What percentage of patients with Sudden Sensorineural Hearing Loss (SSNHL) improve after intratympanic (in the middle ear) steroid injections?

Improvement Rates After Intratympanic Steroid Therapy for SSNHL

Approximately 37-48% of patients with Sudden Sensorineural Hearing Loss (SSNHL) show significant improvement after intratympanic (IT) steroid injections, with better outcomes when used as salvage therapy within 2-6 weeks after onset of symptoms. 1

Efficacy of Intratympanic Steroids

Primary Treatment vs. Salvage Therapy

• When used as primary treatment:

  • 75-87.5% of patients show some degree of improvement 2
  • Comparable to oral steroids (non-inferior) with 28.7 dB improvement vs 30.7 dB with oral steroids 3

• When used as salvage therapy (after failed systemic treatment):

  • 37-48% of patients show significant improvement 1
  • 44.4% of patients improve by 10 dB or more (vs 10.7% with placebo) 4
  • 57.1% show improvement of at least 15 dB 2

Factors Affecting Recovery Rates

1. Timing of intervention:

   • Critical factor - earlier treatment yields better results
   • No significant benefit observed when IT steroids administered after 36 days 5
   • Improvement rate increases from 26.9% to 39.3% when excluding patients treated after 6 weeks 5

2. Definition of improvement:

   • Using 10 dB improvement criteria: 33-55% of patients 6
   • Using 15 dB improvement criteria: 47-75% of patients 6
   • Using 20 dB improvement criteria: 26.7-27.5% of patients 6, 5
   • Using 30 dB improvement criteria: 53.3% of patients 6

3. Steroid type and concentration:

   • Methylprednisolone shows superior outcomes (84% improvement) compared to dexamethasone (64% improvement) 6
   • Higher concentrations yield better results:
     • Dexamethasone 24 mg/mL: 53% improvement
     • Dexamethasone 10 mg/mL: 17% improvement
     • Methylprednisolone 40-62.5 mg/mL: 55-75% improvement 6

Treatment Protocol

The American Academy of Otolaryngology-Head and Neck Surgery recommends:

• Dosing:

  • Dexamethasone 24 mg/mL or methylprednisolone 40-62.5 mg/mL
  • 0.4-0.8 mL injected into middle ear space

• Administration:

  • 3-4 injections over a 2-week period
  • Patient positioned with affected ear up for 15-30 minutes after injection 1, 6

• Timing:

  • Optimal window: 2-6 weeks after onset of symptoms (as salvage therapy)
  • Earlier administration associated with better outcomes 1, 6

Long-term Outcomes

• Final hearing levels are typically reached by:

  • 1 month in 90% of patients
  • 3 months in 98.3% of patients 1

• Stability of improvement:

  • Hearing improvements are generally stable at 6 months post-treatment 1

Clinical Pearls and Pitfalls

• Key pitfall: Delaying treatment beyond the optimal window (2-6 weeks)

  • No patient showed significant benefit from IT steroids after 36 days 5

• Monitoring recommendation:

  • Obtain audiograms before each injection and at completion of treatment course 6
  • Follow-up audiometric evaluation at 1,3, and 6 months to assess stability 1

• Patient selection:

  • Particularly beneficial for patients who cannot tolerate systemic steroids
  • Safe alternative for patients with diabetes, hypertension, glaucoma, and other conditions that contraindicate systemic steroids 6

In conclusion, intratympanic steroid therapy offers a viable treatment option for SSNHL with approximately 37-48% of patients showing significant improvement when used as salvage therapy, and higher rates when used as primary treatment. The timing of intervention is critical, with optimal results achieved when treatment is initiated within 2-6 weeks after symptom onset.