Sensorineural Hearing Loss (neuritis Of The Auditory Nerve) - What Is It? Treatment Methods

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Sensorineural hearing loss

If a person's hearing aid function is disrupted, then he is not able to normally perceive the sounds of the surrounding world. Sensorineural hearing loss is one of the most common causes of hearing loss (about 75% of all cases of hearing loss). The disease causes damage to the auditory nerve. Hearing is often not restored.

Content:

• Auditory nerve anatomy
• Disease classification
• Degree of sensorineural hearing loss
• Causes of sensorineural hearing loss
• Symptoms of sensorineural hearing loss
• Diagnostics
• Treatment
• Adaptation of patients with sensorineural hearing loss
• Answers to popular questions

Auditory nerve anatomy

The auditory nerve belongs to the 8th pair of cranial nerves.

Features of the development of sensorineural hearing loss and their relationship with the anatomy of the auditory nerve can be traced in such moments as:

• The auditory nerve has a fibrous structure, which is represented by plexuses of nerve fibers. They are unevenly distributed. Fibers are located along the edge of the trunk, which are responsible for the transmission of low frequency sounds. The fibers running down the center transmit high-pitched sounds. Therefore, with sensorineural hearing loss, first of all, a person ceases to distinguish precisely low tones.
• Since the vestibular part of the eighth pair of cranial nerves goes along with the auditory pair, with the development of sensorineural hearing loss, people often suffer from dizziness, nausea, and poor balance.
• In the early stages of the development of pathology, complete deafness is not observed, since the nerve trunk is damaged gradually.
• If the auditory nerve suffers from a lack of oxygen for a long time, it begins to die off. This will lead to permanent deafness.

Sensorineural hearing loss affects the part of the auditory nerve outside the brain. Therefore, a person deafs most often in one ear. Although sometimes the pathological process develops from two sides at once.

Disease classification

Depending on the concentration of the pathological process, the following types of sensorineural hearing loss are distinguished:

• Unilateral lesion (observed most often).
• Bilateral pathology. She, in turn, can be symmetrical and asymmetrical. With a symmetrical lesion, both ears begin to perceive sounds equally poorly. With asymmetric hearing loss, hearing impairment has varying degrees of severity.

Depending on the rate of progression of the disease, the following types are distinguished:

• Sudden hearing loss that develops in 12 hours. Symptoms may persist for 14-21 days.
• Acute hearing loss that develops within 3 days. Its maximum duration is 5 weeks.
• Subacute hearing loss that develops in 7-21 days. The symptoms of the disease persist for 1-3 months.
• Chronic hearing loss that develops in 1-3 weeks and lasts longer than 3 months. Sometimes hearing cannot be restored.

Degree of sensorineural hearing loss

Depending on the frequency of sounds a person can perceive, the degrees of hearing loss differ:

1. From 25 to 39 dB - 1 degree of hearing loss. A person hears a whisper at a distance of 3 meters, and spoken speech at a distance of 6 meters.
2. From 40 to 54 dB - 2 degree of hearing loss. He distinguishes a whisper at a distance of a meter, and spoken speech at a distance of 4 m.
3. From 55 to 69 dB - 3 degree of hearing loss. A person does not distinguish a whisper at all, and spoken speech is at a distance of 1 m.
4. From 70 to 89 dB - 4 degree of hearing loss. A person hears only loud speech if shouted directly into his ear.
5. Above 90 dB - complete deafness. The person does not hear speech at all.

Causes of sensorineural hearing loss

With sensorineural hearing loss, the nerve always lacks nutrition and is pinched by some structures, for example, edematous tissues, a growing tumor, etc.

Such violations can be due to the following reasons:

• Past infections. Some viruses and microbes are capable of damaging the nervous tissue, which leads to irreversible consequences. Therefore, hearing loss can be a consequence of ARVI, herpes, flu, mumps, meningitis, neurosyphilis.
• Vascular pathologies: atherosclerosis, circulatory disorders in the vertebrobasilar basin, hypertension, diabetes mellitus. All these diseases lead to the fact that hearing receptors receive less nutrition and oxygen. They gradually begin to lose their function and the person deafens. In addition, blood microcirculation in the structure of the nerve trunk is disturbed.
• Spine diseases. These include spondylosis, uncovertebral arthrosis, spondylolisthesis, accompanied by the development of vertebral artery syndrome.
• Injuries received: TBI, trauma to the hearing aid due to exposure to loud sounds, barotrauma, which occurs with sudden changes in pressure. Most often, it is the receptors of the auditory nerve that are injured, but with strong blows to the temple area, its trunk can be damaged.
• Poisoning by chemicals. Alcohol, nicotine, arsenic, mercury, benzene, aniline, hydrogen sulfide, fluoride can damage the auditory nerve and lead to the development of hearing loss. In this regard, drugs are dangerous, such as: Streptomycin, Gentamicin, Vancomycin. Amikacin, Cisplatin, Endoxan, Quinidine, and malaria drugs.
• Irradiation of the body. Sensorineural hearing loss rarely develops due to exposure to radiation. This can happen when patients undergo radiation therapy for the treatment of cancerous tumors, as well as when they come into contact with a radiation source in an emergency. Radiation can destroy any tissue in the human body, but nerves rarely suffer.

Sometimes the causes of sensorineural hearing loss cannot be established. In this case, they talk about the idiopathic form of the disease.

Symptoms of sensorineural hearing loss

The first symptom of auditory neuritis is hearing loss. At first, a person begins to hear worse low tones, for example, bass. As the pathology progresses, the audibility of high-frequency sounds worsens.

About 92% of patients complain of tinnitus, which can occur on one or both sides. The timbre of the noise is different, one tone changes into another. At the same time, the ears do not hurt with neuritis of the auditory nerve, unless the violation develops due to the injury.

Other symptoms of sensorineural hearing loss include:

• Dizziness.
• Unsteadiness of gait.
• Deterioration in coordination.
• Nausea, which may end with vomiting.

Diagnostics

Patients with suspected sensorineural hearing loss are hospitalized. A preliminary diagnosis is made based on the patient's complaints.

In a specialized hospital, he is assigned a number of examinations:

• Speech research of hearing. The doctor gets up from the patient at a distance of 6 meters and begins to whisper words in a low tone, and then with high sounds. If a person does not hear what the doctor is saying, then he begins to come closer to him. Normally, the patient should hear a whisper already at a distance of 6 meters.
• Hearing test using a tuning fork. It is an instrument that makes sounds of different frequencies. With the help of a tuning fork, the Rinne test is performed (if the hearing is impaired, the test result will be negative) and the Weber test (a healthy ear will hear sounds better).
• Hearing examination using the audiometry method. A device called an audiometer is used to conduct the test. The patient is offered to listen to sounds of different frequencies, and the device will register the tones that he hears. Based on the data obtained, a curve is built that represents the function of hearing. There are several types of audiometry: tonal suprathreshold audiometry, the method of auditory sensitivity to ultrasound, speech audiometry.

If a tumor growing in the temporal region is suspected, the patient is referred for computed tomography. Another diagnostic method clarifying the reason is ultrasound of the vessels of the vertebrobasilar basin.

Treatment

Therapy largely determines the form of neuritis of the auditory nerve. Therefore, you need to consider these areas separately.

Treatment of acute hearing loss

Patients with this diagnosis are immediately hospitalized. In this case, it is necessary to exclude any factors damaging his hearing, including loud sounds.

Drug therapy is reduced to the appointment of drugs such as:

• Hormonal agents, in particular Dexamethasone. It is administered intravenously. The course of treatment is a week, after which the dose is gradually reduced.
• Drugs that contribute to the normalization of blood microcirculation: Vinpocetine, Pentoxifylline. They are administered intravenously. The course of treatment is 8-10 days.
• Vitamin E, ascorbic acid, Ethylmethylhydroxypyridine succinate. These drugs are used in the treatment of hearing loss, as they have pronounced antioxidant properties.

If the course of treatment is to be extended by some means, then it is no longer administered intravenously, but is prescribed for oral administration.

Treatment of chronic and subacute neuritis

To stop the progression of the disease, it is required to implement the following measures:

• Creation of a protective auditory mode for the patient.
• Treatment of diseases that led to the development of neuritis.
• The use of a treatment regimen, which is prescribed for the acute form of the disease. It is practiced for chronic hearing loss 2 times a year.

If hearing loss worsens a person's quality of life, then it is advisable to use special devices that allow you to bring it back to normal.

Adaptation of patients with sensorineural hearing loss

Hearing loss is a serious problem. However, there are effective methods that allow such people to adapt in society.

These include:

• Hearing aids with special devices. Each person can receive such treatment absolutely free of charge if he is diagnosed with 2 or 3 degrees of hearing loss. Hearing aids can be in the ear or in the ear. With their help, a person begins to hear normally.
• Middle ear implant that can help people with grade 3 hearing loss. It is implanted if there is no possibility of using an external hearing aid.
• Cochlear implant. Such a drug is implanted in patients with grade 4 hearing loss, provided that other methods of treatment have been ineffective. In addition, a person of his own free will and for his own money can go to a private clinic, where he will have an operation. The implant acts like a person's own ear, transmitting signals to the trunk of the auditory nerve and then to the brain.

The sooner treatment is started, the more effective it is. Therefore, when the first signs of hearing impairment appear, you should seek medical help.

Answers to popular questions

• Is it possible to cope with acoustic neuritis using traditional medicine? No, they are not effective. However, some physiotherapeutic techniques can accelerate recovery, for example, endaural electrophoresis with Dibazol, Nicotinic acid and other drugs, massage, and treatment with currents.
• Is hearing restored after the therapy? In 93% of patients with acute hearing loss, hearing is restored within the first 30 days from the start of treatment. If the disease has a chronic course, then the prognosis worsens.
• How can you replace your hearing aid? You can resort to the method of vibro-sound stimulation, to pedagogical activation of hearing, to electroreflexotherapy. They allow you to restore the receptors of the damaged nerve, but their effectiveness is lower than when wearing a hearing aid. In addition, these techniques are not widely used in Russia.
• Is the disease inherited? Hearing loss can be transmitted with syphilis, with congenital otosclerosis and with a progressive labyrinth.
• How to improve vestibular function with neuritis? It is possible to use nootropic drugs, as well as anticholinesterase drugs, for example, Neuromidine.

Author of the article: Sokov Andrey Vladimirovich | Neurologist

Education: In 2005 completed an internship at the IM Sechenov First Moscow State Medical University and received a diploma in Neurology. In 2009, completed postgraduate studies in the specialty "Nervous diseases".