Sudden Sensorineural Hearing Loss Treatment

Introduction to Salvage Therapy

The American Academy of Otolaryngology-Head and Neck Surgery recommends intratympanic steroid injections as salvage therapy for patients with sudden sensorineural hearing loss who have incomplete recovery after initial systemic steroid treatment 1, 2
Local steroid administration has minimal systemic side effects, making it suitable for patients who cannot tolerate systemic steroids due to conditions like diabetes, hypertension, or glaucoma 1, 2

Intratympanic steroid injections are most effective when initiated within 2-6 weeks after onset of symptoms, and should be started within 2-7 days after completion of systemic treatment for optimal results 1
For new-onset SSNHL, if the patient can tolerate systemic steroids, start with oral prednisone (1 mg/kg/day, max 60 mg) for 7-14 days, otherwise proceed directly to IT steroid injections 1
For incomplete recovery after initial treatment (2-6 weeks from onset), offer IT steroid injections as salvage therapy, administering 4 injections over 2 weeks 1

37-48% of patients show significant hearing improvement with intratympanic steroid injections as salvage therapy 1
Meta-analysis shows mean improvement of 13.3 dB compared to placebo (p<0.0001) 1
Hearing improvement criteria:
Improvement rates in pure-tone average (PTA) have been reported:

Wu et al. showed 44.4% improvement with IT steroids vs 10.7% in control group 1
Li et al. demonstrated 37.5% improvement with IT steroids vs 0% in control group 1
Methylprednisolone shows superior outcomes with an 84% improvement rate compared to dexamethasone with a 64% improvement rate, and higher concentrations of dexamethasone yield better results, with 24 mg/mL showing superior outcomes (53% improvement) compared to 10 mg/mL (17% improvement) 2

Specialized delivery systems such as microcatheters, MicroWick, hydrogel applications, and nanoparticles can be used for intratympanic steroid injections 1
The recommended dosing for intratympanic injections is 0.4-0.8 mL of dexamethasone (24 mg/mL) or methylprednisolone (40-62.5 mg/mL) injected into the middle ear space, administered as 3-4 injections over 2 weeks, with the patient positioned with the affected ear up for 15-30 minutes after injection, as recommended by the American Academy of Otolaryngology-Head and Neck Surgery 1, 2
The administration procedure involves positioning the patient with the affected ear up, injecting through an anterosuperior myringotomy after topical anesthetic 2

Audiometric evaluation should be performed at 1 month, 3 months, and 6 months after treatment to assess hearing improvement and stability 2
Final hearing levels are typically reached by 1 month in 90% of patients and 3 months in 98.3% of patients, with hearing improvements generally stable at 6 months post-treatment, according to the American Academy of Otolaryngology-Head and Neck Surgery 1
The American Academy of Otolaryngology-Head and Neck Surgery recommends follow-up audiometric evaluation at 1, 3, and 6 months to assess stability 1

Possible side effects of otic dexamethasone include:

Risk	Description
Transient pain	Pain at injection site
Brief vertigo	Caloric vertigo
Tympanic membrane perforation	Persistent perforation
Infection	Possible infection
Vasovagal or syncopal episode	Possible episode during injection

The treatment has minimal systemic side effects, making it a safe alternative for patients with conditions that contraindicate systemic steroids, such as diabetes, cataracts, glaucoma, and other conditions 1, 2

Patients with moderately severe to mild sensorineural hearing loss and poor word recognition score may benefit from IT steroid injections, particularly those who cannot tolerate systemic steroids due to certain conditions 2, 1