Cochlear implantation as a successful rehabilitation for radiation-induced deafness

Radiotherapy of the head and neck can be associated with conductive and/or sensori-neural hearing loss. We report the case of a 67-year-old man who developed complete bilateral deafness caused by labyrinthitis and radiation-induced neuritis of the acoustic nerve after postoperative radiotherapy of a nasopharyngeal carcinoma. Two years postoperatively extensive clinical workup including computed tomography and magnetic resonance imaging showed no recurrence or secondary brain tumors. To facilitate sound perception a Combi 40 cochlear implant was implanted. Because of fibrosis the insertion depth of the stimulating electrode into the scala tympani was limited and therefore a "short electrode version" was used. Six months after implantation the patient had achieved an excellent environmental sound recognition and moderate speech intelligibility. Present experiences has shown that although radiotherapy can cause damage to the labyrinth and acoustic nerves and central hearing pathways, there may still be surviving auditory nerve fibers that can be stimulated successfully by a cochlear implant.