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Report of the 13th Meeting of the European Pediatric Sleep Club

 

The 13th Meeting of the European Pediatric Sleep Club was held in Rome on November 22nd and November 23rd, 2003. The meeting was strucutred in 6 different symposia and a lecture during the two days:

November 22 Saturday

punto elenco Sleep stability and sleep instability during development
punto elenco Arousability in infant and child pathology
punto elenco Lecture: Infant and children sleep in fine arts
punto elenco Sleep and neurological diseases in children
punto elenco Sleep and epilepsy

November 23 Sunday

punto elenco Attention Deficit Hyperactivity Disorders (ADHD), Periodic Leg Movements (PLMs) and sleep disordered breathing
punto elenco Sleep scoring rules across development: How, when and why to apply the Rechtschaffen and Kales (R&K) criteria in infancy and childhood

 

The topics of the meeting were appealing for the pediatric sleep community.

 

Sleep stability and sleep instability during development

Chiara Zampi and Piero Salzarulo showed that the stability of the behavioural state could be associated with different levels of physiological activities, which change across the first year of life. An individual physiological variable, like EEG, has been used to show changes in the S process level in infants nocturnal sleep in the frame of early development of sleep regulation.

Terzano and Parrino showing data on Cyclic alternating pattern (CAP) during life-span, highlighted that sleep fragmentation is another age-related variable as indicated by the linear evolution of arousals, as expressed by CAP phases subtypes A2 and A3. In contrast, phase A1 subtypes and CAP rate undergo a complex development in association with topical maturational epochs showing a peak in the pre-adolescents and adolescents.

Bruni reported the normative values of CAP in normal preschool age children showing that CAP rate was lower as compared with school aged children. Phases A1 were the most numerous (63.2%) followed by A2 (21.5%) and by A3 (15.3%). In the analysis of CAP and EEG arousals the maturation of EEG must be considered: in younger children the most common pattern of EEG frequency changes associated with an arousal is a shift to a more rhythmic pattern, primarily in the theta range of EEG frequency, considered as A2 phases and that could represent a signal of higher sleep instability in this age range

Ferri analyzed the scalp topography and cortical generators of the components of the “Cyclic Alternating Pattern” (CAP) showing that the low-frequency band (0.25-2.5 Hz) had a clear prevalence over the anterior frontal regions, mostly over the midline and symmetrically spreading over the two hemispheres. On the contrary, the high-frequency band (7-15 Hz) involved mostly the parietal-occipital areas.

Guilleminault oulined the difference between activation and arousal secondary to peripheral events during sleep; depending of intensity and amount of recruitment of sensory afferences, it may arrive at the thalamus and or basal forebrain. The thalamic-basal forebrain gate will let the afferent input reach the cortex only when the sub-cortical gate has been overcome. Initially the cortex will try maintaining sleep with reinforcement of its gates, that are indicated by occurrence of K-Complexes and/or burst of delta frequencies in the sleep EEG. When the thalamic/basal forebrain gate cannot control the afferent inputs, a cortical change is seen translated by an alpha, or a mixed of alpha and beta EEG frequency burst.

 

 

Arousability in infant and child pathology

Patricia Franco reviewed the major confounding factors that influence the determination of arousal thresholds in infants. The levels of arousal thresholds depend on experimental conditions (type and time of administration of the arousal challenge, sleep stage). The infant’s arousability is decreased by maternal factors, such as exposure to cigarette smoke or illegal drugs. The levels of arousal thresholds also depend on the infant’s characteristics (age, previous sleep deprivation, infection, type of feeding, use of pacifier) and on infant’s sleep conditions (room temperature, body sleep position, face covered by a sheet, bedsharing or swaddling).

Donzelli, studied neonates using the near-infrared spectroscopy (NIRS) that is able to measure the concentrations of oxygen in the optically probed volume of cerebral tissue in a non-invasive and continuous manner. The preliminary data does not indicate sleeping position-dependent effects on cerebral absolute oxygenation infants. However, during apneas, cerebral SaO2 showed an earlier and more rapid reduction than peripheral SaO2 (27% vs. 13%) suggesting that short episodes of even slight peripheral desaturation could be associated with more pronounced episodes of cerebral desaturation.

Horne showed that infants aroused more frequently under hypoxic conditions than under normoxic conditions. Arousal latencies were shorter during hypoxia compared to normoxia, in both sleep-states and were longer in QS compared to AS in both hypoxic and normoxic conditions. In sleeping infants mild hypoxia serves as a stimulus for arousal in both AS and QS. In addition, arousal responses to somatosensory and respiratory stimuli are similarly affected by sleep-state, postnatal age and maternal smoking.

Giganti pointed out that the process leading to awakening at early ages is poorly understood. Both in preterm and in full term born infants REM sleep precedes awakenings more frequently than NREM sleep. The analysis of physiological and behavioural variables preceding awakenings in term born infants showed that awakening is not an abrupt event, and that it is preceded by progressive modifications of several variables.

Chervin analyzed the maximum difference between segment powers in the respiratory cycle defining a new parameter as respiratory cycle-related EEG changes (RCREC). He showed that the EEG activity during sleep can vary with non-apneic respiratory cycles, to a degree reflected by RCREC that may represent brief but numerous microarousals that contribute to neurobehavioral morbidity in pediatric SDB.

 

 

Lecture: Infant and children sleep in fine arts

Curzi Dascalova presented a very beautiful and intersting lecture on Infant and children sleep in fine arts based on a database including more than 1600 replicas of paintings, sculptures and engravings on the subject of sleep. She presented the more representative (about 25) examples spanning over a period from the year 2000 B.C. to date.

 

 

Sleep and neurological diseases in children

Sona Nevsimalova surveyed 23 patients with narcolepsy stressing some atypical features of children’s clinical picture, discussing the role of auxiliary examinations at the very onset of the disease, presenting the most common incorrect diagnosis presumed by pediatricians, mentioning the latest therapeutical possibilities and drawing attention to hypocretin/deficiency in secondary cases of narcolepsy-cataplexy or EDS.

Gregory Stores described a case with onset of REM Behavior Disorders at age 14 with increasingly violent manifestations in subsequent years. Following correct diagnosis, based on clinical features and PSG findings, the patient was successfully treated with clonazepam. Then, the literature on RBD in children and adolescents was reviewed in relation to differential diagnosis of RBD and comprehensive evaluation and follow up in view of the various conditions with which early onset RBD has been associated.

Giannotti highlighted that assessment of sleep in Pervasive Developmental Disorders (PDD) children need particular attention, because of the high prevalence, persistence and severity of the problem; this long term follow up study underlined that CR melatonin may provide an interesting safe and well-tolerated treatment for sleep disorders in children with PDD.

 

 

Sleep and epilepsy

Peraita Adrados pointed out that long-term video monitoring during wakefulness and sleep is strongly recommended in the study of night seizures in children. The differential diagnosis between nocturnal epileptic seizures and parasomnias and other sleep disorders is of major importance and requires the use of this methodology.

A comprehensive video session by Nobili and Plazzi clarified most of the differential diagnosis and highlighted the features of the different nocturnal epileptic seizures.

 

 

Attention Deficit Hyperactivity Disorders (ADHD), Periodic Leg Movements (PLMs) and sleep disordered breathing

Chervin presentation suggested that untreated SDB and PLMS cause or contribute to ADHD or ADHD-like behavior in substantial numbers of children. Standard polysomnographic measures of SDB do not predict behavioral comorbidity or surgical outcomes well. Development of SDB measures that better reflect the clinical significance of the condition could improve patient care and shed light on underlying mechanisms by which sleep disorders affect brain function and daytime behavior.

Scholle showed that OSAS in children is characterized by a restless sleep, an enhanced number of leg movements and a significantly enhanced number of movement and EEG-arousals. After treatment, there was a significant diminition of movements and arousals. The reduction of movements and so the normalization of the microstructure of sleep under treatment may be responsible for the significant improvement in behavoir and psychological function after therapy of sleep-disordered breathing in children.

Lecendreux’ presentation demonstrated that children with ADHD have an abnormally strongest tendency to fall asleep during the day. ADHD children who fell asleep more than three times at MSLT had predominantly inattentive type. Children from the predominantly hyperactive-impulsive subgroup were more opposant to the test but once in bed could fall asleep very rapidly (less than 5 minutes in 2 MSLT for 2 subjects). The number of daytime sleep-onsets and the rapidity of sleep-onsets measured by MSLT were pertinent physiological indices to discriminate between ADHD subtypes.

Villa overviewed the relationships between OSAS and hyperactivity. OSAS can lead to mild ADHD-like behaviors that can be readily misperceived and potentially delay the diagnosis and appropriate treatment. The nature of this association could be related to sleep disruption and blood gas abnormalities that occur in OSAS children and that could lead to dysfunction of prefrontal regions of the brain cortex, manifested behaviourally in what neuropsychologists have termed `executive dysfunction.

 

 

Sleep scoring rules across development: How, when and why to apply the Rechtschaffen and Kales (R&K) criteria in infancy and childhood

Guilleminault outlined the scoring criteria modification related to age of children. Starting from 6 months of age the Rechtschaffen and Kales basic criteria can be considered. However these criteria have not been changed for more than 30 years. Similarly to adults there have been adjunctions to the scoring of sleep and its disorders in children compared to the basic scoring of Rechtschaffen and Kales. Sleep scoring, sleep disorder breathing and other scoring criteria were reviewed.

The aim of analysis of Vecchierini and Curzi-Dascalova was to point out on differences and some similarities of polysomnographic characteristics of sleep stages during the first year of life, as compared with the adult criteria. Rechtschaffen and Kales criteria for sleep stages scoring are not adapted before 3-4 months of age. Beyond this age, many differences in EEG amplitude and frequency persist. Moreover, there are important inter-and intra- (from one sleep cycle to another) individual differences, whatever the age.

Scholle pointed out that in infants and children there are marked developmental changes of the central nervous system, which are reflected in the maturation of the electroencephalogram as well as in cardiorespiratory and other autonomic functions. The power spectral analysis of sleep EEG patterns illustrates structural changes of sleep in different age groups and features of the normal pediatric patterns in different sleep stages are changing in dependency on age. In the age group 6 months to 3 years the discrimination of the different sleep EEG patterns is more complicated than in older children because the patterns are not so characteristically shaped. In children older than 3 years the scoring of sleep as proposed by Rechtschaffen and Kales is applicable, if age dependent variations of specific EEG patterns are considered.