Objective: To evaluate the effects of intratympanic methylprednisolone injection by microcatheter in diabetics with a sudden hearing loss.
Methods: From July 2005 to November 2009, 113 diabetics with a sudden hearing loss within an onset of 10 days at our department were recruited. But they received no previous intervention and were assigned to treatment and control groups. Treatment group were made by microcatheter connected with an insulin bump. Microcatheter was placed in a round window niche and methylprednisolone (62.5 mg/ml) infused at a rate of 10 microl/h for 14 days. Then the microcatheter was extracted. Simultaneously vasodilation, neurotrophic, thrombolysis and insulin hypoglycemia were administered in all patients. Pure tone test was conducted at Days 10 and 20 after intervention.
Results: The outcome was as follows: cure (n = 6), efficacy (n = 19), effect (n = 12) and no effect (n = 11) respectively. The overall effective rate of 77.08% in the treatment group was superior to that in the control group. And there was statistical difference (P < 0.05). Pure tone average (PTA) of two groups showed no statistical difference. After 10 days, the PTA values were (66 ± 21) versus (76 ± 14) dB in the treatment and control groups respectively. At Day 20, the values were (50 ± 16) and (59 ± 12) dB respectively. The improvement of pure tone threshold at Days 10 and 20 had significant statistical difference (P < 0.05). Neither group had hypoglycemia or diabetic complications during treatment. And the prognosis had no obvious correlation with the severity of diabetes.
Conclusion: The therapy of intratympanic methylprednisolone injection by microcatheter connected with micropump is both effective and feasible in diabetics with a sudden hearing loss.