Sudden sensorineural hearing loss (SSNHL) is characterized by a rapid hearing decline of 30 dB or more across at least three consecutive frequencies within a 72-hour timeframe.
Its causes are believed to originate from neurological, vascular, infectious, oxidative, immuno-mediated, or degenerative factors, including rupture of the cochlear membrane.
Typically, treatment involves the administration of steroids, either systemically or via intratympanic injection. Poor prognostic indicators include vertigo, advanced age, profound hearing loss, and delayed treatment.
Intratympanic steroid injections are indicated for SSNHL (primary or salvage therapy), Meniere’s Disease, refractory tinnitus, and autoimmune Inner Ear Disease. Natural recovery from SSNHL occurs in approximately 32-70% of cases, though this estimate may be optimistic. The effectiveness of intratympanic steroid injections ranges from 60% to 80%. The choice of treatment mode should consider factors like cost, duration, side effects, and complications.
A successful treatment outcome is defined as a hearing improvement of 15 dBHL or more compared to the pre-treatment pure-tone audiometry (PTA). Early intervention, shortly after diagnosis, enhances treatment efficacy.
For intratympanic steroid injections, I follow this procedure:
– Administer 0.5 ml of Dexamethasone (10mg/ml) using a 25-gauge spinal needle into the middle ear cavity.
– Anesthetize the external auditory canal (EAC) and tympanic membrane (TM) using EMLA or xylocaine 10% spray applied to cotton wool for 30 minutes.
Frequency of injections: Aim for 6 injections, ideally, but a minimum of 6 or up to 8 injections can be considered. Begin with daily injections for 4 days, then switch to every other day (EOD). Other options include daily injections for 6-8 days or 6 injections over a 2-week period.
Pure-tone audiometry (PTA) assessments are conducted at 1 week, 2 weeks, 1 month, and 3 months post-injection. If hearing recovery occurs early, further PTAs may not be necessary.
Post-injection precautions include lying in a lateral position for 30 minutes without swallowing, yawning, or speaking. Keep the treated ear dry during the entire course of treatment.
Decide to discontinue treatment when hearing has improved or if the patient experiences reluctance, dizziness, ear infection, or syncope during the procedure.
In cases of treatment failure, consider recommending hearing aids for the patient.
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