Abstract. Seizures are one of the most common neurological symptoms in neonatal and infantile periods. Seizures arise in 1,5-5,5 of 1,000 live births, 80 % of which occur in the first week of life of a newborn [1]. Neonatal convulsions are one of the main indicators of central nervous system dysfunction, in 40-50 % of cases they are secondary due to hypoxic-ischemic encephalopathy, infection, cortical malformation, or inborn errors of metabolism [1, 2]. Patients with IEM and seizures have a recurrent nature of attacks that are usually inert to antiepileptic drugs as well as the presence of other neurological and multi-organ symptoms. As a result of a selective screening (2011-2017) of inherited disorders of amino acids and acylcarnitines metabolism 724 patients with seizures were selected. In 331 patients from this group, the level of certain amino acids and/or acylcarnithines went beyond the reference values, and in 396 patients all the rates were within the normal range. Among these 331 patients, 6 patients were detected with maple syrup urine disease, 3 - with non-ketotic hyperglycemia, 3 - with median-chain acyl-CoA dehydrogenase deficiency and 1 - with phenylketonuria. In the other 318 patients who formed the main study group, the following metabolic deviations were observed: 44 patients (13.8 %) had elevated concentrations of citrulline, 30 – of arginine (9.4 %), 63 – of leucine (19, 8 %), 41 – of C5OH (12.9 %), 45 – of C8:1 (14.2 %), 95 – decreased level of C0 (29.9 %). As a result of the study, in dry blood spots of patients with seizures certain amino acids and acylcarnitines have been detected, namely the decrease in the level of CO and the increase of C5OH and C8:1, as well as the increase in the concentration of leucine, arginine and citrulline. Alterations of C5OH, C8:1 and CO concentration in the blood of patients with seizures could be related to the influence of anticonvulsants taken by patients. Changes in the concentration of arginine and citrulline can be interpreted as the possible effects of the proconvulsant action of citrulline and the anticonvulsant action of arginine. Such non-specific secondary amino acid and acylcarnitine profiles which have been observed in patients with seizures make the laboratory diagnosis and interpretation of results more time-consuming and complicated. To optimize the interpretation of the results of selective screening of patients with seizures, it was suggested to use the concentration of leucine 583 μmol/L as the upper limit for the diagnosis of maple syrup urine disease, which increases the specificity of the diagnostic method from 98.1 to 99.7 %. Using the obtained data, an algorithm for laboratory diagnosis of patients with seizures was developed which helped to distinguish between primary and secondary changes in metabolite concentrations. Such measures will help speed up the diagnostic process and make a final diagnosis which is especially needed to start treatment as soon as possible and prevent the disability of patients with impaired central nervous system. Recieved: 27.09.2018
Keywords: seizures, inherited disorders of amino acids, acylcarnitines metabolism
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