Abstract

Relevance: As a result of military actions in Ukraine, the number of affected individuals in need of medical care is increasing, especially after explosive trauma. The use of objective research methods in cases of explosive injuries allows early detection of cerebral hemodynamic and auditory function disorders, which is crucial for diagnostics and medical expertise.

Aim: to examine the quantitative and qualitative indicators of rheoencephalography in military personnel who sustained acoustic barotrauma in real combat conditions before and after treatment.

Materials and Methods: Two groups of individuals with combat-related acoustic barotrauma were examined: the first group consisted of 27 patients with mild hearing impairments, while the second group included 26 patients with severe and profound hearing impairments. All patients were examined before and after treatment to assess its effectiveness.

Since we recorded REG indicators characteristic of both increased and decreased cerebral vascular tone, each group of examined soldiers was divided into two subgroups: individuals with increased cerebral vascular tone (A) and those with decreased tone (B).

To study cerebral circulation, rheoencephalography was used in the frontomastoid and occipitomastoid leads, reflecting the state of cerebral circulation in the carotid and vertebrobasilar systems, respectively. The examinations were conducted using a computer-based rheograph from “DX Systems”. Statistical processing of the obtained results was carried out using generally accepted methods of mathematical statistics. The probability of changes and differences between comparative values was assessed using the Student’s t-test.

Results and Discussion: We examined the quantitative and qualitative rheoencephalography indicators in military personnel who sustained acoustic barotrauma in real combat conditions and identified signs of progression of sensorineural hearing loss (SNHL) and the most informative rheoencephalography indicators before and after treatment.

Qualitative analysis of the REG curves revealed disturbances in cerebral circulation in both the carotid (FM) and vertebrobasilar (OM) systems. Quantitative assessment included the analysis of α, DKI, DSI, and Ri indicators.

Normal cerebral circulation indicators according to REG data were not recorded in any patient with acoustic barotrauma. In the carotid system before treatment, a decrease in cerebral vascular tone was recorded in 21,84 % of cases in the first group and 23,64 % in the second group. Cases of unstable vascular tone with a tendency towards an increase were noted in 34,54 % of cases in the first group and 43,91 % in the second group; with a tendency towards a decrease in 19,16 % and 12,18 % of cases, respectively. Venous outflow obstruction in the carotid system before treatment was observed in 42,64 % of cases in the first group and 74,16 % in the second. As for pulse blood filling, its reduction in the carotid system was recorded in 44,18 % of cases in the first group and 60.08% in the second group.

In the vertebrobasilar system among the first group of patients before treatment, a decrease in cerebral vascular tone was recorded in 25,15 % of patients, while cases of unstable vascular tone with a tendency to increase (38,15 %) or decrease (28,56 %) were observed in almost one-third of them. In the second group, these indicators were 17,68 %, 47,65 %, and 23,06 %, respectively. Venous outflow obstruction was observed in 59,27 % of cases in the first group and 89,2 % in the second group. Pulse blood filling reduction was recorded in 69,5 % of cases in the first group and 88,9 % in the second group.

 In subgroup A (patients with increased cerebral vascular tone), the functional state of cerebral hemodynamics improved after treatment in both the carotid and vertebrobasilar systems compared to the control group. Significant (P<0,05) differences were recorded in α, DKI, DSI, and Ri indicators, especially in the vertebrobasilar system. In subgroup B (patients with decreased vascular tone), the quantitative REG indicators also improved after treatment but correlated with the degree of hearing function impairment, with significantly better dynamics observed in the first group.

When comparing the quantitative REG indicators between groups 1 and 2, a significant difference was observed, with values deteriorating as the degree of hearing loss increased. This primarily concerned DKI and DSI in subgroup B,
as well as Ri in all subgroups. This difference was more pronounced in the vertebrobasilar basin.

 A small proportion of military personnel with combat acoustic barotrauma showed a negative treatment response in sensorineural hearing impairment. These patients exhibited significant deviations in REG indicators, which manifested as persistent venous outflow obstruction and a sharp decrease in pulse blood filling, especially in the vertebrobasilar system. There were also significant changes in REG DKI, DSI, and Ri indicators compared to the control group both before and after treatment.

Conclusions

1. Individuals who sustained acoustic barotrauma in combat zones and have hearing impairments show significant changes in cerebral hemodynamic. This is evidenced by a significant (P<0,05) increase in α and an increase in DKI and DSI according to REG data, which respectively characterize increased cerebral vascular tone and venous outflow obstruction in both the carotid and vertebrobasilar systems.
2. The study of cerebral hemodynamic in hearing function disorders due to acoustic barotrauma and the consideration of obtained data during medical and preventive measures contribute to improved treatment outcomes.
3. The deeper the hearing impairments developed after acoustic barotrauma, the more significant the cerebral circulation disorders were recorded in REG data, both in qualitative and quantitative indicators. These changes in cerebral hemodynamics suggest that hemodynamic and sensorineural disorders occur in parallel in these patients. The most informative indicators are DKI, DSI, and Ri.
4. A sharp decrease in pulse blood filling and significant venous outflow obstruction are prognostically unfavorable signs for the effectiveness of SNHL treatment in combat acoustic trauma.

Keywords: auditory analyser, sensorineural hearing loss, acute trauma, cerebral hemodynamic, central nervous system, treatment, diagnostics, prevention, examination.