Hearing outcome does not depend on the interval of intratympanic steroid administration in idiopathic sudden sensorineural hearing loss

We studied the effect of intratympanic steroid administration with different intervals on hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). The subjects were 197 consecutive patients (197 ears) with ISSNHL (hearing level ≥40 dB, interval between onset and treatment ≤30 days). They received systemic administration of prednisolone (100 mg followed by tapered doses) combined with intratympanic injection of dexamethasone (4 mg/ml). Intratympanic injection was performed once a week for 4 weeks in 105 patients (long-interval group), or 4 times in 1 week in 92 patients (short-interval group). The hearing outcomes were evaluated at two points of time: 1 week from the start of treatment, and 1–2 months after the completion of treatment when the hearing level reached a plateau. There was no significant difference in the cure rate, marked-recovery rate, recovery rate, hearing gain, hearing level, or percent hearing improvement between the long- and short-interval groups at either point of time. Multiple regression analysis also showed that the final hearing level did not depend on the interval of intratympanic steroid injection. These results indicate that the hearing outcome of ISSNHL does not improve even if the interval of intratympanic injection is shortened. This implies that a lower total number of intratympanic steroid injections may be as effective as the present protocol.