Faculty Bibliography

Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures DeltaTCMEP (final-initial) and immediate and long-term facial nerve function using House Brackmann (HB) rating scale. Results Intraoperative TCMEP data and immediate and follow-up FN outcome are reported for 52 patients undergoing CPA tumor resection. Patients with unsatisfactory facial outcome (HB >2) at follow-up had an average deltaTCMEP of 57 V, whereas those with HB I or II had a mean deltaTCMEP of 0.04 V (t = -2.6, p < 0.05.) Intraoperative deltaTCMEP did not differ significantly between groups with satisfactory (HB I, II) and unsatisfactory (HB > 2) facial function in the immediate postoperative period. Conclusion Intraoperative TCMEP of the facial nerve can be a valuable adjunct to conventional facial nerve electromyography during resection of tumors at the CPA. Intraoperative deltaTCMEP >57 V may be worrisome for long-term recovery of satisfactory facial nerve function.

This single-institution phase II study was performed to estimate the response rate to lapatinib in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Twenty-one eligible patients were enrolled. Brain and spine MRIs, including 3-dimensional volumetric tumor analysis, and audiograms were performed once at baseline and again every 12 weeks. The primary response end point was evaluable in 17 patients and defined as >/=15% decrease in VS volume. Hearing was evaluable as a secondary end point in 13 patients, with responses defined as an improvement in the pure tone average of at least 10 dB or a statistically significant increase in word recognition scores. Four of 17 evaluable patients experienced an objective volumetric response (23.5%; 95% confidence interval [CI], 10%-47%), with median time to response of 4.5 months (range, 3-12). In responders, reduction in VS volumes ranged from -15.7% to -23.9%. Four of 13 patients evaluable for hearing met hearing criteria for response (30.8%; 95% CI, 13%-58%). One sustained response exceeded 9 months in duration. Median time to overall progression (ie, volumetric progression or hearing loss) was 14 months. The estimated overall progression-free survival and volumetric progression-free survival at 12 months were 64.2% (95% CI, 36.9%-82.1%) and 70.6% (95% CI, 43.1%-86.6%), respectively. Toxicity was generally minor, and no permanent dose modifications were required. Lapatinib carries minor toxicity and has objective activity in NF2 patients with progressive VS, including volumetric and hearing responses. Future studies could explore combination therapy with other molecular targeted agents such as bevacizumab.

OBJECTIVE: To describe and characterize diplopia resulting from skew deviation after cerebellopontine angle (CPA) surgery and labyrinthectomy. PATIENTS AND INTERVENTIONS: Retrospective case series of 4 patients who developed vertical diplopia from skew deviation after resection of tumors in the CPA or labyrinthectomy MAIN OUTCOME MEASURE: Complete neuro-opthalmologic examination including opticokinetic testing, confrontational visual field assessment, color plate, pupillary reflex, slit lamp examination, and head tilt test. RESULTS: Four patients with residual hearing preoperatively developed skew deviation immediately after surgical intervention, including translabyrinthine (n = 1) and retrosigmoid (n = 2) approaches to the CPA and labyrinthectomy (n = 1). Neuro-ophthalmologic examination demonstrated intact extraocular movements, and 2- to 14-mm prism diopter hypertropia on both primary gaze and head tilt testing. In all cases, skew deviation resolved spontaneously with normalization of the neuro-ophthalmologic examination within 10 weeks. CONCLUSION: Patients undergoing CPA surgery or labyrinthectomy can develop postoperative diplopia due to skew deviation as a consequence of acute vestibular deafferentation. Patients with significant hearing preoperatively, a probable marker for residual vestibular function, may be especially at risk for developing skew deviation postoperatively.

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