Consecutive Polysomnography Research Articles

Apnea-hypopnea duration may be a better choice rather than apnea-hypopnea index for forecasting complications in OSAS.

Mean apnea-hypopnea duration (AHD) is the mean duration of apnea-hypopneas experienced during sleep and was found as an indicator of blood oxygenation. The aim of this study was to compare and define the differences in clinical, demographic and polysomnographic characteristics of obstructive sleep apnea (OSA) patients in long and short AHD groups and investigate the relationship between apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and sleepiness. The cross-sectional analysis included 511 OSA patients who were >18 years and followed up between June 2019 and December 2019 in the Sleep Center of university hospital. The consecutive polysomnography reports and patient data were recorded retrospectively. Polysomnographic evaluation of different AHD groups showed obvious differences. Although there were no statistically significant differences in the overall AHI values. The Epworth measurements, ODI, time that saturation is below 90%, and N1 and N2 sleep were higher in the long AHD group. On the contrary, sleep efficiency, total sleep time, N3 and REM sleep, average oxygen saturation (AOS), and lowest oxygen saturation (LOS) were lower in the long AHD group. The findings of this study showed that the AHD is a useful indicator of blood oxygenation and, therefore, tissue oxygenation, independent of the AHI. OSA patients with longer AHD have more vascular complications such as diabetes and hypertension. We suggest that the severity of OSA should be monitored with AHD for preventing potential complications of OSA.

Are scoring respiratory effort-related arousals worth the effort? --A study comparing outcomes between 4 % vs 3 % hypopnea scoring rules

Study objectivesThe respiratory effort-related arousal (RERA) has been combined with apneas and hypopneas into the respiratory disturbance index (RDI). RERAs are characterized by ≥ 10 s of increasing upper airway effort terminating in arousal without meeting hypopnea criteria. The recent change to hypopnea definitions now includes a ≥30 % reduction in airflow for 10 s with EITHER a 3 % oxygen desaturation OR an arousal. Consequently, many events previously categorized as RERAs will now be included in the 3 % hypopneas, likely reducing the number of events scored as RERAs. We hypothesized that the 3 % apnea-hypopnea index (3%AHI) would approximate the 4%RDI, with the number of 3 % RERAs being negligible. Research questionHow does the transition from the 4 % to the 3 % hypopnea rules impact the significance of RERAs in clinical practice, and how we should relate the AHI and RDI using the different hypopnea rules? MethodsWe prospectively collected 76 consecutive polysomnography results in 4 adult age groups. We re-scored the respiratory events utilizing both the 3 % and the 4 % hypopnea rules and compared the outcomes. ResultsAmong 76 diagnostic studies (mean age 47.5 years, males 47.4 %), the 3 % RERA index [0.8 (0.0, 3.1)] [median (Q1, Q3)] was significantly lower than the 4 % RERA index [3.5 (1.0, 7.3)]. The 3%AHI was 3.07 ± 9.23 (mean ± SD) higher than the 4%RDI (p = 0.005). The 3%AHI was 8.63 ± 8.86 higher than the 4%AHI in all age groups (p < 0.001). This was mainly due to an increased hypopnea index (+8.51 ± 9.03, p < 0.001). In patients with obstructive sleep apnea (OSA), the 3%RERA contributes 4.3 % to the 3%RDI, while the 4%RERA contributes 27.7 % to the 4%RDI. InterpretationsBoth 3%RDI and 3%AHI are higher than the 4%RDI, primarily due to identification of more hypopnea events, resulting in more patients being classified as having OSA. This change in criteria complicates the comparison of hypopnea and RERA contributions between sleep studies scored using the different hypopnea rules.

The stability of slow-wave sleep and EEG oscillations across two consecutive nights of laboratory polysomnography in cognitively normal older adults.

Laboratory polysomnography provides gold-standard measures of sleep physiology, but multi-night investigations are resource intensive. We assessed the night-to-night stability via reproducibility metrics for sleep macrostructure and electroencephalography oscillations in a group of cognitively normal adults attending two consecutive polysomnographies. Electroencephalographies were analysed using an automatic algorithm for detection of slow-wave activity, spindle and K-complex densities. Average differences between nights for sleep macrostructure, electroencephalography oscillations and sleep apnea severity were assessed, and test-retest reliability was determined using two-way intraclass correlations. Agreement was calculated using the smallest real differences between nights for all measures. Night 2 polysomnographies showed significantly greater time in bed, total sleep time (6.3 hr versus 6.8 hr, p < 0.001) and percentage of rapid eye movement sleep (17.5 versus 19.7, p < 0.001). Intraclass correlations were low for total sleep time, percentage of rapid eye movement sleep and sleep efficiency, moderate for percentage of slow-wave sleep and percentage of non-rapid eye movement 2 sleep, good for slow-wave activity and K-complex densities, and excellent for spindles and apnea-hypopnea index with hypopneas defined according to 4% oxygen desaturation criteria only. The smallest real difference values were proportionally high for most sleep macrostructure measures, indicating moderate agreement, and proportionally lower for most electroencephalography microstructure variables. Slow waves, K-complexes, spindles and apnea severity indices are highly reproducible across two consecutive nights of polysomnography. In contrast, sleep macrostructure measures all demonstrated poor reproducibility as indicated by low intraclass correlation values and moderate agreement. Although there were average differences in percentage of rapid eye movement sleep and total sleep time, these were numerically small and perhaps functionally or clinically less significant. One night of in-laboratory polysomnography is enough to provide stable, reproducible estimates of an individual's sleep concerning measures of slow-wave activity, spindles, K-complex densities and apnea severity.

The impact of study type and sleep measurement on oxygen desaturation index calculation.

The oxygen desaturation index (ODI) is an important measure of sleep-disordered breathing during polysomnography (PSG); however, the AASM Manual (V3) does not specify whether to include oxygen desaturations occurring during wake epochs. Additionally, an ODI obtained from PSG can differ from an ODI using home sleep apnea tests (HSATs) that do not measure sleep, hampering diagnostic and treatment decision reliability. This study aimed to (1) compare an ODI that included all desaturations with an ODI that excluded desaturations occurring during wake epochs in PSG and (2) compare ODIs obtained from PSG with HSAT. 100 consecutive PSGs for investigation of obstructive sleep apnea were compared. ODIs were calculated including all desaturations (ODIall) and by excluding desaturations entirely during wake epochs (ODIsleep). Additionally, we compared ODIall with an ODI calculated using monitoring time as the denominator (ODIHSAT). The median (interquartile range) 3% ODI for ODIall was 22.8 (13.1, 44.1) events/h and ODIsleep was 17.6 (11.5, 35.2) events/h (median difference: -3.9 events/h [-8.2, -0.9]; 21.0% [8.7%, 33.2%]). This discrepancy was larger with increasing ODI and decreasing sleep efficiency. The ODIHSAT was 17.4 (11.3, 35.2) events/h and the median reduction in ODIHSAT vs ODIall was -4.5 (-10.9, -2.0) events/h (21.6%; 11.1%, 33.8). ODI was significantly reduced when desaturations in wake epochs were excluded, and when ODI was based on monitoring time rather than sleep time, with the potential for underestimation of disease severity. Results suggest that ODI can differ substantially depending on the calculation and study type used, and that there is a need for standardization to ensure consistent diagnosis and treatment outcomes. Whenn CB, Wilson DL, Ruehland WR, Churchward TJ, Worsnop C, Tolson J. The impact of study type and sleep measurement on oxygen desaturation index calculation. J Clin Sleep Med. 2024;20(5):709-717.

The burden of sleep disordered breathing in infants with Down syndrome referred to tertiary sleep center.

Children with Down Syndrome (DS) are at high risk of sleep disordered breathing (SDB). We aimed to examine the burden of SDB in infants with DS referred to tertiary sleep center. Infants (≤12 months old) with DS who underwent consecutive polysomnography (PSG) at a single academic sleep center over a 6-year period were included. obstructive sleep apnea(OSA) (obstructive apnea hypopnea index [oAHI]>1/hr), central sleep apnea (central apnea index > 5/h) and the presence of hypoventilation (% time spent with CO2 > 50 mmHg either by end-tidal or transcutaneous> 25% of total sleep time) and hypoxemia (time spent with O2 saturation <88% >5 min) were ascertained. A total of 40 infants were included (Mean age 6.6 months, male 66%). PSGs consisted of diagnostic (n = 13) and split night (n = 27, 68%) studies. All met criteria for OSA with mean oAHI 34.6/h(32.3). Central sleep apnea was present in 11 (27.5%) of infants. A total of 11 (27.5%) had hypoxemia. Hypoventilation was present in 10 (25%) infants. This study highlights the high prevalence of SDB in infants with DS referred to a sleep center, and supports early PSG assessment in this patient population.

Effects of electrostatic therapy on nighttime sleep and daytime symptoms in patients with chronic insomnia: Evidences from an open label study.

Transcranial electric stimulation (TES) is a neuromodulation approach that applies low-intensity electrical current to the brain and has been proposed as a treatment for insomnia. Electrostatic therapy is a kind of TES and people do not have a feeling of electrical stimuli when the voltage of static electricity is lower than 2,000 volts. However, no studies have examined the effects of electrostatic therapy on objective sleep and daytime symptoms in patients with insomnia. Thirty chronic insomnia patients were included. All patients received a 6 week electrostatic therapy and three comprehensive assessments including two consecutive polysomnography (PSG) and daytime symptoms assessments, at pre-treatment, 3 week and 6 week of treatment. Insomnia Severity Index (ISI) was used to assess the severity of insomnia. Multiple sleep latency test (MSLT), Epworth Sleepiness Scale (ESS), and Flinders Fatigue Scale (FFS) were used to assess objective and self-reported daytime sleepiness and fatigue, respectively. Attention network test (ANT) was used to assess attention levels. Total ISI scores decreased significantly at 3 weeks (p < 0.001) and 6 weeks (p < 0.001) after initiation of treatment. Furthermore, objective total sleep time (TST, p = 0.020) and sleep efficiency (SE, p = 0.009) increased and wake time after sleep onset (p = 0.012) decreased significantly after 6 weeks electrostatic therapy. Regarding daytime symptoms, ESS and FFS scores decreased significantly at 3 weeks (ESS, p = 0.047; FFS, p = 0.017) and 6 weeks (ESS, p = 0.008; FFS, p = 0.003) after initiation of treatment. Moreover, executive control improved significantly from pre-treatment to 3 weeks (p = 0.006) and 6 weeks (p = 0.013) and altering network improved significantly at 6 weeks (p = 0.003) after initiation of treatment. Secondary analyses showed that TST and SE improved significantly after electrostatic therapy in insomnia patients who slept < 390 min (all p-value < 0.05). However, no significant changes regarding TST and SE were observed in insomnia patients who slept ≥ 390 min. Electrostatic therapy improves both nighttime sleep and daytime symptoms in patients with chronic insomnia. The effect on objective sleep appears to be stronger in patient with objective short sleep duration. Electrostatic therapy might be a therapeutic choice for insomnia patients with difficulty maintaining sleep and not responding to behavioral treatments. [www.clinicaltrials.gov], identifier [ChiCTR2100051590].

Montreal Cognitive Assessment Predicts the Short-Term Risk of Lewy Body Disease in Isolated REM Sleep Behavior Disorder with Reduced MIBG Scintigraphy.

Long-term follow-up of isolated rapid eye movement (REM) sleep behavior disorder (IRBD) patients reveals a high risk of α-synucleinopathies. We explored the early clinical predictive factors of phenoconversion from IRBD to Parkinson's disease (PD) or dementia with Lewy bodies (DLB). We assessed baseline office-based cognitive test scores (Montreal Cognitive Assessment [MoCA-J], Mini-Mental State Examination [MMSE], and Frontal Assessment Battery [FAB]), motor function, and olfactory function in 36 consecutive polysomnography (PSG)-confirmed IRBD patients with reduced metaiodobenzylguanidine (MIBG) accumulation. PD or DLB was confirmed by medical chart review retrospectively. Of 36 IRBD patients, 19 (n=19, 52.8%) with abnormal MoCA-J score (< 26) had significantly lower scores in trail making B, phonetic verbal fluency sub-items in the executive domain, and in delayed recall in the memory domain. In total, 12 (33.3%) patients developed PD or DLB; seven of 12 patients (58.3%) developed DLB at a mean follow-up period of 6.8 years. In the normal MoCA-J group (n=17, 47.2%), two patients developed PD, but none developed dementia. Furthermore, in the abnormal MoCA-J group, seven patients developed DLB and three developed PD without dementia. The phenoconverter group had significantly lower scores in delayed recall in the memory domain compared to the disease-free group. Cox hazard analysis showed that MoCA-J was superior to MMSE. Among IRBD patients with reduced cardiac MIBG accumulation, MoCA-J score of <26 (Mild Cognitive Impairment-Lewy body) and a low sub-item score for delayed recall predicted short-term progression to probable DLB.

The impact of treatment of periodic limb movements in sleep on blood pressure in patients with and without sleep apnea

Improving sleep quality in patients with obstructive sleep apnea (OSA) by positive airway pressure therapy is associated with a decrease of blood pressure (BP). It remains elusive, whether treatment of sleep disturbances due to restless legs syndrome with symptomatic periodic limb movements in sleep (PLMS) affects BP as well. The present study provides first data on this issue. Retrospective study on patients undergoing polysomnography in a German University Hospital. Inclusion criteria were first diagnosis of restless legs syndrome with PLMS (PLM index ≥ 15/h and PLM arousal index ≥ 5/h) with subsequent initiation of levodopa/benserazide or dopamine agonists. Exclusion criterion was an initiation or change of preexisting positive airway pressure therapy between baseline and follow-up. BP and Epworth sleepiness scale were assessed at two consecutive polysomnographies. After screening of 953 PLMS data sets, 114 patients (mean age 62.1 ± 12.1 years) were included. 100 patients (87.7%) were started on levodopa/benserazide, 14 patients (12.2%) on dopamine agonists. Treatment was associated with significant reductions of PLM index (81.2 ± 65.0 vs. 39.8 ± 51.2, p < 0.001) and ESS (6 [interquartile range, IQR, 3–10.5] vs. 5 [IQR 3–10], p = 0.013). Systolic BP decreased from 132.9 ± 17.1 to 128.0 ± 15.8 mmHg (p = 0.006), whereas there was no significant change of diastolic BP (76.7 ± 10.9 vs. 75.1 ± 9.2 mmHg, p = 0.15) and heart rate (71.5 ± 11.9 vs. 71.3 ± 12.7, p = 0.84). The number of antihypertensive drugs remained unchanged with a median of 2 (IQR 1–3, p = 0.27). Dopaminergic treatment of PLMS is associated with an improvement of sleep quality and a decrease of systolic BP comparable to treatment OSA.

Performance of Fitbit Charge 3 against polysomnography in measuring sleep in adolescent boys and girls

ABSTRACT We evaluated the performance of Fitbit Charge 3™ (FC3), a multi-sensor commercial sleep-tracker, for measuring sleep in adolescents against gold-standard laboratory polysomnography (PSG). Single-night PSG and FC3 sleep outcomes were compared in thirty-nine adolescents (22 girls; 16–19 years), 12 of whom presented with clinical/subclinical DSM-5 insomnia symptoms (7 girls). Discrepancy analysis, Bland–Altman plots, and epoch-by-epoch analyses were used to evaluate FC3 performance. The influence of several factors potentially affecting FC3 performance (e.g., sex, age, body mass index, firmware version, and magnitude of heart rate changes between consecutive PSG epochs) was also tested. In the sample of healthy adolescents, FC3 systematically underestimated PSG total sleep time by about 11 min and sleep efficiency by 2.5%, and overestimated wake after sleep onset by 9 min. Proportional biases were detected for “light” and “deep” sleep duration, resulting in significant underestimation of these parameters for those participants having longer PSG N1+ N2 and N3 durations, respectively. No significant systematic bias was detected for sleep efficiency and sleep onset latency. Epoch-by-epoch analysis showed sleep-stage sensitivity (average proportion of PSG epochs correctly classified by the device for a given sleep stage) of 68% for wake, 78% for “light” sleep, 59% for “deep” sleep, and 69% for rapid eye movement (REM) sleep in healthy sleepers. Similar results were found in the sample of adolescents with insomnia symptoms. Body mass index was positively associated with FC3-PSG discrepancies in wake after sleep onset (R2 = .16, p = .048). The magnitude of the heart rate acceleration/deceleration between consecutive PSG epochs was an important factor affecting FC3 classifications of sleep stages. Our results are in line with a general trend in the literature, suggesting better performance for the recently introduced multi-sensor devices compared to motion-only devices, although further developments are needed to improve accuracy in sleep stage classification and wake detection. Further insight is needed to determine factors potentially affecting device performance, such as accuracy and reliability (consistency of performance over time), in different samples and conditions.

Reversible Verbal Memory Integration Deficits in Obstructive Sleep Apnoea.

When presented with novel but semantically related elements after learning verbal material, healthy participants tend to endorse these items as previously learned. This reflects the normal integration and association of novel verbal information into long-term memory. How obstructive sleep apnoea (OSA) negatively impacts verbal memory performance, and whether deficits are reversible following positive airway pressure (PAP) treatment, remain elusive. We investigated immediate and delayed OSA- and PAP treatment-related effects on verbal memory integration, using a false memory paradigm. Twenty-three patients with OSA learned lists of words semantically related to target non-presented words (1) at baseline after a polysomnography diagnosis night, (2) after a consecutive polysomnography night under PAP titration, and (3) after three months of compliant PAP treatment. At each session, participants learned 10 different lists of words, each list comprising 15 semantically related items. They had then to recognize 15 minutes later (after an intermediate vigilance task) previously learned words within a list including studied words (learned), unstudied but semantically related items (lures), and non-related unstudied items (controls). Sleep quality and fatigue questionnaires, and psychomotor vigilance tests (PVT) were administered at each session. PAP treatment led to OSA remission and improvement in objective and subjective sleep quality. Crucially, recognition of learned and lure words increased after the first night under treatment and remained stable three months later, suggesting successful memory integration and restoration of semantic processes. No treatment-related outcome was found on PVT performance. OSA exerts a detrimental but PAP-reversible effect on verbal learning and semantic memory integration mechanisms underlying the acquisition of novel memory representations.

Measuring Sleep Quality and Efficiency With an Activity Monitoring Device in Comparison to Polysomnography.

BackgroundMonitoring for physical activity becomes popular and actually many devices are available. Some physical activity monitors (PAMs) provide data about sleep quality for the user, but there are scarce data concerning validity and usability of these measurements. This study compared the data of sleep parameters generated by a PAM with the polysomnography (PSG).MethodsIn 2016, data of 26 patients in two consecutive PSGs as well as in two daytime and nighttime measurements with a PAM according to physical activity and sleep quality were collected. Furthermore, sleep quality, using the Pittsburgh sleep quality index (PSQI), daytime fatigue, using the multidimensional fatigue inventory (MFI-20) and additionally data of a sleep diary were collected.ResultsThere were positive correlations of both methods with respect to total sleep time (TST) (r = 0.76, P < 0.01) and sleep efficiency (r = 0.71, P < 0.01). Data analysis over two nights showed that over 90% of the TST (95% confidence interval (CI) -1.59 to 0.82) and of the sleep efficiency (95% CI -8.28 to 15.51) were within the limits of agreement. The analysis of the PSQI and the sleep efficiency of the PAM showed no significant correlations. The daytime fatigue correlated negatively with the physical activity (r = -0.72, P < 0.01).ConclusionThe sleep efficiency and TST measured with the PAM sufficiently reflect the PSG sleep parameters and the subjects’ subjective feelings. At the same time, PAM results are also correlated with the subjectively perceived quality of sleep. Further investigations to assess the long-term results are pending.

Can positional therapy be simple, effective and well tolerated all together? A prospective study on treatment response and compliance in positional sleep apnea with a positioning pillow.

Until now, there is no clear consensus on optimal care for mild sleep-related breathing disorders (SRBD) in general or for positional obstructive sleep apnea (POSA) in particular. Most proposed treatment options are either invasive and/or expensive. Positional therapy (PT) may therefore present as a valuable first-line intervention in POSA. Twenty-eight patients presenting with POSA were enrolled in a prospective cohort study. The protocol consisted of three nights of polysomnography (PSG) in an academic sleep lab. Inclusion was based on the first PSG. During a consecutive PSG, PT was provided by means of a sleep-positioning pillow (Posiform®). The third PSG was performed after 1month of PT. Sleepiness, fatigue, and sleep quality were assessed with the Epworth Sleepiness Scale (ESS), the fatigue severity scale (FSS), the Pittsburgh Sleep Quality Index (PSQI), and the Function Outcomes of Sleep Questionnaire (FOSQ) at baseline, and after 1 and at 6months of PT alongside satisfaction and compliance ratings. Significant immediate treatment effects after one night and sustained after 1month were observed by significant reductions of sleep in supine position (p < .001), sleep fragmentation (p < .05), apnea-hypopnea (p < .001), respiratory disturbance (p < .001), and oxygen desaturation (p < .001) indices. PSQI (p < .001), ESS (p < .005), and FOSQ (p < .001) also showed significant and persistent improvements. Combined effects on sleep-related respiration and clinical symptoms were observed after PT initiation as well as after 1month using the sleep-positioning pillow. Furthermore, reported compliance and overall satisfaction appeared to be highly concordant both at 1month and 6months follow-up.

Pulse wave amplitude reduction as a surrogate for cortical arousal during sleep hypopnea in children

ObjectivesThe accuracy of respiratory polygraphy (RP) is limited because of the absence of electroencephalography (EEG). Pulse wave amplitude (PWA) reduction has been shown to be a marker of autonomic activation during arousal, and may represent a substitute for obstructive respiratory-related cortical arousal (RRCA). This study tested the hypothesis that PWA could be a surrogate for RRCA in detecting obstructive hypopnea (OH) in a pediatric population. Materials and methodsTwo experienced readers scored 30 consecutive polysomnographies (PSG) using standard scoring rules. Automatic software detected every 20–90% reduction in PWA. A second scoring of respiratory events using PWA reduction as a surrogate for RRCA was performed (RP with PWA) for each percentage of PWA reduction. The final analysis consisted of determining the concordance between the two methods of detecting OH. ResultsA total of 987 episodes of ≥30% flow reduction were analyzed: 330 with RRCA only, 205 with desaturation (DS) only, 134 with both, and 318 without RRCA or DS. As the percentage of reduction in PWA increased, the sensitivity of PWA as a substitute for RRCA decreased, but the specificity increased. For a decrease in PWA of 60% or 70%, the sensitivities of PWA as a substitute for RRCA were 79% and 57%, and the specificities 51% and 76%, respectively. ConclusionPulse wave amplitude reduction lacks sensitivity and specificity to be used as a surrogate for RRCA to detect OH in children. Polysomnography remains the gold standard for the diagnosis of sleep disordered breathing in children.

Complex sleep apnea at auto-titrating CPAP initiation: prevalence, significance and predictive factors.

Obstructive sleep apnea (OSA) patients may develop central respiratory events under continuous positive airway pressure (CPAP), referred to as complex sleep apnea (CompSA). We aimed to assess prevalence and predictive factors of complex apnea and to evaluate treatment response to CPAP. Within a retrospective cohort study, we assessed clinical data of OSA patients, attending the sleep lab during a 15-months period. Included participants underwent two consecutive polysomnographies; baseline diagnosis and treatment trial. Complex apnea patients, defined by a central apnea index ≥ 5 per hour during pressure auto-titration, were compared to remainders. Among 263 included patients, the prevalence of complex apnea was 9.1%. The mean apnea hypopnea index only dropped from 52.7 to 39.9 per hour in CompSA patients, while it improved from 40.9 to 7.3 in patients without CompSA. Although a decreased sleep-fragmentation under CPAP was observable in both groups, the enhancement of Non-REM sleep was superior in patients without CompSA. The CompSA patients showed higher median apnea-hypopnea, mixed apnea and central apnea indices at baseline and displayed higher rates of comorbid heart failure and obstructive pulmonary disease, but no higher severity of associated daytime fatigue and sleepiness symptoms. Despite evidenced partial improvement of obstructive events, nocturnal hypoxemia and sleep fragmentation, the occurrence of complex apnea presented here as a clear therapeutic failure of auto-titrating CPAP and was associated with heart failure, COPD and higher central and mixed apnea indices at baseline.

Overnight Polysomnographic Characteristics and Oxygen Saturation of Healthy Infants, 1 to 18 Months of Age, Born and Residing At High Altitude (2,640 Meters)

Approximately 8% of the world population resides above 1,600 m, with about 10 million people living above 2,500 m in Colombia. However, reference values for polysomnography (PSG) and oxygen saturation (Spo2) of children < 2 years old residing at high altitude are currently unavailable. Healthy infants aged 1 to 18 months born and residing at high altitude (Bogotá: 2,640 m) underwent overnight PSG. Four age groups were defined: group 1, < 45 days; group 2, 3 to 4 months; group 3, 6 to 7 months; and group 4, 10 to 18 months. Of 122 children enrolled, 50 had three consecutive PSG tests and were analyzed as a longitudinal subcohort. A total of 281 PSG tests were performed in 122 infants (56% girls): group 1, 106 PSG tests; group 2, 89 PSG tests; group 3, 61 PSG tests; and group 4, 25 PSG tests. Active sleep diminished and quiet sleep increased with maturation. Apnea-hypopnea indexes (total, central, and obstructive) were highest in group 1 (21.4, 12.4, and 6.8/h total sleep time, respectively) and diminished with age (P < .001). Mean Spo2 during waking and sleep increased with age (P < .001). Nadir Spo2 values during respiratory events were lower in younger infants. Longitudinal assessments of 50 infants confirmed the temporal trends described for the cross-sectional dataset. Healthy infants (≤ 18 months old) born and residing at high altitude show preserved sleep architecture but higher apnea-hypopnea indexes and more prominent desaturation with respiratory events than do those living at low altitude. The current study findings can be used as reference values for infants at high altitude.

Usefulness of a Nocturnal SOREMP for Diagnosing Narcolepsy with Cataplexy in a Pediatric Population.

We investigated the diagnostic accuracy of a nocturnal sleep onset rapid eye movement sleep period (nSOREMP) for the identification of narcolepsy with cataplexy (N+C) among children and adolescents referred to the sleep laboratory for an overnight polysomnography (PSG) and multiple sleep latency test (MSLT). Retrospective chart review of sleep clinic notes and PSG and MSLT reports. Boston Children's Hospital sleep laboratory and outpatient clinics. All patients 6-18 y old, referred for consecutive PSG and MSLT for the evaluation of central hypersomnias, between January 2005 and January 2014. We analyzed the records of 148 patients and established diagnostic categories using the International Classification of Sleep Disorders, 2(nd) Edition. Patient diagnoses included narcolepsy with cataplexy (28.4%), narcolepsy without cataplexy (8.1%), other hypersomnia conditions (9.5%), delayed sleep phase syndrome (12.2%), behaviorally induced insufficient sleep syndrome (4.1%), other sleep disorders (obstructive sleep apnea, periodic limb movements of sleep; 6.8%), isolated cataplexy (2%), and various diagnoses (29.1%). There were 54.8% of the N+C patients who had an nSOREMP, but only 2.4% of all other patients had an nSOREMP. The specificity of an nSOREMP for detection of N+C was high at 97.3% (95% confidence interval [CI]: 92.2-99.4%), but the sensitivity was moderate at 54.8% (95% CI: 38.7-70.2%). Overall, the positive predictive value of an nSOREMP for the diagnosis of N+C was 88.5% (95% CI: 69.8-97.4%). In children, the presence of an nocturnal sleep onset rapid eye movement sleep period is highly suggestive of narcolepsy with cataplexy and provides further evidence of rapid eye movement sleep dysregulation in this condition.

Insomnia sufferers can tolerate laboratory REM sleep dream collection and may improve their sleep perception

This project assessed the feasibility of in-lab dream collection in insomnia sufferers which have been limited, considering their reported sleep difficulties and heightened arousal. Eleven insomnia sufferers and 10 good sleepers underwent 5 consecutive polysomnography recording nights including 2 in-lab REM sleep full narrative dream collection. Dream recall frequency and sleep onset latency after each dream collection procedure were calculated. Analyses revealed no group effect (p=.14) for in-lab dream recall frequency (.96 for insomnia sufferers vs. .88 for good sleepers). Groups did not differ (p=.33) on sleep onset latency after dream collection. For sleep perception, insomnia individuals significantly underestimated their total sleep time at home (p≤.03) but not in the lab. Good sleepers correctly estimated their total sleep time at home but underestimated it in lab. For wake after sleep onset, insomnia sufferers correctly estimated it at home but underestimated it in the lab, while good sleepers underestimated it both at home and in the lab (p≤.02). These results suggest that in-lab full length dream collection can be successfully conducted with insomnia sufferers. Interestingly, dream collection also appeared to contribute to the underestimation of wake after sleep onset in insomnia individuals and good sleepers. It might be that externally induced awakenings attenuate the distress related to sleep difficulties especially in insomnia sufferers, since awakenings are attributed to dream collection.

Night-to-Night Repeatability of Supine-related Obstructive Sleep Apnea

Patients with obstructive sleep apnea (OSA) experience respiratory events with greater frequency and severity while in the supine sleeping position. Postural modification devices (PMDs) prevent supine sleep, although there is a paucity of guidance to help clinicians decide when to use PMDs for their patients. In order for PMDs to treat OSA effectively, patients must experience respiratory events in the supine sleeping position consistently from night to night and must have a low nonsupine apnea and hypopnea index (AHINS). To document the repeatability of traditionally defined supine predominant OSA on consecutive polysomnography, to determine whether the consistency of the supine-predominant phenotype can be improved by altering the definition of it, and to determine whether a low AHINS is repeatable from night to night. We recruited 75 patients for polysomnography on two separate nights. Patients were classified as having supine OSA on each night on the basis of traditional and novel definitions, and the classification systems used were compared on the basis of agreement from night to night. The definition of supine OSA with the highest level of agreement from night to night incorporates a supine AHI (AHIS) to AHINS ratio ≥4:1. In addition, agreement exists for males, but there is poor agreement for female patients, regardless of the definition applied. An AHINS <10 events/hour is highly repeatable from night to night. Males with an AHIS:AHINS ratio ≥4:1 and an AHINS <10 events/hour represent a consistent supine-predominant OSA phenotype from night to night. This patient group is likely to benefit from treatment with PMD.

Altered Dynamics in the Circadian Oscillation of Clock Genes in Dermal Fibroblasts of Patients Suffering from Idiopathic Hypersomnia

From single cell organisms to the most complex life forms, the 24-hour circadian rhythm is important for numerous aspects of physiology and behavior such as daily periodic fluctuations in body temperature and sleep-wake cycles. Influenced by environmental cues – mainly by light input -, the central pacemaker in the thalamic suprachiasmatic nuclei (SCN) controls and regulates the internal clock mechanisms which are present in peripheral tissues. In order to correlate modifications in the molecular mechanisms of circadian rhythm with the pathophysiology of idiopathic hypersomnia, this study aimed to investigate the dynamics of the expression of circadian clock genes in dermal fibroblasts of idiopathic hypersomniacs (IH) in comparison to those of healthy controls (HC). Ten clinically and polysomnographically proven IH patients were recruited from the department of sleep medicine of the University Hospital of Muenster. Clinical diagnosis was done by two consecutive polysomnographies (PSG) and Multiple Sleep Latency Test (MSLT). Fourteen clinical healthy volunteers served as control group. Dermal fibroblasts were obtained via punch biopsy and grown in cell culture. The expression of circadian clock genes was investigated by semiquantitative Reverse Transcriptase-PCR qRT-PCR analysis, confirming periodical oscillation of expression of the core circadian clock genes BMAL1, PER1/2 and CRY1/2. The amplitude of the rhythmically expressed BMAL1, PER1 and PER2 was significantly dampened in dermal fibroblasts of IH compared to HC over two circadian periods whereas the overall expression of only the key transcriptional factor BMAL1 was significantly reduced in IH. Our study suggests for the first time an aberrant dynamics in the circadian clock in IH. These findings may serve to better understand some clinical features of the pathophysiology in sleep – wake rhythms in IH.

Medical technology assessment of polysomnography, type 2: full psg at home. detection of naps and their clinical correlates

Background: Polysomnography (PSG) in a clinical setting (PSG, type 1) is time consuming and expensive. Type 2, i.e. full PSG at home, is thought to be a good alternative, but has never been evaluated in terms of regular Medical Technology Assessment (MTA). In some countries this lack of MTA precludes reimbursement for PSG type 2. This communication is part of a series of posters which adds up to MTA of PSG type 2, and deals with the detection of daytime naps during two consecutive PSG’s at home. If succesfull, such PSG recordings might be an alternative for MSLT. Retrospective study of 442 patients (59% male, mean age = 44.8, SD= 16.7) who underwent full PSG type 2 for two consecutive days. We focus on the daytime naps found on the continuous recording and the recognition of these naps by the patients themselves, as shown in their diaries. Furthermore the results of the two PSG’s, type 2 were compared to continuous actigraphy over a period of 7 days. In our poster we try to give answers to the following questions: 1. Do patients have daytime naps? 2. Do patients who have daytime naps always recognize them? 3. Do the daytime naps contain REM and/or SWS? 4. Are the naps habitual or not? The results indicate that 58% of the patients have daytime naps during 2 consecutive 24-hour PSG’s (type 2). Those daytime naps are in 27% of the cases not recognized by the patients. We discovered that during the daytime naps 50% contains REM and/or SWS. Fifty-five percent of the naps found in the PSG’s (type 2) were habitual when assessed over 1 week actigraphy. Twenty-four-hour PSG’s type 2 gives good insight in the amount and quality of the sleep during daytime. One quarter of all naps was not recognized by the patients themselves. In comparison with the more global assessment through actigraphy, the PSG had a larger sensitivity.