Showing papers by "Carole L. Marcus published in 2008"

Effect of sleep stage on breathing in children with central hypoventilation

Abstract: The early literature suggests that hypoventilation in infants with congenital central hypoventilation syndrome (CHS) is less severe during rapid eye movement (REM) than during non-REM (NREM) sleep. However, this supposition has not been rigorously tested, and subjects older than infancy have not been studied. Given the differences in anatomy, physiology, and REM sleep distribution between infants and older children, and the reduced number of limb movements during REM sleep, we hypothesized that older subjects with CHS would have more severe hypoventilation during REM than NREM sleep. Nine subjects with CHS, aged (mean ± SD) 13 ± 7 yr, were studied. Spontaneous ventilation was evaluated by briefly disconnecting the ventilator under controlled circumstances. Arousal was common, occurring in 46% of REM vs. 38% of NREM trials [not significant (NS)]. Central apnea occurred during 31% of REM and 54% of NREM trials (NS). Although minute ventilation declined precipitously during both REM and NREM trials, hypoventilation was less severe during REM (drop in minute ventilation of 65 ± 23%) than NREM (drop of 87 ± 16%, P = 0.036). Despite large changes in gas exchange during trials, there was no significant change in heart rate during either REM or NREM sleep. We conclude that older patients with CHS frequently have arousal and central apnea, in addition to hypoventilation, when breathing spontaneously during sleep. The hypoventilation in CHS is more severe during NREM than REM sleep. We speculate that this may be due to increased excitatory inputs to the respiratory system during REM sleep.

Cortical processing of respiratory afferent stimuli during sleep in children with the obstructive sleep apnea syndrome.

Abstract: A COMBINATION OF STRUCTURAL AND NEUROMUSCULAR CONTROL FACTORS CONTRIBUTE TO THE PATHOGENESIS OF CHILDHOOD OBSTRUCTIVE SLEEP APNEA syndrome (OSAS).1–6 However, the cause of the neuromuscular abnormalities is not well understood. Previous work has shown that, compared to normal controls, children with OSAS have selectively elevated arousal thresholds to respiratory stimuli, such as mechanical and hypercapnic stimuli.7,8 Children with OSAS also have impaired upper airway reflex responses to subatmospheric pressure during sleep.1 On the other hand, children with OSAS have normal arousal thresholds to nonrespiratory (e.g., auditory) stimuli.9 The underlying causes of the altered arousal and upper airway responses to respiratory stimuli in OSAS remain unknown. It is also not known whether these altered responses reflect a cause or effect of the OSAS phenomenology. It is possible that, compared to normal controls, children with OSAS have altered afferent processing of mechanoreceptor responses in the upper airway to the negative pressure generated by breathing against occlusions. Such alterations in processing may be secondary to anatomic differences in the physical properties of upper airway tissue affecting their ability to transduce pressure changes into afferent neural signals. Alternatively, they may reflect alterations in the central processing of the afferent information. Respiratory related evoked potentials (RREPs) are one way to measure the central nervous system processing of respiratory afferent information.10–12 RREPs are the averaged surface EEG responses to multiple brief occlusions or loads applied during inspiration.10,11 During wakefulness, a series of early components is evident in the RREPs, reflecting initial sensory and motor processing13,14 and a subsequent series of late components reflecting cognitive processing of the stimuli.15,16 During Non-REM (NREM) sleep, a different series of later components is produced that reflect the elicitation of phasic EEG responses (such as vertex sharp waves and K-complexes) to stimuli.17–19 Stimuli relating to increases in inspiratory effort reliably induce RREPs,20 which in turn provide a unique way to investigate the afferent processing pathway for respiratory load mechanoreception during both wakefulness and sleep.17,21 We have recently demonstrated that inspiratory occlusions reliably produce RREPs in children in stage 2, SWS, and REM sleep.22 While similar to the sleep RREPs previously reported in adults, the predominant late component in children was the N350 waveform rather than the N550, and the scalp topography of the components was more broadly distributed than typically seen in adults. Compared to normal adults, adults with OSAS have fewer K-complexes evoked by inspiratory occlusion stimuli during NREM sleep,23,24 with no difference in K-complex responses to auditory stimuli.24 They also have blunted RREPs during NREM sleep, manifested by a significantly decreased late RREP component N550, which is a reflection of the evoked K-complex in adults.25 However, nothing is known about RREPs in children with OSAS. Compared to adults with OSAS, children with OSAS have a shorter duration of disease and fewer comorbidities, such as chronic obstructive pulmonary disease, and are often effectively treated with surgery to remove tonsils and adenoids.26 Thus the pathophysiology of OSAS in children is likely different from that in adults. Based on previous work showing altered arousal thresholds to respiratory stimuli in children with OSAS,7,8 we hypothesized that children with OSAS would have fewer evoked K-complexes and blunted RREP responses compared to normal children during sleep.

Sleep in children : developmental changes in sleep patterns

Abstract: Introduction, Foreword, Preface, Neurophysiological Basis and Behavior of Early Sleep Development Ontogeny of EEG Sleep Maturation of Sleep Patterns During Infancy and Childhood Maturation of Processes Regulating Sleep in Adolescents Characteristics of Arousal Mechanisms from Sleep in Infants and Children Thermoregulation During Sleep in Infants Behavioral Influences on Sleep in Children and Adolescents Cultural Influences on Infant and Childhood Sleep Biology, and the Science That Studies It: Toward a More Inclusive Paradigm II Pediatric Parasomnias Narcolepsy in Childhood Sleep in Children with Neurologic Disease Sleep and Psychiatric Disorders in Children Restless Legs Syndrome and Periodic Limb Movements in Sleep in Children Gastroesophageal Reflux During Sleep Assessing Neurobehavioral Outcomes in Childhood Sleep-Disordered Breathing: A Primer for Non-neuropsychologists Structural and Functional Magnetic Resonance Imaging as a Research Tool in Pediatric Sleep Research

Cortical Processing of Respiratory Occlusion Stimuli in Children with Central Hypoventilation Syndrome

Abstract: Rationale: The ability of patients with central hypoventilation syndrome (CHS) to produce and process mechanoreceptor signals is unknown.Objectives: Children with CHS hypoventilate during sleep, although they generally breathe adequately during wakefulness. Previous studies suggest that they have compromised central integration of afferent stimuli, rather than abnormal sensors or receptors. Cortical integration of afferent mechanical stimuli caused by respiratory loading or upper airway occlusion can be tested by measuring respiratory-related evoked potentials (RREPs). We hypothesized that patients with CHS would have blunted RREP during both wakefulness and sleep.Methods: RREPs were produced with multiple upper airway occlusions and were obtained during wakefulness, stage 2, slow-wave, and REM sleep. Ten patients with CHS and 20 control subjects participated in the study, which took place at the Children's Hospital of Philadelphia. Each patient was age- and sex-matched to two control subjects. Wakefulnes...

Sleep and breathing in children : developmental changes in breathing during sleep

Abstract: Introduction, Foreword, Preface, Breathing and Sleep States in the Fetus and at Birth Laryngeal Function and Neonatal Respiration Postnatal Development of Carotid Chemoreceptor Function Maturation and Plasticity of Central Components in Cardiovascular and Respiratory Control Maturation of Breathing During Sleep Interaction Between Upper Airway Muscles and Structures During Sleep Craniofacial Development and the Airway During Sleep Breathing and Sleep in Preterm Infants Apnea During Infancy Apparent Life-Threatening Events: Pathogenesis and Management Pathophysiology of Sudden Infant Death Syndrome Sudden Infant Deaths: Risk Factors, Contributory Factors, and Causal Factors Sudden Infant Death Syndrome: Genetic Studies in Cardiorespiratory and Autonomic Regulation Effects of Intermittent Hypoxia on the Developing Organism Influence of Prenatal Nicotine Exposure on Development of Neurotransmission in Central Respiratory Neurons Central Hypoventilation Syndromes Genetic Basis for Congenital Central Hypoventilation Syndrome Epidemiology of Pediatric Obstructive Sleep Apnea Pathophysiology of Childhood OSAS: Structural Factors Pathophysiology of Childhood OSAS: Neuromotor Factors Cognitive and Behavioral Consequences of Childhood OSAS Inflammatory Association with Childhood Obstructive Sleep Apnea Syndrome Metabolic Aspects of Sleep Apnea in Children Cardiovascular Complications of Childhood OSAS Acoustic Reflectance Pediatric Obstructive Sleep Apnea Syndrome

Respiratory-Related Evoked Potentials During Sleep in Children

Abstract: STUDY OBJECTIVES The respiratory related evoked potential (RREP) has been previously recorded in children and adults during wakefulness and in adults during sleep. However, there have been no data on RREP during sleep in children. We thus examined children during sleep to determine whether early RREP components would be maintained during all sleep DESIGN AND PARTICIPANTS Twelve healthy, nonsnoring children, aged 5-12 years, screened by polysomnography and found to have no sleep disorders were assessed during stage 2 sleep, slow wave sleep, and REM sleep. Brief occlusions were presented via an occlusion valve at the inspiratory port of a non-rebreathing valve as interruptions of inspiration. EEG responses were averaged and assessed for the presence of early and late RREP components. RESULTS Robust early components were seen in the majority of subjects in all sleep stages. Late components were also present, although with some apparent differences compared to those previously reported in adults (using the same recording protocol and an almost identical method of stimulus presentation). Specifically, N350 and N550 were less readily differentiated as separate components, and the N550 did not display the clear anterior-posterior amplitude gradient that is ubiquitous in adults. CONCLUSION Cortical processing of respiratory-related information persists throughout sleep in children. The pattern of activation in the late components appear to reflect differences in the structure of the developing brain prior to the process of dendritic pruning associated with adolescence.

Concerns regarding the pediatric component of the AASM clinical guidelines for the manual titration of positive airway pressure in patients with obstructive sleep apnea.

Abstract: I applaud the AASM for putting together clinical guidelines for positive airway pressure (PAP) titration I understand that this was a very challenging task and, as with many areas of sleep medicine, there was a paucity of hard data upon which to base practical recommendations However, I do have concerns regarding some of the pediatric recommendations

Entering a new treatment age for mucopolysaccharidosis VI disease: a search for better markers of disease progression and response to treatment

Abstract: 9. SantosIS,MotaDM,MatijasevichA.Epidemiologyofco-sleepingand nighttime waking at 12 months in a birth cohort. J Pediatr(Rio J). 2008;84(2):114-22.10. BlairPSB89:1106-10.11. Nelson EA, Taylor BJ. International Child Care Practices Study:infant sleeping environment. Early Hum Dev. 2001;62:43-55.12. Araujo CL,Victora CG,Hallal PC,Gigante DP.Breastfeedingandoverweight in childhood: evidence from the Pelotas 1993 birthcohort study. Int J Obes (Lond). 2006;30:500-6.13. MitchellEA,BlairPS,L’HoirMP. Shouldpacifiersbeusedtopreventsudden infant death syndrome? Pediatrics. 2006;117:1755-8.14. Welles-Nystrom B. Co-sleeping as a window into Swedishculture:considerationsofgenderandhealthcare.ScandJCaringSci. 2005;19:354-60.15. Chikritzhs T, Brady M. Fact or fiction? A critique of the NationalAboriginal and Torres Strait Islander Social Survey 2002. DrugAlcohol Rev. 2006;25:277-87.16. ScraggR,MitchellEA,TaylorBJ,StewartAW,FordRP,ThompsonJM,etal.Bedsharing,smoking,andalcoholinthesuddeninfantdeath syndrome. New Zealand Cot Death Study Group. BMJ.1993;307:1312-8.Correspondence:Peter BlairFSID Research Unit, Level DSouthwell St., St. Michaels HospitalBS2 8EG – Bristol – UKTel.: +44 (117) 928.5145Fax: +44 (117) 928.5154E-mail: p.s.blair@bris.ac.uk