Causes of auditory nerve damage

If the auditory nerve is damaged, the most obvious symptom is hearing loss, or even complete hearing loss. There are many reasons for damage to the auditory nerve, among which noise is the most harmful. Long-term exposure to noise will cause serious hearing loss. In addition, the cause of drugs cannot be ignored. For example, some children suffer hearing loss due to gentamicin.

Causes of auditory nerve damage

1. Noise can damage the auditory nerve. The pathway of sound transmission is as follows: sound signals pass through the external auditory canal - eardrum vibration - auditory ossicles (malleus, stapes, incus) - inner ear fluid vibration - cochlear hair cells produce electrical impulses - auditory nerve - central sound receptors in the brain, and then we hear the sound. If there is a problem in any part of this process, no sound may be heard. In the past, industrial noise was the main factor affecting hearing, but with the invention of the Walkman, music has become the culprit causing damage to the auditory nerve. Exposing music for a long time and at a high volume can damage hearing by damaging the hair cells, auditory nerve fibers, auditory neurons in the inner ear and causing spasm of the microvessels in the inner ear. There are two main types of damage to hearing caused by sound: one is sudden loud noise, such as setting off firecrackers; the other is chronic noise, which occurs when working under high noise for a long time and the hearing is damaged unknowingly.

2. Pressure

Stress is likely to cause sudden deafness, a type of sensorineural hearing loss, which is characterized by a sudden loss of hearing in one ear, and may be accompanied by tinnitus, a feeling of stuffiness in the ear, etc. Pathogenesis: Stress, fatigue, emotional excitement, viral infection and other factors lead to increased secretion of adrenaline in the body, spasm and contraction of small arteries in the inner ear microcirculation, leading to ischemia and hypoxia of the inner ear, causing inner ear lesions, damage to the sound-sensing part of the inner ear, and hearing loss.

3. Medication

Commonly used antibiotics that can damage the auditory nerve include streptomycin, dihydrostreptomycin, gentamicin, kanamycin, puromycin, neomycin, vancomycin, tobramycin, and kasugamycin. Some other commonly used drugs can also damage the auditory nerve and cause deafness, such as aspirin, furosemide, propranolol, uric acid, quinidine and anticonvulsants. If these drugs are used in combination, the incidence of adverse drug reactions will increase due to drug interactions.

4. Disease

Otitis media, acoustic neuroma, otosclerosis, etc. are all diseases that may directly cause hearing loss. Through early treatment, most people can avoid deafness. Causes of cochlear nerve damage: Common causes include neuritis, meningitis, trauma, poisoning, tumors, arteriosclerosis, certain genetic diseases, and middle ear and inner ear diseases. Causes of vestibular nerve damage: poisoning, blood circulation disorders (basilar artery sclerosis, hypertension, etc.), neuritis, tumors, trauma, demyelinating disease, inner ear disease, etc. Due to different causes, the pathogenesis is also different, which may be demyelination, inflammatory cell infiltration, cell degeneration and compression.

5. Genetics

50% of deafness is hereditary, which means congenital auditory nerve damage and has a genetic basis. Some children are born with the ability to hear and later lose their hearing. Cochlear implant technology can convert external sounds into electronic sound signals that directly act on the auditory nerve. Through training, children can speak and live like normal children.