Cochlear implants in five cases of auditory neuropathy: postoperative findings and progress.

OBJECTIVES: To review our experiences with some of the preoperative and postoperative findings in five children who were diagnosed with auditory neuropathy and were provided with cochlear implants. We describe changes in auditory function, which enabled these children to have significant improvement in their hearing and communication skills. STUDY DESIGN: Pre- and postoperatively, these children received complete medical examinations at Mayo Clinic, including related consultations in audiology, pediatrics, neurology, medical genetics, otolaryngology, psychology, speech pathology, and radiology. METHODS: These children typically had additional medical and audiological examinations at more than one medical center. The hearing assessments of these children included appropriate behavioral audiometric techniques, objective measures of middle ear function, acoustic reflex studies, transient (TOAE) or distortion product (DPOAE) otoacoustic emissions, auditory brainstem responses (ABR), and, in some cases, transtympanic electrocochleography (ECoG). After placement of the internal cochlear implant devices (Nucleus CI24), intraoperatively we measured electrode impedances, visually detected electrical stapedius reflexes (VESR) and neural response telemetry (NRT). These intraoperative objective measures were used to help program the speech processor for each child. Postoperatively, each child has had regular follow-up to assure complete healing of the surgical incision, to assess their general medical conditions, and for speech processor programming. Their hearing and communication skills have been assessed on a regular basis. Postoperatively, we have also repeated electrode impedance measurements, NRT measurements, otoacoustic emissions, and electrical auditory brainstem responses (EABR). We now have 1 year or more follow-up information on the five children. RESULTS: The five children implanted at Mayo Clinic Rochester have not had any postoperative medical or cochlear implant device complications. All of the children have shown significant improvements in their sound detection, speech perception abilities and communication skills. All of the children have shown evidence of good NRT results. All but case D (who was not tested) showed evidence of good postoperative EABR results. Otoacoustic emissions typically remained in the non-operated ear but, as expected, they are now absent in the operated ear. CONCLUSION: Our experiences with cochlear implantation for children diagnosed with auditory neuropathy have been very positive. The five children we have implanted have not had any complications postoperatively, and each child has shown improved listening and communication skills that have enabled each child to take advantage of different communication and educational options.

Hearing and otopathology in Crouzon syndrome.

OBJECTIVES: To better establish the incidence and types of otologic and auditory abnormalities in patients with Crouzon syndrome. STUDY DESIGN: Retrospective chart review of the otologic and auditory findings of patients diagnosed with Crouzon syndrome who were seen at our institution between 1978 and 1994. METHODS: Charts were reviewed and data recorded on patient sex, family history, appearance, auricular abnormalities, auditory findings, history of otologic disease, and follow-up. RESULTS: Nineteen patients were identified with the diagnosis of Crouzon syndrome: 12 males and 7 females. Twelve cases represented spontaneous mutations. Eight patients had abnormalities involving the external ear: from malalignment of the pinna (6 patients) to external auditory canal atresia (1 patient). Ten patients had documented hearing loss: 4 with conductive hearing loss, 2 with a mixed hearing loss, and 4 with a sensorineural hearing loss, the etiologies of which ranged from ossicular fixation and serous otitis media to unknown sensorineural deficits. CONCLUSIONS: Patients with Crouzon syndrome can exhibit various pathological features of the ear. Although external malformations are unusual, middle ear disease and hearing loss are common. We advocate close otologic and audiologic follow-up in these patients and note a higher frequency of sensorineural hearing loss than previously reported. Recent genetic advances may allow more accurate and earlier diagnosis of this syndrome.