Intratympanic Corticosteroid Therapy for Idiopathic Sudden Sensorineural Hearing Loss

INTERVENTION: Participants will be randomised into one of two groups: A) Receives intratympanic (IT) injection of 24mg/ml dexamethasone to the effected ear within 14 days onset of hearing loss, followed by a placebo injection 14 to 21 days after the initial injection. B) Receives placebo IT injection within 14 days of onset of hearing loss, followed by an IT injection of 24mg/ml dexamethasone 14 to 21 days after initial injection. All IT injections will be administered by an ENT surgeon within Royal Victorian Eye and Ear clinics. Participants in both groups will be prescribed a course of oral prednisolone tablets as standard treatment in addition to the IT injections. The duration of the oral prednisolone is 14 days for all participants. A dosage of 1mg per kg of bodyweight per day (with 75mg as the maximum daily dose) will be administered for the first 7 days, followed by tapering of the dosage for a further 7 days. CONDITION: Ear ‐ Deafness Idiopathic Sudden Sensorineural Hearing Loss; ; Idiopathic Sudden Sensorineural Hearing Loss PRIMARY OUTCOME: Change in pure‐tone hearing thresholds as measured by manual pure‐tone audiometry.[‐ Baseline ; ‐ 2‐3 weeks after 1st injection; ‐ 4‐5 weeks after 2nd injection] SECONDARY OUTCOME: Change in perceived tinnitus using the Tinnitus Handicap Inventory[‐ Baseline ; ‐ 2‐3 weeks after 1st injections ; ‐ 4‐5 weeks after 2nd injection] INCLUSION CRITERIA: 1. Idiopathic sudden sensorineural hearing loss (ISSNHL) defined as a history of a sudden decrease in hearing; not exceeding seven days in duration. 2. A sensorineural hearing loss demonstrable on a pure‐tone audiogram at the time of entry into the trial (a 20 dB or more hearing loss in at least three frequencies compared to the healthy ear). 3. No otological pathological history or examination findings. 4. Absence of other neurological signs except the eighth cranial nerve defect.