What is the recommended initial treatment for idiopathic sudden sensorineural hearing loss presenting within 72 hours in an adult without contraindications?

Treatment of Sudden Sensorineural Hearing Loss

For idiopathic sudden sensorineural hearing loss presenting within 72 hours, initiate oral corticosteroids immediately with prednisone 1 mg/kg/day (maximum 60 mg daily) as a single morning dose for 10-14 days, followed by a taper over a similar period. 1

Diagnostic Confirmation Before Treatment

• Confirm sensorineural hearing loss with audiometry showing ≥30 dB hearing loss across at least 3 consecutive frequencies occurring over a 72-hour period 1
• Rule out conductive hearing loss, which indicates middle ear pathology rather than sudden sensorineural hearing loss 2
• Assess for bilateral hearing loss, recurrent episodes, or focal neurologic findings that suggest non-idiopathic causes requiring different management 1

Initial Corticosteroid Therapy: Dosing and Timing

Oral corticosteroids are the first-line treatment option, though the evidence is classified as an "option" rather than a strong recommendation due to the balance between potential benefit and known side effects. 1

Specific Dosing Regimens

• Prednisone: 1 mg/kg/day as a single daily dose (usual maximum 60 mg/day) for 10-14 days, then taper over 7-14 days 1, 2
• Equivalent alternative doses: Methylprednisolone 48 mg/day OR dexamethasone 10 mg/day 1, 2
• One representative regimen uses maximum dose for 4 days, followed by 10-mg taper every 2 days 1

Critical Timing Considerations

• Treatment must begin immediately, ideally within the first 14 days of symptom onset 1, 2
• Greatest spontaneous improvement and treatment benefit occur within the first 2 weeks 1, 3
• Some benefit reported up to 6 weeks, but efficacy diminishes significantly after 2 weeks 1, 2
• Late recovery beyond 2 weeks is rare 1

Alternative: Intratympanic Corticosteroids

Intratympanic steroids are equally effective as oral steroids for primary treatment and should be considered when patients cannot tolerate systemic steroids or have contraindications such as diabetes. 1, 4

Evidence for Equivalence

• A large randomized trial of 250 patients showed intratympanic methylprednisolone was non-inferior to oral prednisone, with hearing improvement of 28.7 dB vs 30.7 dB respectively 4
• Both routes showed hearing improvement in more than 75% of treated patients 1
• Intratympanic route avoids systemic side effects (88% of oral patients reported elevated blood sugar, increased thirst, sleep/appetite changes) while causing mainly local effects (transient pain, brief caloric vertigo in 90%) 1

Intratympanic Dosing Protocol

• Dexamethasone: 24 mg/mL, 16 mg/mL, or 10 mg/mL 1, 2
• Methylprednisolone: 40 mg/mL or 30 mg/mL 1, 2
• Administered via anterosuperior myringotomy after topical anesthetic 1
• Frequency: 4 doses over 14 days (typically twice weekly for 2 weeks) 4, 5

Salvage Therapy for Incomplete Recovery

If hearing recovery is incomplete after 2-6 weeks of initial treatment, offer intratympanic steroid perfusion as salvage therapy. 1, 3

• Intratympanic dexamethasone shows 37-48% improvement rates in patients with incomplete initial recovery 2
• Extended protocol: 4-6 additional injections over 2 weeks 2
• This is a recommendation (not just an option) in the American Academy of Otolaryngology guidelines 1

Adjunctive Therapy: Hyperbaric Oxygen

Hyperbaric oxygen therapy may be offered within 3 months of diagnosis, though it is classified as an option with modest and imprecise evidence. 1

Patient Selection for Hyperbaric Oxygen

• Most effective when administered within 2-4 weeks of symptom onset 1, 3
• Younger patients (under 50-60 years) respond better than older patients 1
• Patients with moderate to severe hearing loss (≥60 dB) benefit more than those with mild loss 1, 3
• Protocol: 100% oxygen at pressure >1 atmosphere absolute, typically 10-20 sessions of 30-90 minutes each 3

Treatments NOT Recommended

Do not routinely prescribe antivirals, thrombolytics, vasodilators, vasoactive substances, or antioxidants—these are specifically recommended against. 1

Critical Pitfalls to Avoid

Underdosing Steroids

• The commonly prescribed methylprednisolone dose pack provides only 105 mg prednisone equivalent, which is grossly inadequate compared to the recommended 540 mg total over 14 days for a 60-kg adult 3, 2
• Ensure adequate dosing: prednisone 1 mg/kg/day, NOT lower doses 1

Delayed Treatment

• Spontaneous recovery and treatment efficacy both decline rapidly after 2 weeks 1, 2
• Do not wait for "watchful waiting"—treat immediately upon diagnosis 1, 3

Monitoring During Treatment

• Monitor for hyperglycemia, hypertension, mood changes, and sleep disturbances during the steroid course 6, 3
• Patients with diabetes, immunosuppression, or lupus require special caution with systemic steroids 3, 2
• Patients with pre-existing bone/joint problems have higher risk of osteonecrosis and fractures 3

Follow-Up Audiometric Evaluation

• Obtain audiometry before each subsequent intratympanic injection if using that route 1
• Repeat audiometry at completion of treatment (2 weeks) and within 6 months of diagnosis 1, 6
• Follow-up is essential to identify retrocochlear pathology (vestibular schwannoma, stroke, malignancy) that may not be evident at initial presentation 1
• Consider MRI or auditory brainstem response testing to evaluate for retrocochlear pathology 1, 6

Prognosis Factors

• 32-65% of cases may recover spontaneously, though clinical experience suggests this may be an overestimation 1
• Prognosis depends on: patient age, presence of vertigo at onset, degree of hearing loss, audiometric configuration, and time between onset and treatment 1
• Patients with partial or no hearing recovery require ongoing management including consideration of amplification and hearing-assistive technology 1