Histopathological analysis of a 15-year user of an auditory brainstem implant.

Auditory brainstem implants (ABIs) can provide highly beneficial hearing sensations to individuals deafened by bilateral vestibular schwannomas (neurofibromatosis type 2). Relatively little is known about the status of stimulated neurons after long-term ABI use. Direct examination of the cochlear nuclear complex (CN) of one 5-year ABI user indicated no deleterious effect.

Evolution of techniques for the resection of vestibular schwannomas: from saving life to saving function.

The current state of surgery for vestibular schwannomas (VSs) is the result of a century of step-by-step technical progress by groundbreaking surgeons who transformed the procedure from its hazardous infancy and high mortality rate to its current state of safety and low morbidity rate. Harvey Cushing advocated bilateral suboccipital decompression and developed the method of intracapsular tumor enucleation. Walter Dandy supported the unilateral suboccipital approach and developed the technique of gross-total tumor resection.

Audiologic outcomes with the penetrating electrode auditory brainstem implant.

Objective: The penetrating electrode auditory brainstem implant (PABI) is an extension of auditory brainstem implant (ABI) technology originally developed for individuals deafened by neurofibromatosis type 2. Whereas the conventional ABI uses surface electrodes on the cochlear nuclei, the PABI uses 8 or 10 penetrating microelectrodes in conjunction with a separate array of 10 or 12 surface electrodes. The goals of the PABI were to use microstimulation to reduce threshold current levels, increase the range of pitch percepts, and improve electrode selectivity and speech recognition.

Auditory brainstem implants.

The development of cochlear implantation has allowed the majority of patients deafened after the development of language to regain significant auditory benefit. In a subset of patients, however, loss of hearing results from destruction of the cochlear nerves, rendering cochlear implantation ineffective. The most common cause of bilateral destruction of the cochlear nerves is neurofibromatosis type 2 (NF2).

Hearing preservation surgery for neurofibromatosis Type 2-related vestibular schwannoma in pediatric patients.

Object: The authors reviewed the proportion of pediatric patients with neurofibromatosis Type 2 (NF2) in whom hearing was preserved after middle fossa resection of vestibular schwannoma (VS).

Methods: In this retrospective chart review the authors examined the cases of 35 children with NF2 who had undergone middle fossa resection (47 surgeries) between 1992 and 2004 in a neurotological tertiary care center. Surgical outcome was assessed using pure-tone average (PTA) thresholds obtained before and immediately after resection.

Surgical salvage after failed irradiation for vestibular schwannoma.

Objectives/hypothesis: Compare vestibular schwannoma (VS) surgical outcome between patients with prior irradiation and those not previously treated.

Study Design: Retrospective review with matched control group.

Methods: Review of tumor adherence to the facial nerve, facial nerve grade, and complications in 38 patients with radiotherapy as a primary procedure before VS surgical removal and a matched random sample of 38 patients with primary surgery.

Neurotologic skull base surgery in pediatric patients.

Objective: Innovations in diagnosis, surgical techniques, and perioperative care have dramatically improved outcomes in lateral skull base procedures in recent years. There is a belief, however, that children with skull base tumors have yet to benefit from these technological and procedural advances. The purpose of this study is to provide a clinical review of neurotologic skull base surgery in the pediatric population.

Auditory brainstem implantation in 12- to 18-year-olds.

Objective: To assess the effects of the side of implantation (first-side vs second-side vestibular schwannoma); the presence of nonauditory sensations; the general health, expectations, and motivation of the patients; and a support group on the use of a multichannel auditory brainstem implant (ABI) in 12- to 18-year-old patients with neurofibromatosis 2.

Design: Since 1992, 21 individuals (age range, 12-18 years) who were deafened by neurofibromatosis 2 have undergone implantation with a multichannel ABI at the House Ear Institute, Los Angeles, Calif. The patients were categorized regarding side of implantation, presence of remaining hearing (in first-side implant recipients), incidence of nonauditory sensations, and ABI use or nonuse.

The evolution of surgical approaches for posterior fossa meningiomas.

Objective: To evaluate surgical outcomes for the treatment of posterior fossa meningiomas at the House Ear Clinic from 1987 to 2001. We review our current treatment algorithm and present our postoperative outcomes with attention to facial and auditory neural preservation.

Study Design: Retrospective review.

The multichannel auditory brainstem implant: how many electrodes make sense?

Object: Development of multichannel auditory brainstem implant (ABI) systems has been based in part on the assumption that audiological outcome can be optimized by increasing the number of available electrodes. In this paper the authors critically analyze this assumption on the basis of a retrospective clinical study performed using the Nucleus 22 ABI surface electrode array.

Methods: The perceptual performances of 61 patients with neurofibromatosis Type 2 were tested approximately 6 weeks after an eight-electrode ABI had been implanted.

Use of a multichannel auditory brainstem implant for neurofibromatosis type 2.

Neurofibromatosis type 2 (NF 2) typically results in deafness due to disruption of the cochlear nerves, making peripheral devices such as cochlear implants ineffective. Auditory brainstem implants (ABIs), for direct electrical stimulation of the cochlear nucleus, have been used to provide auditory stimulation in this group of patients. Currently, 141 patients have been implanted in our institution, most recently using an advanced multichannel device.

Long-term hearing preservation after middle fossa removal of vestibular schwannoma.

Objective: We sought to determine long-term hearing preservation in vestibular schwannoma patients after undergoing middle fossa resection. STUDY DESIGN, SETTING, AND OUTCOME MEASURES: We conducted a retrospective chart review of patients undergoing middle fossa resection from 1990 to 1995 at a tertiary care center. Pure-tone thresholds, before resection and at least 5 years after resection, and speech discrimination scores are reported.

Multichannel auditory brainstem implant: update on performance in 61 patients.

Object: Neurofibromatosis Type 2 (NF2) has typically resulted in deafness after surgical removal of bilateral vestibular schwannomas (VSs). Cochlear implants are generally ineffective for this kind of deafness because of the loss of continuity in the auditory nerve after tumor removal. The first auditory brainstem implant (ABI) in such a patient was performed in 1979 at the House Ear Institute, and this individual continues to benefit from electrical stimulation of the cochlear nucleus complex.

Growth of postoperative remnants of unilateral vestibular nerve schwannoma: role of the vestibular ganglion.

Histopathological examination of seven temporal bones from patients who underwent a removal of vestibular nerve schwannomas by the translabyrithine or middle fossa approaches has demonstrated small tumor remnants that failed to grow as long as 25 years after surgery. In spite of the high incidence of residual tumors, the clinical recurrence rate of tumors operated at our institution by the translabyrinthine or middle fossa approaches is low (0.3%).