SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Narcolepsy

194

Traditional screen time (e.g. TV and videogaming) has been linked to sleep problems and poorer developmental outcomes in children. With the advent of portable touchscreen devices, this association may be extending down in age to disrupt the sleep of infants and toddlers, an age when sleep is essential for cognitive development. However, this association has not been demonstrated empirically. This study aims to examine whether frequency of touchscreen use is associated with sleep in infants and toddlers between 6 and 36 months of age. An online survey was administered to 715 parents reporting on child media use (daily exposure to TV and use of touchscreens), sleep patterns (night-time and daytime sleep duration, sleep onset - time to fall asleep, and frequencies of night awakenings). Structural equation models controlling for age, sex, TV exposure and maternal education indicated a significant association between touchscreen use and night-time sleep, daytime sleep and sleep onset. No significant effect was observed for the number of night awakenings. To our knowledge, this is the first report linking the use of touchscreen with sleep problems in infants and toddlers. Future longitudinal studies are needed to clarify the direction of effects and the mechanisms underlying these associations using detailed sleep tracking.

Concepts: Infant, Sleep, Sleep disorder, Circadian rhythm, Narcolepsy, Structural equation modeling, Sleep hygiene

168

BACKGROUND: The management of pregnancy in patients with narcolepsy poses many questions regarding therapy, including the risk to the mother and fetus related to the disease, potential risks at the time of conception, the risk to both the mother and the fetus of the medications used to treat narcolepsy, and the risk to the infant from medications that might be secreted in breast milk. There are no detailed practice parameters on the treatment of narcolepsy patients during pregnancy. We surveyed narcolepsy specialists from around the world to determine their clinical approach to the management of patients with narcolepsy at the time of conception, during pregnancy and while breastfeeding. METHODS: Survey invitations were sent via e-mail to 75 clinicians worldwide between 2/2011 and 3/2011 with 34 responses (USA, n=10; Brazil, n=3; Czech Republic, n=2; France, n=2; Italy; n=2; Netherlands, n=2; Canada, n=1; Denmark, n=1; Finland, n=1; Germany, n=1; Japan, n=1; Spain, n=1; unknown n=7). Responders who completed the survey had 20years (median range, 5-35) of experience in sleep medicine practice with a median number of five narcolepsy patients seen per week. The number of pregnant narcoleptic patients followed per physician was five (median range 1-40). RESULTS: The survey results indicated that the management of patients with narcolepsy varies greatly from clinician to clinician and from country to country. The majority of the clinicians stopped the narcolepsy medications at the time of conception, during pregnancy, and during breastfeeding some reduced the dose and others did not change the dosage, depending on the particular medication. CONCLUSIONS: The findings from our survey and literature review suggest that the perceived risks of narcolepsy medication during pregnancy to the mother and the fetus usually are overestimated, as the risk for teratogenic effects from narcolepsy medications in therapeutic doses is essentially nonexistent. However, the potential for rare complications during pregnancy and congenital abnormalities cannot be excluded. Most narcolepsy patients have vaginal delivery without complications. In rare cases patients had cataplexy that interfered with delivery, but if caesarian is required there appears to be no increased anaesthetic or surgical risks. Further prospective information for the appropriate treatment of narcolepsy patients during pregnancy is needed.

Concepts: Pregnancy, Childbirth, Infant, Hospital, Median, Breastfeeding, Dose, Narcolepsy

164

Modafinil, in its two clinical formulations (Provigil(®) and Nuvigil(®)), is a widely prescribed wake-promoting therapeutic agent. It binds competitively to the cell-membrane dopamine (DA) transporter and is dependent on catecholaminergic (dopaminergic and adrenergic) signaling for its wake-promoting effects. The clinical spectrum of effects for modafinil is distinct from the effects seen with other catecholaminergic agents. Relative to other commonly used agents that act through catecholaminergic mechanisms, modafinil has a relatively low abuse potential, produces wakefulness with an attenuated compensatory sleep recovery thereafter, and does not ameliorate cataplexy in narcolepsy. These clinically relevant phenomenological differences between modafinil and agents such as amphetamines and cocaine do not eliminate catecholaminergic effects as a possible mediator of its wake-promoting action; they merely reflect its unique pharmacological profile. Modafinil is an exceptionally weak, but apparently very selective, DA transporter inhibitor. The pharmacodynamic response to modafinil, as measured by DA levels in brain microdialyzate, is protracted relative to other agents that act via catecholaminergic mechanisms. The conformational constraints on the interaction of modafinil with the DA transporter - and probably, as a consequence, its effects on trace amine receptor signaling in the catecholaminergic cell - are unique among catecholaminergic agents. These unique pharmacological properties of modafinil should be considered both in seeking to thoroughly understand its putatively elusive mechanism of action and in the design of novel therapeutic agents.

Concepts: Pharmacology, Attention-deficit hyperactivity disorder, Dopamine, Norepinephrine, Cocaine, Methamphetamine, Narcolepsy, Therapeutic index

35

Several studies have found an association between sleep duration and morbidity and mortality, but no previous studies have examined the association between sleep disturbances and semen quality. We conducted a cross-sectional study among 953 young Danish men from the general population who were recruited in Copenhagen at the time of determination of fitness for military service between January 2008 and June 2011. All of the men delivered a semen sample, had a blood sample drawn, underwent a physical examination, and answered a questionnaire including information about sleep disturbances. Sleep disturbances were assessed on the basis of a modified 4-item version of the Karolinska Sleep Questionnaire, which includes questions on sleep patterns during the past 4 weeks. Sleep disturbances showed an inverse U-shaped association with sperm concentration, total sperm count, percent motile and percent morphologically normal spermatozoa, and testis size. Men with a high level of sleep disturbance (score >50) had a 29% (95% confidence interval: 2, 48) lower adjusted sperm concentration and 1.6 (95% confidence interval: 0.3, 3.0) percentage points' fewer morphologically normal spermatozoa than men with a sleep score of 11-20. This appears to be the first study to find associations between sleep disturbances and semen quality. In future studies, investigators should attempt to elucidate mechanistic explanations and prospectively assess whether semen quality improves after interventions restoring a normal sleeping pattern.

Concepts: Sperm, Sleep, Sleep disorder, Semen, Sleep apnea, Polysomnography, Circadian rhythm, Narcolepsy

30

Background Sleep disturbances are commonly reported in the psychosis prodrome, but rarely explored in relation to psychotic experiences. Aims To investigate the relationship between specific parasomnias (nightmares, night terrors and sleepwalking) in childhood and later adolescent psychotic experiences. Method The sample comprised 4720 individuals from a UK birth cohort. Mothers reported on children’s experience of regular nightmares at several time points between 2 and 9 years. Experience of nightmares, night terrors and sleepwalking was assessed using a semi-structured interview at age 12. Psychotic experiences were assessed at ages 12 and 18 using a semi-structured clinical interview. Results There was a significant association between the presence of nightmares at 12 and psychotic experiences at 18 when adjusted for possible confounders and psychotic experiences at 12 (OR = 1.62, 95% CI 1.19-2.20). The odds ratios were larger for those who reported persistent psychotic experiences. Conclusions The presence of nightmares might be an early risk indicator for psychosis.

Concepts: Sleep, Sleep deprivation, Sleep disorder, Narcolepsy, Sleep disorders, Insomnia, Parasomnia, Night terror

27

There is limited information from population-based investigations of the associations between sleep duration and sleep disorders and parameters of glucose homeostasis. The objective of the present study was to examine cross-sectional associations between sleep duration and sleep disordered breathing with concentrations of insulin, fasting and 2-hour glucose, and HbA1c.

Concepts: Diabetes mellitus, Glucose, Blood sugar, Sleep, Sleep disorder, Circadian rhythm, Glycation, Narcolepsy

27

Narcolepsy is characterised by excessive daytime sleepiness (EDS) and cataplexy. Histamine neurons are crucial to maintain wakefulness. We assessed the safety and efficacy of pitolisant (previously called BF2.649), a selective histamine H3 receptor inverse agonist that activates these neurons, in patients with narcolepsy.

Concepts: Pharmacology, Histamine, Receptor antagonist, Agonist, Inverse agonist, Excessive daytime sleepiness, Narcolepsy, Histamine H3 receptor

27

Sodium oxybate (γ-hydroxybutyric acid, GHB) is a neurotransmitter in the human brain which exerts sedative effects and is used therapeutically in the treatment of narcolepsy. Current safety recommendations have been formulated for the use of GHB in patients with preexisting breathing disorders. We report the case of a 39-year-old female with narcolepsy and cataplexy revealing the de novo emergence of central sleep apneas in a Cheyne-Stokes pattern under constant treatment with GHB. After discontinuation of GHB, polysomnographic re-evaluation demonstrated the disappearance of central sleep apneas. To our knowledge, this is the first report of de novo central sleep apneas induced by GHB in a patient without pre-existing sleep-disordered breathing, suggesting that there is a need for further investigation and potentially an extension of the safety guidelines to patients without a pre-existing breathing disorder.

Concepts: Nervous system, Neuron, Brain, Sleep, Human brain, Narcolepsy, Gamma-Hydroxybutyric acid, Cataplexy

25

Cognitive enhancers (CE) such as methylphenidate, amphetamines and modafinil are becoming more commonly used in non-medical situations. This study explored the prevalence and motivations for CE use in a New Zealand university.

Concepts: Attention-deficit hyperactivity disorder, Controlled Substances Act, Narcolepsy, Enhancer, Modafinil, Cognitive enhancer, Nootropic, Nootropics

25