers were initially identified from the PubMed database using a specified set of keywords defined by population, intervention, comparison and outcome (PICO) criteria, along with a concatenated graph of the 5 most cited papers in the field extracted from ConnectedPapers platform. Following a rigorous filtering process that considered the preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach, 32 papers were ultimately included in this review. Among these, 28 papers primarily focused on developing methodology, while the remaining 4 papers delved into the clinical perspective of the association between OSA and speech. In the next step, we investigate the physiological similarities between OSA and speech. Subsequently, we highlight the features extracted from speech, the employed feature selection techniques, and the details of the developed models to predict OSA severity. By thoroughly discussing the current findings and limitations of studies in the field, we provide valuable insights into the gaps that need to be addressed in future research directions.

Early detection and treatment of obstructive sleep apnoea in infants with Down syndrome: a prospective, non-randomised, controlled, interventional study

Infants with Down syndrome (DS) are at high risk of obstructive sleep apnoea (OSA) which is associated with neurocognitive dysfunction and behaviour problems. The aim of our study was to evaluate the effect of early OSA treatment in infants with DS on neurocognitive development and behaviour. In this prospective, interventional, non-randomised study, 40 infants with DS underwent polysomnography (PSG) every 6 months in room air between 6 and 36 months of age (Screened Group) and were compared to a control group of 40 infants with DS receiving standard of care and a single, systematic PSG in room air at 36 months of age (Standard Care Group). When present, OSA was treated. The primary endpoint was the total score of the Griffiths Scales of Child Development, Third Edition (Griffiths III) and its subscores at 36 months. Secondary endpoints included a battery of neurocognitive and behaviour questionnaires, and PSG outcomes. On the Griffiths III, the total score was significantly higher in the Screened Group compared to the Standard Care Group (difference: 4.1; 95%CI: 1.3; 7.6; p=0.009). Results in Griffiths III subscores and secondary endpoints were in support of better neurocognitive outcomes in the Screened Group compared with the Standard Care Group. At 36 months, median (Q1; Q3) apnoea-hypopnea index was higher in the Standard Care Group (4.0 [1.5; 9.0] events/hour) compared to the Screened Group (1.0 [1.0; 3.0] events/hour, p=0.006). Moderate and severe OSA were more frequent in the Standard Care Group as compared to the Screened Group (18.9% versus 3.7% for moderate OSA and 27.0% versus 7.4% for severe OSA). Early diagnosis and treatment of OSA in infants with DS may contribute to a significantly better neurocognitive outcome and behaviour at the age of 36 months. The study was funded by the Jérôme Lejeune Foundation.

Investigating the Link between Circadian Clock Gene Expressions, Chronotype, Insomnia, and Daytime Sleepiness in Patients with Obstructive Sleep Apnea.

This study aimed to investigate the relationship between obstructive sleep apnea (OSA), circadian rhythms, and individual sleep-wake preferences, as measured by chronotype, and to assess the association between circadian clock gene expression and subjective sleep-related variables. A total of 184 individuals were recruited, underwent polysomnography (PSG), and completed questionnaires including a chronotype questionnaire (CQ), insomnia severity index (ISI), and Epworth sleepiness scale (ESS). Blood samples were collected in the evening before and morning after PSG. Gene expression analysis included BMAL1, CLOCK, PER1, CRY1, NPAS2, and NR1D1. In the OSA group, the subjective amplitude (AM score of CQ) positively correlated with all circadian clock genes in the morning (R ≥ 0.230 and p < 0.05 for each one), while the morningness-eveningness (ME score of CQ) was only associated with the evening BMAL1 level (R = 0.192; p = 0.044). In healthy controls, insomnia severity correlated with evening expression of BMAL1, PER1, and CRY1. The findings highlight the complex interplay between OSA, circadian rhythms, and sleep-related variables, suggesting potential determinants of morning chronotype in OSA and implicating disrupted circadian clock function in subjective feelings of energy throughout the day. Further research is warranted to elucidate underlying mechanisms and guide personalized management strategies.

Patient preference of level I, II and III sleep diagnostic tests to diagnose obstructive sleep apnoea among pregnant women in early to mid-gestation.

There is a paucity of data on preferences for obstructive sleep apnoea (OSA) diagnostic tests during pregnancy. Simple test completion rates fail to capture patient preference or experience of completing sleep diagnostic tests. We assessed preference, ease of use, convenience, and the repeatability of level I, II and III sleep diagnostic tests, using questionnaires, in pregnant women in early to mid-gestation. Pregnant women with signs or symptoms of OSA, or at high risk of cardiometabolic disorders of pregnancy completed level I, II and III sleep studies by 24 weeks gestation. Participants then completed a questionnaire to rank test preference. Additional questionnaires assessed ease of use, convenience, and acceptability to repeat test, using 5-point Likert scale questions, yes/no response and optional linked text fields. Of fifty-two consented participants, 43 completed any questionnaire (mean age 32.7 ± 5.4 years, BMI 32.7 ± 5.4, median gestation at Level I polysomnography (PSG) of 14.2 weeks (interquartile range (IQR) 13.5-17.6)). Of the 29 respondents who completed test ranking questionnaire, level III was the preferred test ((n = 21 / 29,75%)), followed by level 1 (n = 6 / 29,20.7%) and level II (n = 2 / 29,7.1%) (p for diff < 0.001). Level III was reported the easiest test(very easy to complete) (n = 16,51.6%), followed by level I(n = 10, 33.3%), and level II (n = 9, 9.1%) (p for diff < 0.001)). Level III was reported most convenient test (very convenient to complete) (n = 16,51.6%), followed by level I(n = 4, 13.3%) and level II (n = 4, 13.3%) (p for diff < 0.001)). Level III was reported most acceptable to repeat (very acceptable to repeat) (n = 13, 41.9%), followed by level I (n = 3, 10.0%) and level II(n = 3, 10.0%) (p for diff < 0.001)). Pregnant women being assessed for OSA by 24 weeks gestation preferred to undertake level III sleep studies and found level III easier to use, more convenient and most acceptable to repeat than Level I and II studies. Given autonomy is an important principle, patient preference of sleep diagnostic tests should be taken into consideration in sleep clinical services and research involving pregnant women.

Comparison of Home Sleep Devices and Sleep Study Testing in Hypoglossal Nerve Stimulation Patients.

Hypoglossal nerve stimulation (HGNS) is an implantable therapy for obstructive sleep apnea (OSA). Therapy efficacy is currently confirmed by a formal sleep study after empiric adjustment by the patient at home based on their subjective experience with the device. Home-based longitudinal apnea hypopnea index (AHI) measurements have the potential to refine HGNS therapeutic amplitude selection with objective data. Our objective was to compare AHI derived from routine sleep studies and two different home sleep devices in new HGNS recipients. Prospectively enrolled patients receiving HGNS therapy were provided a Sleep Tracking Mat (Withings, Issy-les-Moulineaux, France) and NightOwl peripheral arterial tonometry (PAT) sensor (Ectosense, Leuven, Belgium) for longitudinal, home AHI monitoring from 1 to 6 months post-implant. Therapy efficacy was assessed at 3 and 6 months post-implant using in-lab polysomnography (PSG) or home sleep apnea test (HSAT). The sleep mat and PAT sensor AHI were compared against PSG and HSAT for accuracy of OSA severity identification. Sixty patients were enrolled across 5 centers and followed for 6 months. The sleep mat had sensitivity and specificity for identifying AHI <15 of 61% and 82% and AHI <30 of 77% and 100%. The PAT device had sensitivity and specificity for identifying AHI <15 of 57% and 77% and AHI <30 of 81% and 80%. The sleep mat and PAT sensor demonstrated high sensitivity and specificity for detection of mild and moderate OSA in patients with HGNS therapy and may enable longitudinal objective monitoring of HGNS efficacy in the home setting. 3 Laryngoscope, 2024.

Multidimensional prediction of continuous positive airway pressure adherence

ObjectiveContinuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA). Unsatisfactory adherence to CPAP is an important clinical issue to resolve. Cluster analysis is a powerful tool to distinguish subgroups in a multidimensional fashion. This study aimed to investigate the use of cluster analysis for predicting CPAP adherence using clinical polysomnographic (PSG) parameters and patient characteristics. Patients/methodsParticipants of this multicenter observational study were 1133 patients with OSA who were newly diagnosed and implemented CPAP. Ward's method of cluster analysis was applied to in-laboratory diagnostic PSG parameters and patient characteristics. CPAP adherence was assessed during 90- and 365-day periods after CPAP initiation in each cluster. We adopted the Centers for Medicare and Medicaid Services criterion for CPAP adherence, i.e., CPAP use ≥4 h per night for 70 % or more of the observation period. Logistic regression analysis was performed to stratify clusters according to CPAP adherence. ResultsFive clusters were identified through cluster analysis. Clustering was significantly associated with CPAP adherence at 90- and 365-day periods after CPAP initiation. Logistic regression revealed that the cluster with features including apnea predominant sleep-disordered breathing, high apnea-hypopnea index, and relatively older age demonstrated the highest CPAP adherence. ConclusionCluster analysis revealed hidden connections using patient characteristics and PSG parameters to successfully identify patients more likely to adhere to CPAP for 90 days and up to 365 days. When prescribing CPAP, it is possible to identify patients with OSA who are more likely to be non-adherent.

Prevalence and impact of sleep-related breathing disorder in multiple system atrophy patients: a cross-sectional study and meta-analysis.

Sleep-related breathing disorder (SRBD) is a prevalent non-motor symptom in multiple system atrophy (MSA). However, the reported prevalence of SRBD in MSA from different studies has shown inconsistency. Additionally, only one study has examined the impact of SRBD on both motor and non-motor symptoms in MSA. Cross-sectional study of 66 patients with probable MSA from China. SRBD was ascertained with polysomnography (PSG). All the MSA individuals were assessed using the Epworth Sleepiness Scale (ESS), Unified Multiple-System Atrophy Rating Scale (UMSARS), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), the Mini-mental State Examination (MMSE), Non-Motor Symptoms Scale (NMSS), and Pittsburgh Sleep Quality Index (PSQI). Moreover, a meta-analysis was conducted by searching studies related to MSA and SRBD in PubMed, Web of Science, Embase, and Cochrane databases. Data were pooled as necessary to calculate prevalence of SBRD with 95% confidence intervals (CI). Our study included 66 patients with MSA, 52 of whom had a diagnosis of SRBD (78.8%). There were no significant differences between the MSA with SRBD and without SRBD groups on the age, sex, disease onset, disease duration, UMSARS I, II, and IV, the NMSS, the HAMA, HAMD, the ESS the FSS, the MMSE, and the PSQI scales. However, MSA patients with SRBD having a significant higher obstructive apnea index and percentage of snoring during sleep than MSA patients without SRBD [10.0 (4.1-10.6) vs. 0.1 (0-0.3), and 8.3 (5.1-12.2) vs. 4.2 (0-7.5)]. Also, between the two groups, the mean and minimum oxygen concentrations during sleep were lower in MSA patients with SRBD than in those without SRBD [93.7 (93-95) vs. 95.5 (95.8-97), p = 0.001] and [83.9 (81.2-89.0) vs. 90.3 (89.8-93.3), p = 0.000]. The primary search strategy identified 701 articles, with 10 meeting the inclusion criteria. The overall prevalence of SRBD in a combined sample of 295 MSA patients was found to be 60.5% (95% CI, 43.2-76.5%). Further analysis revealed that the prevalence of SRBD in MSA patients in Asia was 79.2% (95% CI, 54.7-96.3%), which was higher than that in Europe (41.6, 95% CI, 32-51.5%). The study found a prevalence of 78.8% of SRBD in MSA patients, with a notably higher prevalence in Asia compared to Europe. The majority of SRBD cases in MSA were attributed to obstructive apnea. Furthermore, the presence of SRBD did not show a significant impact on the motor and non-motor symptoms of MSA patients.

Sex-based disparities in dopamine agonist response in patients with restless legs syndrome.

This study aimed to investigate sex-related differences in the response to ropinirole and pramipexole in patients with restless legs syndrome (RLS). By analysing clinical parameters and polysomnographic (PSG) findings, we sought to elucidate the potential factors related to sex disparities modulating treatment responses and sleep quality in RLS. A total of 41 drug-free patients with RLS, aged ≥18 years, underwent two consecutive nocturnal PSG recordings, without medication at baseline; before the second night, 26 patients received an oral dose of 0.25 mg pramipexole whereas 15 received 0.5 mg ropinirole. After each PSG recording, patients self-evaluated the severity of their previous night symptoms by means of an ad hoc visual analogue scale (VAS). At baseline, sleep efficiency and percentage of Stage N2 tended to be higher in females while wakefulness after sleep onset was significantly higher in males. After treatment, total leg movements during sleep (LMS), periodic LMS (PLMS), and periodicity indexes were significantly lower in females than in males. The VAS score was lower after treatment in all patients, without differences between the two sexes. This study demonstrates a higher acute responsiveness of PLMS to dopamine agonists (pramipexole and ropinirole) in females than in males with RLS. These findings might be explained by differential sex-related expression of dopamine receptors, especially D3, within the central nervous system. In addition, our findings provide translational hints toward a better tailored and sex-specific approach to the treatment of RLS associated with PLMS, with dopamine agonist possibly associated with a better outcome in females than in males.

The actigraphic evaluation of daytime sleep in central disorders of hypersomnolence: comparison with polysomnography.

The role of actigraphy in central disorders of hypersomnolence (CDH) is expanding but evidence of reliability with polysomnography (PSG) is scarce and provided only during nighttime. We explored the agreement between actigraphy and continuous 24-hour PSG at CDH diagnosis. Forty-four consecutive drug-naïve patients (28 narcolepsy, 16 idiopathic hypersomnia) underwent actigraphy during 24 hours of free-running PSG, during multiple sleep latency test (MSLT) and 13 of them also during maintenance of wakefulness test (MWT). Daytime and nighttime sleep features and MSLT and MWT mean sleep latencies (mSL) were estimated with the actigraphic algorithms by Cole-Kripke (CK) Sadeh, and University of California San Diego (UCSD). Agreement to corresponding PSG measures was assessed with Bland Altman plots. Nighttime-total sleep time (TST) in narcolepsy was significantly underestimated with CK (bias 27.8min, 95%CI 13.7-41.9) and Sadeh (bias 56.7min, 95%CI 38.8/74.5). Daytime-TST was overestimated in IH and narcolepsy with all algorithms (CK: bias -42.2, 95%CI -67/-17.4; Sadeh: bias -30.2min, 95%CI -52.7/-7.7; UCSD bias -86.9min, 95%CI -118.2/-55.6). 24-hour-TST was overestimated by CK and UCSD in IH (CK: bias -58.5min, 95%CI -105.5/-11.5; UCSD: bias -118.8min, 95% CI -172.5/-65), and by UCSD in narcolepsy (bias -68.8min, 95%CI -109.3/-38.2). In the entire cohort, actigraphy overestimated MSLT mSL but not MWT mSL. Conventional actigraphic algorithms overestimate 24-hour TST in IH and underestimate nighttime TST in narcolepsy. These discrepancies call for cautious application of actigraphy in the diagnostic process of CDH and the development of new quantitative signal analysis approaches.

Allowing ad libitum sleep during overnight polysomnography impacts Multiple Sleep Latency Test results in patients being assessed for hypersomnolence.

The Multiple Sleep Latency Test (MSLT) is a key diagnostic component in the diagnosis of central disorders of hypersomnolence. Due to time constraints, it is common practice to wake patients at a standard time from overnight polysomnography (PSG) prior to the MSLT. This has the potential to influence MSLT results due to sleep deprivation. We describe the impact of allowing ad libitum sleep on the night prior to the MSLT in patients being assessed for hypersomnolence. 580 consecutive patients undergoing PSG/MSLT for assessment of hypersomnolence were analyzed: 290 either side of a change in laboratory protocol which allowed patients ad libitum sleep during the PSG, rather than being woken at a pre-specified time. Baseline characteristics, PSG and MSLT results were compared between the groups. Groups were similar at baseline, other than there being more females in the ad libitum group. After adjusting for confounding variables, ad libitum patients had later sleep offset time (+58.7 minutes; p<0.001), longer PSG total sleep time (+47.8 minutes; p<0.001), longer MSLT mean sleep latency (+1.3 minutes; p=0.002) and 23% fewer MSLT with mean sleep latency less than 8 minutes (p=0.004) when compared with patients who were woken at a standard time. The common practice of waking patients from their PSG at a standard time has the potential to curtail sleep and impact MSLT results by reducing mean sleep latency. Patients being assessed for hypersomnolence should be allowed ad libitum sleep during the PSG on the night prior to their MSLT.

The relationship between obstructive sleep apnea syndrome severity and vitamin D levels in sera

Aims: Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by complete or partial upper airway obstruction episodes and frequently decreased arterial oxygen saturation. Etiological factors and risk factors of OSAS are still investigated and studies in this topic continue. Until recently, researches were focused on the major effects of vitamin D on the bone metabolism and calcium homeostasis. Today; it has been found that vitamin D plays roles in many cells and tissues of human body additional to its functions in the musculoskeletal system. In our study, we aimed to examine vitamin D levels in patients who are diagnosed as OSAS and to investigate the relationship between OSAS and vitamin D deficiency. Methods: 83 volunteers, who were suspected to have OSAS, were included in the study. They all underwent polysomnography (PSG) in the Sleep Disorders Center in Pulmonary Department, between January 2015 – May 2015. Twenty cases with apnea hypopnea index (AHİ) &lt; 5/hour were evaluated as simple snoring/control group. Cases with AHİ &gt; 5/hour were diagnosed as OSAS; 22 patients were diagnosed as mild, 20 patients were diagnosed as moderate and 21 patients were diagnosed as severe OSAS. Blood samples of these patients were studied for the measurement of vitamin D [25(OH)D3], parathormone (PTH) , calcium (Ca), phosphor (P) levels and the samples were quickly delivered to biochemistry laboratory Results: A statistically significant difference in vitamin D levels were observed (p&lt;0.05) between the control and OSAS groups. However, no statistically significant difference was found in PTH, Ca, P levels among these groups (p&gt;0.05). Vitamin D levels in the control group were significantly higher than the mild and the severe OSAS patients. No statistically significant difference was observed in PTH, Ca, P levels between these patients. Conclusion: Our study indicates that there is a significant relationship between vitamin D deficiency and OSAS. This finding suggests that vitamin D deficiency may play a role in the OSAS physiopathology. There are few studies exists about the association between vitamin D deficiency and OSAS. In this regard, we think our study will contribute to the literature. Moreover; prospective, randomized, controlled studies with large series were needed.

Reproducible, data-driven characterization of sleep based on brain dynamics and transitions from whole-night fMRI.

Understanding the function of sleep requires studying the dynamics of brain activity across whole-night sleep and their transitions. However, current gold standard polysomnography (PSG) has limited spatial resolution to track brain activity. Additionally, previous fMRI studies were too short to capture full sleep stages and their cycling. To study whole-brain dynamics and transitions across whole-night sleep, we used an unsupervised learning approach, the Hidden Markov model (HMM), on two-night, 16-hour fMRI recordings of 12 non-sleep-deprived participants who reached all PSG-based sleep stages. This method identified 21 recurring brain states and their transition probabilities, beyond PSG-defined sleep stages. The HMM trained on one night accurately predicted the other, demonstrating unprecedented reproducibility. We also found functionally relevant subdivisions within rapid eye movement (REM) and within non-REM 2 stages. This study provides new insights into brain dynamics and transitions during sleep, aiding our understanding of sleep disorders that impact sleep transitions.

Effects of different treatments for obstructive sleep apnea on temporomandibular joint: a randomized clinical trial

BackgroundIn recent years, obstructive sleep apnea (OSA) has been increasingly recognized as a significant health concern. No previous studies assessed the effect of recommended treatment modalities of patients with OSA on the temporomandibular joint (TMJ). The current study aimed to evaluate the effect of different treatment modalities of OSA, such as continuous positive airway pressure (CPAP), mandibular advancement device (MAD), and oral myofunctional therapy (OMT) on subjective symptoms, clinical, and radiographic signs of temporomandibular disorders.Patients & MethodsThis hospital-based prospective randomized controlled clinical trial study was approved by the institutional review board and formal patient consent, 39 OSA patients, ranging in age from 19 to 56 after confirmation with full night Polysomnography (PSG) with healthy TMJ confirmed clinically and radiographically with magnetic resonance imaging (MRI) were randomly allocated into three treatment groups. Group 1: 13 patients were managed with CPAP after titration, group 2: 13 patients were managed with digitally fabricated MAD, and group 3: 13 patients were managed with OMT. The following parameters were evaluated before and 3 months after the intervention. Pain using a visual analogue scale (VAS), maximum inter-incisal opening (MIO), lateral movements, and clicking sound of TMJ. MRI was done before and 3 months after the intervention.ResultsOut of the 83 patients enrolled, 39 patients completed the treatment. There were no statistically significant differences in lateral jaw movements or clicking, and no significant difference in MRI findings between the three studied groups before and after the intervention. The OMT group showed a statistically significant difference in pain (p = 0.001), and MIO (p = 0.043) where patients experienced mild pain and slight limitation in mouth opening after 3 months of follow-up in comparison to MAD and CPAP groups.ConclusionCPAP and MAD are better for preserving the health of TMJ in the treatment of OSA patients. While OMT showed mild pain and slight limitation of MIO (that is still within the normal range of mouth opening) compared to CPAP and MAD.Trial registrationThe study was listed on www.clinicaltrials.gov with registration number (NCT05510882) on 22/08/2022.

Decreased Delta/Beta ratio index as the sleep state-independent electrophysiological signature of sleep state misperception in Insomnia disorder: A focus on the sleep onset and the whole night

PurposeSleep State Misperception (SSM) is described as the tendency of Insomnia Disorder (ID) patients to overestimate Sleep Latency (SL) and underestimate Total Sleep Time (TST). Literature exploring topographical components in ID with SSM is scarce and does not allow us to fully understand the potential mechanisms underlying this phenomenon. This study aims to evaluate the existence of sleep EEG topography alterations in ID patients associated with SSM compared to Healthy Controls (HC), focusing on two distinct periods: the Sleep Onset (SO) and the whole night. MethodsTwenty ID patients (mean age: 43.5 ± 12.7; 7 M/13F) and 18 HCs (mean age: 41.6 ± 11.9; 8 M/10F) underwent a night of Polysomnography (PSG) and completed sleep diaries the following morning upon awakening. Two SSM indices, referring to the misperception of SL (SLm) and TST (TSTm), were calculated by comparing objective and subjective sleep indices extracted by PSG and sleep diary. According to these indices, the entire sample was split into 4 sub-groups: ID +SLm vs HC –SLm; ID +TSTm vs HC –TSTm. ResultsConsidering the SO, the two-way mixed-design ANOVA showed a significant main effect of Groups pointing to a decreased delta/beta ratio in the whole scalp topography. Moreover, we found a significant interaction effect for the sigma and beta bands. Post Hoc tests showed higher sigma and beta power in anterior and temporo-parietal sites during the SO period in IDs +SLm compared to HC –SLm.Considering the whole night, the unpaired t-test revealed in IDs +TSTm significantly lower delta power during NREM, and lower delta/beta ratio index during NREM and REM sleep compared to HCs –TSTm.Finally, we found diffuse significant negative correlations between SSM indices and the delta/beta ratio during SO, NREM, and REM sleep. ConclusionThe main finding of the present study suggests that higher SL overestimation and TST underestimation are both phenomena related to diffuse cortical hyperarousal interpreted as a sleep state-independent electrophysiological correlate of the SSM, both during the SO and the whole night.

Validation of the Arabic version of the sleep apnea scale of the sleep disorders questionnaire SDQ-SA

BackgroundObstructive sleep apnea (OSA) is a widespread syndrome characterized by breathing cessation or reduction. It has a wide range of significant symptoms, such as snoring and fatigue. This study aimed to assess the validity of the Arabic version of the Sleep Disorders Questionnaire-Sleep Apnea Scale (SDQ-SA) as a screening tool in Arabic-speaking countries.MethodsThis study was conducted at a sleep disorders clinic at Damascus University’s hospitals from June 2023 to September 2023. Patients aged 18 to 75 who spoke Arabic were included, while those under 18 or over 75, with incomplete questionnaires, previous OSA diagnoses, or certain chronic diseases and sedative drug use were excluded. The questionnaire was translated into the Arabic language by two bilingual researchers. It was then given to around 15 patients to ensure clarity of the questions. The questionnaire was readministered to 30 participants to ensure reliability. After analyzing the results of the Arabic version of the SDQ-SA, we administered Polysomnography (PSG) type III tests to validate our results. Data analysis was conducted using Microsoft Excel and IBM SPSS version 22.ResultsThe study included 103 participants, with an average age of 56.55 years. The SDQ-SA identified 85 (82.5%) participants as being at high risk for having OSA. Among those classified as high risk, 39 (45.9%) had severe OSA, 34 (40%) had moderate OSA, 8 (9.4%) had mild OSA, and 4 (4.7%) had no OSA based on the apnea–hypopnea index (AHI) calculated by the PSG. On the other hand, 18 (17.5%) participants were classified as low risk for OSA, 3 (16.7%) had severe OSA, 3 (16.7%) had moderate OSA, 7 (38.9%) had mild OSA, and 5 (27.8%) had no OSA based on the AHI calculated by the PSG. For AHI ≥ 5, the sensitivity and specificity for men were 0.87 and 0.6, respectively, and for women, they were 0.84 and 0.5, respectively.ConclusionOur study showed that the Arabic version of the SDQ-SA questionnaire had good sensitivity and negative predictive value NPV, especially for patients with moderate to severe OSA. We recommend that physicians use this questionnaire and other similar questionnaires more frequently to identify and treat this underrecognized disease properly.

Accuracy of respiratory event indices downloaded from positive airway pressure devices: can they be relied upon when making treatment decisions?

The gold standard for diagnosis and treatment of obstructive sleep apnea (OSA) is attended overnight polysomnography (PSG) in a sleep laboratory. Alternative diagnostic techniques are urgently needed for both diagnosis and treatment control when initiating positive airway pressure (PAP) in the home setting. Current PAP devices compute data such as residual AHI (apnea-hypopnea index) using their proprietary algorithms to provide an automatic event detection (AED). It was suggested that these should be labeled AHIFLOW. The current study situation shows an acceptable agreement with the tendency of mildly overestimating the AHI by the PAP devices. But, the literature is still limited in terms of accuracy, especially when considering the lack of standardization and different detection algorithms. A validation of PAP devices regarding the agreement of AHIFLOW compared to AHIPSG is extremely important, given that the device analysis is exclusively based on the measured flow. There are considerable concerns about assessing the PAP effectiveness in higher risk groups based on the AED function alone. Given these reservations, the use of PAP event detection can be an important addition to the diagnostic spectrum and, in combination with telemonitoring, offers promising potential.

Evaluation of an OSA Risk Screening Smartphone App in a General, Non-Symptomatic Population Sample (ESOSA).

Background: Obstructive Sleep apnea (OSA) is a prevalent sleep disorder, risk factor for cardiovascular disease and imposes a substantial global socioeconomic and health burden. OSA is insufficiently diagnosed as it often presents with unspecific or no symptoms. This study compares the effectiveness of a smartphone-based screening method to polysomnography (PSG) in a general, non-symptomatic population sample. Methods: Adult subjects were recruited from the general population. Subjects reporting OSA-related symptoms suggesting an increased OSA risk were excluded. Included subjects underwent Type-II PSG and a parallel breathing sound analysis using the Snorefox M smartphone app. The PSG scores were compared with the results of the Snorefox M app for its ability to detect moderate to severe OSA (AHI ≥ 15). Results: 150 subjects were included. All subjects completed the diagnostic night, no adverse events occurred. A valid analysis result was obtained for 142 subjects. A total of 24% of subjects had moderate to severe OSA based on the PSG results. The Snorefox M software app showed a sensitivity of 0.91 (0.76, 0.98), specificity of 0.83, PPV of 0.63 (0.48, 0.77), and NPV of 0.97 (0.91, 0.99) to detect AHI ≥ 15 compared with the reference PSG (95% CI). Conclusions: This study compares for the first time, the performance of an app-based OSA screening tool with PSG in a non-symptomatic population sample. Easily accessible screening tools can play a role in complementing existing diagnostic possibilities, helping to increase the diagnosis rate, with a positive effect on cardiovascular health in a relevant population share.

A novel deep learning model for obstructive sleep apnea diagnosis: hybrid CNN-Transformer approach for radar-based detection of apnea-hypopnea events.

The demand for cost-effective and accessible alternatives to polysomnography (PSG), the conventional diagnostic method for obstructive sleep apnea (OSA), has surged. In this study, we have developed and validated a deep learning model for detecting apnea-hypopnea events using radar data. We conducted a single-center prospective cohort study, dividing participants with suspected sleep-disordered breathing into development and temporally independent test sets. Utilizing a hybrid CNN-Transformer architecture, we performed 5-fold cross-validation on the development set to develop and subsequently validate the model. Evaluation metrics included sensitivity for event detection, mean absolute error (MAE), intraclass correlation coefficient (ICC), and Pearson correlation coefficient (r) for apnea-hypopnea index (AHI) estimation. Linearly weighted kappa statistics (κ) assessed OSA severity. The development set comprised 54 participants (July 2021-May 2022), while the test set included 35 participants (June 2022-June 2023). In the test set, our model achieved an event detection sensitivity of 67.2% (95% CI: 65.8%, 68.5%) and demonstrated a MAE of 7.54 (95% CI: 5.36, 9.72), indicating good agreement (ICC = 0.889 [95% CI: 0.792, 0.942]) and a strong correlation (r = 0.892 [95% CI: 0.795, 0.945]) with the ground truth for AHI estimation. Furthermore, OSA severity estimation showed substantial agreement (κ = 0.780 [95% CI: 0.658, 0.903]). Our study highlights radar sensors and advanced AI models' potential to improve OSA diagnosis, paving the path for future radar-based diagnostic models in sleep medicine research.

Construction and validation of clinical prediction model of tongue base collapse under drug-induced sleep endoscopy in OSA patients

Objective: To analyze the correlation between drug-induced sleep endoscopy (DISE), results, polysomnography (PSG) indicators, and clinical parameters in patients with obstructive sleep apnea (OSA), and to establish and validate a predictive model for tongue base plane obstruction. Methods: This retrospective study analyzed 117 OSA patients diagnosed via PSG and treated at the Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, between October 2014 and March 2022. The cohort comprised of 114 males and 3 females, with an age range of 20 to 54 years (mean age 38.1±8.4 years). Data on DISE results, PSG results, and clinical indicators were collected for all 117 patients. Logistic regression analysis was performed to identify relevant indicators, and a predictive model for tongue base plane obstruction was constructed and internally validated using the R programming language. Results: Univariate logistic regression analysis identified four independent risk factors for predicting tongue root plane obstruction: tonsil grading, N2, N3, and rapid eye movement sleep(REM) stage [OR:0.412(0.260~0.652),1.045(1.012~1.079),0.943(0.903~0.984),0.961(0.925~0.998),P <0.05]. Multivariate logistic regression analysis confirmed tonsil grading and N3 sleep stage (12.48±12.22%) as significant predictors. A nomogram model incorporating these factors demonstrated good predictive performance, with an area under curve(AUC) of 0.82 (95%CI: 0.548-1.000), an optimal cutoff of 0.519, a specificity of 80.0%, and a sensitivity of 86.7%. Internal validation of the model in the validation cohort yielded an AUC of 0.751 (95%CI: 0.625-0.876). Conclusions: Tongue base plane obstruction observed during DISE in OSA patients is associated with tonsil grading and N3 sleep stage duration. The predictive model developed for tongue base plane obstruction based on DISE demonstrates good efficacy, as evidenced by its internal validation.