A case-control study to investigate the prevalence of obstructive sleep apnea and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in children and young people with epilepsy.

STUDY OBJECTIVES: Epilepsy and obstructive sleep apnea syndrome (OSAS) are each relatively common in children. OSAS may affect cognition, such that recognition of OSAS is important for children and young people with epilepsy (CYPWE). Published pilot data reported 55% of CYPWE had symptoms suggestive of OSAS, compared with 7% of typically developing controls. The primary aim of this study was to ascertain OSAS prevalence by polysomnography in CYPWE, with secondary aims being to evaluate the utility of sleep questionnaires in CYPWE. METHODS: CYPWE and age- and sex-matched typically developing controls were studied. A single night of level I attended polysomnography was undertaken, along with questionnaires (Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire, Pittsburgh Sleep Quality Index, and the childhood and adolescent Epworth Sleepiness Scale). OSAS was defined as obstructive apnea-hypopnea index of ≥ 1 event/h. RESULTS: Polysomnography was performed in 72 children including 48 CYPWE (60% male) and 24 controls (54% male). Mean age (11 years) was similar for CYPWE and controls (P = .42), with slightly higher body mass index z scores (0.7 vs 0.1, P = .03) noted in CYPWE. Mean obstructive apnea-hypopnea index was 0.61 in CYPWE vs 0.42 in controls (P = .62). Despite higher Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire scores in CYPWE (0.38 vs 0.12, P < .001), no difference in OSAS prevalence (10% vs 4%, P = .78) was found. CYPWE had higher childhood and adolescent Epworth Sleepiness Scale (6 vs 3.5, P = .01) and Pittsburgh Sleep Quality Index (5 vs 3.3, P = .02) scores, indicating greater levels of daytime sleepiness and poorer sleep quality. CONCLUSIONS: The study found no evidence for increased OSAS prevalence in CYPWE, and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in predicting OSAS appears limited for CYPWE. CYPWE are, however, demonstrably sleepier and have poorer sleep quality. The cause for these findings remains unclear. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Investigation of Sleep Quality and Prevalence of Sleep-disordered Breathing in Children and Young People With Epilepsy; URL: https://www.clinicaltrials.gov/study/NCT03103841; Identifier: NCT03103841. CITATION: Urquhart DS, McLellan AE, Hill LE, et al. A case-control study to investigate the prevalence of obstructive sleep apnea and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in children and young people with epilepsy. J Clin Sleep Med. 2024;20(7):1039-1047.

Cannabinoid CB2 receptor orthologues; in vitro function and perspectives for preclinical to clinical translation.

Cannabinoid CB2 receptor agonists are in development as therapeutic agents, including for immune modulation and pain relief. Despite promising results in rodent preclinical studies, efficacy in human clinical trials has been marginal to date. Fundamental differences in ligand engagement and signalling responses between the human CB2 receptor and preclinical model species orthologues may contribute to mismatches in functional outcomes. This is a tangible possibility for the CB2 receptor in that there is a relatively large degree of primary amino acid sequence divergence between human and rodent. Here, we summarise CB2 receptor gene and protein structure, assess comparative molecular pharmacology between CB2 receptor orthologues, and review the current status of preclinical to clinical translation for drugs targeted at the CB2 receptor, focusing on comparisons between human, mouse and rat receptors. We hope that raising wider awareness of, and proposing strategies to address, this additional challenge in drug development will assist in ongoing efforts toward successful therapeutic translation of drugs targeted at the CB2 receptor.

RAMP and MRAP accessory proteins have selective effects on expression and signalling of the CB1 , CB2 , GPR18 and GPR55 cannabinoid receptors.

BACKGROUND AND PURPOSE: Receptor activity-modifying proteins (RAMPs) and melanocortin receptor accessory proteins (MRAPs) modulate expression and signalling of calcitonin and melanocortin GPCRs. Interactions with other GPCRs have also been reported. The cannabinoid receptors, CB1 and CB2 , and two putative cannabinoid receptors, GPR18 and GPR55, exhibit substantial intracellular expression and there are discrepancies in ligand responsiveness between studies. We investigated whether interactions with RAMPs or MRAPs could explain these phenomena. EXPERIMENTAL APPROACH: Receptors and accessory proteins were co-expressed in HEK-293 cells. Selected receptors were studied at basal expression levels and also with enhanced expression produced by incorporation of a preprolactin signal sequence/peptide (pplss). Cell surface and total expression of receptors and accessory proteins were quantified using immunocytochemistry. Signalling was measured using cAMP (CAMYEL) and G protein dissociation (TRUPATH Gα13 ) biosensors. KEY RESULTS: MRAP2 enhanced surface and total expression of GPR18. Pplss-GPR18 increased detection of cell surface MRAP2. MRAP1α and MRAP2 reduced GPR55 surface and total expression, correlating with reduced constitutive, but not agonist-induced, signalling. GPR55, pplss-CB1 and CB2 reduced detection of MRAP1α at the cell surface. Pplss-CB1 agonist potency was reduced by MRAP2 in Gα13 but not cAMP assays, consistent with MRAP2 reducing pplss-CB1 expression. Some cannabinoid receptors increased RAMP2 or RAMP3 total expression without influencing surface expression. CONCLUSIONS AND IMPLICATIONS: Mutual influences on expression and/or function for specific accessory protein-receptor pairings raises the strong potential for physiological and disease-relevant consequences. Sequestration and/or hetero-oligomerisation of cannabinoid receptors with accessory proteins is a possible novel mechanism for receptor crosstalk.

Obstructive sleep apnea syndrome as a rare presentation in a young girl with a central nervous system tumor.

Sleep-related breathing disorders are a common problem in infancy and childhood. The most common type of sleep-related breathing disorder in this age group is obstructive sleep apnea syndrome (OSAS), generally caused by factors affecting airway patency, such as tonsillar hypertrophy or obesity. However, in adults OSAS can also be caused by processes affecting the brainstem, such as central nervous system tumors. This report describes a 2-year-old girl who presented with symptoms of snoring, restless sleep, repeated night-time waking, and apneic events while asleep. She had no comorbidities, and examination revealed normal-sized tonsils. A sleep study demonstrated severe OSAS with an obstructive apnea/hypopnea index of 34. Her OSAS completely resolved on excision of the tumor. The case highlights the importance of neurological examination as part of evaluation of OSAS, especially in cases where tonsils are not enlarged and there are no other risk factors for OSAS. CITATION: Buller F, Kamal MA, Brown SK, et al. Obstructive sleep apnea syndrome as a rare presentation in a young girl with a central nervous system tumor. J Clin Sleep Med. 2022;18(4):1211-1214.

IMPACT: A generalisable system for simulating public health interventions.

Populations are under-served by local health policies and management of resources, partly because of a lack of realistically complex models to enable a wide range of potential options to be appraised. Rising computing power coupled with advances in machine learning and healthcare information now enables such models to be constructed and executed. However, such models are not generally accessible to public health practitioners because they do not have the requisite technical knowledge or skills. This paper presents a system for creating, executing and analyzing the results of simulated public health and healthcare policy interventions, which is more accessible and usable by modellers and policy-makers alike.

Inflammation in children with neuromuscular disorders and sleep disordered breathing.

INTRODUCTION: Paediatric obstructive sleep apnoea is associated with systemic inflammation and co-morbidities. We assessed whether sleep disordered breathing (SDB) due to neuromuscular weakness was associated with elevated airway and systemic pro-inflammatory cytokines. METHODS: Consecutive neuromuscular children (age 5-18years) underwent overnight full polysomnography and morning collection of serum and breath condensate, analysed for cytokines (Interleukin-10, Interleukin-6, Interleukin-1ß, Tumour Necrosis Factorα, high-sensitivity C-Reactive Protein, Intercellular and Vascular Adhesion Molecules ICAM-1, VCAM-1). Cytokine levels were related to Oxygen desaturation index (ODI), desaturation>4%/h, and levels of transcutaneous carbon dioxide overnight (tcCO2≥6.7 kPa > 2% sleep). RESULTS: A total of 23 patients were included, median age 12.6 years (IQR 8.7-14.6). ODI>3/h was associated with higher breath and serum IL-6 (p = 0.02). Children with elevated CO2 overnight had higher ICAM-1 and VCAM-1. CO2 levels correlated with serum ICAM-1 (rs0.570, p = 0.026) and VCAM-1 (rs0.76, p = 0.001). DISCUSSION: SDB in neuromuscular children is associated with raised serum IL-6, VCAM-1, ICAM-1. This may predispose these children to future cardiovascular and other co-morbidities.

Verbal protocols for assessing the usability of clinical decision support: the retrospective sense making protocol.

We compare the effectiveness of two types of verbal protocol, concurrent think aloud vs. retrospective sense making, for evaluating the usability of a clinical decision support tool. Thirty-five medical and nursing students participated in a usability experiment. Participants were asked to complete seven tasks using the system under evaluation. Eighteen students were allocated to the concurrent think aloud group and the remainder followed the retrospective protocol. The retrospective protocol was significantly more sensitive than the concurrent protocol in recording unique usability problems related to users' cognitive behaviour. These problems concerned the interpretation and comprehension of statistical output, search results and system messages. These findings can be explained by the retrospective protocol's greater ability to detect compound usability problems, capturing the cognitive dimensions of users' interactions with the interface in greater depth. Evaluations of clinical decision support systems should take an evidence-based approach to selecting protocols.