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During the outbreak of coronavirus disease 2019 (COVID-19) clinicians are increasingly involved in the observation of possible neurological complications due to the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Some cases of encephalitis following COVID‐19 pandemic have been reported in literature that can mean possible damage to the central nervous system related to the SARS-CoV-2 infection. Early on, this was thought to be due to the direct effects of the virus itself, but the possibility of immune system mechanisms being implicated was gradually raised in scientific literature. The reports of anti‐NMDA receptor encephalitis among patients with COVID‐19 at different ages may be signs of this condition. We report the case of 16-year teenager with concomitant Anti-N-Methyl-D-Aspartate Receptor (Anti-NMDAR) encephalitis and COVID‐19. This clinical case brings arguments on the possible relationship between SARS-CoV-2 infection and autoimmune encephalitis.

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The aim of this study is to identify clinical and biochemical predictors of neurological disorders in adolescents who have suffered mild perinatal damage of the central nervous system. We examined 120 adolescents (62 girls and 58 boys) aged 13–16 years, who were hospitalized in the city Children’s Neurological Department. It was found that adolescents with perinatal lesions of the central nervous system, activated lipid peroxidation processes and revealed an increase in the concentration of protein S 100, which in the future could lead to the development of neurodegeneration processes. In addition, a positive correlation between the lipid peroxidation processes nd the concentration of the nerve tissue damage marker was revealed. The results indicate that the level of neurospecific protein — protein S 100, parameters of the oxidant‑antioxidant system, perinatal factors can be used as predictors of chronic nervous tissue processes.

We consider the interpolation Nevanlinna-Pick problem with infinitely many interpolation nodes in the class S [ a, b ] and rational matrix functions associated with this problem and orthogonal on the segment [ a, b ]. We obtain a criterion of complete indeterminacy of the Nevanlinna-Pick problem in terms of orthogonal rational matrix functions. The class of analytic functions S [ a, b ] was introduced by Krein in connection with the investigation of the problem of moments on a compact interval [1, p. 527]. A truncated Nevanlinna -Pick problem in the matrix class S [ a, b ] was studied in [2, 3].In the present paper, we consider the Nevanlinna-Pick problem in the class S [ a, b ] with infinitely many complex interpolation nodes and two families of rational matrix functions { P r, (n) } [(see (15)] associated with this problem. Theorems 3 and 4 are the main results of the present paper. Theorem 3 establishes the orthonormality of the family { P 1, (n) } with respect to the matrix weight ( b -t ) dσ ( t ) and the family { P 2, (n) } with respect to the matrix weight ( t -a ) dσ ( t ) [see (16)]. Theorem 4 gives a criterion of complete indeterminacy of the Nevanlinna-Pick problem in terms of convergence of the series from { P r, (n) } [see (18)]. Nevanlinna -Pick Problem in the Class S [ [ [ [ a, b ] ] ] ]We fix real numbers a < b and a natural number m. Denote C -= { z ∈ C : Im z < 0 }, C + = { z ∈ C : Im z > 0 }, and C ± = C -∪ C + . Further, by C m × m we denote the set of complex square matrices of order m, by C H the set of Hermitian matrices, and by C ≥ × m m and C > × m m the sets of nonnegative and positive matrices, respectively. The nonnegative (positive) matrices are also denoted by A ≥ 0 ( A > 0 ). Let I m ∈ C m × m and 0 m ∈ C m × m be the identity and null matrices, respectively, and let S [ a, b ] be the set of holomorphic matrix functions s : C \ [ a, b ] → C m × m such that s z s z z z ( ) − ( ) − * ≥ 0 ∀z ∈ C ± , s ( x ) ≥ 0 ∀x ∈ R \ [ a, b ].