ASSESSMENT OF BRAIN BIOELECTRICAL ACTIVITY IN CLINICALLY HEALTHY FLIGHT PERSONNEL AND FLIGHT TRAINING CANDIDATES FOLLOWING COVID-19 INFECTION

Abstract

Introduction: Electroneurophysiological tests, together with tests to evaluate structures of the central nervous system (CNS), are in neurological diagnostics among the basic additional specialized examinations for diagnostic, therapeutic and certification purposes. The electroencephalographic (EEG) test is one of the methods of elelectroneurophysiological evaluation of the CNS. EEG is a non-invasive objective test of the bioelectrical activity of the brain. Objective: To investigate whether the course of COVID-19 with clinical mild/moderate respiratory tract involvement, in non-hospitalized patients, may affect brain bioelectrical activity. Methods: Eighty-five subjects were selected for evaluation of EEG recordings from clinically initially healthy flight personnel and flight training candidates. Of all the male and female subjects, between 04 January 2021 to 31 January 2022, as part of periodic and qualifying certification examinations at the Military Institute of Aviation Medicine, for the purposes of the Regional Military Aviation and Medical Commission. The selected group consisted of individuals aged 14-60 (average age: 27 years and 6 months), which included 14 women (average age: 24 years and 2 months) and 71 men (average age 29 years and 3.5 months). The subjects were ill with COVID-19 (non-hospitalized) for approximately 3-4 weeks, during the period; June 2020 – December 2021. Routinely made recordings of bioelectrical brain activity with the Grass Technologies EEG TWin 4.5.3 system were visually evaluated. EEG examinations were performed in the supine position, in the before noon hours, in a darkened and acoustically isolated laboratory. Before the study, each person declared min. 6-8 hours of sleep and eating a meal (breakfast). Except for the flight training candidates and one person from flight personnel, all other subjects declared having received one and 29 subjects two SARS-CoV-2 vaccinations, prior to contracting COVID-19. Some subjects had one further revaccination after recovery from the disease. EEG examinations were performed between one and fourteen months after recovery from COVID-19. The mean time between recovery and EEG examination was 6.5 (6.47) months. Results: EEG recordings within normal limits (normal) were found in 79 subjects, while six subjects (7.05%) had abnormal brain bioelectrical activity recordings. Discussion and Conclusion: Infection with SARS-CoV-2 with clinical mild/moderate respiratory tract involvement by initially healthy individuals may adversely affect spontaneous brain bioelectrical activity in some individuals.