Sudden deafness (hereafter referred to as sudden deafness) is a sudden onset of sensory-neural deafness of unknown origin, also known as fulminant deafness. de Klevn (1944) first described this disease, and its incidence has increased yearly, with approximately 10.7 cases in 10,000 people, accounting for 2% of initial ENT cases. The incidence of both ears accounts for 4% of cases, half of which occur simultaneously in both ears, and up to 17% have been reported. There was no significant difference in the incidence between the sexes and the left and right sides. The incidence increases with age, and 3/4 of the patients are 40 years old or older at the time of onset and progression, and the outcome of treatment is directly related to the time of consultation. Etiology of Sudden Deafness Sudden deafness affects approximately 1 in 5000 people each year. Although the sudden onset suggests a vascular cause, similar to vascular accidents of the central nervous system, there is evidence in a large number of patients to support an etiology due to a viral infection. Sudden deafness tends to occur in children without evidence of vascular disease and in young or middle-aged adults. Histopathologic findings in patients with sudden deafness in the temporal bone do not resemble those seen in animals with experimental embolism or inner ear changes following vascular obstruction, but approximate sudden deafness caused by viral infections of the inner ear in humans, such as mumps and measles, influenza, varicella and mononucleosis viruses, adenovirus and other viruses that can also cause sudden deafness. The pathologic findings of permanent deafness caused by viral endolymphatic vaginitis are similar regardless of the virus causing it. There is progressive damage to the Corti apparatus of the basal gyrus of the cochlea, with a decrease in spiral ganglion cells, a tendency for individual hair cells to disappear, and atrophy of the vascular lines. The lid membrane often curls upward and is incorporated into the syncytium. The vestibular membrane may atrophy and adhere to the basement membrane. Ectolymphatic fistulas between the inner and middle ear sometimes occur as a result of drastic changes in external air pressure or forceful activities such as weight lifting. Fistulas with round or oval windows cause sudden or fluctuating sensorineural deafness and vertigo. In the case of fistula, the patient may feel an explosion in the affected ear. The presence of an exolymphatic fistula can be verified by a combination of pressure changes in the ear canal using an acoustic conductivity meter and nystagmography. Nystagmus caused by pressure changes in the external auditory canal can be recorded by nystagmography and indicates the presence of an exolymphatic fistula. Signs and Symptoms Usually profound deafness, but hearing returns to normal in most patients, and partially in others. If hearing improves, it is most likely to occur within 10-14 days. Tinnitus and vertigo may be present at the beginning, and the latter often subsides within a few days. Clinical treatment Although vasodilators, anticoagulants, low molecular dextran, corticosteroids and vitamins have been recommended, none of them have been proven to be effective. Because the inflammatory reaction caused by the virus is characterized by micro petechiae and extravasation of blood, the use of vasodilators and anticoagulants is not indicated. Moreover, in the inflammatory response, cochlear blood flow has increased to a favorable degree. It seems reasonable to apply corticosteroids, such as prednisone 60 mg/d orally for 2 days, then 40 mg/d orally for 5-7 days, and gradually reduce the dose thereafter. Bed rest is desirable. Usually, if an exolymphatic fistula is suspected, a surgical exploration of the middle ear should be performed and the fistula should be repaired with an autologous fascial flap. If hearing cannot be restored by conservative treatment, surgical treatment should be determined according to the degree of hearing stabilization, such as vibroacoustic bridgework for moderate to severe hearing loss, and cochlear implantation for sensorineural deafness above severe. Prevention and recuperation: 1. Patients with sudden deafness should recuperate at home and avoid exposure to noise or excessive sound. Keeping the home environment tidy and the patient in a relaxed mood is conducive to recovery. 2.Prevent colds, some patients with sudden deafness may be indirectly related to colds, so preventing colds can reduce a morbidity factor. 3. Don’t overexert yourself, do not overexert yourself, and do not overexert yourself. This disease is mostly found in middle-aged people, so middle-aged people should pay more attention to this point.