The laboratory assessment of daytime sleepiness in childhood

Reliability and validity of the Daily Cognitive-Communication and Sleep Profile: a new instrument for monitoring sleep, wakefulness and daytime function

The Daily Cognitive Communicative and Sleep Profile (DCCASP) is a seven-item instrument that captures daily subjective sleep quality, perceived mood, cognitive, and communication functions. The objective of this study was to evaluate the reliability and validity of the DCCASP. The DCCASP was self-administered daily to a convenience sample of young adults (n = 54) for two two-week blocks, interspersed with a two-week rest period. Afterwards, participants completed the Pittsburgh Sleep Quality Index (PSQI). Internal consistency and criterion validity were calculated by Cronbach's α coefficient, Concordance Correlation Coefficient (CCC), and Spearman rank (rs) correlation coefficient, respectively. Results indicated high internal consistency (Cronbach-s α = 0.864-0.938) among mean ratings of sleep quality on the DCCASP. There were significant correlations between mean ratings of sleep quality and all domains (rs=0.38-0.55, p<0.0001). Criterion validity was established between mean sleep quality ratings on the DCCASP and PSQI (rs=0.40, p<0.001). The DCCASP is a reliable and valid self-report instrument to monitor daily sleep quality and perceived mood, cognitive, and communication functions over time, amongst a normative sample of young adults. Further studies on its psychometric properties are necessary to clarify its utility in a clinical population.

Challenges in diagnosing narcolepsy without cataplexy: a consensus statement

BACKGROUND

Diagnosing narcolepsy without cataplexy is often a challenge as the symptoms are nonspecific, current diagnostic tests are limited, and there are no useful biomarkers. In this report, we review the clinical and physiological aspects of narcolepsy without cataplexy, the limitations of available diagnostic procedures, and the differential diagnoses, and we propose an approach for more accurate diagnosis of narcolepsy without cataplexy.

METHODS

A group of clinician-scientists experienced in narcolepsy reviewed the literature and convened to discuss current diagnostic tools, and to map out directions for research that should lead to a better understanding and more accurate diagnosis of narcolepsy without cataplexy.

RECOMMENDATIONS

To aid in the identification of narcolepsy without cataplexy, we review key indicators of narcolepsy and present a diagnostic algorithm. A detailed clinical history is mainly helpful to rule out other possible causes of chronic sleepiness. The multiple sleep latency test remains the most important measure, and prior sleep deprivation, shift work, or circadian disorders should be excluded by actigraphy or sleep logs. A short REM sleep latency (≤ 15 minutes) on polysomnography can aid in the diagnosis of narcolepsy without cataplexy, although sensitivity is low. Finally, measurement of hypocretin levels can helpful, as levels are low to intermediate in 10% to 30% of narcolepsy without cataplexy patients.

Pilot study on the validity of the pupillographic sleepiness test in children and adolescents

OBJECTIVE

To report preliminary validation data for the pupillographic sleepiness test (PST) in children and adolescents.

METHODS

Twelve patients (13.1±4.4 years of age) underwent the multiple sleep latency test (MLST) and three PSTs at 09:00, 11:00, and 13:00 on one single day. Correlations were tested between mean sleep latency and gender-adjusted z-values of the natural logarithm of the pupillary unrest index (zlnPUI).

RESULTS

Spearman's correlation (P-value) between the zlnPUI values obtained at 09:00 and 11:00 with the MSL was rS = -0.641 (0.025) and r = -0.553 (0.062).

CONCLUSION

There was satisfactory agreement between PST and the MLST, which is similar to what is found in adults. The PST may be promising for the evaluation of daytime sleepiness in children and adolescents, and should be further evaluated in future studies.

Subjective and objective daytime sleepiness in schoolchildren and adolescents: results of a community-based study

OBJECTIVES

We aimed to assess subjective and objective sleepiness in schoolchildren and adolescents by using questionnaires and the Pupillographic Sleepiness Test (PST).

METHODS

An observational, cross-sectional, community-based study was performed. Participants were recruited and balanced by age and gender from schools using stratified random sampling. Sleep problems and subjective sleepiness were assessed using parent- and self-reported questionnaires. Objective sleepiness was assessed in schools under standardized conditions by using the PST and by calculating the natural logarithm of the pupillary unrest index (lnPUI).

RESULTS

In total 163 children (82 boys; age range, 6.6-17.8 years) were enrolled. Age and sleep problems were predictors of subjective sleepiness. Nine PST recordings (5.5%) were excluded due to artifacts (feasibility, 94%). Gender, sleep problems, and sleep duration were predictors of objective sleepiness. Compared to adults (age range, 20-60 years), the lnPUI was higher in children (mean±standard deviation [SD], 1.5±0.4 vs. 2.0±0.4; P<.001) and showed significant gender differences. There was no agreement between measures of subjective sleepiness and the lnPUI (r<0.3). After excluding children with sleep problems, preliminary reference values (mean±SD) for the lnPUI were 2.01±0.43 for boys and 1.93±0.43 for girls, respectively.

CONCLUSIONS

The PST is a feasible method in schoolchildren and adolescents. Sleep problems are predictors of both subjective and objective sleepiness; there is no agreement between the latter. Results of the PST are influenced by sleep duration and specific pediatric gender-stratified reference values are definitively needed.

High prevalence of precocious puberty and obesity in childhood narcolepsy with cataplexy

STUDY OBJECTIVES

We analyzed the potential predictive factors for precocious puberty, observed in some cases of childhood narcolepsy with cataplexy (NC) and for obesity, a much more common feature of NC, through a systematic assessment of pubertal staging, body mass index (BMI), and metabolic/endocrine biochemical analyses.

DESIGN

Cross-sectional on consecutive recruitment.

SETTING

Hospital sleep center and pediatric unit.

PATIENTS

Forty-three children and adolescents with NC versus 52 age-matched obese children as controls.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Patients underwent clinical interview, polysomnographic recordings, cerebrospinal fluid hypocretin-1 measurement, and human leukocyte antigen typing. Height, weight, arterial blood pressure, and Tanner pubertal stage were evaluated. Plasma lipid and glucose profiles were analyzed. When an altered pubertal development was clinically suspected, plasma concentrations of hypothalamic-pituitary-gonadal axis hormones were determined. Children with NC showed a high prevalence of overweight/obesity (74%) and a higher occurrence of precocious puberty (17%) than obese controls (1.9%). Isolated signs of accelerated pubertal development (thelarche, pubic hair, advanced bone age) were also present (41%). Precocious puberty was significantly predicted by a younger age at first NC symptom onset but not by overweight/obesity or other factors. In addition, overweight/obesity was predicted by younger age at diagnosis; additional predictors were found for overweight/obesity (short disease duration, younger age at weight gain and lower high-density lipoprotein cholesterol), which did not include precocious puberty. NC symptoms, pubertal signs appearance, and body weight gain developed in close temporal sequence.

CONCLUSIONS

NC occurring during prepubertal age is frequently accompanied by precocious puberty and overweight/obesity, suggesting an extended hypothalamic dysfunction. The severity of these comorbidities and the potential related risks require a multidiagnostic approach and a tailored therapeutic management.

Prevalence of narcolepsy with cataplexy in Norway

OBJECTIVES

Narcolepsy is a lifelong disabling disorder that may be alleviated by relevant treatment. Patients frequently report 10-15 years from the first symptoms to the time they get the diagnosis and treatment can be started. In order to offer a sufficient diagnostic and therapeutic service to this patient group, a reliable estimation of the prevalence of the disorder is important. A study of the prevalence of narcolepsy with cataplexy in Norway was therefore undertaken.

MATERIALS AND METHODS

The Ullanlinna Narcolepsy scale (UNS) was sent to 14548 randomly selected Norwegians between 20 and 60 years. Additionally, the study included telephone interviews and clinical evaluation of responders with >or=14 points on the UNS, and in those with suspected narcolepsy, polygraphic sleep recordings and human leucocyte antigen (HLA)-typing.

RESULTS

A total of 8992 responders answered the questionnaire (response rate 61.8%), 267 had >or=14 points on the UNS, 156 were interviewed and 15 had sleep recordings. In two HLADQB1*0602-positive patients sleep recordings were compatible with narcolepsy.

CONCLUSIONS

The results indicate a prevalence of 0.022% and approximately 1000 patients with narcolepsy with cataplexy in Norway.

The clinical and laboratory assessment of the sleepy child

Excessive sleepiness is defined as sleepiness that occurs in a situation when an individual would usually be expected to be awake and alert. Hypersomnia is characterized by recurrent episodes of excessive daytime sleepiness (EDS) or prolonged nighttime sleep, which affects the everyday life of the patient. Clinical surveys have reported that EDS is a complaint observed in up to 68% of normal high school children, with a negative impact in academic achievement and extracurricular activity. Clues toward recognizing childhood daytime sleepiness may be sleeping longer hours than expected for age, daytime naps beyond normal for age, being sleepy when other children of the same age are active and alert, and sleeping more than previously. Causes of EDS are arbitrarily divided into 3 categories: insufficient nighttime sleep, fragmented nighttime sleep, and increased drive of sleep. A list of various causes of EDS in children has been discussed. A detailed history along with examination of the upper airway is crucial in evaluating patients with EDS. Appropriate screening tools such as sleep logs, sleepiness scales, and sleep questionnaires further help in identifying and quantifying the degree of sleepiness. Confirmatory tests such as polysomnography, multiple sleep latency test, and actigraphy along with referral to a sleep physician may be necessary in appropriate cases. Details of other ancillary testing such use of cerebrospinal fluid orexin levels, HLA subtyping, and so on have also been provided.

Sleep disorders in childhood

Childhood sleep-wake disorders are common and associated with significant impairment of quality of life. The recent discovery of hypocretin deficiency as the pathophysiologic basis for narcolepsy-cataplexy is likely to spur the development of hypocretin analogs for definitive treatment [82,83]. The link between disrupted sleep and daytime learning and childhood inattention is a challenging area of mind-brain interaction in which further progress is likely, once methodologic issues have been sorted out. The recent recognition of genetic influences in the control of circadian rhythms also may spur the development of specific therapies for circadian rhythm disorders. In many ways, sleep medicine is benefiting from recent progress in the basic neurosciences, genetics, and technology.

Narcolepsy in children

Core symptoms of narcolepsy are similar in children compared with adults, but expression may be different due to more severe manifestations, maturational factors, and the significant impact of symptoms on behavior and academic performance. Diagnosis of narcolepsy in children is often challenging and requires a detailed history followed by polysomnography and the Multiple Sleep Latency Test. Management involves a comprehensive approach, including patient and family education and emotional support; behavioral strategies, such as good sleep hygiene and planned naps; and pharmacologic intervention. Despite dramatic progress recently in understanding the etiology of human narcolepsy through molecular genetic investigations, the disorder remains a chronic and often disabling disease with major impact on the lives of children and their families.

Assessment of sleepiness in children

Excessive sleepiness is a common but under-recognized problem in children. This article examines the clinical and laboratory evaluation of sleepiness in children, including the use of polysomnography, the multiple sleep latency test, and other varieties of neurophysiologic testing. Where applicable, technical aspects of laboratory testing are reviewed. Alternative laboratory and neurobehavioral techniques used to investigate daytime sleepiness are also briefly covered.

Hypersomnia in the Prader Willi syndrome: clinical-electrophysiological features and underlying factors

OBJECTIVE

Excessive daytime sleepiness is a common symptom in Prader Willi syndrome (PWs). Sleep disordered breathing (SDB) and narcoleptic traits such as REM sleep onsets (SOREMPs) have been reported in these subjects. We evaluated nighttime and daytime sleep patterns in patients with PWs in order to clarify the nature of their hypersomnia.

DESIGN AND METHODS

We performed overnight continuous EEG-polysomnographic studies (with breathing monitoring included) in 14 subjects (6 M,8 F; mean age 17 years, range 8-37) affected by PWs unselected for sleep disturbances. Ten patients underwent a Multiple Sleep Latency Test (MSLT) the day following the nocturnal sleep studies. Patients assessment was completed by means of immunogenetic characterization.

RESULTS

Nocturnal polysomnographic investigation documented sleep related breathing abnormalities such as central apneas, hypopneas or hypoventilation which mainly occurred during REM sleep in 8 subjects and did not cause sleep disruption. Only 4 subjects presented an increase in the Respiratory Disorder Index (RDI) slightly above the normal limits. In 8 subjects out of 10, with and without SDB, the mean daytime sleep latency could be considered abnormal according to the Tanner staging of pubertal development. Five patients showed at least two SOREMPs at MSLT. Subjects with and without SOREMPs had, respectively, a mean age of 18.6 SD 7.9 (4 M, 1 F) and 14.5 SD 2.9 (4 F, 1 M). The paternal deletion:uniparental dysomy ratio at genotypic characterization was 4:1 and 3.5:1 in subjects with and without SOREMPs, respectively. No patient presented DR-15 nor Dq-6.

CONCLUSIONS

Excessive sleepiness is a frequent disturbance in PWs. Subgroups of PW patients show hypersomnolence and SOREMPs. Sleep disordered breathing appears to have a limited role in the genesis of hypersomnia which not seems on the other hand attributable to the coexistence of narcolepsy phenotype. Hypersomnia in PW syndrome is likely to mainly be attributable to a primary hypothalamic dysfunction. The potential interacting role of other factors such as subjects age, sex and genetic pattern is suggested and deserve further investigation.

Sleep disorders in school-age children

This article on school age children reviews relevant issues in sleep physiology, the classification of sleep disorders, their clinical and laboratory assessment, some common sleep disorders, the sleep-epilepsy relationship, as well as the impact of daytime sleepiness on higher cortical functions.