[Genetic background of dyslexia and dysgraphy in children]. / Geneticheskie predposylki disleksii i disgrafii u detei.

The review is devoted to one of the current problems of pediatric neurology - reading and writing disorders in children as part of a partial developmental disorder. With the development of neuroscience, the paradigm of «brain damage¼ in the understanding of a number of pathological conditions was replaced by the concept of «evolutionary neurology¼. The dominance of the ontogenetic approach caused the appearance of a new section in ICD-11 - «Neurodevelopmental disorders¼. Twenty-one genes associated with the acquisition of reading and writing skills have been identified. Modern studies demonstrate the connection of neuropsychological prerequisites for reading and writing, and clinical phenotypes of dyslexia with changes in specific loci. It is assumed that there are different molecular genetic bases for dyslexia and dysgraphia depending on ethnicity, orthographic features of language, including logographic features. Pleiotropy of genes is a cause of comorbidity of reading and writing disorders with attention deficit and hyperactivity disorder, specific speech articulation disorders, and dyscalculia. A key function of many of the identified genes is their involvement in the processes of neurogenesis. Their dysfunctions cause atypical neuronal migration, ectopic formation, inadequate axonal growth, and dendrite branching at the early stage of brain development. Morphological changes can distort the correct distribution and/or integration of linguistic stimuli in critical brain areas, leading to abnormalities in phonology, semantics, spelling, and general reading comprehension. The knowledge gained can form the basis for the development of risk models for dysgraphia and dyslexia formation and be used as a diagnostic and/or screening tool, which is important for evidence-based correction, optimization of academic performance, and mitigation of psychosocial consequences.

[Features of the formation of interzonal connections of the brain according to quantitative electroencephalography in full-term and premature infants]. / Osobennosti formirovaniya mezhzonal'nykh svyazei mozga po dannym kolichestvennoi elektroentsefalografii u donoshennykh i nedonoshennykh mladentsev.

OBJECTIVE: To study the features of functional interzonal integration and its dynamics in infants from 0 to 9 months during prospective observation, taking into account the timing gestation, clinical picture and morphological changes on neurosonography (NSG). MATERIAL AND METHODS: A comprehensive unified examination was carried out in dynamics in 89 infants three times at the age of 3, 6, 9 months and included, in addition to assessing the neurological status, the Denver Developmental Screening Test (DDST), transfontanellar ultrasonography with a vector sensor according to the generally accepted method. We also evaluated the parameters of electroencephalography (EEG) recorded in the waking state with an analysis of background parameters, zonal differences, and the identification of pathological types of activity and calculation of the average coherence power (ACP). In accordance with the gestational age, infants are divided into two groups of full-term and premature babies. RESULTS: In the group of premature babies, the clinical picture in the neonatal period was dominated by cerebral ischemia of I and II degrees. The DDST parameters throughout the entire observation period did not reveal any deviations from the optimal development in all children. There were significant changes in functional connectivity (FC) in premature infants, which were more pronounced by 9 months. Functional hyperintegration was recorded in the intrahemispheric occipital-temporal and occipital-central regions bilaterally, in the anterofrontal-temporal leads on the left and in the interhemispheric anterofrontal regions. The ACP indicators were affected by changes in the NSG. An increase in ACP values in the occipitotemporal leads was associated with the presence of subependymal cysts in both preterm and full-term infants. Intraventricular hemorrhages and increased echogenicity in the periventricular zones in preterm infants were associated with an increase in coherence in the anterior frontal, left occipito-central, and temporo-anterofrontal leads. CONCLUSION: Thus, in preterm infants with cerebral ischemia of grades I and II, as well as in children with subependymal cysts, ACP indicators indicate hyperintegration of brain areas that are of fundamental importance for speech development and the formation of cognitive functions. Changes in the level of FC in the areas of the cerebral cortex in children with low gestational age, cerebral ischemia I and II, even at the optimal rate of motor and preverbal development, require further study, as it can reflect both the physiological processes of maturation in the postnatal period with transient deviations, and act as the role of possible early markers of future variants of deviant development.

[Features of the organization of sleep in children with attention deficit hyperactivity disorder]. / Osobennosti organizatsii sna u detei s sindromom defitsita vnimaniya i giperaktivnosti.

The article presents modern ideas about the clinical features of sleep in children with attention deficit hyperactivity disorder (ADHD), the macrostructure of sleep, its cyclic organization and possible common links in the pathogenesis of sleep disorders and behavioral problems in patients. The relationship between the structure of sleep and impaired executive functions, the level of social maladjustment in patients with ADHD has been proven. Typical of children with ADHD are difficulty in going to sleep and falling asleep for a long time (resistance to sleep time), increased motor activity associated with sleep, including the association of ADHD with Restless legs syndrome (RLS) and periodic leg movement syndrome (PLMS), daytime sleepiness. The presence of circadian desynchrony in children with ADHD explains the relationship between chronotype, circadian typology, and clinical manifestations of the syndrome. Multidirectional data on the representation of REM sleep by nocturnal polysomnography in children with ADHD depend on age. However, the change in the proportion of REM sleep during the night is considered as a leading factor in the pathogenesis of ADHD manifestations. Various variants of metabolic disorders of melatonin, dopamine, serotonin, aggravated by social jet lag, are considered by the conjugatedcommon pathogenetic mechanisms of sleep disturbance and ADHD. As well as changes in the concentration of iron and ferritin in the blood, which may explain the frequency of RLS and PLMS in children with ADHD. The change in the number of sleep cycles during the night in patients has been demonstrated. Possible strategies for correcting sleep disorders in children with ADHD and their impact on the manifestation of ADHD are discussed.

[Current approaches to the diagnosis and treatment of behavioral insomnia in children]. / Sovremennye podkhody k diagnostike i korrektsii povedencheskoi insomnii detskogo vozrasta.

Behavioral insomnia is the most common sleep disorder in young children. It significantly reduces the quality of parent's life and is one of the common complaints to a pediatrician or neurologist. The basis treatment of childhood insomnia is behavioral therapy, which includes sleep hygiene, age-appropriate daily routine and sleep associations, stable bedtime routines, positive reinforcement, bedtime fading, scheduled awakenings. Although a systematic ignoring («crying it out¼) is effective and widely used in behavioral therapy, it has low compliance and its safety is insufficiently studied. Therefore, a systematic ignoring is not a priority method of behavioral therapy and should not be used in children under 6 months of age. Behavioral therapy of childhood insomnia is complemented by psychological and informational support from parents, and in some cases, drug therapy. Prevention includes education of expectant parents on baby sleep hygiene.

[Early infantile epileptic encephalopathy type 14: three cases of epilepsy in infancy with migrating focal seizures due to KCNT1 mutations]. / Rannyaya mladencheskaya epilepticheskaya entsefalopatiya 14-go tipa: tri sluchaya epilepsii mladenchestva s migriruyushchimi fokal'nymi pristupami, obuslovlennymi mutatsiyami gena KCNT1.

OBJECTIVE: To study clinical and neurophysiological data of early infantile epileptic encephalopathy type 14 caused by KCNT1 mutations. MATERIAL AND METHODS: For the period 2017 to 2019, 3 non-relative girls with clinical characteristics of epilepsy of infancy with migrating focal seizures (EIMFS) and mutations in the KCNT1 gene are identified and studied. DNA sequencing was performed using the Hereditary epilepsy panel (Next Generation Sequencing on platform IlluminaNextSeq 500, USA). Dynamical video-EEG monitoring was done with "Encephalan-Video" RM-19/26 ("Medicom MTD", Russia). RESULTS AND CONCLUSION: De novo KCNT1 mutations are identified and studied in three unrelated Russian girls: M.V., 3 years and 3 month old, T.V., 9 month old and M.A., 5 month old. M.V. has the previously unknown mutation in exon 12 (chr9:138656907C>T) with amino acid substitution Arg356Trp. T.V. has the previously described mutation in chromosome 9: 138651532G>A with amino acid substitution Gly288Ser (OMIM: 608167.0010). M.U. has the previously unknown mutation in exon 15 (chr9:138660712A>G) with amino acid substitution Asp480Gly. M.V. has seizure onset at the age of 4 month with behavioral arrest seizures and tonic versive seizures. T.V. developed seizures at 4,5 month in the manner of behavior arrest and ophthalmo-clonic seizures with hyperemia of face. M.U. has neonatal seizures with bilateral tonic-clonic seizures, cyanosis and further development of status epilepticus of alternating hemiconvulsive seizures. Further all the girls develop polymorphic seizures of multiregional genesis up to migrating status epilepticus with typical electro-clinical pattern of EIMFS. Therefore, KCNT1 is likely to be a major gene causing this rare and severe epileptic syndrome.

[Etiopathogenesis of obstructive sleep apnoea and its consequences in the children]. / Étiopatogenez obstruktivnogo apnoé sna i ego posledstvii u detei.

The article presents the modern view of etiology of the obstructive sleep apnoea/hypopnoea syndrome (OAHSS) in the children taking into consideration the ontogenetic stage and the principal mechanisms of its formation including the short-term and long-term consequences of sleep apnoea with special reference to the pathogenetic commonness of OAHSS with endothelial dysfunction, metabolic syndrome, cardiac disorders, and systemic chronic inflammation. The role of ENT diseases in the children with obstructive sleep apnoea is discussed. The results of genetic studies of the processes influencing the formation of the risk of development of sleep apnoea/hypopnoea syndrome and its outcomes in the children are discussed.

[Maturation of integrative sleep apparatus in children in normal and pathological condition]. / Sozrevanie integrativnykh apparatov sna u detei v norme i pri patologii.

AIM: To study and compare clinical characteristics of sleep macrostructure and sleep cycle organization during the night polysomnographic study in children with attention deficit hyperactivity disorder (ADHD) and obstructive sleep apnea syndrome (OSAS) aged from 6 to 9 years. MATERIAL AND METHODS: Polysomnography was performed in 40 children with ADHD and 20 children with OSAS. The control group included 20 healthy children. RESULTS AND CONCLUSION: The changes in sleep architectonics were unidirectional. Typical for the two groups of children was an increase in the latency of REM sleep and a reduction of its duration in total time of sleep. In children with ADHD, there was a significant decrease in the total number of sleep cycles, with a significant increase in the duration of the first sleep cycle. For an objective assessment of the rhythmic organization of ultradian rhythms, the authors propose a formula to calculate the maturity index of sleep in children older than 6 years. From the standpoint of evolutionary neuroscience, results should be considered as manifestations of dysontogenesis.

[The clinical and polysomnographic characteristics of obstructive sleep apnea syndrome in the children].

The objective of the present work was to study peculiarities of the neurological, ororhinolaryngological status of the children presenting with obstructive sleep apnea syndrome (OSAS) as well as their clinical and polysomnographic (PSG) sleep characteristics. A total of 15 children at the age from 6 to 9 years with OSAS confirmed by the PSG study were included in the investigation. All the children suffered nasal obstruction of different etiology and non-specific neurological complaints of transient headache, emotional lability, impaired memory, enhanced fatigue, and poor attention; these conditions were responsible for school desadaptation. All the patients underwent dyssomnic events. The polysomnographic study revealed the disordered sleep structure manifested as the shortened drowsiness phase, lengthened latent period of the rapid eye movement (REM) sleep and its reduced representation in the overall sleep cycle, enhanced duration of delta-sleep. The sleep alertness time also increased alongside with a rise in the number of activations on the sleep electroencephalograms by virtue of increased respiratory efforts. A characteristic feature of the children presenting with obstructive sleep apnea syndrome was vegetative disorder during sleep associated with a rise in the number of tachycardia episodes. The results of this study facilitate the understanding of certain pathogenetic aspects of neurological problems in the children suffering respiratory tract obstruction and OSAS and outline the problems awaiting further investigations.