Sensorineural hearing loss (auditory neuritisnerve): symptoms, treatment, diagnosis, prognosis

Update: December 2018

Hearing – one of the senses, which provides normal
quality of human life. With his defeat a man can not
to fully perceive the sounds of the world: speech, music,
industrial noise and so on. In 73% of cases of hearing loss
due to neurosensory hearing loss. In this condition
one of the auditory nerve sites is damaged, often
irreversible.

“Confusion” with the designation
diagnosis. On the Internet, medical reports and old monographs
you can meet the following terms: cochlear neuritis,
neuritis / neuropathy of the auditory nerve, perceptual hearing loss. All this
outdated concepts that lost their relevance in 1992
with the release of the 10th edition of the International Classification
патологий (МTOБ-10). These recommendations suggest a synthesis
concept – “sensorineural hearing loss”.

Anatomical features of the auditory nerve

The auditory nerve is the eighth cranial pair. His way is not
has clinical significance in this disease, since the level
поражения не влияет на симптомы неврита слухового the nerve. They
occur when any part of the receptor is damaged, which
located in the hair cells of the inner ear, up to the brain stem
(more precisely – its bridge part).

Important features that affect symptoms
sensorineural hearing loss is as follows:

  • The fibers of the trunk of the auditory nerve are distributed non-uniformly. On
    the periphery (on the edge of the trunk) is the path of the low
    sounds. Closer to the center are fibers that conduct higher
    tones. Therefore, in the first place, with this pathology suffers
    perception of low sounds;
  • Due to the fact that the vestibular part of the eighth pair goes together with
    hearing, often in patients with: imbalance,
    dizziness, nausea and other signs of damage to these
    fibers;
  • Since conducting sounds does not suffer with neurosensory
    hearing loss, and the trunk of the nerve is gradually affected, complete deafness
    (anakuziya) rarely occurs in the initial period of the disease;
  • Perhaps the development of atrophy (malnutrition) of the nerve trunk,
    due to its prolonged pressure (swelling, neoplasm and so
    Further). In this case, the hearing loss becomes
    irreversible.

Considering that when sensorineural hearing loss is affected
only the trunk of a nerve (before it enters the brain), lesions more often
возникают на одной partiesе (в одном ухе). However, development is possible
двуpartiesнего процесса.

TOлассификация

The national recommendations of otolaryngologists suggest
classify neurosensory hearing loss according to three criteria:
the localization of the lesion, the pace of development and the degree of “deafness”. Also
the disease is divided into acquired and innate, but the latter
extremely rare. Onпример, при врожденном сифилисе,
otosclerosis, progressive hearing loss with lesions
the maze.

Depending on the location of the pathological process, there are:

  • Одноpartiesнее (право- и левоpartiesнее);
  • Двуpartiesнее:
    • Symmetric – violation of sound perception is the same with two
      parties;
    • Asymmetric – the function of hearing is changed in different ways to the right and
      left.

Чаще всего встречается одноpartiesняя тугоухость, так как для
развития поражения с двух parties требуется какой-то общий
pathological factor.

There are the following options for the development of “deafness”:

Type of sensorineural hearing loss Term development of symptoms How many symptoms persist?
Sudden 12 hours Up to several weeks (2-3)
Sharp Within 3 days No more than 4-5 weeks
Subacute Some weeks (1-3) From 4 weeks to 3 months
Chronic More than 3 months (irreversible changes are possible)

The type of deafness depends on the degree of damage to the auditory
the nerve. If it develops atrophy, as a rule, the disease
acquires a chronic course.

Degree of sensorineural hearing loss

The degree of sensorineural hearing loss is determined by the threshold
audibility of the patient (how loud the sound a person does not hear).
There are five options:

Degree of hearing loss Порог слышимости в децибелах (dB) An example of the noise corresponding to the threshold
1st 25-39
  • Whisper at a distance of 3 meters;
  • The volume of speaking at a distance of 6 meters.
2nd 40-54
  • Whisper at a distance of one meter;
  • The volume of conversational speech at a distance of 4 meters.
3rd 55-69
  • Whisper is not audible to the patient.
  • The volume of speaking at a distance of one meter.
4th 70-89 The patient can distinguish loud speech delivered close to
ear.
Anakuziya (total deafness) more than 90 The patient does not hear sounds of any volume

This is the most common classification approved by WHO.
The degree of sensorineural hearing loss must be
defined according to her.

The reasons

In case of sensorineural hearing loss, the following
negative factors:

  • impaired microcirculation (nutrition) of the auditory receptors, due to
    which reduces their sound perception function;
  • compression of nerve fibers by surrounding tissues (edema, tumor,
    as a consequence of injury and so on), which leads to a violation
    transmission pulse from receptors in the brain.

These conditions may develop for the following reasons:

Group of factors How does the auditory nerve affect? Examples
Consequences of infections (mostly viral)

Certain types of viruses and microorganisms have a tropism.
(prone to damage) to the nervous tissue, especially the cranial
nerves.

By damaging their cells, infectious agents often cause
irreversible changes in hearing function.

  • ARVI;
  • Herpes simplex virus;
  • Flu;
  • Parotitis;
  • Meningitis (of any kind);
  • Neurosyphilis.
Vascular diseases (more often – chronic)

First of all, there is a violation of the power of the receptors of hearing
because of which their function gradually decreases, and then
irreversible.

There is also a violation of microcirculation in the trunk itself.
the nerve.

  • Atherosclerosis;
  • Disturbance of circulation in the vertebrobasilar basin (chronic
    or acute);
  • Hypertension (II-III stages);
  • Diabetes.
Diseases of the spinal column
  • Spondylosis;
  • Unco-vertebral arthrosis of the first cervical vertebrae (up to
    4th);
  • Spondylolisthesis, in which “vertebral syndrome develops
    arteries ”(this vessel is compressed).
Traumatic agents Damage to the auditory nerve receptors usually occurs.
with traumatic agents. However, with a significant impact
the temporal region (more precisely in the region of the mastoid process) may
травмироваться сам ствол the nerve.
  • Mechanical craniocerebral injury (abbreviated – TBI);
  • Acoustic injury. Chronic exposure to loudness of sounds
    more than 70 dB. Acute acutrauma – sound more than 120-130 dB;
  • Barotrauma (due to pronounced pressure drop).
Chemical agents Tropism to the nervous tissue often leads to the defeat of the eighth pair and
neurosensory hearing loss.
  • Substances of industrial origin (benzene, aniline, arsenic,
    mercury, hydrogen sulfide, fluorine, etc.);
  • Household chemical agents (alcohol, nicotine in high
    doses);
  • Some pharmacological drugs: aminoglycoside
    antibiotics (streptomycin, vancomycin, gentomicin, amikacin),
    cytostatics (cisplatin, endoxan), antimalarial and some
    antiarrhythmics (quinidine)
Radiation agents (extremely rare) Radioactive radiation can damage any tissue of the body,
however, the nerves suffer much less than others. Therefore this
factor is extremely rare.
  • Radiotherapy for malignant tumors;
  • Single contact with a significant radiation source and
    prolonged exposure to a small radioactive object
    strength
Idiopathic process Damage to the auditory nerve due to vascular
violations. However, the mechanism is unclear.
No known reason

The clinical picture does not depend on the cause of development
neurosensory hearing loss (exception – cerebrospinal
meningitis), so it is taken into account only in the diagnosis of the disease.

Symptoms

The most significant patient complaint is hearing loss.
Sensorineural hearing loss can occur only in one ear or
immediately from two sides (see why one ear does not hear well). As seen
from the classification, it can be of varying degrees: from
inability to hear a whisper speech before anacusia. Firstly,
the perception of low sounds (bass speech, low tones in
music and so on). In the future, bad hearing is added.
high frequency sound.

  • Tinnitus – at 92%, reduction in sound perception
    accompanied by constant obsessive noise from one / two sides (see
    noise in the head). It can have a different timbre, often mixed noise
    key (high and low sounds go into each other).
  • Ear pain is not characteristic of sensorineural hearing loss (only
    at the time of injury).

Since together with the auditory fibers are vestibular,
patients often experience the following symptoms:

  • Constant dizziness, which increases with
    movement;
  • Instability gait;
  • Lack of coordination (inability to perform accurate
    movements);
  • Persistent nausea, intermittent vomiting.

Perhaps the addition of other signs of the disease, depending
from the cause of hearing loss.

Diagnostics

Violation of sound perception is one of the socially significant.
problems. Therefore, in case of suspected neurosensory hearing loss
the patient must be hospitalized in the ENT department of the hospital,
if there is such an opportunity. In order to suggest this
enough disease:

  • Patient complaints about the above symptoms;
  • A history of possible causes that could lead to
    diseases.

After hospitalization additional diagnostics are carried out, for
confirmation and clarification of the diagnosis.

Speech Test

Elementary test that does not require any equipment.
Firstly, исследуют слышимость шепотной речи. Held by
the following algorithm:

  • The distance between the doctor and the patient should be 6 meters.
    The patient must turn his ear to the doctor, at the same time closing
    another auditory opening;
  • The doctor says the words mostly with low sounds (burrow,
    sea, window and so on), then with high ones (thicket, hare, cabbage soup);
  • If the patient cannot hear low / high sounds –
    the distance is reduced by 1 meter.

Norm: low whisper sounds should be clearly distinguished.
sick from a distance of 6 meters, high – 20.

If necessary, a similar study is conducted with
using colloquial speech.

Study tuning fork

The first and simplest method of instrumental diagnostics
hearing function. Using low and high frequency
tuning forks determine the type of violation (the inability to
sounds or neurosensory hearing loss).

What is a tuning fork? This is a special tool that publishes
sound of a certain frequency. It consists of a leg (for which it holds
doctor) and jaws (when they hit the sound occurs). In medicine
применяют два вида камертонов: С128(низкочастотный) и
С2048(высокочастотный).

For the diagnosis of sensorineural hearing loss matter
following tests:

Test name How to spend? Normal result Result in neurosensory hearing loss
Rinne
  • Tuning fork hit the branches and put a foot on the mastoid
    process (area behind the auricle). This is the method of determining
    �”Bone conduction”;
  • After the patient stops hearing him – bring
    directly to the ear canal. This is the method of determining
    �”Air conduction”;
  • The test is positive if the patient hears the sound of the tuning fork again.
    near the ear canal (at least a few seconds). Negative –
    if not hear.
Positive Positive (отрицательный при нарушении проведения
sound)
Weber A tuning fork hit the branches and put in the middle of the head (between
ears).
The patient hears a sound in the middle of the head or equally from two
parties
The sound is stronger in the healthy ear.

Identification in patients of signs of sensorineural hearing loss
allows you to confidently assume its presence. However, for
final diagnosis is necessary
audiometry.

Audiometry

This survey is conducted using a special generator.
sounds of a certain frequency – audiometer. There are several
methods of its use. Traditionally for diagnosis
sensorineural hearing loss is applied threshold audiometry.

This is the method of determining порога слышимости в децибелах (одна из
functions of the audiometer), bone and air conduction. After
the results of the device automatically builds a curve
patient, which reflects the function of his hearing. OK she
horizontal. With a neurosensory hearing loss, the line becomes
oblique, air and bone conduction decreases
identically.

To clarify the sound perception function, there are additional
modern audiometry techniques:

Audiometry method What shows? Norm Result in neurosensory hearing loss
Tonal overthreshold audiometry

Onличие поражений рецепторов слухового the nerve.

The differential threshold of sound intensity is determined
the patient (DPIZ).

Differential sound intensity threshold 0.8-1 dB Differential sound intensity threshold less than 0.6-0.7
dB
Auditory sensitivity to ultrasound

The presence of damage to the auditory nerve trunk or brain stem.

Determined by a person’s sensitivity to ultrasound.

A person perceives ultrasound up to 20 kHz Raises the threshold of sensitivity
Speech audiometry

The ability to communicate the patient in society.

Its ability to understand someone else’s speech is determined.

100% speech comprehension. Any reduction in word recognition ability.

The above techniques are used to clarify the state
patient, they are rarely used in clinical practice.

National guidelines also show
tomography (CT) of the temporal region to eliminate the presence of tumors
and ultrasound of the vessels of the vertebrobasilar basin.

Treatment

Medical tactics differ significantly, depending on the form
sensorineural hearing loss, therefore their treatment is considered
separately. One thing remains unchanged – the early treatment of the patient (with
appearance of the first symptoms) significantly improves the prognosis
pathology.

Treatment внезапной /острой формы

If acute neuritis of the auditory nerve is suspected,
Immediately place the patient in the ENT / neurology department
hospital The patient is shown a “protective” hearing mode,
which excludes any loud sounds (loud speech, music, noises
environment and so on).

The following standards are recommended by medical standards (MES)
medications:

  • Hormones-glucorticosteroids intravenously (Dexamethasone). how
    usually assigned to 7-8 days, with a gradual decrease
    doses;
  • Drugs to improve blood circulation, including in the nervous
    tissue (pentoxifylline / vinpocetine). Recommended scheme
    destination: intravenous within 8-10 days;
  • Antioxidants (vitamins C, E; Succinate
    ethylmethylhydroxypyridine).

If after hospital treatment there is still a need for
preparations, they are prescribed for further use, but in the form of
preformed forms.

Treatment подострой /хронической формы

With these forms, the pathology becomes stable or
slowly progressive course. In order to slow the decline
sound perception function shown to the patient following
activity:

  1. �”Protective” hearing mode;
  2. Treatment других сопутствующих болезней, которые могли привести к
    the development of sensorineural hearing loss;
  3. A supportive treatment that is similar to the treatment
    neurosensory hearing loss acute form. On average, 2 times a
    year.

In addition, due consideration should be given to adaptation
patient in society with the help of specialized medical
instrumentation.

Methods for the rehabilitation of patients

Currently, effective techniques have been developed for
adaptation of patients with chronic sensorineural hearing loss. TO
Unfortunately, most of them involve surgical
intervention, and only one way is accomplished
federal funding (free for the patient).

Technique Installation conditions how это работает?
Hearing aids with devices for air conducting
(preferential method)
2-3 degrees of neurosensory hearing loss The term “hearing aid” is common among the population.
which designate these devices. In size they are divided into:

  • BTE;
  • Intra ear.

They are fixed in the ear. Perceiving environmental sounds
environments, devices strengthen them and direct along the ear canal.

Installing a middle ear implant
  • 3rd degree of hearing loss;
  • The inability to use an external device.
Its principle is similar. The difference is that the device
set surgically in the middle ear of the patient.
Installing a cochlear implant
  • Двуpartiesняя нейросенсорная тугоухость 4-й степени;
  • The ineffectiveness of “hearing aids”;
  • The desire of the patient;
  • The absence of contraindications for the patient to the operation.
This is a device that is operatively installed in
inner ear. The implant converts the sound coming from the external
medium, into electrical impulses that are transmitted further along
nerve trunk to the brain.

Sensorineural hearing loss is a socially significant disease that
reduces the quality of life of patients. That is why if you suspect
this diagnosis, the patient should be hospitalized immediately and
start treatment to increase chances to return
жизнеспособность the nerve. However, in the absence of such a possibility,
developed rehabilitation methods that will allow a person
feel comfortable in society.

Frequently asked questions from patients

Are there effective methods of folk treatment of neurosensory
hearing loss?

No, but there are physiotherapy methods that
proven to be effective: endoural electrophoresis of certain
drugs (Galantamina, Dibazol, Nicotinic to-you, and so on),
massage of parotid and collar areas, impulse currents.

Will my hearing recover after treatment?

Это зависит от формы neurosensory hearing loss. In patients with
sudden / acute forms of recovery occurs during the 1st
month in 93% of cases. With subacute and chronic hearing loss
the prognosis is more negative.

Is there an alternative to hearing aids?

Yes, however, with less efficiency. A group of scientists in 2011
conducted a study on the following methods: low frequency
vibrosonic stimulation, electroreflexotherapy and pedagogical
activation of the hearing system. They are aimed at restoring
auditory nerve receptors, however, are not common in Russia.

Is neurosensory inherited by children
hearing loss?

Significantly known transmission of hearing loss in syphilis,
progressive maze and congenital otosclerosis. With others
pathologies role of heredity is not proven.

how лечить нарушение координации и головокружение при
Do not lie?

They are treated in a similar way. Possible inclusion in the course
nootropes (Cerebrolysin) and anticholinesterase substances
(Neuromidine). Supplement therapy and choose the final tactic.
can only a treating neurologist.

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