Local hypothermia in the treatment of idiopathic sudden sensorineural hearing loss.

Objective: The additive effects of local hypothermia and restricted activity in the treatment of idiopathic sudden sensorineural hearing loss (ISSHL) were investigated by case-matched study as a multicenter (13 hospitals) pilot trial.
Patients and Methods: In a preliminary experiment, we evaluated the effects of cooled water pillow (15 degrees C). Cooling the neck and mastoid with the pillow decreased the tympanic membrane temperature for 1.4 degrees C in 2h without causing uncomfortable sensation or frostbite. In this study, 86 patients with ISSHL were enrolled in the hypothermic group, which received hypothermic treatment with restricted activity in addition to medication, and 86 ISSHL patients constituted the control group, which received the same medication but without cooling and rest. Control patients were selected retrospectively from case records by matching the experimental patients with respect to age, gender, days until the start of treatment, hearing loss, shape of the audiogram, and accompanying vertigo. The patients in the hypothermic group were admitted and treated with a cooled water pillow for 48h, in addition to conventional drug treatment (e.g., 60 mg of prednisone) for 7 days. The water pillow was cooled to 15 degrees C and was changed 4-5 times per day. The patients used the water pillow for the first 48 h after admission, with restricted activity. The control patients received only the medications.
Results: Hearing results were evaluated using criteria proposed by the Sudden Sensorineural Hearing Loss Research Group of the Japanese Ministry of Health and Welfare. The recovery rates were judged 6 months after onset. The recovery rate in the hypothermic group was significantly (p<0.05) better than that in the control group. When the comparison was limited to younger patients, the use of the cooled water pillow was effective in facilitating the recovery of hearing.
Conclusions: Hearing restoration in ISSHL may be improved by adding mild hypothermia and restricted activity to the conventional treatment.
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