Abstract

Relevance: With the coronavirus infection of COVID-19, a significant number of disorders with various clinical manifestations are observed, including damage to the cardiovascular, central nervous systems and other organs and systems of the human body, in particular, sensory ones.

Objective: to assess the functional state of the central nervous system based on the analysis of electroencephalography data in persons who have contracted COVID-19 and have disorders of the auditory, olfactory, and vestibular analysers.

Research materials and methods: 54 people who got sick with COVID-19 and had disorders of auditory, olfactory and vestibular analysers were examined. Electroencephalography (EEG) was performed with the help of a computer electroencephalograph of the company “DH-systems” (Ukraine).

Research results and their discussion: During the analysis of electroencephalograms in persons who fell ill with COVID-19, deviations from the norm in the functional state of the central nervous system were detected, which were manifested in changes in the percentage content of the main rhythms and qualitative signs, expressed to varying degrees.
Thus, the patients of the examined group mostly had desynchronized EEGs with vague α-rhythm modulation. Many had manifestations of a general brain irritative nature, periodically sharp peaks and potentials. About a third of patients (35,2 %) had manifestations of hypersynchronous activity, especially during hyperventilation. In most patients, we observed smoothing of zonal discrepancies.
In the patients examined by us, a slightly different percentage ratio of the main EEG rhythms is observed than in the subjects of the control group. The content of the alpha rhythm in them was significantly (Р<0.05) lower than the control values in the occipital and temporal leads. However, a significant (Р<0.05) increase in the representation of beta oscillations up to (26,36±0,37 and 25,80±0,46) % was found in the same leads.
In the patients examined by us with deviations from the norm in the state of the sensory systems after COVID-19, there was a significant (Р<0,05) increase in the content of Δ-rhythm compared to the control group in the frontal and temporal leads both during background recording and during photostimulation and hyperventilation. Thus, during background recording in the frontal and temporal leads, the Δ-rhythm was equal to 14,26±0,29 and 10,60±0,20 %, respectively; with photostimulation – 15,21±0,11 and 10,72±0,18 %, respectively, and with hyperventilation – 15,46±0,31 and 10,46± 0,17 %, respectively.
Thus, the EEG studies conducted by us indicate that in patients who have suffered a coronovirus infection and had certain disorders on the part of the organ of hearing and other analyzer systems, there is a redistribution of the main rhythms with a decrease in the representation of the alpha rhythm and an increase in the representation of beta and slow waves, especially in the frontal and temporal leads.

Conclusions: Conducted studies of the bioelectric activity of the brain in persons who have contracted COVID-19 indicate a redistribution of the main EEG rhythms both during background recording and during functional loads, in the direction of an increase in the presented beta and slow waves, which indicates the presence of functional changes in the central nervous system in such patients. The most pronounced changes in the percentage content of the main EEG rhythms in patients with COVID-19 relate to the Δ-rhythm, which can be a sign of dysfunction of the deep structures of the brain.

Key words: bioelectric activity of the brain, electroencephalography, hearing, auditory analyzer, COVID-19.