Schon F, Muller J, Helms J (2002) Speech reception thresholds obtained in a symmetrical four- loudspeaker arrangement from bilateral users of MED-EL cochlear implants. Otology and Neurotology 23(5): 710–714. Tyler RS, Gantz BJ, Rubinstein JT, Wilson BS, Parkinson AJ, Wolaver A, Preece JP, Witt S, Lowder MW (2002) Three-month results with bilateral cochlear implants. Ear and Hearing 23(Suppl): 80S–89S. Van Hoesel R, Ramsden R, O’Driscoll M (2002) Sound-direction identification, interaural time delay discrimination, and speech intelligibility advantages in noise for a bilateral cochlear implant user. Ear and Hearing 23(2): 137–149. Vestibular schwannoma and cochlear implantation P GARIN, N DEGGOUJ, M DECAT, M GERSDORFF, Cliniques Universitaires Saint Luc, Brussels, Belgium Introduction It is fairly uncommon to be faced with a clinical situation combining the presence of vestibular schwannoma and cochlear implantation. This complex situation is found mainly in patients suffering from type II neurofibromatosis (NF2) and calls for delicate therapeutic options. We describe three clinical cases. Case 1 A 42-year-old male patient suffered from complete deafness in his left ear, which was ascribable to Alport syndrome, and had a grade I vestibular schwannoma in the right internal auditory canal, causing severe deafness in the right ear. To deal with his deafness, he wore a conventional hearing aid; however, this was of limited help. In spite of his hearing handicap, he continued to act as a lawyer, and now sought our advice in his quest for a more efficient hearing aid. The patient refused to have his right schwannoma removed, since we could not guarantee that his residual hearing would be preserved. Hence, we placed a Nucleus CI24M cochlear implant in his left ear. This resulted in outstanding acoustic rehabilitation, which can be compared to the results we have obtained, on average, in adults who have had an implant because of acquired postlingual deafness with an anatomically normal inner ear and cochlear nerve . Discussion There are several possible options for monitoring the development of the vestibular schwannoma, which has remained in place in the ear contra-lateral to the implant (Arriaga and Marks, 1995; Tono et al., 1996; Graham et al., 1999): • cerebral computed tomography (CT) scan with contrast: may not involve any risk whatsoever for the cochlear implant’s magnet, yet it won’t tell us anything but about the growth of the schwannoma outside the internal auditory meatus, in the cerebellopontine angle • cerebral magnetic resonance, using magnetic fields of weak intensity (less than 1.5 tesla); even when using a bandeau tightly squeezed around the patient’s head may involve a minor risk of mobilizing the cochlear implant, but each sequence of diagnostic imaging will partially demag- netize the cochlear implant’s magnet, which in the end may lose up to 10% of its power in each of these sequences • removing the magnet of the Nucleus cochlear implant prior to each magnetic resonance and replacing it immediately; this can be carried out under local anaesthesia, but will cause fibrosis and possible cicatrization problems which may render the procedure unfeasible when carried out repeatedly on too many occasions 28 Proceedings of the 4th International Symposium on Electronic Implants in Otology