The aim of this study was to determine whether patients with neurofibromatosis Type 2 (NF2) who have intact ipsilateral cochlear nerves can have open-set speech discrimination following cochlear implantation.
Records of 7 patients with documented NF2 were reviewed to determine speech discrimination outcomes following cochlear implantation. Outcomes were measured using consonant-nucleus-consonant words and phonemes; Hearing in Noise Test sentences in quiet; and City University of New York sentences in quiet and in noise.
Preoperatively, none of the patients had open-set speech discrimination. Five of the 7 patients had previously undergone excision of ipsilateral vestibular schwannoma (VS). One of the patients who received a cochlear implant had received radiation therapy for ipsilateral VS, and another was undergoing observation for a small ipsilateral VS. Following cochlear implantation, 4 of 7 patients with NF2 had open-set speech discrimination following cochlear implantation during extended follow-up (15–120 months). Two of the 3 patients without open-set speech understanding had a prolonged period between ipsilateral VS resection and cochlear implantation (120 and 132 months), and had cochlear ossification at the time of implantation. The other patient without open-set speech understanding had good contralateral hearing at the time of cochlear implantation. Despite these findings, 6 of the 7 patients were daily users of their cochlear implants, and the seventh is an occasional user, indicating that all of the patients subjectively gained some benefit from their implants.
Cochlear implantation can provide long-term auditory rehabilitation, with open-set speech discrimination for patients with NF2 who have intact ipsilateral cochlear nerves. Factors that can affect implant performance include the following: 1) a prolonged time between VS resection and implantation; and 2) cochlear ossification.
Abbreviations used in this paper: ABI = auditory brainstem implant; CNC = consonant-nucleus-consonant; CNCp, CNCw = CNC phonemes and words; CROS = contralateral routing of sound devices; CUNY = City University of New York; CUNYn, CUNYq = CUNY sentences in noise and in quiet; HINT = Hearing in Noise Test; HINTn, HINTq = HINT performed in noise and in quiet; MCF = middle cranial fossa; NF2 = neurofibromatosis Type 2; RS = retrosigmoid; SDT = speech detection threshold; SNHL = sensorineural hearing loss; SRT = speech reception threshold; VS = vestibular schwannoma.
Address correspondence to: Pamela Roehm, M.D., Ph.D., Department of Otolaryngology, New York University School of Medicine, 530 First Avenue, Suite 7Q, New York, New York 10016. email: firstname.lastname@example.org.
Please include this information when citing this paper: published online July 15, 2011; DOI: 10.3171/2011.5.JNS101929.
ArísteguiMDeniaA: 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 Neurotol26:205–2102005
HulkaGFBernardEJPillsburyHC: 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 Surg121:465–4681995
NölleCTodtIBastaDUnterbergAMautnerVFErnstA: Cochlear implantation after acoustic tumour resection in neurofibromatosis type 2: impact of intra- and postoperative neural response telemetry monitoring. ORL J Otorhinolaryngol Relat Spec65:230–2342003
UK Cochlear Implant Study Group: Criteria of candidacy for unilateral cochlear implantation in postlingually deafened adults III: prospective evaluation of an actuarial approach to defining a criterion. Ear Hear25:361–3742004
WongHKLahdenrantaJKamounWSChanAWMcClatcheyAIPlotkinSR: Anti-vascular endothelial growth factor therapies as a novel therapeutic approach to treating neurofibromatosis-related tumors. Cancer Res70:3483–34932010