Faculty Bibliography

BACKGROUND: Mandibular osteoradionecrosis is the most devastating complication after radiation therapy for head and neck malignancies. Quality of life (QOL) after surgical treatment is unclear. METHODS: A retrospective cohort analysis (1997-2007) was conducted of all patients treated at our institution for stage II and III mandibular osteoradionecrosis. Nineteen of 35 patients responded to a modified University of Washington QOL questionnaire. Twenty had undergone reconstruction using free flaps, and the remainder with plates, plates and local flaps, or debridement alone. RESULTS: Complications included 3 infections, 5 with hardware, 5 flap-specific, and 1 nonunion. Four patients had recurrent squamous cell carcinoma (SCC). The factors of greatest concern to patients were appearance, swallowing, and chewing. Average overall QOL was good to very good, and very good compared to preoperative. CONCLUSION: Despite a 37% complication rate, a multidisciplinary team approach with adequate debridement, resection, and reconstruction can greatly improve QOL. (c) 2011 Wiley Periodicals, Inc. Head Neck, 2012.

Today most cochlear implant users achieve above 80% on standard speech recognition in quiet testing, and enjoy excellent device reliability. Despite such success, conventional designs often fail to provide the frequency resolution required for complex listening tasks. Furthermore, performance variability remains a vexing problem, with a select group of patients performing poorly despite using the most recent technologies and processing strategies. This article provides a brief history of the development of cochlear implant technologies, reviews current implant systems from all 3 major manufacturers, examines recently devised strategies aimed at improving device performance, and discusses potential future developments.

Cochlear implants have become a viable treatment option for individuals who present with severe to profound hearing loss. While there are several parameters that affect the successful use of this technology, quality programming of the cochlear implant system is crucial. This review chapter focuses on general device programming techniques, programming techniques specific to children, objective programming techniques, a brief overview of programming parameters of the currently commercially available multichannel systems, and managing patient complaints and device failures. The chapter also provides what the authors believe the future may hold for new programming techniques

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

Electrophysiological recordings from behaving animals provide an unparalleled view into the functional role of individual neurons. Intracellular approaches can be especially revealing as they provide information about a neuron's inputs and intrinsic cellular properties, which together determine its spiking output. Recent technical developments have made intracellular recording possible during an ever-increasing range of behaviors in both head-fixed and freely moving animals. These recordings have yielded fundamental insights into the cellular and circuit mechanisms underlying neural activity during natural behaviors in such areas as sensory perception, motor sequence generation, and spatial navigation, forging a direct link between cellular and systems neuroscience.

This article highlights variables that affect cochlear implant performance, emerging factors warranting consideration, and variables shown not to affect performance. Research on the outcomes following cochlear implantation has identified a wide spectrum of variables known to affect pos0timplantation performance. These variables relate to the device itself as well as individual patient characteristics. Factors believed to affect spiral ganglion cell survival and function have been shown to influence postoperative performance. Binaural hearing affects performance. Social and educational factors also affect postoperative performance. Novel variables capable of affecting performance continue to emerge with increased understanding of auditory pathway development and neural plasticity

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

The developmental plasticity of excitatory synapses is well established, particularly as a function of age. If similar principles apply to inhibitory synapses, then we would expect manipulations during juvenile development to produce a greater effect and experience-dependent changes to persist into adulthood. In this study, we first characterized the maturation of cortical inhibitory synapse function from just before the onset of hearing through adulthood. We then examined the long-term effects of developmental conductive hearing loss (CHL). Whole cell recordings from gerbil thalamocortical brain slices revealed a significant decrease in the decay time of inhibitory currents during the first 3 mo of normal development. When assessed in adults, developmental CHL led to an enduring decrease of inhibitory synaptic strength, whereas the maturation of synaptic decay time was only delayed. Early CHL also depressed the maximum discharge rate of fast-spiking, but not low-threshold-spiking, inhibitory interneurons. We then asked whether adult onset CHL had a similar effect, but neither inhibitory current amplitude nor decay time was altered. Thus inhibitory synapse function displays a protracted development during which deficits can be induced by juvenile, but not adult, hearing loss. These long-lasting changes to inhibitory function may contribute to the auditory processing deficits associated with early hearing loss.

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