Acute Hearing Loss.

Abstract

Acute hearing loss (AHL) is a medical urgency. The management of patients presenting with sudden deafness involves detecting the causal mechanism and administering emergency therapeutic drugs to restore hearing by minimizing the period of cellular ischemia to the inner ear. Acute management of AHL consists of administering a 10-day course of high-dose corticosteroids (prednisone 60 to 80 mg) until a cause can be established. Magnetic resonance imaging with gadolinium is indicated, with a study dedicated to the internal auditory canals. The natural history of idiopathic AHL is characterized by spontaneous improvement in two thirds of patients. Maximum improvement occurs within 2 weeks of onset of AHL. In the vast majority of patients (>90%), the AHL is idiopathic. For an identifiable etiology, the treatment is specific and may consist of stopping ototoxic medications, repair of perilymphatic fistulas, administering antimicrobial agents for viral or bacterial infections, correction of metabolic imbalances, management of stroke, and possible surgery for cerebellopontine angle tumors. Management of idiopathic AHL is controversial. Various therapeutic agents, such as vasodilators, diuretics, anticoagulants, plasma expanders, contrast agents, and carbogen inhalation, have been tried in single therapy or as a combination therapy. The empiric use of these drugs is mainly based on improving the blood circulation and restoring the oxygen tension to the inner ear. The use of interventional procedures, such as low-density lipoprotein apheresis as well as newer drug delivery systems for corticosteroids, and immunosuppressive agents have opened new options in the treatment of AHL secondary to immune-mediated diseases of the inner ear. Prognosis for AHL is best when patients are seen early, begin recovery within 2 weeks, and have a mild hearing loss (<90 dB) with upward-sloping audiograms. Greater than 90 dB of hearing loss along with flat or down sloping audiogram, advanced age, and presence of vertigo are adverse prognostic factors for recovery of hearing loss.