Faculty Bibliography

Acoustic neuromas (ANs) are the most common tumors of the cerebellopontine angle. Although numerous advances have occurred in the operative management of AN and perioperative care leading to a significant decrease in associated morbidity and mortality, there are several characteristic complications that accompany microsurgical resection of AN. Understanding the types and rates of complications in association with the various approaches is essential in patient counseling, establishing patient expectations, and ensuring the best patient outcome. In this article, the justification for incomplete surgical resection is discussed. Also, the most common complications of AN microsurgery and the associated management are reviewed.

Implantation of the ossified and dysplastic cochlea presents many unique challenges to both the surgeon and programming team. Altered embryology and physiology of these labyrinthine dysplasias may result in forms and functions unfamiliar to those casually involved with cochlear implants. Remarkable developments in diagnosis, surgical technique, electrode design, processing strategies, and programming have all contributed to the ability to successfully implant patient populations previously excluded from this life-changing intervention

Since the first cochlear implant approved by the US Food and Drug Administration in the early 1980s, great advances have occurred in cochlear implant technology. With these advances, patient selection, preoperative evaluation, and rehabilitation consideration continue to evolve. This article describes the current practice in pediatric candidacy evaluation, reviews the medical and surgical considerations in pediatric cochlear implantation, and explores the expanding criteria for cochlear implantation within the pediatric population

OBJECTIVE: To generate an evidence-based algorithm for the use of intraoperative testing during cochlear implantation (CI). STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: A total of 277 children (aged 6 mo to 17 yr) and adults 18 years and older with normal cochlear anatomy who underwent primary and revision cochlear implantation at a single center between 2005 and 2010 were included. INTERVENTION: Intraoperative electrophysiologic monitoring and intraoperative Stenver's view plain film radiography. MAIN OUTCOME MEASURE: Intraoperative testing included the following: 1) individual electrode impedance measurements; 2) neural response telemetry (tNRT) levels for electrodes E20, E15, E10, and E5; and 3) plain film radiograph assessment of electrode position. RESULTS: No patient demonstrated abnormalities on all 3 modalities. Open or short electrodes on impedance testing were found in 6% of patients; half of these normalized when remeasured. Absent tNRT responses on 1 or more electrodes occurred in 14% of patients, although complete lack of response was rare (1.4%) and did not correlate with a dysfunctional device. Spread of excitation was performed in 1 patient and was consistent with a tip rollover. Intraoperative radiography identified tip-rollover and extracochlear electrode placement in all cases (n = 5, 1.8%) and prompted the use of the backup device. CONCLUSION: Immediate intraoperative determination of device functionality and optimal electrode placement is advantageous. Of the modalities tested, including electrode impedance, tNRT, and plain radiograph, only the radiographic results impacted intraoperative surgical decision making and led to the use of the backup device

Cochlear implants have a remarkable history and a promising future. As the cochlear implant has evolved, so has the surgical technique. This review encompasses a history of the cochlear implant, a summary of the evolution of the implant incision and the methods used to secure the device and the electrode, the cochleostomy versus round window debate, and a discussion of the validity of intraoperative tests. Advanced technology, new surgical techniques, and refining established techniques are hallmarks of cochlear implant surgery. Advancements, including image-guided surgery, hearing preservation with full insertion, and telemetry-based advanced programming, are expected to be standard in the future

OBJECTIVES: To determine the efficacy of cochlear implantation (CI) in prelingually deafened adolescent children and to evaluate predictive variables for successful outcomes. DESIGN: Retrospective medical record review. PARTICIPANTS: Children aged 10 to 17 years with prelingual hearing loss (mean length of deafness, 11.5 years) who received a unilateral CI (mean age at CI, 12.9 years). Intervention Unilateral CI. MAIN OUTCOME MEASURES: Standard speech perception testing (Consonant-Nucleus-Consonant [CNC] monosyllabic word test and Hearing in Noise [HINT] sentence test) was performed preoperatively, 1 year postoperatively (year 1), and at the last follow-up/end of the study (EOS). RESULTS: There was a highly significant improvement in speech perception scores for both HINT sentence and CNC word testing from the preoperative testing to year 1 (mean change score, 51.10% and 32.23%, respectively; P < .001) and from the preoperative testing to EOS (mean change score, 60.02% and 38.73%, respectively; P < .001), with a significantly greater increase during the first year (P < .001). In addition, there was a highly significant correlation between improvements in performance scores on the CNC word and HINT sentence speech perception tests and both age at CI and length of deafness at the year 1 testing (P </=.009) but not from the year 1 testing to EOS testing. Adolescents with progressive deafness and those using oral communication before CI performed significantly better than age-matched peers. CONCLUSIONS: Adolescents with prelingual deafness undergoing unilateral CI show significant improvement in objective hearing outcome measures. Patients with shorter lengths of deafness and earlier age at CI tend to outperform their peers. In addition, patients with progressive deafness and those using oral communication have significantly better objective outcomes than their peers

OBJECTIVE: To evaluate and compare image quality between flat-panel volumetric computed tomography (fpVCT) and multislice CT (msCT) in temporal bones with cochlear implants (CIs), and to evaluate fpVCT imaging for accuracy in determining CI electrode positioning. METHODS: Six cadaveric temporal bones were imaged prior to CI using fpVCT. Each bone was implanted with an electrode array and rescanned in order to create radial reformatted images through each electrode contact. Electrode-modiolar interval (EMI) distances were measured. The bones were fixed and cut in order to grossly evaluate for CI intrascalar positioning and insertional trauma. MAIN OUTCOME MEASURE: To compare image quality between fpVCT and msCT in temporal bones with CI, and to evaluate the utility of fpVCT in post-implantation temporal bone analysis. RESULTS: The mean EMI distances did not differ significantly between fpVCT and msCT images, while the image quality was significantly better for fpVCT. Furthermore, information about intracochlear trauma and intrascalar electrode array positioning can be ascertained using this radiographic technique. CONCLUSION: fpVCT and msCT do not differ significantly in the evaluation of EMI distances in implanted temporal bones, but the image quality is significantly better using fpVCT. Additionally, useful information regarding intracochlear trauma, electrode depth of insertion, and intrascalar positioning can be gained from fpVCT imaging. Given the ease of use, superior image quality, improved convenience, reduced levels of radiation, and agreement with histology, fpVCT is a valuable option for post-implantation temporal bone imaging

OBJECT: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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