Preliminary study on intratympanic dexamethasone injection for management of patients with profound sudden hearing loss

Objective To evaluate the effects of intratympanic dexamethasone injection on patients with profound sudden heating loss. Methods All patients in the present study were profound sudden hearing loss, with initial heating loss of more than 90 dB, but no previous interventions was conducted on the 78 patients within 2 weeks onset of sudden heating loss. Patients were assigned to 3 groups according to patients' choice, Group Ⅰ （local and general dexamethasone administration, 22 cases ）, Group Ⅱ （ Intravenous dexamethasone injection, 44 cases ） , Group Ⅲ （ intratympanic dexamethasone injection, 12 cases）. In addition, vessel dilation drugs, neurotrophy and hyperbaric oxygen therapy were also conducted on all patients. Intravenous dexamethasone was applied 15 mg/d × 3 d, 10 mg/d × 3 d and 5 mg/d× 3 d, respectively. Intratympanic dexamethasone （5 mg/ml, 0. 8 ml） injection was performed during 10 days （ 1 injection/2 days）. Pure tone test was conducted on 10th, 20th, and 30th day after intervention. Results The factors which may impact on the prognosis were matched in all three groups. The threshold improvement more than 30 dB was 81.82% in group Ⅰ , 83.3% in group Ⅱ and 88.64% in group Ⅲ. Statistical study showed there was no significant different among 3 groups （P =0. 726）. On the 30th day after intervention, pure tone threshold improvement was 41.36 dB in group Ⅰ （local and general dexamethasone administration）, 43.08 dB in group Ⅱ （intravenous dexamethasone injection） and 51.70 dB in group Ⅲ （intratympanic dexamethasone injection ）. Furthermore, pure tone threshold improvement among the 3 groups was no statistical different （F = 1.58, P =0. 2133）. Obvious hearing improvement was noted on the 10th day after intervention, but no further improvement showed after 20 days intervention. More hearing improvement was revealed in the low frequency, while less hearing improvement was achieved in the high frequency. Conclusions Comparison with intravenous dexamethasone injection, intratympanie dexamethasone injection did not provide more hearing improvement on patients with profound sudden hearing loss. Key words: Hearing loss, sudden; Dexamethasone; Audiometry, pure-tone; Drug administration routes