Auditory nerve damage

Outlined by the auditory nerve and the cochlear nerve vestibular nerve components, which together with the internal auditory canal to the inner ear, can also damage tissue, performance for the hearing and balance the two McGREGOR symptoms, although two of the same nerve in two different components, But the cause of the reaction is not consistent. Cause pathogenesis one. Cochlear nerve damage because of the following reasons : the common neuritis, meningitis, trauma, poisoning, cancer, arteriosclerosis, certain genetic diseases and middle ear, inner ear disease. 2. Vestibular nerve damage causes : poisoning, the blood circulation disorder (basement arteriosclerosis, hypertension, etc.), neuritis, tumors, trauma, demyelinating disease, the inner ear disease. Because the cause of their different pathogenesis is not the same, it can be demyelination, inflammation, cell degeneration and oppression. A clinical performance. Hearing impairment : tinnitus patients often to the canal obstruction flu, hearing impairment, especially for the Treble feeling poor, This deafness called sensorineural hearing loss or sensorineural deafness. Test for performance tuning fork over a gas conduction bone conduction strong, Rinne (Rinne)'s test was positive. Bone conduction with the normal side (or check), the sound lasts a short time, Schwabach (Schwabach)'s test was positive. Jason (Weber)'s test beep contralateral bias. 2. Balance disorder : patients feel dizziness, nausea and vomiting, and performance paleness sweating vagus nerve stimulation symptoms. Can detect eye level shook, the pilot was instructed that the two patients with upper extremity level extension to the front, shut illness to the affected limbs skewed, dumping, the legislature and shut difficult test more significant. time test abnormal, that is interested in a straight line forward, five steps back, repeatedly, to the patients were on the side of the tilt, infantry stellate track is, also known as Star trace gait. Differential diagnosis (1) Vertigo inner ear disease (aural vertigo) also known as the United States and Nigeria (Meniere) 's disease. Occur in the 30-50-year-old, clinically to hearing impairment, tinnitus and vertigo characteristic. Often a sudden bout of vertigo, tinnitus often before the attack aggravated attack with the level of transient nystagmus, with severe nausea, vomiting, paleness, sweating, and so on vagus nerve stimulation symptoms, attack lasted a few minutes, a few hours or a few days. Intermittent varying periods, so that each attack receded further hearing, with the attack and reduce the increasing deafness. To complete deafness, loss of function lost, it would mean the end of vertigo. Glycerol test positive. (2) vestibular neurons Yan (vestibular neuronitis) often occur in the upper respiratory tract infection after a few days, with vestibular neurons suffered against the virus. Clinical features of acute onset of dizziness, nausea, vomiting, nystagmus and postural imbalance. Side of the vestibular dysfunction, but no hearing impairment. Vertigo often sustained about two weeks. Temperature tests showed vestibular dysfunction, cured recovery. (3) labyrinthitis (labyrinthitis) often secondary to otitis media or middle ear infection, Fever, headache, ear pain, ear canal discharging, post-traumatic injury, such as infection. Arises paroxysmal vertigo, tinnitus severe, with nausea, vomiting, spontaneous nystagmus, 1 ~ 2 days of hearing the right to disappear. Peripheral blood infection, as suggested changes. Visibility canal inspection perforated eardrum. (4) Positional Vertigo (location vertigo) ventigo often with a particular head position, without tinnitus and deafness. Central positional vertigo, frequently with the first-specific vertical nystagmus, often with no latency. repeated experiments can be repeated there was no fatigue relative phenomenon. Peripheral positional vertigo, known as benign paroxysmal positional vertigo, and nystagmus often certain incubation period, the level was rotating type, many checks can be gradually reduced or disappear, is fatigue. The prognosis is good, can self-healing. (5) acoustic neurinoma (acoustic neurilemoma) is intracranial schwannoma incidence of the most A high, acoustic neurinoma occurred hearing, or within the District Earhor nerve sheath with the vestibular nerve. The first symptoms of the auditory nerve irritation or damage symptoms and the performance of the affected tinnitus, deafness or dizziness, accounting for 74%. Tinnitus to shout, continuity; tinnitus and hearing loss more than the same time, but often not aware of the patient. Many other symptoms for a hearing test done only to be found; tumor to the cerebellopontine crypt development trigeminal nerve and facial nerve caused ipsilateral facial numbness, pain receded, corneal reflex receded, trigeminal neuralgia and hemifacial spasm, and so on. To the development of the medial and oppression, there will be the brainstem contralateral hemiparesis and pyramidal tract sign, the contralateral side who feel subside; Brainstem called spaces, Atrium oppression contralateral notch when there may be ipsilateral pyramidal tract levy and feeling dissipated. Cerebellopontine angle can cause compression of ipsilateral cerebellar ataxia, ataxia, and distinguish from the bad, language ambiguous and difficult to speak. Meanwhile, there will be increased intracranial pressure symptoms and signs, such as Sprague, vomiting, palilledema, secondary optic nerve atrophy. Listening to X-ray showed the internal auditory canal expansion, brain CT and MRI showed the cerebellopontine angle occupying. (6) poisoning (drug poisoning) drugs can cause many of the eighth cranial nerve toxicity loss harm, common amino glycoside drugs antibiotics, phenytoin, primidone, aspirin, quinine, caffeine, furosemide, Lee uric acid and Thiazide diuretics, etc.. Mostly bilateral, toxicity and dose-related, often after repeated applications, However, it can be the short-range conventional dose increased application can be associated with visual impairment, most without spontaneous nystagmus. Vertigo often sustained improvement in a few days, but the vestibular dysfunction is often hard to restore.