On the rise and fall of the apnea-hypopnea index: A historical review and critical appraisal.

The publication of "The Sleep Apnea Syndromes" by Guilleminault et al. in the 1970s hallmarked the discovery of a new disease entity involving serious health consequences. Obstructive sleep apnea was shown to be the most important disorder among the sleep apnea syndromes (SAS). In the course of time, it was found that the prevalence of obstructive sleep apnea reached the proportions of a global epidemic, with a major impact on public health, safety and the economy. Early on, a metric was introduced to gauge the seriousness of obstructive sleep apnea, based on the objective measurement of respiratory events during nocturnal sleep. The apnea index and later on the apnea-hypopnea index, being the total count of overnight respiratory events divided by the total sleep time in hours, were embraced as principle measures to establish the diagnosis of obstructive sleep apnea and to rate its severity. The current review summarises the historical evolution of the apnea-hypopnea index, which has been subject to many changes, and has been criticised for not capturing relevant clinical features of obstructive sleep apnea. In fact, the application of the apnea-hypopnea index as a continuous exposure variable is based on assumptions that it represents a disease state of obstructive sleep apnea and that evocative clinical manifestations are invariably caused by obstructive sleep apnea if the apnea-hypopnea index is above diagnostic threshold. A critical appraisal of the extensive literature shows that both assumptions are invalid. This conclusion prompts a reconsideration of the role of the apnea-hypopnea index as the prime diagnostic metric of clinically relevant obstructive sleep apnea.

European guideline for the diagnosis and treatment of insomnia.

This European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia. The guideline is based on a systematic review of relevant meta-analyses published till June 2016. The target audience for this guideline includes all clinicians involved in the management of insomnia, and the target patient population includes adults with chronic insomnia disorder. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to grade the evidence and guide recommendations. The diagnostic procedure for insomnia, and its co-morbidities, should include a clinical interview consisting of a sleep history (sleep habits, sleep environment, work schedules, circadian factors), the use of sleep questionnaires and sleep diaries, questions about somatic and mental health, a physical examination and additional measures if indicated (i.e. blood tests, electrocardiogram, electroencephalogram; strong recommendation, moderate- to high-quality evidence). Polysomnography can be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders), in treatment-resistant insomnia, for professional at-risk populations and when substantial sleep state misperception is suspected (strong recommendation, high-quality evidence). Cognitive behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (strong recommendation, high-quality evidence). A pharmacological intervention can be offered if cognitive behavioural therapy for insomnia is not sufficiently effective or not available. Benzodiazepines, benzodiazepine receptor agonists and some antidepressants are effective in the short-term treatment of insomnia (≤4 weeks; weak recommendation, moderate-quality evidence). Antihistamines, antipsychotics, melatonin and phytotherapeutics are not recommended for insomnia treatment (strong to weak recommendations, low- to very-low-quality evidence). Light therapy and exercise need to be further evaluated to judge their usefulness in the treatment of insomnia (weak recommendation, low-quality evidence). Complementary and alternative treatments (e.g. homeopathy, acupuncture) are not recommended for insomnia treatment (weak recommendation, very-low-quality evidence).

Melatonin use in managing insomnia in children with autism and other neurogenetic disorders - An assessment by the international pediatric sleep association (IPSA).

Though it is widely prescribed for improving sleep of children with autism and other neurogenetic disorders, there is a need for practical guidance to clinicians on the use of melatonin for managing insomnia in this population. Because data were either lacking or inconclusive, a task force was established by the International Pediatric Sleep Association (IPSA) to examine the literature based on clinical trials from 2012 onwards. A summary of evidence pertaining to melatonin's utility and potential side effects, practice-related caveats, and insights for use are published herewith.

Early onset West syndrome with severe hypomyelination and coloboma-like optic discs in a girl with SPTAN1 mutation.

Recent study has shown that mutations in the alpha-II-spectrin (SPTAN1) gene cause early onset intractable seizures, severe developmental delay, diffuse hypomyelination, and widespread brain atrophy. We report a Slovene girl with hypotonia, lack of visual attention, early onset epileptic encephalopathy, and severe developmental delay. The patient presented with segmental myoclonic jerks at the age of 6 weeks, and infantile spasms at the age of 3.5 months. Her seizures were resistant to treatment. Multiple electroencephalography recordings showed deterioration of the background activity, followed by multifocal abnormalities before progressing to hypsarrhythmia. Ophthalmologic examination revealed bilateral dysplastic, coloboma-like optic discs. Brain magnetic resonance imaging showed diffusely reduced white matter and brainstem volumes with hypomyelination. A de novo heterozygous in-frame deletion was detected in SPTAN1: c.6619_6621delGAG (p.E2270del). This report supports the causative relationship between SPTAN1 mutations and early onset intractable seizures with severe hypomyelination and widespread brain volume reduction. Coloboma-like optic discs might be an additional feature observed in patients with SPTAN1 mutations.

Sleep Measurement in Children-Are We on the Right Track?

Sleep plays a critical role in the development of healthy children. Detecting sleep and sleep disorders and the effectiveness of interventions for improving sleep in children require valid sleep measures. Assessment of sleep in children, in particular infants and young children, can be a quite challenging task. Many subjective and objective methods are available to evaluate various aspects of sleep in childhood, each with their strengths and limitations. None can, however, replace the importance of thorough clinical interview with detailed history and clinical examination by a sleep specialist.

Daylight Saving Time: Pros and Cons.

The original rationale for the adoption of daylight saving time (DST) was to conserve energy; however, the effects of DST on energy consumption are questionable or negligible. Conversely, there is substantial evidence that DST transitions have the cumulative effect on sleep deprivation with its adverse health effects. In light of current evidence, the European Commission in 2018 decided that biannual clock change in Europe would be abolished. Current indirect evidence supports the adoption of perennial standard time, which aligns best with the human circadian system and has the potential to produce benefits for public health and safety.

Cardiorespiratory parameters in newborns during sedation with chloral hydrate.

We commonly use chloral hydrate sedation in newborns, though its cardiorespiratory side effects have not yet been fully investigated. Our study aimed to analyze the impact of chloral hydrate on cardiorespiratory parameters in term newborns. We performed a prospective, pre-post single-arm interventional study in 42 term, respiratorily and hemodynamically stable newborns. Oxygen saturation (SpO2), end-tidal CO2 (ETCO2), the apnea-hypopnea index and the respiratory and heart rates were recorded by polygraphy, starting 0.5-1 hour before oral administration of chloral hydrate at a dose of 40 mg/kg and ceasing 4 hours post-administration. After administration of chloral hydrate, the mean basal SpO2 dropped by 2.0% (from 97.1% to 95.1%; p < 0.001) and the mean basal ETCO2 increased by 3.9 mmHg (25.6 to 29.5 mmHg; p < 0.001). We found a significant decrease in the minimal SpO2 values (p < 0.001) and an increase in the percentage of time spent with SpO2 < 95% and < 90% (p < 0.001). The mean increase in the estimated apnea-hypopnea index was 3.5 events per hour (p < 0.001). The mean respiratory and heart rates were significantly lower 150 min after the administration of chloral hydrate when compared with pre-sedation values (51/min and 127/min versus 61/min and 138/min respectively; p < 0.001). A considerable number of patients exhibited changes in cardiorespiratory parameters that differed considerably from the normal ranges. In conclusion, SpO2, ETCO2, the estimated apnea-hypopnea index and the respiratory and heart rates changed after the administration of chloral hydrate. They remained within normal limits in most newborns, but the inter-individual variability was high in the studied population.

Guidelines for diagnosis and management of congenital central hypoventilation syndrome.

BACKGROUND: Congenital Central Hypoventilation Syndrome (CCHS) is a rare condition characterized by an alveolar hypoventilation due to a deficient autonomic central control of ventilation and a global autonomic dysfunction. Paired-like homeobox 2B (PHOX2B) mutations are found in most of the patients with CCHS. In recent years, the condition has evolved from a life-threatening neonatal onset disorder to include broader and milder clinical presentations, affecting children, adults and families. Genes other than PHOX2B have been found responsible for CCHS in rare cases and there are as yet other unknown genes that may account for the disease. At present, management relies on lifelong ventilatory support and close follow up of dysautonomic progression. BODY: This paper provides a state-of-the-art comprehensive description of CCHS and of the components of diagnostic evaluation and multi-disciplinary management, as well as considerations for future research. CONCLUSION: Awareness and knowledge of the diagnosis and management of this rare disease should be brought to a large health community including adult physicians and health carers.

Diagnostic efficacy and new variants in isolated and complex autism spectrum disorder using molecular karyotyping.

Autism spectrum disorder (ASD) is a group of the neurodevelopment disorders presenting as an isolated ASD or more complex forms, where a broader clinical phenotype comprised of developmental delay and intellectual disability is present. Both the isolated and complex forms have a significant causal genetic component and submicroscopic genomic copy number variations (CNV) are the most common identifiable genetic factor in these patients. The data on microarray testing in ASD cohorts are still accumulating and novel loci are often identified; therefore, we aimed to evaluate the diagnostic efficacy of the method and the relevance of implementing it into routine genetic testing in ASD patients. A genome-wide CNV analysis using the Agilent microarrays was performed in a group of 150 individuals with an isolated or complex ASD. Altogether, 11 (7.3%) pathogenic CNVs and 15 (10.0%) variants of unknown significance (VOUS) were identified, with the highest proportion of pathogenic CNVs in the subgroup of the complex ASD patients (14.3%). An interesting case of previously unreported partial UPF3B gene deletion was identified among the pathogenic CNVs. Among the CNVs with unknown significance, four VOUS involved genes with possible correlation to ASD, namely genes SNTG2, PARK2, CADPS2 and NLGN4X. The diagnostic efficacy of aCGH in our cohort was comparable with those of the previously reported and identified an important proportion of genetic ASD cases. Despite the continuum of published studies on the CNV testing in ASD cohorts, a considerable number of VOUS CNVs is still being identified, namely 10.0% in our study.

Menkes kinky hair disease (Menkes syndrome). A case report.

Menkes disease (MD) is a rare genetic neurodegenerative disorder. It is caused by a mutation in the ATP7A gene, which codes for the copper-transporting ATPase in the cell organelles. Dysfunction of many copper-dependent enzymes results in low concentrations of copper in some tissues and accumulation of copper in others. We report on a boy that at the age of 2 months presented with encephalopathy with epileptic seizures and later had a progressive developmental disorder. Despite treatment with various antiepileptic drugs, some seizures still persisted. Our diagnosis was made on the basis of clinical and laboratory findings. We also plan to confirm the diagnosis genetically. To the best of our knowledge, this is the first reported case of MD in Slovenia. Treatment of MD is usually not successful, especially in sporadic cases, because it usually begins too late. Early neonatal treatment may be successful in half of the cases.

TBC1D24 genotype-phenotype correlation: Epilepsies and other neurologic features.

OBJECTIVE: To evaluate the phenotypic spectrum associated with mutations in TBC1D24. METHODS: We acquired new clinical, EEG, and neuroimaging data of 11 previously unreported and 37 published patients. TBC1D24 mutations, identified through various sequencing methods, can be found online (http://lovd.nl/TBC1D24). RESULTS: Forty-eight patients were included (28 men, 20 women, average age 21 years) from 30 independent families. Eighteen patients (38%) had myoclonic epilepsies. The other patients carried diagnoses of focal (25%), multifocal (2%), generalized (4%), and unclassified epilepsy (6%), and early-onset epileptic encephalopathy (25%). Most patients had drug-resistant epilepsy. We detail EEG, neuroimaging, developmental, and cognitive features, treatment responsiveness, and physical examination. In silico evaluation revealed 7 different highly conserved motifs, with the most common pathogenic mutation located in the first. Neuronal outgrowth assays showed that some TBC1D24 mutations, associated with the most severe TBC1D24-associated disorders, are not necessarily the most disruptive to this gene function. CONCLUSIONS: TBC1D24-related epilepsy syndromes show marked phenotypic pleiotropy, with multisystem involvement and severity spectrum ranging from isolated deafness (not studied here), benign myoclonic epilepsy restricted to childhood with complete seizure control and normal intellect, to early-onset epileptic encephalopathy with severe developmental delay and early death. There is no distinct correlation with mutation type or location yet, but patterns are emerging. Given the phenotypic breadth observed, TBC1D24 mutation screening is indicated in a wide variety of epilepsies. A TBC1D24 consortium was formed to develop further research on this gene and its associated phenotypes.

Early-onset epileptic encephalopathy with hearing loss in two siblings with TBC1D24 recessive mutations.

BACKGROUND: Recent studies have shown that recessive mutations in the TBC1D24 gene cause a variety of epilepsy syndromes, DOORS syndrome and nonsyndromic deafness. METHODS/RESULTS: We report on two siblings with hypotonia, early-onset epileptic encephalopathy, and severe developmental delay. The patients presented with clonic and myoclonic jerks within 1 h after birth. The seizures were resistant to treatment. Audiologic examination showed bilateral sensorineural hearing loss in both siblings. Genetic analysis revealed compound heterozygous mutations in the TBC1D24 gene: a novel missense mutation c.32A > G (p.Asp11Gly) in exon 2 and a frameshift mutation c.1008delT (p.His336Glnfs*12) in exon 4. CONCLUSION: This report supports previous observations that mutations in TBC1D24 cause diverse phenotypes. In fact, early-onset epileptic encephalopathy with sensorineural hearing loss is an additional phenotype observed in patients with recessive TBC1D24 mutations.

Clinical spectrum of SCN2A mutations expanding to Ohtahara syndrome.

OBJECTIVE: We aimed to investigate the possible association between SCN2A mutations and early-onset epileptic encephalopathies (EOEEs). METHODS: We recruited a total of 328 patients with EOEE, including 67 patients with Ohtahara syndrome (OS) and 150 with West syndrome. SCN2A mutations were examined using high resolution melt analysis or whole exome sequencing. RESULTS: We found 14 novel SCN2A missense mutations in 15 patients: 9 of 67 OS cases (13.4%), 1 of 150 West syndrome cases (0.67%), and 5 of 111 with unclassified EOEEs (4.5%). Twelve of the 14 mutations were confirmed as de novo, and all mutations were absent in 212 control exomes. A de novo mosaic mutation (c.3976G>C) with a mutant allele frequency of 18% was detected in one patient. One mutation (c.634A>G) was found in transcript variant 3, which is a neonatal isoform. All 9 mutations in patients with OS were located in linker regions between 2 transmembrane segments. In 7 of the 9 patients with OS, EEG findings transitioned from suppression-burst pattern to hypsarrhythmia. All 15 of the patients with novel SCN2A missense mutations had intractable seizures; 3 of them were seizure-free at the last medical examination. All patients showed severe developmental delay. CONCLUSIONS: Our study confirmed that SCN2A mutations are an important genetic cause of OS. Given the wide clinical spectrum associated with SCN2A mutations, genetic testing for SCN2A should be considered for children with different epileptic conditions.