Rafael Pelayo

Sleep disordered breathing: Surgical outcomes in prepubertal children

Objective To evaluate the treatment outcomes of sleep disordered breathing (SDB) in prepubertal children 3 months following surgical intervention.

Sleep-disordered breathing in children

Sleep disordered breathing (SDB) is increasingly being recognised as a cause of morbidity even in young children. With an estimated prevalence of 1 to 4 per cent, SDB results from having a structurally narrow airway combined with reduced neuromuscular tone and increased airway collapsibility. SDB in children differs from adults in a number of ways, including presenting symptoms and treatment. Presentation may differ according to the age of the child. Children have a more varied presentation from snoring and frequent arousals to enuresis to hyperactivity. Those with Down syndrome, midface hypoplasia or neuromuscular disorders are at higher risk for developing SDB. First line definitive treatment in children involves tonsillectomy and adenoidectomy. Rapid maxillary expansion, allergy treatment and continuous positive airway pressure (CPAP) are other options. As untreated SDB results in complications as learning difficulties, memory loss and a long term increase in risk of hypertension, depression and poor growth, it is important to diagnose SDB.

Narcolepsy in Children

Narcolepsy is a neurological syndrome characterised by daytime somnolence and cataplexy which often begins in childhood. Failing to recognise the condition may lead to mislabelling a child as lazy or depressed. The diagnostic criteria for narcolepsy vary with age. In children 8 years and older a Multiple Sleep Latency Test with an average latency of less than 8 minutes, and 2 or more sleep onset REM episodes supports the diagnosis.Human leucocyte antigen (HLA) marker DQβ1-0602 has been associated with narcolepsy. The current evidence supports the hypothesis that transmission of narcolepsy is multifactorial, with at least two genes, one of which is non-HLA related. The goal of all therapeutic approaches in narcolepsy is to control the narcoleptic symptoms and allow the patient to continue to fully participate in personal and academic activities. This usually requires a combination of behavioural therapy along with medication.Medications for patients with excessive sleepiness are usually stimulants, including amphetamines. However, a novel wake promoting agent, modafinil, is now available. Cataplexy can be controlled by medications with noradrenergic reuptake-blocking properties, such as clomipramine and fluoxetine, through their active metabolites. Increased awareness of narcolepsy is important to allow earlier diagnosis. Research on the effects different medications have, specifically on children with narcolepsy, has been very limited.

Pediatric sleep-related breathing disorders

Sleep-related breathing disorders (SRBD) can occur at any age. Obstructive sleep apnea, upper airway resistance syndrome and obstructive hypopnea syndrome all lie on the pathological continuum of SRBD. These disorders can have a great impact on a childs quality of life and can progress to significant complications. The symptoms, signs, work-up, and treatment of SRBD in children are discussed.

Narcolepsy in children: a practical guide to its diagnosis, treatment and follow-up.

Narcolepsy is a neurological syndrome characterised by daytime somnolence and cataplexy which often begins in childhood. Failing to recognise the condition may lead to mislabelling a child as lazy or depressed. The diagnostic criteria for narcolepsy vary with age. In children 8 years and older a Multiple Sleep Latency Test with an average latency of less than 8 minutes, and 2 or more sleep onset REM episodes supports the diagnosis. Human leucocyte antigen (HLA) marker DQbeta1 -0602 has been associated with narcolepsy. The current evidence supports the hypothesis that transmission of narcolepsy is multifactorial. with at least two genes, one of which is non-HLA related. The goal of all therapeutic approaches in narcolepsy is to control the narcoleptic symptoms and allow the patient to continue to fully participate in personal and academic activities. This usually requires a combination of behavioural therapy along with medication. Medications for patients with excessive sleepiness are usually stimulants, including amphetamines. However, a novel wake promoting agent, modafinil, is now available. Cataplexy can be controlled by medications with noradrenergic reuptake-blocking properties, such as clomipramine and fluoxetine, through their active metabolites. Increased awareness of narcolepsy is important to allow earlier diagnosis. Research on the effects different medications have, specifically on children with narcolepsy, has been very limited.

Abnormal blood pressure in prepubertal children with sleep-disordered breathing

The purpose of this study was to investigate the association between low blood pressure (BP) with mild symptoms of orthostatism, sleep-disordered breathing (SDB) and tilt test results in 7- to 12-y-old children. A retrospective chart review of 301 children, ages 7 to 12 y, was initially performed to evaluate the frequency of abnormal BP measurements. Then a prospective study was performed on 7- to 12-y-old prepubertal children with SDB, looking for both abnormal BP and mild orthostatism. All children had polysomnography. Those identified with abnormal (high or low) BP measurements (called “BP outliers”) were studied with a new polysomnogram followed by a head-up tilt test as an indicator of autonomic activity. Four of the children with low BP were treated with nasal continuous positive airway pressure and received a second head-up tilt test 3.5 to 7 mo after starting treatment. The prospective study included 78 children, eight of whom were BP outliers. Seven of these outliers had low BP. Compared with all of the SDB subjects, SDB subjects with low BP and indicators of mild orthostatic hypotension had a significantly higher incidence of craniofacial dysmorphism, symptoms of SDB early in life, chronically cold extremities, and dizziness on standing up (χ2, p = 0.01 to 0.0001). They had a significantly greater drop in BP without evidence of autonomic neuropathy than all other children on head-up tilt testing (Kruskal-Wallis ANOVA with Bonferroni adjustment, p = 0.001 to 0.0001). However, the normotensive SDB controls also had significantly different BP drops than the normal controls (p = 0.0001). The four children placed on nasal continuous positive airway pressure had a nonsignificant trend toward normalization of tilt test response. SDB in prepubertal children can lead to different abnormal stimulation of the autonomic nervous system, with different impacts on BP. The severity and frequency of oxygen saturation drops during sleep, nonhypoxic increases in respiratory effort, and the duration of abnormal breathing are suspected of playing a role in the difference in autonomic nervous system stimulation.

Pediatric sleep pharmacology.

This article reviews common sleep disorders in children and pharmacologic options for them. Discussions of pediatric sleep pharmacology typically focus on treatment of insomnia. Although insomnia is a major concern in this population, other conditions of concern in children are presented, such as narcolepsy, parasomnias, restless legs syndrome, and sleep apnea.

Reliability of Respiratory Polygraphy for the Diagnosis of Sleep Apnea-Hypopnea Syndrome in Children

OBJECTIVE Overnight polysomnography (PSG) is the gold standard diagnostic tool for sleep apnea-hypopnea syndrome (SAHS) in children. The aim of the present study was to evaluate the usefulness of diagnostic respiratory polygraphy in children with clinically suspected SAHS referred to our sleep-disordered breathing clinic. PATIENTS AND METHODS We studied 53 children referred with clinical suspicion of SAHS; 29 (54.7%) were boys and the mean (SD) age was 6.4 (2.9) years. After a medical history was taken and a physical examination performed, patients underwent respiratory polygraphy (Edentec) simultaneously with overnight PSG in the sleep laboratory. The 2 diagnostic tools were compared using statistical analysis. RESULTS SAHS was defined by an obstructive apnea-hypopnea index (OAHI) of 3 or more in overnight PSG and a respiratory disturbance index (RDI) of 3 or more in respiratory polygraphy. The rate of diagnostic agreement was 84.9%. The difference between the mean OAHI and RDI values was not significant (0.7 +/- 5.4; P=.34). The intraclass correlation coefficient between the OAHI and RDI was 89.4 (95% confidence interval, 82.4-93.7; P< .001). When receiver operating characteristic curves were calculated for the OAHI cutoff points used for the diagnosis of SAHS (> or =1, > or =3, and > or =5), the best RDI cutoff for all 3 OAHI values considered was found to be 4.6. When age strata were considered, in children 6 years or older the best RDI cutoff for the 3 OAHI values was 2.1. In children younger than 6 years the best RDI cutoff was 3.35 for OAHI > or =1 and 5.85 for OAHI > or =3 and > or =5. CONCLUSIONS Respiratory polygraphy in the sleep laboratory is a valid method for the diagnosis of SAHS in children.

Development of circadian rhythmicity of temperature in full-term normal infants.

Twelve full-term infants (7 girls and 5 boys) with normal neurological, behavioral and somatic development were followed at regular intervals during the first 5 months of life to appreciate the development of circadian rectal temperature rhythmicity. Activity and temperature (oral at birth, rectal thereafter) were monitored for a minimum of 60 hours on seven separate occasions: at birth, 3 weeks, 6 weeks, 8 weeks, 10 weeks, 16 weeks and 20 weeks of age. Activity was measured using an actigraph worn on the infants wrist, and rectal temperature was measured using a rectal probe attached to a portable microprocessor (Vitalog TM). Data points were collected every 2 minutes. No fewer than ten infants were monitored at each session, and no infant missed more than one session. Missing recordings were due to equipment malfunctions, probe expulsions and minor health problems. Six infants out of 12 were successfully monitored at each of the first four sessions, from birth to 8 weeks of age inclusively, and two subjects were successfully monitored at all seven sessions. Periodic regression analysis was performed by least squares curve fit with secondary analysis of variance. Analysis of covariance was performed on repeated measures. There was no evidence of rectal temperature circadian rhythmicity at 3 weeks. Two infants demonstrated a circadian rhythmicity at 6 weeks, and all infants had a circadian rhythmicity at 10 weeks post-natal age. At the time of the first observance of circadian rhythmicity of rectal temperature, the mean delta in temperature from peak to trough was 0.6 +/- 0.3 degrees C. This delta was greater at the 16th week, with a mean value of 1.2 +/- 0.3 degrees C. The trough was seen during the first part of the long nocturnal inactivity period. Circadian rhythmicity of rectal temperature was always observed in the studied subjects before the establishment of a consolidated, long daytime wake period.

Apparent life-threatening events, facial dysmorphia and sleep-disordered breathing.

Abstract A standardized clinical evaluation and questionnaire was, beginning in 1985, applied to infants referred for an apparent life-threatening event (ALTE). All children who underwent this “core evaluation protocol” during a 10-year period were reviewed. Documentation of clinical complaints, symptoms and signs of sleep-disordered breathing, sleep/wake evaluation, systematic evaluation of the face and naso-oro-pharynx, nocturnal polygraphic recording, and systematic follow-up was conducted. A total of 346 infants had complete data sets, with a smaller group of 46 age-matched healthy infants as controls. A scorer blind to the clinical data analyzed the polygraphic investigation and divided the 346 referred into two groups. Group A, 42.6% of the population, included infants with no abnormal findings based on nocturnal polygraphic recording. These infants were no different from controls at initial evaluation and during follow-up. Group B, 57.4% of the population, included infants who had obstructive breathing during sleep which became more obvious over time. Two-thirds of these infants not only had clinical symptoms of sleep-disordered breathing but also had mild facial dysmorphia that could be seen clearly at 6 months of age. Conclusion A subgroup of infants with apparent life-threatening events present an indication of a sleep-disordered breathing syndrome which is associated with a mild dysmorphia. This mild facial dysmorphia needs to be recognized early to distinguish these infants from other infants with apparent life-threatening events and to initiate appropriate treatment.