Abstract
The relationship between the treatment outcome and three important prognostic factors; the time from onset, initial hearing level, and vertigo, in idiopathic sudden sensorineural hearing loss were investigated for grading of the severity of diseases based on prognosis. The borderlines that induced different outcome were indicated between ten and eleven days from onset, 59 and 60dB, 89 and 90dB, and 99 and 100dB of initial hearing level. Vertigo also affected the outcome independent both of the time from onset and the initial hearing level. Although the grading system previously established by the Ministry of Health and Welfare in Japan was almost seemed valid, we recommended some small revisions in the criterion of day from onset and initial hearing level.
