FEATURES OF IMPAIRED BIOELECTRICAL ACTIVITY OF THE BRAIN IN PATIENTS WITH CONSEQUENCES OF COMBAT TRAUMATIC BRAIN INJURY DEPENDING ON THE SEVERITY

In the context of modern military conflicts, this problem is of particular importance duet the growing number of patients with such injuries. According to statistics, every third-party with TBI has a wide range of neurological, cognitive and mental disorders that significantly affect the quality of life. It is known that the pathogenesis of post-traumatic disorders may be associated with the dysfunction of nonspecific brain structures, including the limbic reticular complex (LRC). One of the key methods of assessing the functional state of the brain is electroencephalography (EEG), which allows to detect abnormalities in the bioelectrical activity of the brain (BEAB).The aim of this study is to determine the peculiarities of BEAB changes in patients with consequences of TBI and their correlation with clinical manifestations. The study involved 350 patients with consequences of TBI. The patients were divided intergroups depending on the severity of the injury: 145 people with mild TBI (mTBI), 125 people with moderate TBI (MtTBI) and 80 people with severe TBI (sTBI). Injury history was also takeninto account: from 6 months to 1 year, from 1 year to 3 years, and from 4 years to 7 years.The average age was 38.5 ± 1.5 years. The control group consisted of 30 healthy individuals without TBI. All patients underwent a clinical and neurological examination to assess the neurological status and identify the main syndromes, as well as electroencephalography (EEG) withanalysis of focal EEG changes and basic brain activity rhythms. EEG recording was performed using the NeuroCom "KHAI-Medica" electroencephalographic complex, STC of Radio electronic Medical Devices and Technologies of the National Aerospace University "KHAI", in patients who did not have open wounds and postoperative sutures at the site of electrode application,metal fragments and metal plates in the head and neck area, which can lead to the appearanceof artefacts during EEG recording. We examined 97 patients with (mTBI) (66.9 %), 80 patients with MtTBI (64.0 %) and 47 patients with sTBI (58.75 %)Based on the results obtained, it can be said that the vast majority of patients with mTBIhad mild or moderate changes in the EEG. This was dominated by a modulated "spindle-shaped" alpha-rhythm, with an emphasis on the middle and posterior brain regions. In forebrain, a beta-rhythm was recorded with an average amplitude of 15-20 µV and a frequency of 14-24 oscillations per second. Zonal differences were preserved. Thus, only 34 patients(35.05 %) of this group had dysfunction of the diencephalic brainstem structures. In patients with MtTBI normal EEG parameters are almost absent. Thus, dysfunction of the diencephalic stem structures of the brain was recorded in 32 (40.0 %). Minor focal symptoms were presenting 28 (35.0 %), and paroxysmal activity was detected in 11 patients (13.75 %). The remaining patients had spontaneous epileptic activity. The group with TBI also had no normal EEG findings. Dysfunction of the diencephalic brainstem structures was recorded in 18 (38.2 %)patients, focal activity was observed in 17 (36.2 %), and paroxysmal activity in 8 (17.02 %)patients. Spontaneous epi-activity occurred in 4 (8.51 %) of the patients. Patients with MtTBIand sTBI had no reaction to hyperventilation. There was an increase in synchronization within increase in the amplitude of biopotentials in the form of acute waves of the alpha range, increased disorganization of the alpha rhythm, and the appearance of acute and slow waves. The appearance of a high amplitude alpha rhythm indicates depression of brain biopotentials, apparently due to insufficient hemodynamics and brain hypoxia. Thus, disorders of electrogenesis reflect dysregulation of the brain and its response to insufficient blood supply, which were found in groups of patients with MtTBI and sTBI. The BEABstudy showed that the consequences of TBI are characterized by changes in the frequency and amplitude of alpha-rhythm, which indicate dysfunction of nonspecific brain structures as a result of mTBI and are close to those in patients with MtTBI and sTBI. The more severe the TBI, the more pronounced changes in BEAB were observed in patients with MtTBI and sTBI.