We investigated 211 inpatients in our hospital who underwent treatment within 2 weeks of the onset of idiopathic sudden sensorineural hearing loss over an eight year-period (January 2003 to December 2010). Some prognostic factors analyzed in this study were as follows; age, sex, side, smoking, the initial averaged five-frequency hearing level, grade, vestibular symptom, complications such as diabetes mellitus (DM) and hypertension (HT), and the period to fixation of hearing level.
The ages of patients ranged from 10 to 85 years (median 56.5 yr). Males and females accounted for 106 and 105 cases, respectively. The sides of hearing impairment were 105 in the right, 105 in the left and 1 in the bilateral ears. The smoking rate of our cases was lower than that of the general population as reported by the Ministry of Health, Labour and Welfare. The main hearing types were horizontal and deaf before treatment, and high-frequency impairment and normal hearing after treatment. The overall results of the treatment showed 87 (41.0%) patients with a complete recovery, 53 (25.0%) with a marked improvement, 40 (18.9%) with some improvement and 32 (15.1%) with no change. Hearing improvement of 4000 Hz was worse than those of 250, 500 and 1000 Hz. Hearing improvement was good in the valley and low tone senseorineural hearing loss types, on the other hand, it was worst in the deaf type. Hearing improvement of Grade 4 was worse than those of Grade 1, 2 and 3. Smoking and DM had no influence on the prognosis. The complete recovery rate of those over 60 years of age was worse than in those under 60 years of age. The prognoses of patients with vestibular symptom and HT were worse than those without them.
Important prognostic factors strongly related to the complete recovery rate were the presence of vertigo and the grade of initial hearing level as determined by multiple logistic regression analyses. The period to fixation of hearing level in Grade 4 was prolonged as compared with those of Grade 1, 2 and 3. We recommend to follow up for two weeks in Grade 1, two months in Grade 2 and 3, and six months in Grade 4 to obtain an accurate evaluation of hearing improvement.