Hypothermia Facilitates Hearing Restoration in the Treatment of Severe Sudden Deafness

Abstract

Idiopathic sudden sensorineural hearing loss (sudden deafness) that occurs in 27,000 cases a year in Japan, mainly involves adults in 50 and 60 years in age and devastates their quality of life. Although it is supposed to have many different origins, including disturbance of vascular circulation, viral infection, rupture of the membranous labyrinth and immune-mediated disorder, the exact etiology remains undetermined. We think disturbance of vascular circulation is the basic cause of this disease, since it occurs suddenly without preceding any sign or symptom. At present, management of sudden deafness is controversial. Various therapeutic agents such as steroid, vasodilators, diuretics, anticoagulants, contrast agents, and carbogen inhalation, have been attempted as a single therapy or as a combination therapy, aiming to alleviate cellular ischemia to the inner ear. According to recent double blind randomized control studies [1-5], there is no specific agent or treatment, which might dramatically restore hearing. Sudden deafness is thought to heal spontaneously in two thirds of the patients as a natural history, however, complete recovery rate remains in the range of 24-63% by a single therapy [6], when hearing impairment is more than 40 dB in pure tone average in speech frequencies and the treatment starts within 14 days after the onset.