STUDY OBJECTIVES: The vagal nerve stimulator (VNS) is a nonpharmacological treatment for refractory epilepsy. A side effect of the VNS is sleep-disordered breathing. The purpose of this study was to demonstrate how a surface electrode placed over the VNS lead can help distinguish whether sleep-disordered breathing is due to VNS discharge. METHODS: Seven pediatric patients (aged 7.7 ± 2.2 years) with a VNS underwent a polysomnogram with an additional surface electrode on the left anterolateral neck to detect VNS discharge. The VNS-associated apnea-hypopnea index was calculated by determining the number of hypopneas and apneas occurring during VNS discharge. We evaluated the veracity of the VNS electrode by comparing signal duration and total number to those expected by programmed settings. We compared these findings to chin electromyogram signal change. RESULTS: Three patients had an obstructive pattern with VNS discharge, and 3 had an increase in respiratory rate without gas exchange abnormalities, including 1 with both patterns; 1 patient experienced no respiratory abnormalities. The mean obstructive apnea-hypopnea index was 8.2 ± 8.3 events/h. The mean VNS-associated apnea-hypopnea index was 4.8 ± 6.2 events/h and accounted for 46.9 ± 30.2% of the total obstructive apnea-hypopnea index. The additional electrode captured a statistically high percentage of expected discharges (94.7 ± 6.5%) compared to chin electromyogram (36.1 ± 35.8%; P < .05). CONCLUSIONS: We demonstrated that a surface electrode on the VNS lead can temporally coregister VNS discharges and enabled us to attribute sleep-disordered breathing to VNS stimulation in 4 patients. We propose that this sensor be standard procedure in patients with VNS undergoing polysomnogram. CITATION: Chan JHM, DelRosso LM, Ruth C, Wrede JE. A surface electrode adjacent to vagal nerve stimulator lead can aid in characterizing vagal nerve stimulator-mediated pediatric sleep-disordered breathing: a case series of 7 patients. J Clin Sleep Med. 2022;18(8):1973-1981.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

STUDY OBJECTIVES: Restless sleep is a very common parental complaint in children with attention-deficit/hyperactivity disorder (ADHD), but restless sleep has been seen in association with other comorbidities such as restless legs syndrome and obstructive sleep apnea. Restless sleep disorder (RSD) needs to be identified from other disorders when evaluating children with ADHD. In this study we aim to identify the prevalence of RSD in children with ADHD referred to our sleep center. METHODS: This is a retrospective study of children with ADHD who underwent polysomnography. The following diagnostic and descriptive data were obtained for each patient: age, sex, presence/absence of RSD, other sleep disorders, psychiatric comorbidities, and medications. RSD was diagnosed per diagnostic criteria. RESULTS: There were 66 children with ADHD. All of them underwent polysomnography, 17 were females, and 49 were males. Mean age was 11.6 years (± 3.6 standard deviation). The complaint of restless sleep was reported by the parents of 54 (81.1%) of the children; however, only 6 of them (9.1%) were diagnosed with RSD. Seventy-one percent had obstructive sleep apnea and 19.7% had restless legs syndrome. A significant number of patients had psychiatric comorbidities and were on various medications. CONCLUSIONS: Although restless sleep is a common complaint reported in 81.1% of children with ADHD, only 9.1% had RSD. Most causes of restless sleep are secondary and associated with other sleep disorders, psychiatric comorbidities, or medication use.

(1) Background: Breathing is an essential function that requires both metabolic (or au-tomatic) and voluntary (behavioral) control during wakefulness but during sleep depends on metabolic control via peripheral and central chemoreceptors. Breathing during sleep disordered breathing also depends on the maturity of the neural centers and the strength of the respiratory muscles. We do not know if the response to apnea varies with age. (2) Methods: We measured the obstructive apneas and hypopneas during REM and NREM in polysomnography studies from children referred for snoring. Exclusion criteria: younger than 1 year of age, neuromuscular or syndrome comorbidity, oxygen or positive airway pressure, central apnea, and studies with loss of airflow sensors. (3) Results: Two-hundred-and-sixty-eight sleep studies were included. Mean age was 8.7 years (4.68 SD), range 1-18 years, 160 were male, and 108 were female. The 5th centile of apnea duration during NREM is above 8 s at all ages, with a tendency to increase in the oldest groups up to 10 s. During REM sleep, it shows a gradual increase from 6 s in the youngest children to 10 s in the oldest. (4) Conclusions: Apnea/hypopnea length increases with age in children and adolescents independently from sex or severity of OSA. Using adult criteria in teens seems to be accurate.