Human hypocretin-deficient narcolepsy - aberrant food choice due to impaired taste?

Sleep Pathologies and Eating Disorders: A Crossroad for Neurology, Psychiatry and Nutrition

The intricate connection between eating behaviors and sleep habits is often overlooked in clinical practice, despite their profound interdependence. Sleep plays a key role in modulating psychological, hormonal and metabolic balance and exerting an influence on food choices. Conversely, various eating disorders may affect sleep continuity, sometimes promoting the development of sleep pathologies. Neurologists, nutritionists and psychiatrists tend to focus on these issues separately, resulting in a failure to recognize the full extent of the clinical conditions. This detrimental separation can lead to underestimation, misdiagnosis and inappropriate therapeutic interventions. In this review, we aim to provide a comprehensive understanding of the tangled relationship between sleep, sleep pathologies and eating disorders, by incorporating the perspective of sleep experts, psychologists and psychiatrists. Our goal is to identify a practical crossroad integrating the expertise of all the involved specialists.

Metabolic profile in patients with narcolepsy: a systematic review and meta-analysis

Narcolepsy, a sleep disorder characterized by loss of hypocretin neurons, has been associated with metabolic disturbances. Although the metabolic alterations in narcolepsy patients are widely investigated in the literature, the results are controversial. We performed a systematic search of literature to identify metabolic profiling studies in narcolepsy patients. A total of 48 studies were included in the meta-analysis. Narcolepsy patients exhibited higher prevalence of obesity (log OR = 0.93 [0.73-1.13], P < 0.001), diabetes mellitus (log OR = 0.64 [0.34, 0.94], P < 0.001), hypertension (log OR = 0.33 [0.11, 0.55], P < 0.001), and dyslipidemia (log OR = 1.19 [0.60, 1.77], P < 0.001) compared with non-narcoleptic controls. Narcolepsy was associated with higher BMI (SMD = 0.50 [0.32-0.68], P < 0.001), waist circumference (MD = 8.61 [2.03-15.19], P = 0.01), and plasma insulin (SMD = 0.61 [0.14-1.09], P = 0.01). Levels of fasting blood glucose (SMD = -0.25 [-0.61,0.10], P = 0.15), BMR-RMR (SMD = -0.17 [-0.52-0.18], P = 0.34), systolic blood pressure (SMD = 0.29 [-0.39-0.97], P = 0.40), diastolic blood pressure (SMD = 0.39 [-0.62, 1.40], P = 0.45), CSF melanin-concentrating hormone (MD = 5.56 [-30.79-41.91], P = 0.76), serum growth hormone (SMD = 7.84 [-7.90-23.57], P = 0.33), as well as plasma and CSF leptin (SMD = 0.10 [-1.32-1.51], P = 0.89 and MD = 0.01 [-0.02-0.04], P = 0.56, respectively) did not significantly differ between narcolepsy patients and controls. These findings necessitate early screening of metabolic alterations and cardiovascular risk factors in narcolepsy patients to reduce the morbidity and mortality rates.

Oligoantigenic Diet Improves Children's ADHD Rating Scale Scores Reliably in Added Video-Rating

OBJECTIVES

The influence of food intake on behavioural disorders was already described in the early 20th century. Elimination of individually allergenic food items from individual diets ["oligoantigenic diet" (OD)] showed promise to improve attention-deficit/hyperactivity disorder (ADHD) symptoms. However, only few of the positive results were evaluated by blinded symptom rating. Therefore the present study's purpose was to evaluate the reliability of a non-blinded rating of the ADHD Rating Scale IV (ARS) for the assessment of OD effects in comparison to a blinded rating of the ARS based on pseudonymized video recordings.

METHODS

Ten children (8m/2f) aged 8 to 14 with ADHD according to ICD-10 participated in an uncontrolled, open-label dietary intervention study. Food items, commonly related to intolerances, were eliminated for four weeks. Participants with > 40% improvement in the ARS between T1 (before the diet) and T2 (after the diet) were defined as responders. Nutrients with individual relevance to ADHD symptoms were identified in a following reintroduction phase (T3-T4) lasting 8-16 weeks. The ARS was completed by a non-blinded child and adolescent psychiatrist (T0-T4). Sessions were recorded on video, pseudonymized, and evaluated by three blinded raters. Complete data were captured for eight children. The inter-rater reliability between the non-blinded therapist and every blinded rater was determined by the intra-class correlation coefficient (ICC). Correlations according to Pearson and Spearman between the non-blinded and blinded rating were calculated for each rater.

RESULTS

Two blinded raters and the non-blinded rater considered 5 of 8 (62.5%) children as responders, whereas one blinded rater disagreed as to the success of one case thus considering only 4 of 8 children as responders to the diet. Inter-rater reliability was assessed after each rater having scored 33 videos: The intra-class coefficients were >.9 for all raters (rater 1: ICC=.997, rater 2: ICC=.996, rater 3: ICC=.996) and the Spearman rho between the raters were high (n=33; rater 1: rho =.989, p<.0001, rater 2: rho=.987, p<.0001, rater 3: rho=.984, p<.0001), respectively.

DISCUSSION

As both, blinded and non-blinded ratings of the ARS, revealed relevant significant improvement of ADHD scores in children following an OD in this uncontrolled trial, Randomized controlled trials appear as highly desirable in order to replicate these improvements and to establish reliable and unbiased effect sizes thereby fostering further more objective confirmatory measurements.

The olfactory bulb: A link between environmental agents and narcolepsy

Narcolepsy with cataplexy is a lifelong sleep disorder associated with orexin/hypocretin deficiency in the central nervous system. In addition to a genetic predisposition, a variety of environmental factors, such as influenza viruses, have been implicated in the pathogenesis of the disease. In this article, a hypothesis is proposed that environmental agents access the olfactory bulb and trigger neuroinflammation, which in turn induces neurodegeneration of orexinergic neurons in the lateral hypothalamus and other neuronal subpopulations regulating the sleep-wake cycle, which triggers the development of narcolepsy.