Sleep in children from northeastern Brazil with congenital Zika syndrome: assessment using polysomnography.

STUDY OBJECTIVES: We performed this study to describe the characteristics of sleep in children with congenital Zika syndrome through polysomnographic assessment. METHODS: Polysomnography with neurological setup and capnography was performed. Respiratory events were scored according to American Academy of Sleep Medicine criteria. Children were classified based on neuroclinical examination as having corticospinal plus neuromuscular abnormalities or exclusively corticospinal abnormalities. Neuroradiological classification was based on imaging exams, with children classed as having supratentorial plus infratentorial abnormalities or exclusively supratentorial abnormalities. RESULTS: Of 65 children diagnosed with congenital Zika syndrome, sleep apnea was present in 23 children (35.4%), desaturation in 26 (40%), and snoring in 13 (20%). The most prevalent apnea type was central in 15 children (65.2%), followed by obstructive apnea in 5 (21.7%) and mixed type in 3 (13%). The average of the lowest saturation recorded was slightly below normal (89.1 ± 4.9%) and the mean partial pressure of end-tidal carbon dioxide value was normal. Periodic leg movements were present in 48 of 65 children. Lower ferritin levels were observed in 84.6% of children. Palatine and pharyngeal tonsils (adenoids) were small in most children and not associated with the presence of obstructive apnea. Ventriculomegaly and subcortical and nucleus calcification were the most frequent neuroimaging findings. Supratentorial and infratentorial anomalies were present in 26.7% (16 of 60) and exclusively supratentorial changes in 73.3% (44 of 60). In the neuroclinical classification, isolated corticospinal changes were more frequent and the mean peak in capnography was lower in this group. There was no difference regarding the presence of apnea for children in the neuroclinical and neuroradiological classification groups. CONCLUSIONS: Sleep disorders were frequent in children with congenital Zika syndrome, with central sleep apnea being the main finding. CITATION: Brandão Marquis V, de Oliveira Melo A, Pradella-Hallinan M, et al. Sleep in children from northeastern Brazil with congenital Zika syndrome: assessment using polysomnography. J Clin Sleep Med. 2023;19(10):1759-1767.

Sleep disorders in Down syndrome: a systematic review / Distúrbios do sono na síndrome de Down: revisão sistemática

ABSTRACT Background: Sleep disorders are commonly observed in children with Down syndrome (DS) and can lead to significant behavioral and cognitive morbidities in these individuals. Objective: To perform a systematic review evaluating sleep disorders in individuals with DS. Methods: Search strategies were based on combinations of keywords: "Down syndrome"; "trisomy 21"; "sleep disorders"; "dyssomnias"; "sleep apnea"; "obstructive"; "sleeplessness"; "insomnia"; "parasomnias"; and "excessive daytime sleepiness". PubMed and Science Direct were used. Only original studies and retrospective reviews in English published between January 2011 and March 2021 were included. Results: 52 articles were included, most of them involving children and adolescents under 18 years of age. The main sleep disorder associated with DS was obstructive sleep apnea (OSA). Some studies reported the presence of cognitive dysfunction in patients with DS and sleep-disordered breathing, and few have been found about parasomnia, insomnia, and daytime sleepiness in these patients. Movement disorders and unusual postures during sleep may be related to disordered sleep breathing in DS. The main treatment options for OSA are continuous positive airway pressure therapy (CPAP), surgery, and weight control. Computational modeling associated with MRI has been used to plan surgical interventions in these patients. Conclusions: Individuals with DS are at high risk of developing sleep-related breathing disorders. The main sleep disorder associated with DS was OSA. The presence of sleep-disordered breathing contributes to a worsening of cognitive function in patients with DS.

RESUMO Antecedentes: Os distúrbios do sono são comumente observados em crianças com síndrome de Down (SD) e podem levar a morbidades comportamentais e cognitivas significativas nesses indivíduos. Objetivo: Realizar uma revisão sistemática para avaliar os distúrbios do sono em indivíduos com SD. Métodos: As estratégias de busca foram baseadas em combinações de palavras-chave: "Síndrome de Down"; "trissomia 21"; "distúrbios do sono"; "dissonias"; "apneia do sono"; "obstrutivo"; "insônia"; "insônia"; "parassonias" e "sonolência diurna excessiva". PubMed e Science Direct foram usados. Apenas estudos originais e revisão retrospectiva de prontuários escritos em inglês e publicados de janeiro de 2011 a março de 2021 foram incluídos. Resultados: Foram selecionados 52 artigos, a maioria com crianças e adolescentes menores de 18 anos. O principal distúrbio do sono associado à SD foi a apneia obstrutiva do sono (AOS). Alguns estudos relatam a presença de disfunção cognitiva em pacientes com SD e distúrbios respiratórios do sono, e poucos foram encontrados sobre parassonia, insônia e sonolência diurna nesses pacientes. Distúrbios do movimento e posturas incomuns durante o sono podem estar relacionados ao distúrbio respiratório do sono na SD. As principais opções de tratamento para AOS são pressão positiva contínua nas vias aéreas (CPAP), abordagem cirúrgica e controle de peso. A modelagem computacional associada à ressonância magnética tem sido usada para planejar intervenções cirúrgicas nesses pacientes. Conclusões: Indivíduos com SD apresentam alto risco de desenvolver distúrbios respiratórios relacionados ao sono. O principal distúrbio do sono associado à SD foi a AOS. A presença de distúrbios respiratórios do sono contribui para a piora das funções cognitivas em pacientes com SD.

Sleep disorders in Down syndrome: a systematic review.

BACKGROUND: Sleep disorders are commonly observed in children with Down syndrome (DS) and can lead to significant behavioral and cognitive morbidities in these individuals. OBJECTIVE: To perform a systematic review evaluating sleep disorders in individuals with DS. METHODS: Search strategies were based on combinations of keywords: "Down syndrome"; "trisomy 21"; "sleep disorders"; "dyssomnias"; "sleep apnea"; "obstructive"; "sleeplessness"; "insomnia"; "parasomnias"; and "excessive daytime sleepiness". PubMed and Science Direct were used. Only original studies and retrospective reviews in English published between January 2011 and March 2021 were included. RESULTS: 52 articles were included, most of them involving children and adolescents under 18 years of age. The main sleep disorder associated with DS was obstructive sleep apnea (OSA). Some studies reported the presence of cognitive dysfunction in patients with DS and sleep-disordered breathing, and few have been found about parasomnia, insomnia, and daytime sleepiness in these patients. Movement disorders and unusual postures during sleep may be related to disordered sleep breathing in DS. The main treatment options for OSA are continuous positive airway pressure therapy (CPAP), surgery, and weight control. Computational modeling associated with MRI has been used to plan surgical interventions in these patients. CONCLUSIONS: Individuals with DS are at high risk of developing sleep-related breathing disorders. The main sleep disorder associated with DS was OSA. The presence of sleep-disordered breathing contributes to a worsening of cognitive function in patients with DS.

Restless Legs Syndrome, and symptoms of Restless Syndrome in patients with Graves' disease: a cross-sectional survey.

OBJECTIVES: Restless legs syndrome (RLS) is a frequent comorbid condition associated with distinct unrelated diseases. While the incidence of RLS has not been definitively confirmed, RLS-like symptoms have been reported in a section of Asian population who also had hyperthyroidism. The prevalence of RLS is generally low in Asian populations. Under these circumstances, we hypothesized that in a population where RLS is common, such as in Brazil, RLS could manifest as a comorbid ailment alongside Graves' disease, a common hyperthyroid condition. METHODS: In a cross-sectional survey, 108 patients who presented with Graves' disease were analyzed for restless legs or associated symptoms. RESULTS: Twelve patients (11.1%) displayed symptoms of RLS prior to the incidence of Graves' disease. These patients experienced worsening of the symptoms during their hyperthyroid state. Six patients (5.6%) developed RLS, consequent upon the incidence of Graves' disease as per the consensus of the panel of the experts. Fifteen patients (13.9%) also presented with RLS-like symptoms without any discernible circadian feature of the syndrome. CONCLUSION: Our findings confirm that Graves' disease might trigger restless legs-like symptoms, while the condition of hyperthyroidism could also be complicated by definite RLS.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not.

OBJECTIVES: Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScoreFM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2). METHODS: Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScoreFM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups. RESULTS: Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScoreFM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups. CONCLUSION: SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS: Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI. METHODS AND RESULTS: 114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScoreFM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScoreFM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScoreFM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05). CONCLUSIONS: The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases. CLINICAL TRIALS: NCT03466359, NCT02588469 and NCT01358773.

Influence of Ear Protectors on the Sleep of Preterm Newborns: A Randomized Controlled Clinical Study.

The purpose of this study was to compare the effect of ear protectors on the sleep of preterm newborns during the "quiet" times in intermediate care nursery. This was a clinical, randomized, controlled crossover study conducted in two neonatal units in São Paulo, Brazil. The sample consisted of preterm infants who met the inclusion and exclusion criteria for the study. Polysomnography and unstructured observation were used for data collection. Twenty-four preterm infants with a mean gestational age of 33.2 weeks and current weight of 1.747 g were analyzed. There was no significant difference in the total sleep time of preterm infants with and without the use of ear protectors. Newborns with lower gestational age showed a significant reduction in total sleep time with the use of ear protectors (p < .05). The use of ear protection did not increase the total sleep time for preterm infants.

Restless Legs Syndrome, and symptoms of Restless Syndrome in patients with Graves disease: a cross-sectional survey

OBJECTIVES: Restless legs syndrome (RLS) is a frequent comorbid condition associated with distinct unrelated diseases. While the incidence of RLS has not been definitively confirmed, RLS-like symptoms have been reported in a section of Asian population who also had hyperthyroidism. The prevalence of RLS is generally low in Asian populations. Under these circumstances, we hypothesized that in a population where RLS is common, such as in Brazil, RLS could manifest as a comorbid ailment alongside Graves' disease, a common hyperthyroid condition. METHODS: In a cross-sectional survey, 108 patients who presented with Graves' disease were analyzed for restless legs or associated symptoms. RESULTS: Twelve patients (11.1%) displayed symptoms of RLS prior to the incidence of Graves' disease. These patients experienced worsening of the symptoms during their hyperthyroid state. Six patients (5.6%) developed RLS, consequent upon the incidence of Graves' disease as per the consensus of the panel of the experts. Fifteen patients (13.9%) also presented with RLS-like symptoms without any discernible circadian feature of the syndrome. CONCLUSION: Our findings confirm that Graves' disease might trigger restless legs-like symptoms, while the condition of hyperthyroidism could also be complicated by definite RLS.

Sleep duration on a population of children referred to sleep study - cross-sectional data from 2003 to 2009.

INTRODUCTION: Sleep is essential for human beings, especially children. Insufficient sleep is linked to somatic and psychological problems. This study aims to describe nocturnal sleep patterns in children aged 7 to 13 years and investigate if sex or weekdays influence sleep habits. It also analyses factors associated with sleep length and the difference between sleep habits on weekends and weekdays. METHODS: A retrospective cross-sectional study with questionnaires from children with sleep complaints referred to our service (December 2003 to June 2009) in Sao Paulo City, Brazil. Median of sleep hours, time going to bed, waking up, and the difference in amount of sleep during weekends and weekdays were calculated. A generalized linear model was used to find associations between covariates and a) sleep hours, and b) sleep weekend minus - weekdays. RESULTS: We analyzed 577 children (median 9.5 y, 61% boys). Median bedtime was 22h. Median wake up time was 7h on weekdays and 9h on weekends. Median sleep duration was 9.5h during weekdays and 10h on weekends. The median difference in the amount of sleep during weekends and weekdays was 0.5h (IQR=1.5). Shorter sleep duration was associated with age and school schedule. Higher difference weekend - weekdays was associated with older children, girls, and school schedule. CONCLUSION: Children 7 to 13 years usually sleep more on weekends. Age, morning and full-time classes are associated with shorter sleep duration on weekdays and higher weekend-weekdays; girls sleep more during weekends.

Correlation of Premature Infant Sleep/Wakefulness and Noise Levels in the Presence or Absence of "Quiet Time".

BACKGROUND: Peak sound levels during sleep can compromise the development of hospitalized infants. Quiet time is a strategy implemented in neonatal units to promote the sleeping of neonates by reducing noise levels, luminosity, and handling during particular periods of the day. PURPOSE: To determine the impact of quiet time on reducing sound levels and increasing total sleep time. METHODS: This longitudinal study was conducted at a neonatal intermediate care unit with a convenience sample of 12 premature infants. Four times per day, 60-minute quiet times were provided in the neonatal unit. Sleep-awake states and sound levels were evaluated during quiet times as well as 60 minutes before and afterward. Polysomnography was used for sleep-awake state assessment, and a noise dosimeter was used to check sound levels every 24 hours. RESULTS: The preterm infants had a corrected gestational age of 35.0 ± 1.5 weeks and weighed 1606.0 ± 317.8 g. Total sleep time was highest during quiet time (P = .005). Premature infants remained awake for longer following quiet times (P = .005). There was also a reduction in sound level during quiet times compared with the other time frames (P = .006). No statistically significant relationship was found between total sleep time and sound levels more than 24 hours. IMPLICATIONS FOR PRACTICE: Quiet time is a nursing intervention that should be implemented in all neonatal units. IMPLICATIONS FOR RESEARCH: Future research should use a greater sample size and other factors that influence sleep should be further investigated.

Sleep and salivary cortisol in preterm neonates: a clinical, randomized, controlled, crossover study.

OBJECTIVE: Analyze the influence of ear protectors on the baseline levels of salivary cortisol and response and total sleep time of preterm neonates during two periods of environmental management of a neonatal intermediate care unit. METHOD: A clinical, randomized, controlled and crossover study conducted with 12 preterm neonates. The use of ear protectors was randomized in two periods. Sleep evaluation was performed using one Alice 5 Polysomnography System and unstructured observation. RESULTS: No significant difference was observed between the baseline levels of salivary cortisol and response in preterm neonates from the control and experimental groups, and no statistical significance was observed between the total sleep time of both groups. No relationship was observed between the baseline levels of cortisol and response and total sleep time. CONCLUSION: Ear protectors in preterm neonates did not influence the salivary cortisol level and total sleep time in the studied periods.

Sleep and salivary cortisol in preterm neonates: a clinical, randomized, controlled, crossover study / Sueño y cortisol salival en prematuros: ensayo clínico, aleatorio, controlado, cruzado / Sono e cortisol salivar em prematuros: ensaio clínico, randômico, controlado, cruzado

ABSTRACT Objective: Analyze the influence of ear protectors on the baseline levels of salivary cortisol and response and total sleep time of preterm neonates during two periods of environmental management of a neonatal intermediate care unit. Method: A clinical, randomized, controlled and crossover study conducted with 12 preterm neonates. The use of ear protectors was randomized in two periods. Sleep evaluation was performed using one Alice 5 Polysomnography System and unstructured observation. Results: No significant difference was observed between the baseline levels of salivary cortisol and response in preterm neonates from the control and experimental groups, and no statistical significance was observed between the total sleep time of both groups. No relationship was observed between the baseline levels of cortisol and response and total sleep time. Conclusion: Ear protectors in preterm neonates did not influence the salivary cortisol level and total sleep time in the studied periods.

RESUMEN Objetivo: Certificar la influencia del uso de protectores auriculares en los niveles de cortisol salival basal y la respuesta y en el tiempo total de sueño de prematuros durante dos períodos de manejo del ambiente de una unidad de cuidado intermedio neonatal. Método: Ensayo clínico, aleatorio, controlado y cruzado conducido en 12 prematuros. El uso de protectores auriculares ha sido aleatorio en dos períodos. La evaluación del sueño ha sido realizada por medio del aparato de polisomnografía Alice 5 y de la observación no estructurada. Resultados: No ha habido diferencia significante entre los niveles de cortisol salival basal y la respuesta en los prematuros de los grupos control y experimental, no habiendo también significancia estadística entre el tiempo total de sueño de los dos grupos. No ha sido observada la relación entre los niveles de cortisol basal y la respuesta y el tiempo total de sueño. Conclusión: Los protectores auriculares en los prematuros no han influenciado el nivel de cortisol salival y el tiempo total de sueño en los períodos estudiados.

RESUMO Objetivo: Verificar a influência do uso de protetores auriculares nos níveis de cortisol salivar basal e resposta e no tempo total de sono de prematuros durante dois períodos de manejo do ambiente de uma unidade de cuidado intermediário neonatal. Método: Ensaio clínico, randomizado, controlado e cruzado conduzido em 12 prematuros. O uso de protetores auriculares foi randomizado em dois períodos. A avaliação do sono foi realizada por meio do polissonígrafo Alice 5 e da observação não estruturada. Resultados: Não houve diferença significante entre os níveis de cortisol salivar basal e resposta nos prematuros dos grupos controle e experimental, não havendo também significância estatística entre o tempo total de sono dos dois grupos. Não foi observada relação entre os níveis de cortisol basal e resposta e o tempo total de sono. Conclusão: Os protetores auriculares nos prematuros não influenciaram o nível de cortisol salivar e o tempo total de sono nos períodos estudados.

Sleepiness in Children: An Update.

Sleep is essential for children's learning, memory processes, school performance, and general well-being. The prevalence of sleepiness in children is approximately 4%. Reductions of sleep duration have daytime consequences, including sleepiness, behavior problems, cognitive deficits, poor school performance, inflammation, and metabolic dysfunction. Chronic pain, movement disorders, and sleep-disordered breathing also may lead to daytime somnolence, inattention, hyperactivity, oppositional behaviors, and mood dysregulation. Parent-report questionnaires are useful tools to assess subjective sleepiness in children. Sleepiness in children may be secondary to a sleep problem, such as narcolepsy, central hypersomnia, Kleine-Levin disease, or circadian rhythm disorder.

Auditory behavior and auditory temporal resolution in children with sleep-disordered breathing.

OBJECTIVE: Intermittent hypoxia caused by obstructive sleep apnea syndrome (OSAS) may lead to damage in brain areas associated to auditory processing. The aim of this study was to compare children with OSAS or primary snoring (PS) to children without sleep-disordered breathing with regard to their performance on the Gaps-in-Noise (GIN) test and the Scale of Auditory Behaviors (SAB) questionnaire. METHODS: Thirty-seven children (6-12 years old) were submitted to sleep anamnesis and in-lab night-long polysomnography. Three groups were organized according to clinical criteria: OSAS group (13 children), PS group (13 children), and control group (11 children). They were submitted to the GIN test and parents answered SAB questionnaire. The Kruskal-Wallis statistical test was used to compare the groups; p < 0.05 was considered statistically significant. RESULTS: The OSAS group performed significantly worse than PS (p = 0.011) and Control (p = 0.029) groups on gap detection percentage, while PS and Control groups showed no significant differences. The three groups showed similar gap detection thresholds. Regarding SAB questionnaire, PS group had significantly worse scores when compared to Control (p = 0.011), but not to OSAS (p = 0.101) groups. No statistical difference between OSAS and Control groups were found. CONCLUSION: Children with OSAS showed worse performance on GIN test in comparison to children with PS and children without sleep-disordered breathing. PS negatively affected auditory behavior in children. These findings suggest that sleep-disordered breathing may lead to auditory behavior impairment.

Effects of Handling and Environment on Preterm Newborns Sleeping in Incubators.

OBJECTIVE: To describe the total sleep time, stages of sleep, and wakefulness of preterm newborns and correlate them to levels of sound pressure, light, temperature, relative air humidity, and handling inside incubators. DESIGN: Observational, correlational study. SETTING: A neonatal intermediate care unit. PARTICIPANTS: Twelve preterm newborns, who were 32.2 ± 4.2 weeks gestational age and weighed 1,606 ± 317 g. METHODS: Sleep records were assessed by polysomnograph. Environmental variables were measured with a noise dosimeter, light meter, and thermohygrometer. To record time and frequency of handling, a video camera was used. All recordings were made for an uninterrupted 24-hour period. RESULTS: Mean total sleep time in 24 hours was 899 ± 71.8 minutes (daytime = 446 ± 45.3 and nighttime = 448 ± 60.2). Mean wakefulness was 552 ± 94.0 minutes. The predominant stage was quiet sleep. A significant correlation was identified only between the levels of light and wakefulness (r = 0.65 and p = .041). CONCLUSION: The environmental conditions and care provided to hospitalized preterm newborns did not influence sleep except for high light levels, which increased wakefulness. Nurses in clinical practice should implement strategies to promote and protect sleep by decreasing newborns' exposure to excessive light.

Secondary to excessive melatonin synthesis, the consumption of tryptophan from outside the blood-brain barrier and melatonin over-signaling in the pars tuberalis may be central to the pathophysiology of winter depression.

Seasonal affective disorder is defined as recurrent episodes of major depression, mania, or hypomania with seasonal onset and remission. In this class of mood disturbances, a unipolar major depressive disorder known as winter depression is common in populations living in northern latitudes far from the equator. Winter depression repeatedly occurs in the autumn or winter and remits in the spring or summer, and its etiopathogenesis is currently unknown. However, one can surmise that excessive melatonin production during the reduced duration of daily sunlight in the autumn and winter plays a role in its pathophysiology. Melatonin is synthesized from tryptophan within the pineal gland, which is located outside the blood-brain barrier, and overproduction of melatonin may lead to augmented consumption of tryptophan, from which serotonin is synthesized. As tryptophan is captured from the blood and excessively utilized by the pineal gland, tryptophan blood levels may decline; as such, it is more difficult for tryptophan to pass through the blood-brain barrier and reach the serotonergic neurons as the ratio of tryptophan to the other amino acids that compete for the same transporter to enter the brain is diminished. As such, less tryptophan is available for serotonin synthesis. Moreover, melatonin is known to modulate thyrotropin expression in the thyrotrophic cells of the pars tuberalis of the pituitary gland, and overproduction of melatonin in the autumn or winter months may cause excessive signaling in the pars tuberalis, diminishing its release of thyrotropin and resulting in central hypothyroidism. Both conditions reduced serotonin production and central hypothyroidism may cause depression. Furthermore, the excessive synthesis of melatonin during the autumn and winter may negatively affect the expression of neuromedin U in the pars tuberalis, causing an increased appetite, which is common in winter depression patients. The hypersomnia common in winter depressive patients can be ascribed to excessive circulating melatonin, a hormone that increases the propensity for sleep. Furthermore, central hypothyroidism may also increase sleepiness, as it is known that hypothyroid patients usually experience excessive somnolence. In this theoretical article, we also propose studies to evaluate winter depression patients with regard to the necessity, or not, of offering them an increased amount of tryptophan in their diets during the autumn and winter. We also suggest that the administration of triiodothyronine to winter depressive patients may mitigate their central hypothyroidism.

Identification of emotional expressiveness in facial photographs over 36†h of extended vigilance in healthy young men-a preliminary study.

Changes in sleep patterns negatively influence some emotional responses, but their effects on facial expressiveness identification are unclear. To investigate these effects, 21 young, healthy, male volunteers of intermediate chronotype evaluated emotional expressiveness of faces depicting 6 basic emotions in 5 emotional gradients every 4 h over 36 h of continuous wakefulness. To measure attention and mood we used the Psychomotor Vigilance test and the Positive and Negative Affect Schedule Expanded, respectively. We found effects of emotional gradient for all types of emotions (100% > 80% > 60% > 40% > 20%) during all tested periods, with no indications of circadian effects. The only emotional rating to be affected was disgust, which was progressively blunted throughout the experiment. This effect did not parallel homeostatic and circadian changes in mood, alertness or attention. We conclude that identifying disgust on facial photographs is particularly sensitive to lack of sleep irrespective of sleep-induced changes in mood and attention in males.

Effect of sleeping position on arousals from sleep in preterm infants.

PURPOSE: To evaluate the frequency of preterm infant positions during sleep, and to investigate the association among positions, arousals, sleep patterns, and time of day. DESIGN AND METHODS: This observational study was conducted in a neonatal unit with 10 preterm infants. Polysomnographic and video recordings during 24 hr identified sleep positions, arousals, sleep patterns, and time of day. RESULTS: Preterm infants were placed most frequently in the supine position (58.4%), followed by right side (24.9%), left side (15.5%), and prone (1.2%). The longest amount of time spent sleeping, and the most frequent number of arousals, occurred in the supine position, followed by prone, left-side, and right-side positions. After controlling for length of time spent in each position, the number of arousals per hour was the greatest in the supine position (13.562 ± 0.732) and least in the prone position (11.56 ± 4.754; p < .001). There were no significant differences in arousals according to position and sleep pattern (indeterminate, quiet, active sleep) or position and time of day (morning, afternoon, twilight, night). PRACTICE IMPLICATIONS: Nurses should evaluate the frequency of preterm infant arousals in each position, and use more often those positions that lead to a lower frequency of arousals and better sleep quality.

Infancy narcolepsy: Streptococcus infection as a causal factor.

Streptococcal infections are suggested as a risk factor for narcolepsy. This hypothesis is supported by the presence of anti-streptolysin antibodies in 65% of patients with narcolepsy. These infections are associated with the activation of general immunity and concomitant increased permeability of blood-brain barrier after T cell activation during inflammation and fever. It has also been shown a significant association between birth order and narcolepsy in genetically susceptible patients, with positivity for HLA-DQB1⁎0602 allele. Watson and colleagues showed a significant association between birth order and narcolepsy in genetically susceptible patients, with positivity for HLA-DQB1⁎0602 allele. In that study, the disease was predominant in young children cases compared to controls. We report here the case of a child diagnosed with narcolepsy with cataplexy, positivity for the HLA-DQB1⁎0602 and previous history of streptococcal infection.