Transvenous phrenic nerve stimulation for treating central sleep apnea may regulate sleep microstructure.

STUDY OBJECTIVES: To assess the impact of transvenous phrenic nerve stimulation (TPNS) on non-rapid eye movement sleep microstructure quantified by cyclic alternating pattern (CAP) in individuals with central sleep apnea (CSA). METHODS: We analyzed baseline and 6-month follow-up overnight polysomnograms (PSG) in 134 CSA patients enrolled in the remede System Pivotal Trial implanted with TPNS randomized (1:1) to neurostimulation (treatment group) or no stimulation (control group). Differences in CAP rate, A1 index, and A2+A3 index between study arms at follow-up were assessed using Analysis of Covariance adjusted for baseline values. RESULTS: On follow-up PSG, the treatment group showed a decrease in the frequency of A2+A3 phases compared to controls (-5.86 ± 11.82 vs. 0.67 ± 15.25, p = 0.006), while the frequency of A1 phases increased more in the treatment group (2.57 ± 11.67 vs. -2.47 ± 10.60, p = 0.011). The change in CAP rate at follow-up was comparable between study arms. CONCLUSIONS: TPNS treatment for central sleep apnea may affect sleep microstructure. Brief phases of rapid cortical activity appear to be replaced by short phases of slower cortical activity, which may promote sleep continuity. Further investigations are warranted to elucidate the mechanisms underlying the effect of TPNS on CAP.

Symbolic dynamics of sleep heart rate variability is associated with cognitive decline in older men.

We aimed to investigate the association between autonomic and cognitive functions in older men. We investigated heart rate variability (HRV) during sleep using time domain metrics and symbolic dynamics analysis of inter-beat intervals. These metrics were statistically analysed for associations with cognitive function which was elicited by administering the modified mini-mental state examination (3MS) and the Trail making test part-B in older men participating in the MrOS sleep study.Multivariable linear regression adjusted for age, body-mass-index (BMI), apnea-hypopnea index (AHI) and arousal index (A.I.) showed that symbolic dynamics of HRV especially the 0V% which is a measure of sympathetic outflow to the heart during rapid eye movement (REM) sleep is significantly associated with 3MS and Trail B scores. In conclusion, nonlinear HRV during sleep provides a unique window to probe the association between cognitive and autonomic function.Clinical Relevance- This study shows that cognitive decline is associated with altered cardiac autonomic function.

Transvenous phrenic nerve stimulation is associated with normalization of nocturnal heart rate perturbations in patients with central sleep apnea.

STUDY OBJECTIVES: To determine the effect of transvenous phrenic nerve stimulation (TPNS) on nocturnal heart rate perturbations in patients with CSA. METHODS: In this ancillary study of the remede System Pivotal Trial, we analyzed electrocardiograms from baseline and follow-up overnight polysomnograms (PSG) in 48 CSA patients in sinus rhythm with implanted TPNS randomized to stimulation (treatment group; TPNS on) or no stimulation (control group; TPNS off). We quantified heart rate variability in the time and frequency domain. Mean change from baseline and standard error is provided. RESULTS: TPNS titrated to reduce respiratory events is associated with reduced cyclical heart rate variations in the very low-frequency domain across REM (VLFI: 4.12 ± 0.79% vs. 6.87 ± 0.82%, p = 0.02) and NREM sleep (VLFI: 5.05 ± 0.68% vs. 6.74 ± 0.70%, p = 0.08) compared to the control group. Further, low-frequency oscillations were reduced in the treatment arm in REM (LFn: 0.67 ± 0.03 n.u. vs. 0.77 ± 0.03 n.u., p = 0.02) and NREM sleep (LFn: 0.70 ± 0.02 n.u. vs. 0.76 ± 0.02 n.u., p = 0.03). CONCLUSION: In adult patients with moderate to severe central sleep apnea, transvenous phrenic nerve stimulation reduces respiratory events and is associated with the normalization of nocturnal heart rate perturbations. Long-term follow-up studies could establish whether the reduction in heart rate perturbation by TPNS also translates into cardiovascular mortality reduction. CLINICAL TRIAL: A Randomized Trial Evaluating the Safety and Effectiveness of the remede® System in Patients With Central Sleep Apnea, ClinicalTrials.gov, NCT01816776.

Heart Rate Variability for Evaluating Psychological Stress Changes in Healthy Adults: A Scoping Review.

The utility of heart rate variability (HRV) for characterizing psychological stress is primarily impacted by methodological considerations such as study populations, experienced versus induced stress, and method of stress assessment. Here, we review studies on the associations between HRV and psychological stress, examining the nature of stress, ways stress was assessed, and HRV metrics used. The review was performed according to the PRISMA guidelines on select databases. Studies that examined the HRV-stress relationship via repeated measurements and validated psychometric instruments were included (n = 15). Participant numbers and ages ranged between 10 and 403 subjects and 18 and 60 years, respectively. Both experimental (n = 9) and real-life stress (n = 6) have been explored. While RMSSD was the most reported HRV metric (n = 10) significantly associated with stress, other metrics, including LF/HF (n = 7) and HF power (n = 6) were also reported. Various linear and nonlinear HRV metrics have been utilized, with nonlinear metrics used less often. The most frequently used psychometric instrument was the State-Trait Anxiety Inventory (n = 10), though various other instruments have been reported. In conclusion, HRV is a valid measure of the psychological stress response. Standard stress induction and assessment protocols combined with validated HRV measures in different domains will improve the validity of findings.

Transvenous phrenic nerve stimulation for the treatment of central sleep apnea reduces episodic hypoxemic burden.

STUDY OBJECTIVES: To determine the effect of transvenous phrenic nerve stimulation (TPNS) on the composition of the nocturnal hypoxemic burden in patients with CSA. METHODS: We analysed oximetry data from baseline and follow-up overnight polysomnograms (PSG) in 134 CSA patients with implanted TPNS randomised (1:1) to neurostimulation (treatment group; TPNS on) or no stimulation (control group; TPNS off) from the remede System Pivotal Trial. The hypoxemic burden was quantified using a battery of metrics, including the oxygen desaturation index (ODI), the relative sleep time spent below 90% SpO2 (T90) due to acute episodic desaturations (T90desat) and due to non-specific and non-cyclic drifts of SpO2 (T90non-specific). Mean change from baseline is provided. RESULTS: TPNS titrated to reduce respiratory events significantly reduced the ODI in the treatment group by -15.85 h-1 ± 1.99 compared to the control group, which increased 1.32 h-1 ± 1.85 (p ã€ˆ0001) and shortened the relative T90 duration by -3.81 percentage points ± 1.23 vs. 0.49 percentage points ± 1.14 increase (p = 0.012). This shortening of T90 was primarily accomplished by reducing the brief cyclic desaturations (T90desaturation: -4.32 percentage points ± 0.98 vs. 0.52 percentage points ± 0.91, p = 0.0004) while notable non-specific drifts in SpO2 remained unchanged (T90non-specific: 0.18 percentage points ± 0.62 vs. -0.13 percentage points ± 0.57, p = 0.72). CONCLUSIONS: TPNS appears to significantly reduce the nocturnal hypoxemic burden due to sleep-disordered breathing, but a considerable nocturnal hypoxemic burden from other sources remains. Further investigations are warranted to identify the best strategy to reduce the nocturnal hypoxemic burden beyond preventing respiratory events.

Utilisation of machine learning to predict surgical candidates for the treatment of childhood upper airway obstruction.

OBJECTIVE: To investigate the effect of adenotonsillectomy on OSAS symptoms based on a data-driven approach and thereby identify criteria that may help avoid unnecessary surgery in children with OSAS. METHODS: In 323 children enrolled in the Childhood Adenotonsillectomy Trial, randomised to undergo either early adenotonsillectomy (eAT; N = 165) or a strategy of watchful waiting with supportive care (WWSC; N = 158), the apnea-hypopnea index, heart period pattern dynamics, and thoraco-abdominal asynchrony measurements from overnight polysomnography (PSG) were measured. Using machine learning, all children were classified into one of two different clusters based on those features. The cluster transitions between follow-up and baseline PSG were investigated for each to predict those children who recovered spontaneously, following surgery and those who did not benefit from surgery. RESULTS: The two clusters showed significant differences in OSAS symptoms, where children assigned in cluster A had fewer physiological and neurophysiological symptoms than cluster B. Whilst the majority of children were assigned to cluster A, those children who underwent surgery were more likely to stay in cluster A after seven months. Those children who were in cluster B at baseline PSG were more likely to have their symptoms reversed via surgery. Children who were assigned to cluster B at both baseline and 7 months after surgery had significantly higher end-tidal carbon dioxide at baseline. Children who spontaneously changed from cluster B to A presented highly problematic ratings in behaviour and emotional regulation at baseline. CONCLUSIONS: Data-driven analysis demonstrated that AT helps to reverse and to prevent the worsening of the pathophysiological symptoms in children with OSAS. Multiple pathophysiological markers used with machine learning can capture more comprehensive information on childhood OSAS. Children with mild physiological and neurophysiological symptoms could avoid AT, and children who have UAO symptoms post AT may have sleep-related hypoventilation disease which requires further investigation. Furthermore, the findings may help surgeons more accurately predict children on whom they should perform AT.

Differences in Temporal Relapse Characteristics Between Affective and Non-affective Psychotic Disorders: Longitudinal Analysis.

Objective: Multiple relapses over time are common in both affective and non-affective psychotic disorders. Characterizing the temporal nature of these relapses may be crucial to understanding the underlying neurobiology of relapse. Materials and Methods: Anonymized records of patients with affective and non-affective psychotic disorders were collected from SA Mental Health Data Universe and retrospectively analyzed. To characterize the temporal characteristic of their relapses, a relapse trend score was computed using a symbolic series-based approach. A higher score suggests that relapse follows a trend and a lower score suggests relapses are random. Regression models were built to investigate if this score was significantly different between affective and non-affective psychotic disorders. Results: Logistic regression models showed a significant group difference in relapse trend score between the patient groups. For example, in patients who were hospitalized six or more times, relapse score in affective disorders were 2.6 times higher than non-affective psychotic disorders [OR 2.6, 95% CI (1.8-3.7), p < 0.001]. Discussion: The results imply that the odds of a patient with affective disorder exhibiting a predictable trend in time to relapse were much higher than a patient with recurrent non-affective psychotic disorder. In other words, within recurrent non-affective psychosis group, time to relapse is random. Conclusion: This study is an initial attempt to develop a longitudinal trajectory-based approach to investigate relapse trend differences in mental health patients. Further investigations using this approach may reflect differences in underlying biological processes between illnesses.

Opportunities for Technology-Assisted Healthy Ageing in a Local Government Context.

Current legislation aims to enable older Australians to age in place, and puts public healthcare within the remit of local governments. As Australia's population ages, local governments will need to explore new methods of service delivery in order to meet the increasing need for services that promote healthy ageing. Information technology (IT) may provide one such solution, however older Australian adults are reported to have low levels of technology use. In this simple descriptive qualitative study, focus groups with local government staff and community-dwelling older adults explored their perspectives regarding: a) IT solutions that councils could use to promote community-based healthy ageing, and (b) the enablers and challenges for adopting such solutions. Twenty-four adults participated in focus groups, and eleven of these adults also provided written data in response to visual prompts. Field notes were recorded by attending researchers. These three data sources were combined through narrative synthesis. Local government staff and community-dwellers alike perceived the utility of IT solutions in connecting community members, and connecting people to services (such as transport and providers of health information). While local government staff identified that IT solutions could provide benefits to the council when implemented in conjunction with existing services (e.g., to track data and identify information about community engagement and needs), community-dwellers placed stronger emphasis on adopting technology which had a clear purpose for its use. Due to limited digital literacy and some ambivalence towards embracing technology, IT solutions should be implemented with support to increase digital literacy, be widely advertised, and be centered in community needs. Personas have been generated and provided as possible case studies for technology adoption.

Composition of nocturnal hypoxaemic burden and its prognostic value for cardiovascular mortality in older community-dwelling men.

AIMS: To investigate the composition of nocturnal hypoxaemic burden and its prognostic value for cardiovascular (CV) mortality in community-dwelling older men. METHODS AND RESULTS: We analysed overnight oximetry data from polysomnograms obtained in 2840 men from the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study (ClinicalTrials.gov Identifier: NCT00070681) to determine the number of acute episodic desaturations per hour (oxygen desaturation index, ODI) and time spent below 90% oxygen saturation (T90) attributed to acute desaturations (T90desaturation) and to non-specific drifts in oxygen saturation (T90non-specific), respectively, and their relationship with CV mortality. After 8.8 ± 2.7 years follow-up, 185 men (6.5%) died from CV disease. T90 [hazard ratio (HR) 1.21, P < 0.001], but not ODI (HR 1.13, P = 0.06), was significantly associated with CV death in univariate analysis. T90 remained significant when adjusting for potential confounders (HR 1.16, P = 0.004). Men with T90 > 12 min were at an elevated risk of CV mortality (HR 1.59; P = 0.006). Approximately 20.7 (5.7-48.5) percent of the variation in T90 could be attributed to non-specific drifts in oxygen saturation. T90desaturation and T90non-specific were individually associated with CV death but combining both variables did not improve the prediction. CONCLUSION: In community-dwelling older men, T90 is an independent predictor of CV mortality. T90 is not only a consequence of frank desaturations, but also reflects non-specific drifts in oxygen saturation, both contributing towards the association with CV death. Whether T90 can be used as a risk marker in the clinical setting and whether its reduction may constitute a treatment target warrants further study.

Mean nocturnal respiratory rate predicts cardiovascular and all-cause mortality in community-dwelling older men and women.

Respiratory frequency (f R) predicts in-hospital and short-term mortality in patients with a variety of pathophysiological conditions, but its predictive value for long-term cardiovascular and all-cause mortality in the general population is unknown. Here, we investigated the relationship between mean nocturnal f R and mortality in community-dwelling older men and women.We measured mean nocturnal f R during sleep from overnight polysomnography in 2686 men participating in the Osteoporotic Fractures in Men Study (MrOS) Sleep study and 406 women participating in the Study of Osteoporotic Fractures (SOF) to investigate the relationship between mean nocturnal f R and long-term cardiovascular and all-cause mortality.166 (6.1%) men in the MrOS cohort (8.9±2.6 years' follow-up) and 46 (11.2%) women in the SOF cohort (6.4±1.6 years' follow-up) died from cardiovascular disease. All-cause mortality was 51.2% and 26.1% during 13.7±3.7 and 6.4±1.6 years' follow-up in the MrOS Sleep study and the SOF cohorts, respectively. Multivariable Cox regression analysis adjusted for significant covariates demonstrated that f R dichotomised at 16 breaths·min-1 was independently associated with cardiovascular mortality (MrOS: hazard ratio (HR) 1.57, 95% CI 1.14-2.15; p=0.005; SOF: HR 2.58, 95% CI 1.41-4.76; p=0.002) and all-cause mortality (MrOS: HR 1.18, 95% CI 1.04-1.32; p=0.007; SOF: HR 1.50, 95% CI 1.02-2.20; p=0.04).In community-dwelling older men and women, polysomnography-derived mean nocturnal f R ≥16 breaths·min-1 is an independent predictor of long-term cardiovascular and all-cause mortality. Whether nocturnal mean f R can be used as a risk marker warrants further prospective studies.

Effect of adenotonsillectomy for childhood obstructive sleep apnea on nocturnal heart rate patterns.

Study Objectives: To assess the effect of adenotonsillectomy for relieving obstructive sleep apnea syndrome (OSAS) symptoms in children on cardiac autonomic modulation. Methods: In 354 children enrolled in the Childhood Adenotonsillectomy Trial, randomized to undergo either early adenotonsillectomy (eAT; N = 181) or a strategy of watchful waiting with supportive care (WWSC; N = 173), nocturnal heart rate control was analyzed during quiet, event-free sleep at baseline and at 7 months using overnight polysomnography (PSG). The relative frequency of patterns indicating monotonous changes in heart rate was quantified. Results: Children who underwent eAT demonstrated a significantly greater reduction in heart rate patterns postsurgery than the WWSC group. On assessing those heart rate patterns regarding normalization of clinical PSG, heart patterns were reduced to a similar level in both groups. In children whose AHI normalized spontaneously, heart rate patterns were already significantly less frequent at baseline, suggesting that upper airway obstruction was milder in this group at the outset. Conclusions: Adenotonsillectomy reduces monotonous heart rate patterns throughout quiet event-free sleep, reflecting a reduction in cardiac autonomic modulation. Heart rate pattern analysis may help quantifying the effect of OSAS on autonomic nervous system activity in children. Clinical Trial Registration: The study was registered at Clinicaltrials.gov (#NCT00560859).

Altered Nocturnal Cardiovascular Control in Children With Sleep-Disordered Breathing.

Study objectives: To assess cardiovascular control during sleep in children with sleep-disordered breathing (SDB) and the effect of adenotonsillectomy in comparison to healthy nonsnoring children. Methods: Cardiorespiratory signals obtained from overnight polysomnographic recordings of 28 children with SDB and 34 healthy nonsnoring children were analyzed. We employed an autoregressive closed-loop model with heart period (RR) and pulse transit time (PTT) as outputs and respiration as an external input to obtain estimates of respiratory gain and baroreflex gain. Results: Mean and variability of PTT were increased in children with SDB across all stages of sleep. Low frequency power of RR and PTT were attenuated during non-rapid eye movement (REM) sleep. Baroreflex sensitivity was reduced in children with SDB in stage 2 sleep, while respiratory gain was increased in slow wave sleep. After adenotonsillectomy, these indices normalized in the SDB group attaining values comparable to those of healthy children. Conclusions: In children with mild-to-moderate SDB, vasomotor activity is increased and baroreflex sensitivity decreased during quiet, event-free non-REM sleep. Adenotonsillectomy appears to reverse this effect.

Adenotonsillectomy for childhood obstructive sleep apnoea reduces thoraco-abdominal asynchrony but spontaneous apnoea-hypopnoea index normalisation does not.

The efficacy of adenotonsillectomy for treating obstructive sleep apnoea syndrome (OSAS) in children has been established, but its precise effects on inspiratory effort are not well documented.In 353 children enrolled in the Childhood Adenotonsillectomy Trial, randomised to undergo either early adenotonsillectomy (n=182) or a strategy of watchful waiting with supportive care (WWSC) (n=171), thoraco-abdominal asynchrony (TAA) was analysed during quiet, non-apnoeic and non-hypopnoeic breathing during sleep at baseline and at 7 months using overnight polysomnography.Children who underwent early adenotonsillectomy demonstrated a reduction in TAA post-surgery while the WWSC arm showed no change. On assessing TAA with regard to normalisation of clinical polysomnography findings at follow-up, TAA was reduced in children who had surgical resolution of OSAS (based on apnoea-hypopnoea index), but not in children who displayed spontaneous normalisation of apnoea-hypopnoea index. In the latter group, TAA was inversely correlated with quality of life.We conclude that adenotonsillectomy reduces TAA during quiet sleep. Monitoring of instantaneous TAA may yield additional insight in the dynamic changes of inspiratory effort. In combination with traditional indices of obstruction, TAA may more accurately characterise the degree of sleep-disordered breathing in children.

The effect of adenotonsillectomy for childhood sleep apnoea on cardiorespiratory control.

The efficacy of adenotonsillectomy for relieving obstructive sleep apnoea symptoms in children has been firmly established, but its precise effects on cardiorespiratory control are poorly understood. In 375 children enrolled in the Childhood Adenotonsillectomy Trial, randomised to undergo either adenotonsillectomy (n=194) or a strategy of watching waiting (n=181), respiratory rate, respiratory sinus arrhythmia and heart rate were analysed during quiet, non-apnoeic and non-hypopnoeic breathing throughout sleep at baseline and at 7 months using overnight polysomnography. Children who underwent early adenotonsillectomy demonstrated an increase in respiratory rate post-surgery while the watchful waiting group showed no change. Heart rate and respiratory sinus arrhythmia were comparable between both arms. On assessing cardiorespiratory variables with regard to normalisation of clinical polysomnography findings during follow-up, heart rate was reduced in children who had resolution of obstructive sleep apnoea syndrome, while no differences in their respiratory rate or respiratory sinus arrhythmia were observed. Adenotonsillectomy for obstructive sleep apnoea increases baseline respiratory rate during sleep. Normalisation of apnoea-hypopnoea index, spontaneously or via surgery, lowers heart rate. Considering the small average effect size, the clinical significance is uncertain.

Effect of respiration on heartbeat-evoked potentials during sleep in children with sleep-disordered breathing.

OBJECTIVE: Heartbeat-evoked potentials (HEPs) in electroencephalogram (EEG) provide a quantitative measure of cardiac interoception during sleep. We previously reported reduced HEPs in children with sleep-disordered breathing (SDB), indicative of attenuated cardiac information processing. The objective of this study was to investigate the link between HEP and respiration. PATIENTS/METHODS: From the overnight polysomnograms of 40 healthy children and 40 children with SDB, we measured HEPs during epochs of stage 2, slow-wave and rapid eye movement (REM) sleep free of abnormal respiratory events. HEPs were analysed with respect to respiratory phase. RESULTS: We observed a marked association between respiratory phase and HEP in children with SDB during REM sleep, but not in normal children. In children with SDB, HEP waveforms were attenuated during expiration compared to inspiration. Following adenotonsillectomy, expiratory HEP peak amplitude increased in the SDB children and was no longer different from those of normal children. CONCLUSIONS: The expiratory phase of respiration is primarily associated with attenuated cardiac information processing in children with SDB, establishing a pathophysiological link between breathing and HEP attenuation.

Increased thoracoabdominal asynchrony during breathing periods free of discretely scored obstructive events in children with upper airway obstruction.

OBJECTIVE: This study aims to investigate the impact of upper airway obstruction (UAO) in children by measuring thoracoabdominal asynchrony (TAA) during periods of sleep apnea/hypopnea and during scored-event-free (SEF) breathing periods. METHODS: Respiratory inductive plethysmographic signals were extracted from polysomnographic data, recorded before and after adenotonsillectomy in 40 children with UAO and 40 healthy, matched children at equivalent time points. Thoracoabdominal asynchrony was computed using a Hilbert transform-based phase difference estimation method in SEF periods during stage 2, stage 4 non-rapid eye movement (NREM), and rapid eye movement (REM) sleep and compared between the groups. RESULTS: At baseline, in the UAO group, TAA during obstructions were significantly higher than TAA during SEF periods in both stage 2 and REM sleep. Compared to controls, children with UAO had a significantly higher TAA during SEF periods in stage 2, stage 4 sleep, and REM sleep. This between-group difference was not significant post adenotonsillectomy. UAO group showed a significant decrease in TAA compared to their baseline during SEF stage 2 and 4 NREM, but not in REM. CONCLUSION: Upper airway obstruction in children is associated with increased TAA during SEF periods, indicative of continuous partial obstruction of the upper airway. Adenotonsillectomy decreased this effect significantly in non-REM sleep as evidenced by reduced asynchrony levels post-surgery. TAA assessment during sleep may therefore provide additional diagnostic information.

Symbolic dynamics of pulse transit time and heart period in children with upper airway obstruction.

Upper airway obstruction (UAO) is a relatively common condition during childhood that is characterized by periods of partial or complete upper airway closure, resulting in restless sleep. It has also been suggested that UAO triggers early cardiovascular changes that may predispose to an increased risk of developing cardiovascular diseases later in life. The aim of this study was to assess the temporal dynamics of heart period (HP) and pulse transit time (PTT) during quite, event-free periods of sleep in children with UAO (n = 40) and matched healthy controls. The dynamics of HP and PTT were symbolized based on the sextiles of their distribution and words of length three were formed and classified into four types based on their patterns. Joint symbolic dynamics represent the concomitant occurrence of words in HP and PTT. Children with UAO showed a significantly increased frequency in word types of monotonously increasing and decreasing HP and PTT as well as joint dynamics across all stages of sleep. The dynamics of HP showed a marked sleep stage dependence, while PTT dynamics appeared to be relatively unaffected. In conclusion, cardiovascular dynamics are altered in children with UAO during scored event-free sleep, indicative of frequent bursts in sympathetic nervous system activity, possibly reflecting subcortical arousal responses to brief and subtle increases in UAO.

Heartbeat evoked potentials during sleep and daytime behavior in children with sleep-disordered breathing.

RATIONALE: Event-related brain potentials allow probing of cortical information processing, but when evoked with externally induced stimuli may disrupt sleep homeostasis and do not provide insight into intrinsic cortical information processing. To investigate if cortical processing of intrinsic information in children with sleep-disordered breathing (SDB) is different from healthy children and, if so, whether it resolves with treatment, we used heartbeat as a source of interoceptive event-related brain potentials. OBJECTIVES: To investigate heartbeat evoked potentials (HEP) during sleep in healthy children and in children with SDB before and after treatment and to explore if there are any associations between HEP and daytime behavioral deficits in children with SDB. METHODS: Heartbeat-aligned EEG was assessed for presence of HEP within stage 2, slow-wave sleep, and REM sleep in 40 children with primarily mild to moderate SDB before and after adenotonsillectomy and in 40 matched control subjects at similar time points. MEASUREMENTS AND MAIN RESULTS: In both groups, nonrandom HEP were present in all sleep stages analyzed; however, amplitude of HEP were significantly lower in children with SDB during non-REM sleep (stage 2: P = 0.03; slow-wave sleep: P = 0.001). This between-group difference was not significant post adenotonsillectomy. Significant negative associations between HEP and daytime behavioral scores were observed at baseline. CONCLUSIONS: Children with SDB displayed reduced HEP amplitude during sleep, which might be indicative of changes in afferent sensory inputs to the brain and/or signify differences in sensory gating of cardiac-related information in the insular cortex. Adenotonsillectomy appears to reverse this effect.

Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.

STUDY OBJECTIVE: To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep. DESIGN: Interventional case-control repeated measurements design. SETTING: Paediatric sleep laboratory in a hospital setting. PARTICIPANTS: Forty children with SDB and 40 healthy, age- and sex-matched children. INTERVENTIONS: Adenotonsillectomy in children with SDB and no intervention in controls. MEASUREMENTS AND RESULTS: Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy. CONCLUSION: The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy. CITATION: Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.