Treatment of sensorineural hearing loss

Indications for hospitalization

An indication for emergency hospitalization is acute sensorineural hearing loss, regardless of the etiological factor, as well as, in some cases, progressive NST.

Treatment goals for sensorineural hearing loss

In acute sensorineural hearing loss, the most important goal is to restore hearing function. This goal can only be achieved if treatment is started as soon as possible. In chronic hearing loss, the goal of the treatment is to stabilize the reduced hearing function. In addition, social rehabilitation of people comes first in chronic sensorineural hearing loss. An individual approach to the treatment of sensorineural hearing loss is very important (the mental state, age, and the presence of concomitant diseases, etc. are taken into account).

Non-drug treatment of sensorineural hearing loss

In sensorineural hearing loss, the effect of stimulating therapy in the form of acupuncture, electropuncture, electrical stimulation of the inner ear structures, endaural phono-electrophoresis of drugs that can penetrate the hematolabyrinthine barrier, laser puncture (10 sessions immediately after completion of infusion therapy), and hyperbaric oxygenation has been described.

Non-drug treatment should be aimed at rehabilitation of the auditory function. Rehabilitation of the auditory function in sensorineural hearing loss is aimed at restoring social activity and quality of life of the patient and consists of hearing aids and cochlear implantation.

With a hearing loss of more than 40 dB, speech communication is usually difficult and the person needs hearing correction. In other words, with a hearing loss at vowel speech frequencies (500-4000 Hz) by 40 dB or more, a hearing aid is indicated. In foreign practice, hearing aids are recommended for the patient if the hearing loss on both sides is 30 dB or more. Readiness to wear a hearing aid is largely determined by the patient's social activity and increases with the degree of hearing loss. In children, especially in the first years of life, the indications for hearing aids have expanded significantly. It has been proven that hearing loss of more than 25 dB in the range of 1000-4000 Hz leads to a violation of the child's speech formation,

When performing hearing aid fitting, it is necessary to take into account the fact that sensorineural hearing loss is a complex disorder of social adaptation. In addition to the fact that there is a deterioration in hearing thresholds in the frequency range important for understanding speech, there is a violation of our final hearing. Despite the variety of causes of sensorineural hearing loss, in most cases the outer hair cells are affected. They are completely or partially destroyed in the cochlea. Without normally functioning outer hair cells, the inner hair cells begin to react only to a sound that exceeds the normal hearing threshold by 40-60 dB. If the patient has a descending audiometric curve typical of sensorineural hearing loss, the zone of perception of high-frequency components of speech, important for understanding consonants, is lost first. Vowels suffer less. The main acoustic energy of speech is located in the vowel zone, that is, in the low-frequency range. This explains the fact that with the loss of high-frequency hearing, the patient does not perceive speech as quieter. Due to the limited perception of consonants, it becomes "only" unclear for him, more difficult to understand. Considering that there are more consonants in the Russian language than vowels, consonants are much more important for understanding the meaning of speech than vowels. The feeling of a decrease in speech volume appears only with deterioration of hearing and in the low-frequency zone. In addition to lowering the thresholds of hearing, that is, the boundary between what is heard and what is not heard, the loss of outer hair cells causes hearing impairment in the suprathreshold hearing zone, the phenomenon of accelerated increase in volume, narrowing of the dynamic range of hearing appears. Considering that with neurosensory hearing loss, the perception of high-frequency sounds is significantly lost while low-frequency sounds are preserved, the greatest amplification is required in the high-frequency region, this requires the presence of several channels of amplification adjustment in the hearing aid to create adequate sound. The proximity of the microphone and the telephone in the hearing aid due to their miniature size can lead to acoustic feedback, which occurs when the sound amplified by the device again reaches the microphone. One of the problems that arises when wearing hearing aids is the "occlusion" effect. It occurs when the body of the in-the-ear device or the earmold of the behind-the-ear hearing aid blocks the external auditory canal, causing excessive amplification of low frequencies, which is uncomfortable for the patient.

Taking all this into account, in order to carry out comfortable hearing aid fitting, the hearing aid must:

• selectively compensate for the disturbance in the perception of volume and frequency of sounds;
• ensure high intelligibility and natural speech perception (in silence, in a noisy environment, during group conversation):
• automatically maintain a comfortable volume level:
• adapt to different acoustic situations:
• ensure the absence of acoustic feedback ("whistling"). Modern multi-channel digital devices with compression in a wide frequency range meet such requirements to the greatest extent. In addition, digital hearing aids for open prosthetics have recently appeared, which, in addition, ensure the absence of the "occlusion" effect.

According to the method of signal processing in the amplifier, there are analog and digital hearing aids. In analog hearing aids, the sound signal is processed using analog electronic amplifiers, they transform the stimulus with full preservation of the signal shape. In a digital hearing aid, incoming signals are converted into a binary code and processed with high speed in the processor.

Hearing aid fitting can be monoaural, when one ear, usually the better hearing one, is fitted, and binaural, when both ears are fitted with two hearing aids. Binaural fitting has the following main advantages:

• binaural hearing has a reduced volume (by 4-7 dB), which leads to an expansion of the useful dynamic range;
• the localization of the sound source approaches the physiological norm, which makes it much easier to focus your attention on a specific interlocutor.

Depending on where they are worn, there are the following types of hearing aids:

• Behind-the-ear hearing aids are placed behind the ear and must be supplemented with a custom-made earmold. Modern behind-the-ear hearing aids are distinguished by their great possibilities in prosthetics, high reliability and miniature size. Recently, miniature behind-the-ear hearing aids for open prosthetics have appeared, which allow for comfortable correction of high-frequency sensorineural hearing loss for the patient.
• In-the-ear hearing aids are placed in the ear canal and are individually manufactured according to the shape of the patient's ear canal; the miniature size of the device also depends on the degree of hearing loss. With the same capabilities as behind-the-ear devices, they are less noticeable, provide greater wearing comfort and a more natural sound. However, in-the-ear devices also have disadvantages: they do not allow for prosthetics of significant hearing losses, and are more expensive to operate and maintain.
• Pocket hearing aids are becoming less and less popular and can be recommended for patients with limited fine motor skills. A pocket hearing aid can compensate for significant hearing loss, as the significant distance between the phone and microphone helps avoid acoustic feedback.

Today, the technical capabilities of modern hearing aids allow in most cases to correct even complex forms of sensorineural hearing loss. The effectiveness of hearing aids is determined by how well the individual characteristics of the patient's hearing correspond to the technical capabilities of the hearing aid and the settings. Properly selected hearing aids can improve communication for 90% of people with hearing impairments.

Currently, there is a real opportunity to provide effective assistance to patients with complete loss of hearing function in cases where deafness is caused by the destruction of the spiral organ with intact function of the auditory nerve. Hearing rehabilitation using the method of cochlear implantation of electrodes into the cochlea in order to stimulate the fibers of the auditory nerve is becoming increasingly widespread. In addition, the system of trunk cochlear implantation in case of bilateral damage to the auditory nerve (for example, in tumor diseases of the auditory nerve) is currently actively developing. One of the important conditions for the successful implementation of cochlear implantation is a strict selection of candidates for this operation. For this purpose, a comprehensive study of the state of the patient's hearing function is carried out, using subjective and objective audiometry data, a promontory test. Cochlear implantation issues are considered in more detail in the corresponding section.

Patients with sensorineural hearing loss combined with vestibular system dysfunction require vestibular function rehabilitation using an adequate system of vestibular exercises.

Drug treatment of sensorineural hearing loss

It is important to remember that the outcome of acute sensorineural hearing loss directly depends on how quickly treatment is started. The later the treatment is started, the less hope there is for hearing recovery.

The approach to choosing treatment tactics should be based on the analysis of clinical, laboratory and instrumental data obtained before the start of treatment. during it, and after the completion of the course of treatment. The treatment plan is individual for each patient, determined taking into account the etiology, pathogenesis and duration of the disease, the presence of concomitant pathology, intoxication and allergies in the patient. However, there are general rules that must always be strictly observed:

• conducting a multifaceted examination of the patient in the shortest possible time;
• treatment of a patient with sensorineural hearing loss in a specialized hospital;
• immediate initiation of treatment after diagnosis of sensorineural hearing loss;
• adherence to a protective regimen and a gentle diet.

Taking into account the characteristics of the disease, means are used aimed at restoring blood circulation, improving blood rheological parameters, normalizing blood pressure, improving nerve impulse conduction, and normalizing microcirculation. Detoxifying drugs, drugs with angio- and neuroprotective properties are used. According to randomized studies, glucocorticoids are effective in sudden hearing loss (up to 15 hours). They are prescribed in a shortened course for 6-8 days, starting with a loading dose, then with a gradual reduction. In particular, there is a scheme for using prednisolone at a dosage of 30 mg / day with a sequential reduction to 5 mg over 8 days.

Numerous scientific studies and clinical experience prove the advisability of infusion therapy with vasoactive and detoxifying agents from the first day of hospitalization of a patient suffering from acute sensorineural hearing loss. Such drugs as vinpocetine, pentoxifylline, cerebrolysin, piracetam, ethylmethylhydroxypyridine succinate (mexidol) are used parenterally (intravenously by drip) for the first 14 days. Subsequently, they switch to intramuscular and oral use of drugs. In addition, venotonics and drugs stimulating neuroplasticity are used in complex treatment, in particular, ginkgo biloba leaf extract is used at a dose of 40 mg three times a day. The drug, in addition, helps regulate ion exchange in damaged cells, increase central blood flow and improve perfusion in the ischemic area.

A positive effect on the state of the auditory function is described when administering drugs using the phonoelectrophoresis method (complex use of ultrasound with electrophoresis). In this case, drugs that improve microcirculation and tissue metabolism can be used.

For the treatment of sensorineural hearing loss of various etiologies, accompanied by dizziness, histamine-like drugs with a specific effect on the microcirculation of the inner ear are successfully used, in particular, betahistine is used in a dosage of 16-24 mg three times a day. The drug should be taken during or after meals to prevent possible adverse effects on the gastric mucosa.

It should be emphasized that even adequately selected and timely, fully administered therapy for a patient with sensorineural hearing loss does not exclude the possibility of a relapse of the disease under the influence of a stressful situation, exacerbation of cardiovascular pathology (for example, hypertensive crisis), acute respiratory viral infection or acoustic trauma.

In chronic progressive hearing loss, courses of drug therapy should be administered to stabilize the hearing function. The drug complex should be aimed at improving neuronal plasticity and microcirculation in the inner ear.

Surgical treatment of sensorineural hearing loss

Recently, a number of randomized studies have appeared demonstrating hearing improvement with transtympanic administration of glucocorticosteroids (dexamethasone) into the tympanic cavity of patients with sensorineural hearing loss in the absence of an effect from conservative therapy. Surgical treatment of sensorineural hearing loss is required for neoplasms in the posterior cranial fossa, Meniere's disease, and during cochlear implantation. In addition, surgical treatment can be used as an exception for painful tinnitus (performed by resection of the tympanic plexus, removal of the stellate ganglion, and superior cervical sympathetic ganglion). Destructive operations on the cochlea and vestibulocochlear nerve are rarely performed and only in cases of sensorineural hearing loss of the fourth degree or complete deafness.

Further management

Drug treatment of sensorineural hearing loss is carried out with the aim of stabilizing hearing.

For each specific patient, the period of disability is determined by the need for conservative treatment, as well as the possibility of conducting a comprehensive examination on an outpatient basis.

Information for the patient

It is important to remember that acquired sensorineural hearing loss is often a consequence of non-compliance with occupational safety rules. A reduction in cases is possible during a visit to a disco, during underwater diving and hunting. When hearing loss occurs, it is especially important to contact a specialized institution early for adequate diagnosis and treatment. Of great importance is adherence to a protective regimen and a gentle diet, cessation of smoking and drinking alcoholic beverages.