During the last 15 years, cochlear implantation became available as a method of treatment for different types of hearing impairment. Leading, specialized centers have now introduced the analysis of the nonsurgical factors that could contribute to improve rates of hearing preservation in preoperative period, during surgery, or in postoperative period in patients who suffer from partial deafness. One of the approaches is using pharmacotherapy (glucocorticoids) as a factor that may improve hearing functions. Preservation of hearing in patients who suffered from partial deafness and underwent cochlear implantation by using two different regimes of corticosteroid therapy was the aim of the study carried out by the World Hearing Center (WHC). Forty-six patients were enrolled in the trial and divided into three subgroups. Hearing preservation (HP) was evaluated using pure tone audiometry (PTA) (11 frequencies ranging from 125 to 8000 Hz). The impact of administrated substances was evaluated by pure tone audiometry during six different periods: before cochlear implant surgery, during activation of audio processor, and 1, 6, 9, and 12 months after activation of audio processor in comparison with control group. According to hearing preservation (HP) classification, patients from the second group, to whom combined glucocorticoid therapy was administrated, achieved the best HP results. The complete hearing preservation index was observed in the highest percentage of patients from the second subgroup. The dispersion of measured values was lesser than in other subgroups. According to the results, administration of glucocorticoids (dexamethasone and prednisone or dexamethasone only) to the patients, who suffered from partial deafness and underwent cochlear implantation surgery, may be important in stabilization of hearing thresholds and in protection of hearing.
Part of the book: The Human Auditory System