What is the role of intratympanic (within the tympanic cavity) steroid injections, such as dexamethasone (generic name) or methylprednisolone (generic name), in treating sudden sensorineural hearing loss or Meniere's disease?

Intratympanic Steroid Injections for Sudden Sensorineural Hearing Loss and Meniere's Disease

Intratympanic steroid injections should be offered as salvage therapy for patients with incomplete recovery from sudden sensorineural hearing loss (SSNHL) 2-6 weeks after onset of symptoms, and can be considered as primary therapy for patients who cannot tolerate systemic steroids. 1

Role in Sudden Sensorineural Hearing Loss (SSNHL)

As Salvage Therapy

Intratympanic (IT) steroids play a crucial role as salvage therapy for SSNHL when initial treatment fails to produce complete recovery. The evidence strongly supports this approach:

• Timing: Should be administered 2-6 weeks after onset of symptoms when initial management (systemic steroids or observation) has failed 1
• Efficacy: Multiple randomized controlled trials demonstrate significant hearing improvement:
  • 37.5-47.6% of patients show ≥10 dB improvement with IT steroids vs 0-16% in control groups 1
  • The most recent evidence shows 44.4% of patients improved with IT dexamethasone compared to 10.7% in placebo group 2

As Primary Therapy

IT steroids can be used as primary therapy in specific situations:

• Patient selection: Particularly beneficial for patients who cannot receive systemic steroids due to:
  • Insulin-dependent or poorly controlled diabetes
  • Labile hypertension
  • Glaucoma
  • Tuberculosis
  • Peptic ulcer disease
  • Prior psychiatric reactions to corticosteroids 1
• Efficacy: Studies show 66-85% success rates when used as primary initial treatment 3

Role in Meniere's Disease

IT steroid injections can be effective for Meniere's disease patients experiencing acute hearing deterioration:

• In patients with Meniere's disease and sudden hearing loss who failed intravenous steroid treatment, 15 out of 21 patients (71%) showed hearing improvement after IT dexamethasone with hyaluronic acid 4
• IT steroids may help control vertigo symptoms, though evidence is less robust than for hearing improvement

Administration Protocol

Medication Options

• Dexamethasone: 10-24 mg/mL (higher concentrations appear to have better outcomes)
• Methylprednisolone: 30-40 mg/mL 1

Administration Technique

1. Fill the middle ear with steroid solution (0.4-0.8 mL)
2. Keep the patient's head positioned with affected ear up for 15-30 minutes
3. Typically administered as multiple injections:
   • For salvage therapy: 4 injections over a 2-week period
   • For primary therapy: Twice weekly injections for 2 weeks 1, 3

Monitoring

• Audiogram at completion of treatment and at delayed intervals
• Inspect tympanic membrane to ensure healing 1

Benefits and Risks

Benefits

• Delivers higher concentration of steroids to the inner ear compared to systemic administration
• Avoids systemic side effects of oral/IV steroids
• Safe for patients with diabetes, cataracts, myasthenia gravis, and glaucoma 1
• Can be performed as an office-based procedure 3

Risks

• Pain during injection
• Transient dizziness
• Infection
• Persistent tympanic membrane perforation (rare)
• Possible vasovagal or syncopal episode during injection 1
• Multiple office visits required

Clinical Decision Algorithm

1. For new-onset SSNHL:

   • If patient can tolerate systemic steroids → Start with oral prednisone (1 mg/kg/day, max 60 mg) for 7-14 days
   • If patient cannot tolerate systemic steroids → Proceed directly to IT steroid injections

2. For incomplete recovery after initial treatment (2-6 weeks from onset):

   • Offer IT steroid injections as salvage therapy
   • Administer 4 injections over 2 weeks

3. For Meniere's disease with acute hearing deterioration:

   • Consider IT steroid injections, particularly if patient has failed conventional treatments
   • Consider adding hyaluronic acid as a round window membrane facilitator to improve steroid penetration 4

Important Considerations

• Timing is critical: Earlier administration of IT steroids (within 2 weeks of onset for primary therapy, within 7 days after systemic treatment failure for salvage therapy) is associated with better outcomes 1
• Concentration matters: Higher concentrations of steroids appear to yield better results (24 mg/mL dexamethasone showed 53% improvement vs 17% with 10 mg/mL) 1
• Combination therapy: Some evidence suggests combining IT steroids with hyaluronic acid may improve outcomes, particularly in Meniere's disease 4
• Standardized outcome measures: Success is typically defined as ≥10 dB improvement in pure tone average or ≥15-20% improvement in speech discrimination 2, 5

IT steroid therapy represents an important treatment option that can significantly improve quality of life through hearing recovery, particularly for patients who have failed initial treatment or cannot tolerate systemic steroids.