NEW ETIOLOGICAL FACTORS OF OCCUPATIONAL HEARING LOSS

Annotation. On the example of railway and air transport, a number of new issues of occupational hearing loss are shown, requiring study and subsequent implementation in practical health care, as new etiological factors in the development of hearing loss. This concerns the factor of labor intensity, which has a potentiating, pathogenetic significance, along with noise, in the development of hearing loss due to the formation of chronic stress, leading to additional ischemia of the vascular stria and damage to the neuroepithelium of the inner ear. There is a need, along with the development of a methodology for assessing the factor of labor intensity for SOUT of workplaces, to determine the criteria for its negative action when used for the examination of the connection between the disease of the organ of hearing and the profession. In the «List of occupational diseases» in clause 2.4.2. indicated diseases associated with exposure to infrasound (IZ), among the manifestations of which, called sensorineural hearing loss bilateral. However, IZ, as well as low-frequency noise (LFN), were not previously considered as significant adverse factors in relation to the hearing organ in mass clinical trials, therefore, there are no expert criteria for the relationship between hearing loss and their impact, which could be applied in practice, which requires accumulation of evidence base for the subsequent substantiation of an independent nosological form of a disease of the organ of hearing, associated with mechanoacoustic exposure.

Tuned vibration modes in a miniature hearing organ: Insights from the bushcricket

Bushcrickets (katydids) rely on only 20 to 120 sensory units located in their forelegs to sense sound. Situated in tiny hearing organs less than 1 mm long (40× shorter than the human cochlea), they cover a wide frequency range from 1 kHz up to ultrasounds, in tonotopic order. The underlying mechanisms of this miniaturized frequency-place map are unknown. Sensory dendrites in the hearing organ (crista acustica [CA]) are hypothesized to stretch, thereby driving mechanostransduction and frequency tuning. However, this has not been experimentally confirmed. Using optical coherence tomography (OCT) vibrometry, we measured the relative motion of structures within and adjacent to the CA of the bushcricket Mecopoda elongata. We found different modes of nanovibration in the CA that have not been previously described. The two tympana and the adjacent septum of the foreleg that enclose the CA were recorded simultaneously, revealing an antiphasic lever motion strikingly reminiscent of vertebrate middle ears. Over the entire length of the CA, we were able to separate and compare vibrations of the top (cap cells) and base (dorsal wall) of the sensory tissue. The tuning of these two structures, only 15 to 60 μm (micrometer) apart, differed systematically in sharpness and best frequency, revealing a tuned periodic deformation of the CA. The relative motion of the two structures, a potential drive of transduction, demonstrated sharper tuning than either of them. The micromechanical complexity indicates that the bushcricket ear invokes multiple degrees of freedom to achieve frequency separation with a limited number of sensory cells.

Special acoustic devices of law enforcement agencies: a short history, medical and biological effects on the hearing organ

Relevance. The introduction of special acoustic devices into the security system necessitates a medical and biological assessment of the impact of acoustic signals.Intention – To analyze domestic and foreign literature on the history of acoustic weapons and their medical and biological effects, as well as to study current ideas about sound-induced damage to operators of this equipment and exposed persons.Methodology. In this paper, we analyzed domestic and foreign publications (monographs, articles) about creation and use of special acoustic devices as non-lethal acoustic weapons. Besides, regulatory documents on safe levels of noise exposure were analyzed. PubMed, Russian Science Citation Index, Сonsultant plus database were also searched.Results and Discussion. Non-lethal acoustic weapons were developed and their effects studied mainly by foreign researchers (USA, UK). Sources of special acoustic signals (sound generators, cannons, grenades) are mainly used to disperse crowds of people and control illegal actions against law-enforcement officers. Such weapons are widely used by foreign police and military personnel (USA, Georgia, Ukraine etc.). Only a few publications in Russian describe special acoustic effects on the hearing organ of animals and humans.Conclusion. Safety assessment of acoustic effects of special devices is very important and requires further study in relation to the national legislation.

The role of computed and magnetic resonance imaging in assessment of the local advancement of malignant tumors of the hearing organ

Introduction. Сomputed tomography (СТ) and magnetic resonance imaging (MRI) are the main methods of radiological diagnostics, which makes it possible to objectively assess the local advancement of malignant tumors of the hearing organ and decide on the possibility of surgical intervention.The objective of this scientific research – to determine the main indications for surgical intervention, taking into account the radiological criteria for the lesion of the temporal bone (CT, MRI) in locally advanced outer ear skin cancer. Materials and methods. This research work based on a retrospective and prospective analysis case history for patients with locally advanced external ear skin cancer. These are 45 patients, who received treatment in surgical department of head and neck tumors in N. N. Blokhin National Medical Research Center of Oncology between 1994 and 2020. Patient observation time averaged 30.0 ± 32.3 months (from 0.7 to 117.4 months, median – 12.0 months).Results. The prevalence of the tumor process in cancer of the skin of the external auditory canal in accordance with the staging system for lesions of the temporal bone structures (University of Pittsburgh, 1990), which takes into account CT and MRI signs of damage to the temporal bone and adjacent anatomical structures, is a factor that significantly affects the long-term results of treatment (for disease-free survival: hazard ratio (HR) 4.76, 95 % confidence interval (CI) 1.93–11.73, р = 0.00069; for tumor-specific survival: HR 4.25, 95 % CI 1.74–10.39, р = 0.0015; for overall survival: HR 1.96, 95 % CI 1.07–3.58, р = 0.029).Conclusion. CT and MRI are mandatory methods of radiological diagnosis of patients with skin cancer of the external auditory canal.

Molecular Mechanisms for Frequency Specificity in a Drosophila Hearing Organ

Discrimination for sound frequency is essential for auditory communications in animals. Here, by combining in vivo calcium imaging and behavioral assay, we found that Drosophila larvae can sense a wide range of sound frequency and the behavioral specificity is mediated with the selectivity of the lch5 chordotonal organ neurons to sounds that forms a combinatorial coding of frequency. We also disclosed that Brivido1 (Brv1) and Piezo-like (Pzl), each expresses in a subset of lch5 neurons and mediate hearing sensation to certain frequency ranges. Intriguingly, mouse Piezo2 can rescue pzl-mutant's phenotypes, suggesting a conserved role of the Piezo family proteins in high-frequency hearing.

Vertigo as One of the Symptoms of Lyme Disease

Objectives: The aim of the study was to evaluate the frequency of vertigo symptoms and potential labyrinth damage in patients with diagnosed Lyme disease (LD). LD can affect the vestibulocochlear nerve, leading to hearing loss and vertigo/dizziness. Material and Methods: The study included a group of 38 patients between the ages of 20 and 77, who were hospitalized due to vertigo/dizziness between 2018 and 2019. All of the patients underwent a detailed medical interview and an otolaryngological and neurological examination, including video electronystagmography (VENG), in addition to audiological and diagnostic tests. Additionally, ELISA and Western blot tests were performed to confirm the diagnosis of LD. Results: In 20 patients (53%), the Romberg trial was positive (p < 0.001). The degree of vestibular dysfunction as shown by the VENG test was associated with the rate of hearing loss as confirmed by the Auditory Brainstem Response (ABR) test (p = 0.011), and it mainly concerned high-frequency sounds (p = 0.014). Conclusion: Vertigo can be a symptom of LD. It is often associated with labyrinth and hearing-organ damage, which can imply that the inner ear or nerve VIII is dysfunctional in the course of this disease. Antibiotic therapy is effective in reducing otoneurological symptoms.

Navigating Hereditary Hearing Loss: Pathology of the Inner Ear

Inherited forms of deafness account for a sizable portion of hearing loss among children and adult populations. Many patients with sensorineural deficits have pathological manifestations in the peripheral auditory system, the inner ear. Within the hearing organ, the cochlea, most of the genetic forms of hearing loss involve defects in sensory detection and to some extent, signaling to the brain via the auditory cranial nerve. This review focuses on peripheral forms of hereditary hearing loss and how these impairments can be studied in diverse animal models or patient-derived cells with the ultimate goal of using the knowledge gained to understand the underlying biology and treat hearing loss.

Drug-induced diseases in otolaryngology – causes, clinical signs, treatment

<b>Introduction:</b> In the daily practice of an otolaryngologist, we encounter cases where the symptoms are not the result of disease but result from pharmacotherapy. In the case of symptoms such as hearing loss, tinnitus, or dizziness, polytherapy may be used as the basis for their occurrence, which, due to the lack of rationality in combining drugs, leads to symptoms that the patient and the doctor very often interpret as a new disease syndrome. <br><b>Aim:</b> The aim of the study is to show and to raise awareness of the fact that the symptoms of hearing organ impairment are frequently drug-related and only a modification of the currently used pharmacotherapy is a rational procedure in such cases. <br><b>Material:</b> This paper describes 30 cases who developed side effects of polypharmacy in the form of hearing disorders, dizziness, and tinnitus. The causes of drug-related complications were discussed, as well as effective methods of their prevention.