How effective is intratympanic dexamethasone (ITD) injection for the treatment of sudden sensorineural hearing loss (SSNHL) compared to systemic administration?
There is no sufficient scientific evidence to support a difference between ITD and alternative therapy for SSNHL. Larger andomized controlled clinical trials (RCCTs) are needed to determine ITD effectiveness compared to oral steroid therapy.
Background: Idiopathic SSNHL has been widely studied. The majority of treatment protocols are centered on glucocorticoids due to their antioxidant and anti-inflammatory properties, but there are potential adverse effects. IT steroid administration is a promising technique, but a consensus has not been reached on IT steroid indications, concentrations, dosage, and a standardized treatment protocol.
Study design: Systematic review and meta-analysis of eight RCTs, with 416 participants across the studies (192 treatment, 224 control).
Setting: Cochrane, Embase, and MEDLINE electronic databases from January 1950 to August 2014, with an update performed on Nov. 10, 2014.
Synopsis: ITD dosing regimens and ITD concentrations varied, ranging from 4 mg/mL23 to 12 mg/mL. ITD volume injected varied between 0.3 and 0.7 mL. Efficacy rates varied between 89% and 50% as a second-line treatment for refractory SSNHL. Hearing improvement was seen in 72% of all treatment patients; complete hearing recovery was achieved in 20%, with 52% achieving partial hearing improvement and 28% showing no improvement. A meta-analysis comparing treatment groups to control groups did not reach statistical significance. There were no serious or life-threatening side effects (SE).
SE Group 1 (procedure-related, very short-term, self-resolving) included 54 events (81% of all SE; 13% of study population) such as otalgia, ear fullness, headache, short-lived vertigo, and dizziness. SE Group 2 (procedure-related short-term, requiring medical or surgical intervention) included five events (7.7% of all SE; 1.2% of study population). SE Group 3 (procedure-related long-term, requiring medical or surgical intervention) included three events (4.6% of all SE; 0.7% of study population). SE Group 4 (drug-related) included one case of acne.
Limitations included potential bias from not blinding participants, personnel, and assessors, and a lower data reporting quality.
Citation: El Sabbagh, NG, Sewitch MJ, Bezdjian A, Daniel SJ. Intratympanic dexamethasone in sudden sensorineural hearing loss: a systematic review and meta-analysis. Laryngoscope. 2017;127:1897–1908.