Objective: We aimed to evaluate and compare the auditory performance of neurofibromatosis type 2 (NF2) patients with bilateral total deafness fitted with cochlear or auditory brainstem implants. Patients and Methods: A retrospective case review was performed. Nine patients suffering from NF2 who underwent hearing rehabilitation by means of cochlear (4 patients) or auditory brainstem (5 patients) implantation participated in the study. Postoperative auditory performance was assessed using closed- and open-set tests. Results: In the group of patients fitted with a cochlear implant, 3 subjects achieved open-set speech recognition abilities comparable to those of standard adult postlingual implant patients; the remaining patient scored 0% in all open-set format tests, reporting benefits only in environmental sound detection and lip-reading. Among the 5 patients who underwent auditory brainstem implantation, 1 reached good open-set speech recognition skills, scoring 70% in the common phrases comprehension test, and she was able to communicate on the telephone. Two other patients achieved open-set speech understanding (respectively, 33 and 41% in the common phrases comprehension test), reporting daily use of their device. The remaining 2 patients did not achieve any level of open-set speech perception, obtaining only improved access to environmental sound and lip-reading skills. Conclusions: Our study confirmed literature data reporting that cochlear implantation may offer open-set speech communication in NF2 patients. In this small cohort, cochlear implant patients performed better than auditory brainstem implant patients, even if variability in auditory performance was observed with both devices. More studies are needed in order to clarify the role and reliability of electrophysiological tests in predicting the residual functionality of the cochlear nerve after tumor removal.

Keywords:
Neurofibromatosis type 2, Deafness, Cochlear implantation, Auditory brainstem implantation, Acoustic tumors
1.
Ahsan S, Telischi F, Hodges A, Balkany T: Cochlear implantation concurrent with translabyrinthine acoustic neuroma resection. Laryngoscope 2003;113:472–474.
2.
Aristegui M, Denia A: Simultaneous cochlear implantation and translabyrinthine removal of vestibular schwannoma in an only hearing ear: report of two cases (neurofibromatosis type 2 and unilateral vestibular schwannoma). Otol Neurotol 2005;26:205–210.
3.
Belal AA: Is cochlear implantation possible after acoustic tumor removal? Otol Neurotol 2001;22:497–500.
4.
Chen DA, Linthicum FH, Rizer FM: Cochlear histopathology in the labyrinthectomized ear: implications for cochlear implantation. Laryngoscope 1988;98:1170–1172.
5.
Cohen NL, Ransohoff J, Kohan D, Hoffman R: Cochlear implants in the treatment of acoustic neuromas: a treatment algorithm for bilateral acoustic neuromas (BAN) – acoustic neuroma; in Tos M, Thomsen J (eds): Proceedings of the First International Conference on Acoustic Neuroma, Copenhagen, Denmark, 1991. Amsterdam, Kugler Publications, 1992, pp 857–862.
6.
Colletti V, Carner M, Miorelli V, Guida M, Colletti L, Fiorino F: Auditory brainstem implant (ABI): new frontiers in adults and children. Otolaryngol Head Neck Surg 2005;133:126–138.
7.
Cueva RA, Thedinger BA, Harris JP, Glasscock ME 3rd: Electrical promontory stimulation in patients with intact cochlear nerve and anacusis following acoustic neuroma surgery. Laryngoscope 1992;102:1220–1224.
8.
Facer GW, Facer ML, Fowler CM, Brey RH, Peterson AM: Cochlear implantation after labyrinthectomy. Am J Otol 2000;21:336–340.
9.
Friedman RA, Brackmann DE, Mills D: Auditory-nerve integrity after middle-fossa acoustic-tumor removal. Otolaryngol Head Neck Surg 1998;119:588–592.
10.
Graham J, Lynch C, Weber B, Stollwerck L, Wei J, Brookes G: The magnetless Clarion cochlear implant in a patient with neurofibromatosis 2. J Laryngol Otol 1999;113:458–463.
11.
Hoffman RA, Kohan D, Cohen NL: Cochlear implants in the management of bilateral acoustic neuromas. Am J Otol 1992;13:525–528.
12.
House WF, Hitselberger WE: Twenty-year report of the first auditory brainstem nucleus implant. Ann Otol Rhinol Laryngol 2001;110:103.
13.
Hulka GF, Bernard EJ, Pillsbury HC: Cochlear implantation in a patient after removal of an acoustic neuroma: the implications of magnetic resonance imaging with gadolinium on patient management. Arch Otolaryngol Head Neck Surg 1995;121:465–468.
14.
Jackler RK: Acoustic neuroma (vestibular schwannoma); in: Jackler RK, Brackman DE (eds): Neurotology. St Louis, Mosby, 1994, pp 729–785.
15.
Kanovitz SJ, Shapiro WH, Golfinos JG, Cohen NL, Roland JT Jr: Auditory brainstem implantation in patients with neurofibromatosis type 2. Laryngoscope 2004;114:2135–2146.
16.
Kveton JF, Abbott C, April M, Drumheller G, Cohen N, Poe DS: Cochlear implantation after transmastoid labyrinthectomy. Laryngoscope 1989;99:610–613.
17.
Lenarz T, Lim HH, Reuter G, Patrick JF, Lenarz M: The auditory prosthesis for neural deafness – concept and device description. Otol Neurotol 2006;27:838–843.
18.
Lustig LR, Yeagle J, Driscoll CLW, Blevins N, Francio H, Niparko JK: Cochlear implantation in patients with neurofibromatosis type 2 and bilateral vestibular schwannoma. Otol Neurotol 2006;27:512–518.
19.
Marangos N, Stecker M, Laszig R: Topodiagnosis of deafness: strategy for treatment of neurofibromatosis type 2. J Laryngol Otol 2000;114:3–7.
20.
Neff BA, Wiet RM, Lasak JM, Cohen NL, Pillsbury HC, Ramsden RT, Welling DB: Cochlear implantation in the neurofibromatosis type 2 patient: long-term follow-up. Laryngoscope 2007;117:1069–1072.
21.
Nevison B, Laszig R, Sollmann WP, Lenarz T, Sterkers O, Ramsden R, Fraysse B, Manrique M, Rask-Andersen H, Garcia-Ibanez E, Colletti V, von Wallemberg E: Results from a European clinical investigation of the Nucleus multichannel auditory brainstem implant. Ear Hear 2002;23:170–183.
22.
Nolle C, Todt I, Basta D, Unterberg A, Mautner VF, Ernst A: Cochlear implantation after tumor resection in neurofibromatosis type 2: impact of infra- and postoperative neural response telemetry monitoring. ORL 2003;65:230–234.
23.
Otto SR, Brackmann DE, Hitselberger WE, Shannon RV, Kuchta J: Multichannel auditory brainstem implant: update on performance in 61 patients. J Neurosurgery 2002;96:1063–1071.
24.
Sanna M, Saleh E, Panizza B, Russo A, Taibah A: Decision making in acoustic neurinoma surgery; in: Sanna M (ed): Atlas of Acoustic Neurinoma Microsurgery. New York, Thieme, 1998, pp 35–38.
25.
Temple RH, Axon PR, Ramsden RT, Keles N, Deger K, Yucel E: Auditory rehabilitation in neurofibromatosis type 2: a case for cochlear implantation. J Laryngol Otol 1999;113:161–163.
26.
Tono T, Ushisako Y, Morimitsu T: Cochlear implantation in an intralabyrinthine acoustic neuroma patient after resection of an intracanalicular tumor. J Laryngol Otol 1996;110:570–573.
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2008
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