Cochlear neuritis — the damage of an acoustical nerve leading to a hearing impairment and emergence of constant noise in an ear. Cochlear neuritis can be near is caused the factors causing defeat of various departments of the acoustic analyzer from the sound perceiving cells of an inner ear to the acoustical center of a cerebral cortex. Clinically it is shown by decrease in hearing and noise in an ear which in certain cases are followed by vestibular violations. Diagnosis of cochlear neuritis includes an audiometriya and other methods of a research of hearing, an otoskopiya, a research of vestibular function, biochemical analyses, a X-ray analysis, KT and MPT. Treatment is carried out by vascular medicines, neuroprotectors, dezintoksikatsionny solutions, physiotherapeutic means. At considerable decrease in hearing hearing aid is shown. Application of surgical methods of treatment is in some cases possible.
According to world statistics about 6% of all people inhabiting the globe in a varying degree have a hearing disorder. The most part of cases of decrease or loss of hearing are the share of cochlear neuritis. A disease sensonevralny or neurotouch relative deafness, neuritis of an acoustical nerve also carries names. More often it has unilateral character, bilateral damage of an acoustical nerve is less often noted. Except decrease in hearing of various expressiveness in 90% of cases cochlear neuritis is followed by noise in an ear.
Classification of cochlear neuritis
By the cause cochlear neuritis in otolaryngology is classified on congenital and acquired. The last is also subdivided on post-traumatic, ischemic, post-infectious, toxic, beam, allergic, professional. On emergence time cochlear neuritis is divided into prelingvalny — arising at children before development of the speech and postlingvalny — coming at patients with the developed speech.
By the level of defeat of the acoustic analyzer cochlear neuritis is classified on peripheral, connected generally with violations of sound perception in an inner ear, and central — caused by pathological processes in acoustical structures of a brain.
Depending on prescription of a disease allocate 3 forms of the acquired cochlear neuritis: sharp (no more than 1 month), subsharp (from 1 to 3 months) and chronic (more than 3 months). On character of a current distinguish the reversible, stable and progressing cochlear neuritis.
According to a threshold audiometriya allocate 4 degrees of relative deafness at cochlear neuritis: easy (the I degree) with a threshold of the perceived sounds in 26-40 dB, moderated (the II degree) with a threshold 41-55 dB, moderately heavy (the III degree) — 56-70 dB and heavy (the IV degree) — 71-90 dB, and also full deafness.
Reasons of congenital cochlear neuritis
Congenital cochlear neuritis can be caused by pathology at the genetic level or the violations which happened at the time of delivery. Hereditary cochlear neuritis is more often observed in combination with other genetic disorders. With an autosomno-prepotent way of transfer which clinic includes cochlear neuritis treat hereditary diseases: syndrome of Vaardenburga, Stikler's syndrome, brankhiootorenalny syndrome. Autosomno-retsessivnymi diseases of which cochlear neuritis is characteristic are: Usher's syndrome, Pendred's syndrome, Refsum's disease, biotinidazny insufficiency. Cochlear neuritis can be inherited and as the pathology linked to the H-chromosome. For example, at a syndrome of Alport who is shown the decrease in hearing progressing glomerulonefrity and various violations of sight.
Developing of cochlear neuritis in labor is connected with a patrimonial trauma or a hypoxia of a fruit which can develop at the dicoordinated patrimonial activity, premature birth, the long course of childbirth because of weakness of patrimonial activity, a narrow basin of the woman in labor or pelvic prelying of a fruit.
The reasons of the acquired cochlear neuritis
The acquired cochlear neuritis in 30% of cases is caused by infectious diseases. First of all it is a rubella, epidemic parotitis, flu, measles, a SARS, a herpetic infection, then there are scarlet fever, epidemic meningitis, syphilis, sypny and a typhoid.
About 10-15% of cochlear neuritis are caused by toxic damage of an acoustical nerve. Treat the ototoksichesky substances applied in medicine: antibiotics (Neomycinum, , gentamycin, streptomycin, etc.), cytostatics (, ), salycylates, quinine medicines, diuretics, medicines for treatment of arrhythmia. Intoxications caused by arsenic, salts of heavy metals, gasoline, phosphorus and so forth can become the reason of cochlear neuritis. Toxic cochlear neuritis can be connected with professional activity. The cochlear neuritis developing at chronic impact of noise and vibration has also professional character.
Developing of cochlear neuritis can be caused by violation of its blood supply as a result of atherosclerosis, thrombosis, a hypertension, vascular disorders in the vertebro-bazilyarny pool at chronic ischemia of a brain, consequences of the had hemorrhagic or ischemic stroke.
Post-traumatic cochlear neuritis is connected with a craniocereberal injury, injury of an acoustical nerve during surgeries, violation of operation of the sound perceiving device as a result of a barotrauma and the aero otitis which developed after it. In certain cases emergence of cochlear neuritis was observed after the acoustic trauma got at influence of a strong sound (a whistle, a shot, etc.).
Refer allergic reactions to the other factors provoking developing of cochlear neuritis, nevriny an acoustical nerve, , diabetes, serpovidnokletochny anemia, influence of radiation, Pedzhet's disease, brain tumors. Development of cochlear neuritis can be a consequence of the processes of aging happening in an acoustical nerve at people 60 years are more senior.
Symptoms of cochlear neuritis
The clinic of cochlear neuritis in most cases consists of two main symptoms: decrease in hearing and constant noise in an ear. Also violation of a lateralization of a sound is characteristic. At unilateral defeat the shift of the perceived sound closer to a healthy ear is noted, at bilateral — to that ear which hears better.
Suddenly arising cochlear neuritis is characterized by the hearing disorder developing within several hours usually having unilateral character. In most cases the patient finds the appeared problems with hearing after awakening from a night dream. In other cases the sharp form of cochlear neuritis can develop within 2-3 days. Sharp cochlear neuritis can pass into a subsharp and chronic form. During chronic cochlear neuritis allocate 2 stages: stable and progressing. The last is shown by aggravation of a hearing disorder eventually and can lead to deafness.
In certain cases cochlear neuritis relative deafness is followed by various vestibular symptoms: pristupoobrazny dizziness which can proceed with nausea and vomiting; balance violation; the instability amplifying at sharp turn of the head; uncertainty when walking. Bilateral cochlear neuritis often leads to decrease in emotionality and expressiveness of the speech of patients, is the reason of their isolation and a social dezadaptirovannost.
Diagnosis of cochlear neuritis
Not only installation of the diagnosis of cochlear neuritis, but also definition of the reason and level of defeat of the acoustic analyzer, assessment of degree and dynamics of decrease in hearing is important. During diagnostic testings the otolaryngologist needs to exclude existence of other diseases which are followed by a hearing impairment (Menyer's disease, otitis, an otoskleroz, a foreign matter of an ear, a labirintit).
Detection of a hearing impairment is carried out by an audiometriya. The voice-frequency threshold audiometriya allows to define relative deafness degree. At the same time lack of a bone and air interval and the descending character of an audiogramma demonstrating violation of perception of mainly high-pitch tones is characteristic of cochlear neuritis. The research of a lateralization of a sound is conducted by means of Weber's test. At a nadporogovy audiometriya acceleration of increase of loudness is defined. At small children the main way of detection of a hearing disorder is the research of the acoustical caused potentials. The acoustic impedansometriya is carried out for an exception of the hearing disorder caused by sound carrying out pathology. Elektrokokhleografiya gives the chance to differentiate cochlear neuritis from Menyer's disease. For an exception of diseases of an external ear and changes from an eardrum the otoskopiya and a mikrootoskopiya is carried out.
Along with inspection of the acoustic analyzer to patients with cochlear neuritis appoint a research of vestibular function: vestibulometriya, stabilografiya, elektronistagmografiya, videookulografiya, indirect otolitometriya. For diagnostics of the cause of cochlear neuritis consultations of adjacent experts can be recommended: otonevrologa, neurologist, ophthalmologist, vestibulolog, endocrinologist, traumatologist, neurosurgeon, geneticist. With the same purpose additional examinations are conducted: a X-ray analysis of a skull, KT and MPT of a brain, UZDG of vessels of the head and neck, a backbone X-ray analysis in cervical department, survey of an eye bottom (oftalmoskopiya), a research of sugar of blood and tireoidny hormones, biochemical blood test and urine.
Treatment of cochlear neuritis
The main objective of treatment of sharp cochlear neuritis is hearing restoration. Treatment of a chronic form of a disease it is directed to stabilization of acoustical function. Sharp cochlear neuritis and some cases of the progressing course of chronic cochlear neuritis are the indication to treatment in a hospital. Therapy of cochlear neuritis has to is carried out together with correction of violations which could become its reason. First of all this elimination of arterial hypertension and hormonal dysfunction, exception of influence of ototoksichesky factors (medicines and other substances, noise, vibration, radioactive radiation).
Medicamentous therapy of cochlear neuritis is carried out by vasodilating medicines, dezagregant, venotonik, neuroprotectors, dezintoksikatsionny solutions. The combined therapy pentoksifilliny, vinpotsitiny, piracetam, ethylmethylhydroxypyridine and tserebroliziny in the first 2 weeks is performed by intravenous administrations, then passed to intramuscular injections and administration of drugs inside. The good effect at cochlear neuritis gives use in treatment of medicines of a ginkgo of a biloba. In therapy of suddenly arisen cochlear neuritis in addition use glucocorticoids. Apply gistaminopodobny medicines to knocking over of dizzinesses.
The positive stimulating effect is rendered by physiotherapeutic methods of treatment: reflexotherapy (elektropunktura, lazeropunktura, acupuncture), electrostimulation, medicines, oksigenobaroterapiya.
Bilateral decrease in hearing to 40 dB complicates speech communication of the patient and is the indication to hearing aid. The Prelingvalny form of cochlear neuritis serves as the indication to carrying the hearing aid at an acoustical threshold 25 dB as it is proved that such relative deafness causes violations in development of the speech in the child. For the purpose of hearing aid at cochlear neuritis analog, digital and linear hearing aids can be used. Selection and setup of the device are carried out by the doctor-slukhoprotezist.
Surgical treatment of cochlear neuritis is carried out for implementation of stem or cochlear implantation, removal of a nevrinoma of an acoustical nerve, a hematoma or a tumor of a brain. Need of surgical treatment can be caused by painful ear noise or attacks of intensive dizziness. In such cases carry out removal of star-shaped knot, a resection of a drum texture or a cervical simpatektomiya, at deafness or relative deafness of the IV degree — destructive operations on a snail.
Forecast of cochlear neuritis
In case of early diagnostics of a sharp form of a disease the complete recovery of hearing occurs at 50% of patients, at 30-40% of patients considerable improvement of acoustical function is noted. At chronic cochlear neuritis decrease in hearing is irreversible. The main task is the relative deafness progressing stop then restoration of acoustical function is possible by cochlear implantation or hearing aid.