The experimental group included 68 children over 6 years of age who had recovered from COVID-19. The control group included 22 children over 6 years of age who have never had COVID-19. Research methods included neurological examination, verification of cognitive status, examination by an otolaryngologist, and smell and taste assessment. The examination was performed 6–8 weeks after COVID-19 recovery and after 1 year in some patients. Children who recovered from COVID-19 had a reduction in their ability to smell compared to children who had never had COVID-19. The olfactory thresholds and taste identification scores after recovery from COVID-19 were identical, whether the parents had reported anosmia in their children during COVID-19 or not, and irrespective of hyperthermia level and the presence or absence of headache and hyperhidrosis during COVID-19. Analysis of correlation with neuropsychiatric symptoms showed no differences in the olfactory thresholds in children irrespective of the presence of neuropsychiatric symptoms (tics, tremors, enuresis, compulsive movements, seizures, speech disorders, attention deficit, and easy fatigability) both in general, and in particular among subjects performing or not any compulsive movements, and experiencing or not a combination of easy fatigability and daytime sleepiness. Evidence suggests that in children and adolescents, partial hyposmia is associated with depressive symptoms, varying in severity from low to high, but symptoms of depression were not caused by COVID-19 infection itself. Analysis in subgroups with different degrees of state and trait anxiety did not reveal any significant differences in the olfactory threshold. A re-examination of 21 children was performed after 1 year. An objective olfactometric examination showed that the sensitivity to odorants increased significantly. In 1 year, we compared the thresholds of smell in children who had COVID-19 and those who did not have this disease: olfactory sensitivity after COVID-19 in children is restored to normal values. Schulte correction test showed that none of 14 children with asthenic manifestations in the form of fluctuations or exhaustion when performing the test immediately after COVID-19 had these manifestations after 1 year. Thus, asthenization of cognitive activity was recorded within the next 1.5 months after suffering from COVID-19 but was absent after 1 year.

Background. The study of digital activity correlation with cognitive-emotional features, as well as with other parameters of adolescents’ life-activity in non-capital regions of Russian Federation remains relevant.Objective. The aim of the study is to analyze the digital activity structure in adolescents and its correlation with cognitive-emotional features, school performance and social and age factors.Methods. Participants are secondary school students of the 8th–11th grades. Digital activity was examined via online survey among adolescents. We took into account the use of social media, information search, watching videos on the Internet, using of messengers, playing games with electronic devices. Cognitive features (memory, thinking, executive functions, sensory information procession, reading and speech, understanding of emotions, decision-making) and emotional state of adolescents (anxiety) were evaluated by clinical psychologists via various tests. School performance was determined by the recent results of the school quarters/semester finished by the time of the survey. Social and age factors included regular out-of-school physical activity and family structure (complete/ incomplete).Results. We have examined 438 teenagers. 53 (12%) respondents spend more than 5 hours a day with digital devices on weekdays, 133 (30%) — on weekends, 147 (34%) — during the holidays. Structure of digital activity during weekdays (≥ 1 hour) among adolescents was the following: activity in social media prevailed (63.5% of respondents), fewer teenagers searched for information or watched videos on the Internet (47.3 and 42.9%, respectively), about a third (34.9%) played via electronic devices. Structure of digital activity changed over the weekend and during the holidays. We have revealed differences between the information search activity and the volume of short-time memory, understanding the verbal messages, and verbal-logical operations level. Adolescents with different levels of computer gaming activity have shown diversity in sensomotor reaction speed, visuospatial memorization accuracy, number of errors in high-speed reading, reading pace, and understanding text basic meaning.Conclusion. The greater time of digital activity among 8th–11th grades students is associated with negative results of cognitive activity and school performance.

Background. The role of recently discovered neurospecific peptides in the pathogenesis of acute and progressive neurologic disorders, their neuroprotective features, and possibilities to use them as markers for the course and prognosis of certain diseases have been actively studied in recent decades. However, neurospecific peptides are almost not studied in chronic residual diseases. In our study we measured the levels of neurospecific peptides and some other markers to achieve understanding of general neurophysiological trends in congenital and acquired chronic non-progressive brain pathology with reference to the selection of relevant groups — study objects. Objective. The aim of the study is to study patterns of neurospecific peptides, neurotransmitters and neuroreceptor markers distribution in the serum of children with various pathogenetic variants of chronic neuropathology. Methods. The study included children from 3 to 16 years old with different pathologies. The sample was divided into groups by pathology type: no sensory and neurological disorders, congenital sensory deficit due to mutation of genes expressed and not expressed in the brain, early acquired sensory deficit of multifactorial nature, congenital mild and severe organic disorders of central nervous system (CNS) in residual stage without baseline sensory deficit, acquired functional CNS disorders without baseline organic defect and sensory deficit. The following laboratory data (neurophysiological components) was studied: nerve growth factor, brain-derived neurotropic factor, neurotrophin-3, neurotrophin-4, neuregulin-1-beta-1, beta-secretase, sirtuin-1, synaptophysin, neuronal nitric oxide synthase, and anti-NR2 glutamate receptor antibodies. The parameters of cognitive activity, sense of vision, sense of smell, and acoustic sense were also evaluated. Results. The study included 274 participants. Neuropeptides and markers have shown a variable degree and range in the group spectrum of differences from normal levels. The most variable in the examined sample was NO-synthase, as well as levels of both neurotrophins, beta-secretase, and glutamate receptor marker. All visual deficits were associated with increased NO-synthase levels (p < 0.001). Neuroplasticity peptides (beta-secretase, neurotrophin-3 and 4) have been activated in all pathological conditions. Nerve growth factor and brain-derived neurotropic factor were specifically activated in mild organic CNS lesions (mild cognitive impairments), while neuregulin — in congenital genetically determined visual deficits. There was no specific activation of neuropeptides and NO-synthase level tended to decrease in cases of severe CNS lesions. Conclusion. The study results suggest that all types of early visual impairment are associated with increased physiological neuronal activity, and non-organic neurological functional disorders — mainly with increased physiological synaptic activity. General neuroplasticity processes were activated in all cases of visual deficits but more specific. However, more specific and well-studied processes were activated in mild organic CNS lesions, and neuroplasticity processes did not activate adequately in severe organic CNS lesions probably due to the limited neuronal and synaptic resources.

The other contributors confirmed the absence of a reportable conflict of interests The influence of dynamically changing habits associated with the use of digital devices (DD) on the child’s brain is one of the most topical issues of the last decade. Ambiguous or contradictory data on this issue indicate the need of systematizing all the results of scientific research. This analysis shows negative effect of large amount of screen time on the development of children at early age, their academic performance, and attention at older ages due to media absenteeism, as well as the correlation between the use of digital devices with delayed reward. It is necessary to update and to conduct qualitative research to understand the issue in more comprehensive way.