Memory consolidation in children with epilepsy: does sleep matter?

INTRODUCTION: Children with epilepsy have frequent sleep disturbance and challenges in learning and memory. There is little research on the consolidation of memory during sleep in this population. The goal of this pilot study was to determine whether children with epilepsy are able to consolidate memories better after a sleep versus wake period as has been demonstrated in typically developing children. METHODS: This study was a prospective evaluation of children with epilepsy to determine if sleep improved episodic memory (using word lists) as compared with memory following a wake period of similar duration. The study was conducted in patients in the Epilepsy Monitoring Unit at a single academic health science center. In the sleep recall condition, the learning trials were presented in the evening, and delayed recall of the words was tested in the morning. In the wake condition, the learning took place in the morning, and the delayed recall took place later in the day. Subjects wore an actigraph to evaluate sleep/wake patterns. Data regarding the children's epilepsy, antiepileptic medications, and frequency of interictal epileptiform discharges were also documented. RESULTS: Ten children (agd 8-17years) participated in the study. For the entire sample, recall after sleep was better than recall after awake (p=0.03), and 7 of the 10 children showed this effect. However, reanalyses removing an outlier showed no difference between the two recall conditions. The mean number of interictal epileptiform discharges was 8.8 during the recall after sleep and 7.8 during the recall after awake. Three children had seizures during the evaluation. CONCLUSION: In this pilot study, we demonstrated that a small cohort of children with epilepsy, with similar interictal epileptiform discharges during sleep and wake, showed no advantage in memory for a word list after a period of sleep than after a period of being awake. This finding requires further study in a larger cohort. Poor memory consolidation during sleep may contribute to the cognitive deficits in children with epilepsy.

14 and 6 Hz like spike wave activity is a common finding in young patients with Prader-Willi syndrome.

STUDY OBJECTIVES: Our aim was to characterize the 14 and 6 like spike wave activity seen on electroencephalograms (EEG) in children with Prader-Willi syndrome (PWS) undergoing polysomnograms. METHODS: We performed a retrospective review of children with PWS and healthy controls who underwent diagnostic polysomnograms between January 1, 2007, and December 31, 2020, at SickKids, Toronto, Canada. EEGs from the polysomnograms were reviewed for the presence of the 14 and 6 like spike wave activity and its characteristics. Clinical correlation of the EEG variant with sleep-disordered breathing indices from the polysomnograms was also evaluated. RESULTS: A total of 94 children with PWS and 50 healthy controls were included. The median age and interquartile range for the cohort was 1.42 (0.6, 4.2) years. There were 50 (53.2%) males in the PWS cohort. The EEG variant prevalence in this cohort was 51.0% (n = 48) in children with PWS and 0% for the healthy controls. 14 and 6 Hz like spike wave activity was bilateral in 52% (25/48) children with PWS. The waves had a negative deflection in almost all patients, 44/48 (92%), with PWS. It was predominantly located in the frontal leads for children with PWS, 23/48 (47.9%). It most frequently occurred during non-rapid eye movement stage 2 sleep for children with PWS, 25/48 (52.0%). The mean (standard deviation) frequency was 6.8 (0.97) Hz. The median (interquartile range) length of the waves was 1.1 (0.8, 1.4) seconds in children with PWS. There was no correlation between the presence of the EEG variant and sleep-disordered breathing indices in children with PWS. CONCLUSIONS: The 14 and 6 Hz like spike wave activity EEG variant was present in more than 50% of a pediatric cohort of children with PWS compared with 0% in healthy children. This EEG variant did not appear to be associated with sleep-disordered breathing indices in children with PWS and is of unknown clinical significance. CITATION: Alzaid M, Sunkonkit K, Massicotte C, Otsubo H, Amin R, Al-Saleh S. 14 and 6 Hz like spike wave activity is a common finding in young patients with Prader-Willi syndrome. J Clin Sleep Med. 2024;20(8):1227-1232.

Sleep apnea-specific hypoxic burden and pulse rate response in children using high flow nasal cannula therapy compared with continuous positive airway pressure.

BACKGROUND: Elevated sleep apnea-specific hypoxic burden (HB) and pulse rate response (ΔHR) are associated with a higher cardiovascular risk in adults. The clinical significance of HB and ΔHR in children with obstructive sleep apnea (OSA) and their responses to therapy have not yet been investigated. This study aimed to compare the efficacy of high flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) in reducing HB and ΔHR in children. METHODS: This analysis included 17 children (11 males, mean age: 12.6 ± 3.9 years) with obesity and/or medical complexity and moderate-to-severe OSA. Each participant underwent two additional sleep studies: one for HFNC titration and another for CPAP titration. HB and ΔHR were derived from the oximetry and pulse rate signals from overnight sleep studies, respectively. RESULTS: Both HFNC and CPAP demonstrated significant reductions in HB from baseline, with similar magnitudes [HFNC: -129 (standard error, SE 55) %min/h, p = 0.003; CPAP: -138 (SE 53) %min/h, p = 0.005]. However, for ΔHR, a significant reduction from baseline was observed only in the CPAP group [-2.7 (SE 1.1) beats/min, p = 0.049], not the HFNC group [-1.0 (SE 1.4) beats/min, p = 0.67]. CONCLUSIONS: HFNC is as effective as CPAP in treating hypoxia in children with OSA, but HFNC might be less effective than CPAP in mitigating cardiovascular stress from autonomic disturbances during obstructive events.

Polysomnography in hospitalized children: Characteristics and clinical practice at a single tertiary care center.

BACKGROUND: Polysomnography (PSG) is the gold standard for the diagnosis of pediatric sleep-disordered breathing (SDB). However, the literature characterizing the indications for inpatient PSGs and the impact on clinical decision-making is limited. OBJECTIVE: To determine the indications, results, and outcomes for children undergoing inpatient PSGs at our institution. METHODS: We performed a retrospective review of children aged 0-18 years who underwent inpatient diagnostic PSGs between July 2018 and July 2021 at SickKids, Toronto, Canada. Baseline characteristics, indications, and management were reviewed and characterized by descriptive statistics. RESULTS: Eighty-eight inpatient PSGs were performed in 75 children (male 62.7%). Median (interquartile range) age and body mass index z-score were 1.5 (0.2, 10.8) years and 0.27 (-1.58, 2.66), respectively. The most common indication for inpatient PSG was initiation and titration of ventilation (n = 34/75, 45.3%). Of the 75 children, 48 (64%) had multiple complex chronic conditions (CCCs). Sixty children (80%) underwent a baseline PSG for either the entire night or a portion of the night. Of these studies, 54 (90%) had clinically significant SDB of which isolated obstructive sleep apnea (OSA; 17/60, 28.3%) was the most common. The following management was undertaken for the 54 patients with SDB; respiratory technology (88.9%), surgical intervention (31.5%), positional therapy (1.9%), intranasal steroids (3.7%), and no further intervention (5.6%), respectively. CONCLUSIONS: Our study highlights that inpatient PSG was an important diagnostic tool resulting in directed medical and surgical management. Future multicenter studies are needed to compare indications for inpatient PSGs across institutions to develop evidence-based clinical practice guidelines.

Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences?

STUDY OBJECTIVES: Individuals with Duchenne muscular dystrophy (DMD) frequently develop sleep-disordered breathing. Noninvasive ventilation is often prescribed for sleep-disordered breathing treatment based on the American Academy of Sleep Medicine (AASM) criteria. In 2018, DMD disease-specific criteria for sleep-disordered breathing were established. Our study aimed to examine the clinical interpretation differences using these different criteria. METHODS: We performed a multicenter, retrospective chart review of children with DMD followed at The Hospital for Sick Children, Toronto, Canada, and Rady Children's Hospital, San Diego, California, who underwent polysomnography from August 1, 2012, to February 29, 2020. Baseline characteristics and polysomnography data were summarized using descriptive statistics. Agreement for the diagnosis of sleep-disordered breathing evaluated by kappa statistics and sensitivity/specificity analysis was assessed. RESULTS: One hundred five male children with DMD (mean ± SD age: 12.1 ± 3.8 years; body mass index z score: 0.2 ± 2.3) were included. The proportions of children with DMD that met at least 1 AASM criterion and at least 1 DMD criterion were 45.7% and 67.6%, respectively. We found that 32.4% of children met neither AASM nor DMD criteria. Overall agreement between AASM and DMD criteria was moderate (k = 0.57). There was almost perfect agreement in sleep apnea diagnosis (k = 0.90); however, there was only slight agreement in hypoventilation diagnosis (k = 0.12) between AASM and DMD criteria. CONCLUSIONS: There were more children with DMD diagnosed with nocturnal hypoventilation and prescribed noninvasive ventilation using DMD criteria compared with AASM criteria. Future studies should address whether the prescription of noninvasive ventilation for children with DMD based on both criteria is associated with different clinical outcomes. CITATION: Hurvitz MS, Sunkonkit K, Massicotte C, Li R, Bhattacharjee R, Amin R. Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences? J Clin Sleep Med. 2022;18(2):609-615.

Positional device therapy for the treatment of positional obstructive sleep apnea in children: a pilot study.

BACKGROUND: There is a critical gap in identifying effective interventions for children with obstructive sleep apnea (OSA) who do not tolerate continuous positive airway pressure therapy. Positional OSA (POSA) is a common clinical phenotype whereby OSA occurs predominantly while sleeping in supine position. POSA may be amenable to treatment with a positional device, a belt worn around the chest with cushions on the back to prevent supine positioning, but no data exists in children. The primary aim of this study was to evaluate the efficacy of positional device therapy for the treatment of POSA in children. METHODS: This observational study included children aged 4-18 years with POSA and an obstructive apnea-hypopnea index (OAHI) ≥ 5 events/hour on baseline polysomnogram (PSG) who underwent a second PSG to evaluate the efficacy of a positional device. The primary outcome was the change in OAHI. RESULTS: Ten children were included (8 male, median age 11.2 years, median body mass index z-score 1.6). Compared to the baseline PSG, PSG data obtained while using a positional device showed a reduced median (interquartile range) OAHI (15.2 [8.3-25.6] versus 6.7 [1.0-13.7] events/hour respectively; p = 0.004) and percentage of total sleep time in supine position (54.4 [35.0-80.6]% versus 4.2 [1.1-25.2]% respectively; p = 0.04). Despite observed improvements in the oxygen desaturation index, these results were not statistically significant. SIGNIFICANCE AND CONCLUSIONS: In this novel pilot study, positional device therapy was effective for the treatment of POSA. Positional device therapy may potentially change clinical practice as a cost-efficient and non-invasive treatment option for POSA.

Positional obstructive sleep apnea in an obese pediatric population.

STUDY OBJECTIVES: Positional obstructive sleep apnea (POSA) is a phenotype of obstructive sleep apnea (OSA) where sleep-related obstructive events occur predominantly in the supine position. Limited knowledge exists regarding the presence of POSA in children with obesity. The study objective was to determine the prevalence of POSA while identifying factors associated with POSA in children with obesity. METHODS: This was a cross-sectional study of children with obesity, aged 8 to 18 years, with a diagnostic polysomnogram (PSG) between 2012 to 2019, who were referred for the evaluation of sleep-related breathing. POSA was defined as an overall obstructive apnea-hypopnea index (OAHI) ≥5 events/h and a supine OAHI to nonsupine OAHI ratio of ≥2. Patient demographics, anthropometrics, and PSG data were recorded. RESULTS: Of the 112 children with obesity with a diagnostic PSG, 43 (38%) had OSA. Among those with OSA, 25 of 43 (58%) had POSA (mean age: 14.6 ± 2.3 years; mean body mass index: 37.7 ± 7.6 kg/m²; 68% male) and 18 of 43 (42%) had non-POSA (mean age: 13.9 ± 2.8 years; mean body mass index: 37.9 ± 7.2 kg/m²; 78% male). Among those with POSA, 13 of 25 (52%) had mild OSA, 7 of 25 (28%) had moderate OSA, and 5 of 25 (20%) had severe OSA. No significant differences were found in age, sex, and anthropometric measures between POSA and non-POSA groups. Time spent in supine and nonsupine sleep did not differ significantly between groups. CONCLUSIONS: In children with obesity and OSA, POSA occurs frequently. Identifying POSA allows for potential targeted positional therapy for children with obesity.

The Accuracy of an Ambulatory Level III Sleep Study Compared to a Level I Sleep Study for the Diagnosis of Sleep-Disordered Breathing in Children With Neuromuscular Disease.

STUDY OBJECTIVES: Polysomnography (PSG) surveillance recommendations are not being met for children with neuromuscular disease (NMD) because of limited diagnostic facilities. We evaluated the diagnostic accuracy of an ambulatory level III device as compared to a level I PSG. METHODS: A cross-sectional study was conducted at a tertiary pediatric institution. Eligibility criteria included: (1) children with NMD; (2) age 6 to 18 years; (3) booked for a clinically indicated overnight level I PSG. Participants were randomized to an overnight level I PSG followed by an ambulatory level III study with end tidal carbon dioxide (etCO2) or vice versa. Sensitivity and specificity of the ambulatory level III device to diagnose sleep-disordered breathing (SDB) at an apnea-hypopnea index (AHI) cutoff of > 1.0 events/h was the primary outcome. RESULTS: Moderate to severe SDB was found in 46% of participants (13/28). The device's sensitivity and specificity to detect SDB was 61.5% and 86.7%, respectively. The positive predictive value of the level III study was 80.0% and the negative predictive value was 72.0%. Fifty percent of the cohort were either missing or had incomplete or falsely low ambulatory etCO2 data. CONCLUSIONS: A level III device with etCO2 is not yet able to be implemented in clinical practice as a diagnostic tool for SDB in pediatric patients with NMD. COMMENTARY: A commentary on this article appears in this issue on page 1973.

The utility of a portable sleep monitor to diagnose sleep-disordered breathing in a pediatric population.

BACKGROUND: Central and/or obstructive sleep-disordered breathing (SDB) in children represents a spectrum of abnormal breathing during sleep. SDB is diagnosed using the gold standard, overnight polysomnography (PSG). The limited availability and access to PSG prevents its widespread use, resulting in significant delays in diagnosis and treatment of SDB. As such, portable sleep monitors are urgently needed. OBJECTIVE: To evaluate the utility of a commercially available portable sleep study monitor (PSS-AL) (ApneaLink, ResMed, USA) to diagnose SDB in children. METHODS: Children referred to a pediatric sleep facility were simultaneously monitored using the PSS-AL monitor and overnight PSG. The apnea-hypopnea index (AHI) was calculated using the manual and autoscoring function of the PSS-AL, and PSG. Sensitivity and specificity were compared with the manually scored PSS-AL and PSG. Pearson correlations and Bland-Altman plots were constructed. RESULTS: Thirty-five children (13 female) completed the study. The median age was 11.0 years and the median body mass index z-score was 0.67 (range -2.3 to 3.8). SDB was diagnosed in 17 of 35 (49%) subjects using PSG. The AHI obtained by manually scored PSS-AL strongly correlated with the AHI obtained using PSG (r=0.89; P<0.001). Using the manually scored PSS-AL, a cut-off of AHI of >5 events/h had a sensitivity of 94% and a specificity of 61% to detect any SDB diagnosed by PSG. CONCLUSIONS: Although PSG is still recommended for the diagnosis of SDB, the ApneaLink sleep monitor has a role for triaging children referred for evaluation of SDB, but has limited ability to determine the nature of the SDB.

Presentation and treatment of monozygotic twins with congenital central hypoventilation syndrome.

Congenital central hypoventilation syndrome is a rare genetic disorder characterized by hypoventilation during sleep secondary to a blunted response to hypercapnia and hypoxia. The current case report describes developmentally normal four-year-old monozygotic twin boys who presented in infancy with variable presentations and clinical severity of congenital central hypoventilation syndrome. Both were managed with noninvasive positive pressure ventilation.