[Analysis of the relevant factors for recurrent sudden sensorineural hearing loss]

Objective: To investigate the possible factors related to recurrence and prognosis of sudden sensorineural hearing loss(SSNHL). Methods: Four hundred and ninety-five patients with unilateral sudden sensorineural hearing loss between January 2013 to April 2014 were analyzed retrospectively(34 patients lost to follow-up with a dropout rate of 6.87%). Twenty of the 495 patients were diagnosed as recurrent SSNHL and treated again in the same hospital. The data of the patients were summarized to analyze the related factors which might influence the recurrence and prognosis of SSNHL. Results: In the 20 patients with recurrent SSNHL, 19 had the second attack in same ear as the first attack, and the other one had in both ears. There were seven male patients, and thirteen female patients. Patients ranged in age from 24 to 77years, with a median age of 39.5 years. Types of hearing loss: low frequency in eight patients, high frequency in two patients, flat frequency in eight patients, total deafness in two patients, the types of the second attack in 17 patients were same as the first attack, only one patient was changed from total deafness to flat frequency, one case was changed from flat frequency to high frequency, one case changed from flat frequency to total deafness. The intervals between of the first attack time and the second attack time were 1-36 months with the median time of 3.5 months. After systemic oral and (or) transtympanic steroid treatment, recovered in three cases, effective in three cases and 14 cases invalid, the cure rate was 15%, and the total effective rate was 30%. There were statistically significant differences in the recovery rate(χ²=8.640, P<0.05) and the overall response rate(χ²=12.379, P<0.01)between the first and the second treatments. For the patients with vertigo and/or dizziness, with a history more than seven days, with hypertension or diabetes mellitus, and with a type of hearing loss except low frequency type, the treatment effect was invalid. The patients with hearing loss at low frequency had the best outcomes. The total effective rates were significant different between patients younger and old than 34 years old(P<0.05). There was no difference in the total effective rate between genders, and patients with or without tinnitus and/or aural fullness in the recurrent SSNHL(P>0.05). The recurrence rates of patients with various types of hearing loss were different(F=7.744, P<0.05), with a highest recurrence rate in patients with hearing loss at low frequency. Other factors such as gender, age, accompanied diseases (hypertension or diabetes mellitus), associated symptoms, interval from onset to treatment had no effects on the recurrence rate. Conclusions: Recurrence of SSNHL is more likely to be found in patients with hearing loss of low frequency and flat type. The prognosis of recurrent SSNHL is poorer than that of the first episode, and may be related to the age and type of hearing loss.