[Idiopathic sudden deafness].
OBJECTIVE
Sudden idiopathic deafness is a sensorineural hearing loss with no recognized causes at the time of onset. The impairment site is usually localized in the cochlea, but some cases of retrocochlear lesions (e.g., cerebellopontine angle tumors, degenerative neural diseases, neuraxial ischemic lesions) can induce sensorineural deafness. The medical management of patients presenting with sudden deafness aims at detecting a causal mechanism, and at administering emergency therapeutic drugs. The diagnosis of idiopathic sudden deafness can be definitely made when no causes are found. Usually, the impairing mechanism involves the cochlea. The pathophysiology of this sensorineural alteration is still unknown. It is most likely that several mechanisms are associated together, their common point being an impairment to the feedback loop of the organ of Corti.


BACKGROUND
It is very likely that reactivation of neurotropic viruses and/or cochlear ischemia are frequent etiologies. Whatever the cause, the treatment is to be administered urgently, and consists of a high-dose corticotherapy at the least. Other treatments have never really proven to be effective. It is secondarily checked that no retrocochlear pathological processes, such as a cerebellopontine angle tumor, is present, in particular in young people.


CONCLUSIONS
One of the current objectives is to determine when cochlear ischemia is involved, in a mini-invasive manner, such as with laser Doppler flowmetry, so that the treatment can be optimized. From a therapeutic point of view, early acoustic protection has been proven to be effective in cases of cochlear ischemia in small laboratory animals. Its efficacy in case of sudden deafness, non-exclusive of other causes than ischemia, is being assessed in a multicentric project.
Mom
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Service d'ORL et de chirurgie cervicofaciale, laboratoire de biophysique sensorielle (EA 2667), CHU, 30, place Henri-Dunant, 63000 Clermont-Ferrandcedex, France. tmom@chu-clermontferrand.fr
Avan
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Gilain
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D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D003051:Cochlea / Q000098:blood supply / Q000503:physiopathology; D003639:Hearing Loss, Sudden / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006438:Hemodilution; D006801:Humans; D006931:Hyperbaric Oxygenation; D017078:Laser-Doppler Flowmetry; D008279:Magnetic Resonance Imaging; D009464:Neuroma, Acoustic / Q000150:complications / Q000175:diagnosis; D011379:Prognosis; D012181:Retrocochlear Diseases / Q000150:complications; D014055:Tomography, Emission-Computed; D014665:Vasodilator Agents / Q000627:therapeutic use
D000305:Adrenal Cortex Hormones; D000998:Antiviral Agents; D014665:Vasodilator Agents
Les surdités brusques idiopathiques.