Sleep spindle evolution from infancy to adolescence

OBJECTIVE

To investigate the development of frontally recorded sleep spindles from infancy to adolescence to provide normative data for pediatric sleep medicine.

METHODS

Sleep spindle activity was investigated in 120 healthy subjects aged 3 months to 16 years in 12 age groups. At 2 a.m. (min 1:17 a.m., max 3:18 a.m.) 10 min of NREM 2 was checked. Spindles were visually scored in the electroencephalogram from F4/A1.

RESULTS

The age dependency of interspindle interval, length of spindle, and spindle density, was statistically significant (Kruskal-Wallis p<0.0001). There were U-shaped curves for spindle length, spindle density, and an inverted U-shaped curve for the interspindle interval. Results of the post hoc U-test p<0.05 (Bonferroni corrected, m=66): Spindle length was minimal at 1.7 up to 3.0 years. Spindle density (number of spindles) was minimal between the ages of 1.7 and 2.3 years, thereafter there was a high increase that reached a plateau at age 5 years and remained up to 16 years. Interspindle interval was maximal at 1.7 and 2.3 years.

CONCLUSIONS

Sleep spindle activity changes with maturation in terms of length and density.

SIGNIFICANCE

The establishment of age-related normative data of sleep spindle activity can improve identification of NREM 2 in infancy, childhood, and adolescence, and enable detection of delayed neural maturation and/or sleep instability.

Das Restless-legs-Syndrom im Kindesalter

The diagnostic criteria of restless legs syndrome were defined in 1995 by the International Restless Legs Syndrome Study Group (IRLSSG). In light of the latest scientific evidence and increasing clinical experience, the diagnostic criteria were revised in a consensus workshop. Participants of the workshop considered the development of new diagnostic criteria especially important for the following subgroups: (1) for children and (2) for the cognitively impaired elderly. The common characteristic of both groups lies in their difficulty in expressing subjective symptoms adequately. This considerably impedes the diagnosis of restless legs syndrome. In 2002, a proposal for diagnostic criteria of restless legs syndrome in childhood was formulated by members of the study groups "Movement Disorders and Sleep" and "Paediatrics" of the German Sleep Society. The proposal was partially incorporated into the diagnostic criteria for restless legs syndrome in childhood suggested by the IRLSSG. The current criteria are recommendations to enhance further research and must be validated by clinical studies. The following article gives an overview of published studies on restless legs syndrome in childhood, reviews the proposals for diagnostic criteria, and summarizes the peculiarities to be considered in diagnosing restless legs syndrome in children.

First night effect in children and adolescents undergoing polysomnography for sleep-disordered breathing

OBJECTIVE

To establish whether there is a first night effect (FNE) in children and adolescents with suspected obstructive sleep apnoea undergoing polysomnography (PSG) and whether this affects sleep and breathing, furthermore, to determine the extent to which age may influence the sleep and cardiorespiratory parameters.

METHODS

One hundred and thirty-one children and adolescents (age classes-A: 2-6 years n=37; B: 7-12 years n=60; C: 13-17 years n=34) underwent PSG on 2 consecutive nights (I and II) under identical conditions for suspected sleep-related respiratory disorders. One hundred and five patients including 3 patients with obstructive sleep apnoea syndrome (OSAS) treated by adenotonsillectomy and 18 OSAS patients receiving nCPAP-therapy had no PSG-abnormalities (Group 1-A: n=28; B: n=53; C: n=24). A further 26 patients (Group 2) had clinically and polysomnographically confirmed untreated OSAS (A: n=9; B: n=12; C: n=5).

RESULTS

There were no statistically significant differences between children with no PSG-abnormalities (Group 1) and those with OSAS (Group 2) in terms of sleep parameters (arousal indices excluded), oxygen saturation (SaO(2)) and heart rate (HR), and these parameters have, therefore, been pooled for the entire group (n=131) in the 3 age classes A, B and C. In the second and third age classes, sleep efficiency on the first night was reduced. In all age classes, there was significantly more wakefulness during the first night. In the second and third age ranges, the proportion of NREM 1 in the first night was significantly higher, with a correspondingly reduced proportion of NREM 4 in the third age group. In all age classes, REM sleep was significantly less during the first night, but REM latency was comparable on both nights. On the first night, the mean HR was higher. There were significant differences in apnoea/hypopnoea-index (AHI), electroencephalogram (EEG)-arousal-index (AI) and motoric arousal index (jerk index, JI) between Groups 1 and 2. In neither group, were there any significant differences in AHI, mean SaO(2) or number of EEG-arousals between nights 1 and 2. Only in the age class A, in Group 2 (n=9) was the number of motoric arousals significantly higher on the first night. Comparison of the age classes A, B, and C revealed that most polysomnographic parameters were age-dependent. Increasing age was found to correlate with a higher proportion of NREM 1, especially on the first night. Also, there was an age-dependent increase in NREM 2 on both nights, a decrease in NREM 3 on the first night, and a decrease in NREM 4 on both nights. In older children, we also found a lower proportion of REM sleep on the first night and a lower HR on both nights. In Group 1, we found a lowered AHI, AI and JI (for JI significant only on the first night) in older patients. No such age dependence of AHI, AI and JI was seen in OSAS patients (Group 2).

CONCLUSIONS

In children and adolescents, there is an FNE comparable with that described in adults. In OSAS children and also in children with no PSG-abnormalities, there is night-to-night-variability in sleep parameters, but not in respiratory parameters. An adaptation night is, therefore, necessary when sleep architecture is to be studied, but not when only the nocturnal respiratory pattern is investigated. Sleep parameters, HR and arousal indices are all age-dependent.

Monitoring and enforcing cultural competence in Medicaid managed behavioral health care

In recent years cultural competence has expanded beyond language provisions to include understanding and factoring into services provision the cultural perspectives clients may have that are different from the majority culture. The federal government requires state Medicaid programs to offer culturally competent services, but little is known about how states implement such mandates and monitor and enforce them. We reviewed the origins and implications of cultural competence mandates and conducted a brief case study of 5 states to learn about the implementation of cultural competence provisions in behavioral managed care contracts. We found that states and managed behavioral health organizations (MBHOs) vary in their definitions and implementation of standards to ensure mental health care access for vulnerable populations. Although states had a variety of oversight mechanisms, varying contractual requirements ranging from optional to required, vague contract language, no existing standardized indicators or definitions, and scant data on the cultural characteristics of the populations enrolled in Medicaid managed care hamper monitoring and enforcement of cultural competence by states. Implications for MBHOs, states, and the federal government, as well as services researchers, follow.

Arousals and obstructive sleep apnea syndrome in children

OBJECTIVE

Observations of children with obstructive sleep apnea syndrome (OSAS) show a restless sleep. But there is no significant disturbance of sleep macrostructure as in adult OSAS patients. It will be proved, whether the analysis of arousals permits a comprehensive characterization of this respiratory related sleep disturbance. Considering the problems in EEG-arousals detection in dependence of age and maturation we will compare the results of analysis of EEG- and movement arousals to find out a more practicable way for arousal analysis in childhood.

METHODS

Twenty OSAS pediatric patients (aged 3.1-14.3 years, median 7.5 years) and 20 age matched children with no OSAS (aged 3.3-13.9 years, median 7.9 years) were examined polysomnographically. Clinically confirmed OSAS patients with an apnea/hypopnea index (AHI) > or = 5/h TST (total sleep time) were examined during 1 whole night before treatment (diagnostic night - baseline) and after/under receiving therapy. Various polygraphic parameters to describe the macrostructure of sleep (sleep efficiency, NREM 1-4, REM) and the microstructure of sleep (EEG- and movement arousals) were analyzed. Furthermore the AHI, heart rate and oxygen saturation were evaluated.

RESULTS

Patients with clinically and polysomnographically confirmed OSAS had significantly more EEG (median 21.0/interquartile range 9.31 /h TST) and movement arousals (20.4/13.1 /h TST) before therapy than after/under therapy (EEG: 9.9/6.3 /h TST; movement: 9.2/3.8/h TST). The frequency of arousals was comparable in OSAS children after/under treatment and controls (EEG: 9.0/4.2/h TST; movement 9.3/3.4/h TST). In the 3 groups there was no significant correlation between AHI and number of EEG-arousals and movement arousals. AHI was significantly higher in OSAS children in comparison to controls and treated OSAS. In contrast to adults, sleep efficiency and macrostructure of sleep were not different in controls and OSAS children with or without treatment. Also, oxygen saturation and heart rate, had the same values in controls, OSAS children and OSAS children after/under treatment.

CONCLUSIONS

OSAS in children is characterized by a restless sleep, i.e. by an enhanced number of movement and EEG-arousals. The microstructure of sleep but not the macrostructure is changed. There is a high coincidence between EEG arousals and movement arousals. The evaluation of arousals especially the analysis of movement arousals is helpful to estimate treatment effect in OSAS patients.

[Theophylline in the treatment of sleep-related breathing disorders]

The methylxanthine derivates are known to have respiratory stimulant properties. Therefore theophylline is used in sleep related disturbances of breathing. Theophylline reduces central apneas and periodic breathing in infants. The efficiency of theophyllin is confirmed in reducing central apneas in patients with neurologic diseases or Cheyne Stokes breathing in patients with congestive heart failure. In patients with obstructive sleep apnoea the effect of theophylline is doubtful. An effect of therapy exists in some mild forms of sleep apnoea (apnoea index < 20/h total sleep time). Further studies are necessary to investigate the precise mechanism of of theophylline in obstructive sleep apnoea.

A comparison of ambulatory Medicaid claims to medical records: a reliability assessment

This study compares the documentation of ambulatory care visits and diagnoses in Medicaid paid claims and in medical records. Data were obtained from Maryland Medicaid's 1988 paid claims files for 2407 individuals who were continuously enrolled for the fiscal year, had at least one billed visit for one of six indicator conditions, and had received the majority of their care from one provider. The patients sampled were also stratified on the basis of the case-mix adjusted cost of their usual source of care. The medical records for these individuals as maintained by their usual source of care were abstracted by trained nurse reviewers to compare claims and record information. Linked claim and medical record data for sampled patients were used to calculate: (i) the percent of billed visits documented in the record, (ii) the percent of medical record visits where both the date and the diagnosis agreed with the claims data, and (iii) the ratio of medical record visits to visits from billed claims. Included in the analysis were independent variables specifying place of residence, type and costliness of usual care source, level of patient utilization, and indicator condition on which patient was sampled. Ninety percent of the visits chronicled in the paid claims were documented in the medical record with 82% agreeing on both date and diagnosis. Compared to the medical records kept by private physicians and community health centers, a significantly lower percent of hospital medical records agreed with the claims data. Total volume of visits was 2.6% higher in the medical records than in the claims. Claims data substantially understated visits in the medical record by 25% for low cost providers and by 41% for patients with low use rates (based on claims information). Conversely, medical records substantially understated billed visits by 19% for rural patients and by 10% for persons with high visit rates. Although Medicaid claims are relatively accurate and useful for examining average ambulatory use patterns, they are subject to significant biases when comparing subgroups of providers classified by case-mix adjusted cost and patients classified by utilization rates. Medicaid programs are using claims data for profiling and performance assessment need to understand the limitations of administrative data.

[Adeno-tonsillar hyperplasia and obstructive sleep related respiratory disorders]

The most common cause of obstructive apnoeas in children is adenotonsillar hyperplasia. Possibilities of therapy are surgical intervention (adeniodectomy, tonsillectomy) or nasal CPAP. The decision on the most appropriate therapy must be individual. 26 children aged 2-5 years were investigated polysomnographically before therapy, after operation or with nCPAP-therapy. Polygraphy is a helpful aid in making up one's mind in favour of one of the possibilities of therapy, but also for controlling the therapeutic effect.

[Sleep evaluation in infancy, early childhood and childhood]

There is no common strategy for the determination of sleep stages in the childhood. In the first year of life, the differentiation in active and quiet sleep has been established. But there are several opinions about necessary parameters for the characterization of sleep states in this period of life. Therefore, the results of these evaluations are quite different. Our presented concept of sleep staging reflects neurophysiological, vegetative as well as behavioral parameters. The concept divides the sleep into light sleep, deep sleep and REM-periods. The determination of sleep states is possible by this concept both in infants and in children of different age, because it considers developmental changes of used physiological criteria.

[nCPAP/nBIPAP therapy in sleep-related obstructive respiratory disorders in childhood]

nCPAP/nBIPAP-therapy is a possibility of treatment of sleep related disturbances also in childhood. We will demonstrate the therapeutic effect of therapy in 13 patients in the age range 3 to 14 years on behaviour, school performance, number of infections in the upper airways as well as on polygraphic parameters, i.e., sleep structure, number of apneas, oxygen saturation and mean heart rate.

[Experiences with therapy of pediatric sleep apnea syndrome and obstructive nasopharyngeal respiratory pattern with nasal BIPAP and CPAP therapy]

Sleep-apnea in childhood shows a frequency similar to adults but it is caused by many other reasons. Therapeutic effects of nasal CPAP and BIPAP can replace surgical ENT-Therapy in large extent mainly in ages at 2-5 years. But also in older children is it possible to treat obstructive sleep apnea and hypoventilation neuromuscular diseases by BIPAP. Examples for treatment of children by BIPAP who are two years old were given. Other demonstrated cases cover children with stridor congenitus, obstructive sleep apnea, hypoventilation, adenoidal breathing disturbances with primary surgical treated tonsillar hyperplasia and one case of thoracal postobstructive malformation with therapeutic BIPAP options.

Plasma levels of DSIP in infants in the first year of life and SIDS risk

In searching for abnormalities related to the sudden infant death syndrome (SIDS), delta sleep-inducing peptide (DSIP), a regulatory peptide with sleep promoting actions, was investigated in the first year of life in four groups of children: (1) preterm infants (n = 28), (2) infants with a high mean apnea duration evaluated polysomnographically (n = 26), (3) healthy full-term infants (n = 37) and (4) siblings of SIDS-victims (n = 26). DSIP was radioimmunoassayed in plasma. Half of the infants were also investigated polygraphically during sleep. The ratio between quiet sleep and active sleep was determined. There was no age dependence of the plasma level of DSIP in the first year of life but there was an increase in the ratio of quiet/active sleep depending of maturity. The level of DSIP in healthy full-term infants was significantly higher (P less than 0.05) (median: 1885 pmol/l, interquartile range: 757 pmol/l) than in preterms (1595; 385) and in infants with a high mean apnea duration (1542; 373). There was no significant difference in DSIP concentrations between healthy full-term infants and SIDS-siblings (1605; 271).

[Anamnestic factors in at-risk SID children with peculiar breathing pattern]

436 out of about 9000 infants who were born between April 1987 and November 1990 in Jena were selected by means of a risk score for a polygraphy monitoring. This score contains anamnestic factors of the mother and the infant which are characteristic of an enhanced risk for the sudden infant death syndrome (SIDS). We performed a day-time polysomnography (ECG, heart rate, respiration, EEG, EOG, EMG) with a sleep duration of at least one hour. 23 of the infants investigated demonstrated abnormal breathing patterns (increased mean apnea duration, apneas longer than 15 s, apneas with bradycardia) and were treated with aminophylline to prevent a possible SIDS event. Now we investigated the statistical relation between 26 anamnestic factors of our risk score and the need for treatment. In univariate statistical comparisons treated infants differed from untreated infants concerning the occurrence of intraventricular haemorrhages (IVH), the gestational age (GA) (preterm of fullterm) and the occurrence of hyperbilirubinemia (HB) in their anamnesis. In a multivariate analysis with all 26 factors the birth weight was the third important factor beside IVH and GA, but only factor IVH was statistically significant. A cluster analysis of the variables with respect to the separation of the two groups of infants indicates that the variables IVH, GA and HB strongly correlate. In the light of these results we can underline that abnormal breathing patterns can be expected especially in infants with IVH, short GA and low birth weight.

[The diagnosis of sleep apnea--possibility for the prevention of SID?]

Groups of children with a statistically enhanced risk for SIDS: siblings of SIDS-victims and other full-term and preterm infants with anamnestic signs for an enhanced risk of SIDS and a control group of healthy infants without anamnestic signs of risk were polysomnographically investigated in the first year of life. The mean apnoea duration (MA-value estimated by frequency and length of apnoeas greater than or equal to 3s) in the sleep states active and quiet sleep was calculated. During active sleep there is a significant inverse correlation between MA and postnatal age in the full-term and preterm SIDS-risk infants but not in the controls and siblings of SIDS-victims. In all age groups there are some children in the full-term and preterm infants with extremely enhanced MA-values. For 6 age groups of the first year of life the 90% percentile of the MA-value was calculated separately in the sleep states active and quiet sleep to select infants with an abnormal breathing pattern. This limit could be a help for the decision on therapy.

[A screening program for detecting children with an increased SIDS risk (sudden and unexpected infant death)]

The prospective study presented conducted to prevent SIDS (sudden infant death syndrome). One of the proposed hypotheses on SIDS postulates a brainstem abnormality in the neuroregulation of cardiorespiratory processes. Therefore we characterized cardiorespiratory control mechanisms by examining the neurotransmitter substance P in plasma and polysomnographic investigations. With respect to the probable multifactorial origin of SIDS we selected children firstly anamnestically by means of an epidemiologically evaluated pre-, peri- and postnatal risk score. We reported the results of 208 polysomnographically and biochemically examined children anamnestically selected from a group of 2500 neonates. Examinations were performed on infants aged 2-4 weeks up to 1 year. To characterize respiratory control, length and frequency of apnoeas were separately estimated by means of polysomnography in the sleep states active and quiet sleep. If there were polygraphic risk factors representing a disturbance of respiratory control, the children were prophylactically treated with aminophylline 3 x 3 mg/kg b.w. for 4 weeks. We found a significant age dependence both of the mean apnoea duration in active sleep and the substance P level in plasma in the SIDS-risk group but not in the controls. High mean apnoea duration was correlated with low substance P level in the first months of age in SIDS risk infants selected anamnestically. This may reflect a delayed maturation of respiratory control mechanisms. In this way the polysomnography and the investigation of the neuropeptide substance P may be useful for a screening method indicating wether the respiratory control mechanisms are mature or not.

[Sudden and unexpected infant death]

SIDS is a topical problem in pediatrics. The cause of SIDS is still unknown. The paper considers different possible pathomechanisms and on the basis of different observations a variety of hypotheses: There is the apnoe hypothesis, the sleep hypothesis, the QT-hypothesis, the arousal hypothesis and the functional deficit primarily concerning the reticular formation of the brainstem. Therefore there is an urgent need for screening programms to find out children at risk of SIDS. Finally, aspects of prophylaxis and treatment in case of recognized risk are discussed.