Objective: This study aimed to assess the results of hearing restoration with a cochlear or a brainstem implant in posterior fossa tumors.
Patients: Six patients were selected. Two patients with an acoustic neuroma in the only-hearing ear (cases 1 and 2), one patient with a posterior fossa meningioma (case 3), one patient with bilateral facial neuroma (case 4), and two patients with bilateral acoustic neuroma (cases 5 and 6) participated.
Intervention: In cases 1 and 2, the patients had a cochlear implant inserted on the only-hearing ear opposite the acoustic neuroma. In case 3, the patient presented with total deafness on the left side and a 10-mm meningioma on the right side. A cochlear implantation was performed after removal of the meningioma on the right side. In case 4, the patient was operated on on both sides with bilateral postoperative deafness. A cochlear implantation was performed on the better hearing ear. In cases 5 and 6, patients underwent an auditory brainstem implantation after the exeresis of the second tumor.
Results: Promontory test results were positive for patients 1, 2, 3, and 4. After implantation, patients 1, 2, 3, and 4 scored 98%, 13%, 70%, and 30%, respectively, in open-set sentence recognition tests, whereas patients 5 and 6 scored 0% and 20%, respectively.
Conclusions: In case of nonfunctional cochlear nerve, in acoustic neuroma, either bilateral and in the only-hearing ear, promontory test should be performed. If positive results, a cochlear implantation should be performed, because successful results could be expected. Overall results of cochlear implantation on speech discrimination are better than those obtained with a brainstem implant.