PECULIARITIES OF MATURATION OF BIOELECTRICAL ACTIVITY OF THE BRAIN IN PREMATURE INFANTS ACCORDING TO AMPLITUDE-INTEGRATED ELECTROENCEPHALOGRAPHY
Authors: Babintseva A. , Hodovanets Y. 
Published: November 2024

The modern realities of independent Ukraine are associated with many challenges due to the invasion of a neighboring aggressor country. According to national statistics, the number of newborns in 2023 decreased by 31.05 % compared to 2021, while the incidence of low birth weight babies, including premature births, increased from 5.99 % to 6.09 %.The central nervous system is one of the target organs affected by adverse effects of various pathological ante-, intra- and postnatal factors against the background of morphological and functional immaturity of organ systems. Amplitude- integrated electroencephalography (aEEG) is a modern method of long-term monitoring of brain function in newborns with the possibility of simultaneous continuous video monitoring. The main indications for this research method in premature infants include 1) assessment of cerebral function and degree of cerebral damage in hypoxic- ischemic encephalopathy or birth asphyxia (often in combination with therapeutic hypothermia); 2) assessment of sleep-wake cycle; 3) detection of seizures; 4) assessment of the maturity of cerebral function. Interpretation of aEEG results should be based on «physiological» norms for diff erent gestational ages.The aim of the study is to investigate the peculiarities of the maturation of bioelectrical activity of the brain in premature infants according to the data of amplitude- integrated electroencephalography. Materials and methods. A comprehensive clinical and paraclinical examination of 62 children born before the physiological gestational age (up to 37 weeks) was conducted, and 131 studies were performed using the aEEG method. Recording was performedwith an amplitude- integrated electroencephalograph «EEG-CMF Simplex» (UKRMEDSPECTOR LLC, Kharkiv, Ukraine) or an electroencephalographic computer complex «BRAINTEST» (DX-SYSTEMS LLC, Kharkiv, Ukraine). For stratifi cation of the severity of the disorder of bioelectrical activity of the brain the classifi cation system for aEEG according to L. Hellström- Westas was used. The study was conducted in accordance with the «Rules of Ethical Principles for Scientifi c Medical Research Involving Human Subjects» approved by the Declaration of Helsinki (1964-2013), ICH GCP (1996), EEC Directive 609 (dated 24.11.1986), Order of the Ministry of Health of Ukraine No. 690 dated 23.09.2009 and confi rmed by the conclusion of the Commission on Biomedical Ethics of the Bukovinian State Medical University (Protocol No. 1 dated 21.09.2023). Written informed consent was obtained from the parents of the newborns.For statistical analysis of the results the licensed programs Statistica (StatSoft Inc., version 7), Microsoft Excell (AtteStat, version 12.5) and MedCalc Software Ltd (version 22.021) were used. The study was conducted within the framework of the joint budget research work of the Department of Pediatrics, Neonatology and Perinatal Medicine and the Department of Obstetrics and Gynecology of the Bukovinian State Medical University on the topic:«Improvement of the areas of care for pregnant women, newborns and infants in war and post-war conditions in Ukraine» (KPKVK 2301020, implementation period 2024-2026). Results of the study. The analysis of 131 AEG recordings in preterm infants revealed that the background pattern of continuousnormal voltage (CNV) was observed in 39.7 % of cases, discontinuous normal voltage (DNV) – in 27.5 % of cases, burst suppression (BS) – in 24.4 % of cases, low voltage (LV) – in 5.3 % of cases, inactive background pattern (fl at trace, FT) – in 3.1 % of cases. The study found inverse correlations between the severity of the aEEG pattern (from CNV to FT) and gestational age of the newborns (r = – 0.63, p < 0.0001), postconceptional age (r = –0.53, p < 0.0001), Apgar score at the end of the fi rst (r = –0. 46, p = 0.0002) and fi fth (r = –0.49, p < 0.0001) minutes of life; positive correlation with intraventricular hemorrhage grade II-IV (r = 0.57, p < 0.0001) and duration of mechanical ventilation (r = 0.67, p < 0.0001). Direct correlations between the sleep-wake phases and the aEEG were demonstrated in preterm infants with gestational age (r = 0.43, p = 0.0005) and postconceptional age (r = 0.49, p < 0.0001) and their formation after 32 weeks of gestation. Electroencephalographic seizures were diagnosed in 12.9 % of cases, allowing timely anticonvulsant therapy. The criteria for pathological aEEG in preterm infants with perinatal pathology are proposed, in particular: Low voltage (LV) and inactive background pattern (fl at trace, FT) in children of any gestational or postconceptional age; burst suppression (BS) pattern in children of gestational or postconceptional age greater than 32 weeks; discontinuous normal voltage (DNV) pattern in children of gestational or postconceptional age greater than 36 weeks; absence of sleep-wake phases in children of gestational or postconceptional age greater than 32 weeks; seizure graph elements in children of any gestational or postconceptional age.Conclusions. 1. The aEEG is a mandatory method of monitoring the bioelectrical activity of the brain in patients in neonatal intensive care units, the main tasks of which are to identify the main pattern, to determine the sleep-wake phases, and to detect electroencephalographic seizures. 2. In premature infants, the evaluation of aEEG results should be performed with regard to the physiological characteristics of brain maturation depending on the gestational age at birth and postconceptional age at the time of examination, as well as the severity of somatic pathology and the complexity of therapeutic interventions. 3. Premature infants meeting the above criteria should be included in the program of monitoring and early intervention for early diagnosis, prevention and treatment of the consequences of damage to the central nervous system.