The value of intraoperative EABRs in auditory brainstem implantation

OBJECTIVE

To compare the intraoperative electrically evoked auditory brainstem response (EABR) morphologies between neurofibromatosis II (NF2) adult auditory brainstem implant (ABI) recipients who had auditory percepts post-operatively and those who did not and between NF2 adult ABI recipients and non-NF2 pediatric ABI recipients.

METHODS

This was a retrospective case series at a single tertiary academic referral center examining all ABI recipients from 1994 to 2016, which included 34 NF2 adults and 11 non-NF2 children. The morphologies of intraoperative EABRs were evaluated for the number of waveforms showing a response, the number of positive peaks in those responses, and the latencies of each of these peaks.

RESULTS

27/34 adult NF2 patients and 9/10 children had EABR waveforms. 20/27 (74.0%) of the adult patients and all of the children had ABI devices that stimulated post-operatively. When comparing the waveforms between adults who stimulated and those who did not stimulate, the proportion of total number of intraoperative EABR peaks to total possible peaks was significantly higher for the adults who stimulated than for those who did not (p < 0.05). Children had a significantly higher proportion of total number of peaks to total possible peaks when compared to adults who stimulated (p < 0.02). Additionally, there were more likely to be EABR responses at the initial stimulation than intraoperatively in the pediatric ABI population (p = 0.065).

CONCLUSIONS

The value of intraoperative EABR tracing may lie in its ability to predict post-operative auditory percepts based on the placement of the array providing the highest number of total peaks.

Cochlear implantation under conscious sedation with local anesthesia; Safety, Efficacy, Costs, and Satisfaction

OBJECTIVE

To evaluate the safety, efficiency, cost effectiveness, and satisfaction of patients undergoing cochlear implantation under conscious sedation versus general anesthesia.

STUDY DESIGN

Retrospective case review of 20 patients who underwent cochlear implantation under conscious sedation which was compared to 20 age-matched patients where surgery was performed under general anesthesia.

METHODS

Perioperative times, length of stay, anesthesia drug costs, postoperative complications, and patient satisfaction were compared between the two groups.

RESULTS

Conscious sedation was associated with decreased drug costs, surgery time, and anesthesia time. Length of stay was significantly longer for patients undergoing general anesthesia. Patient satisfaction was superior with conscious sedation. Perioperative morbidity was not significantly different between the two groups.

CONCLUSION

Conscious sedation for cochlear implantation is a safe, efficient, and cost-effective alternative to general anesthesia. The efficacy of conscious sedation for cochlear implant surgery may expand the treatment of profound hearing loss to the elderly who are deemed too sick for general anesthesia or are fearful of the cognitive or medical consequences of general anesthesia.

A matched cohort comparison of clinical outcomes following microsurgical resection or stereotactic radiosurgery for patients with small- and medium-sized vestibular schwannomas

OBJECTIVE

A randomized trial that compares clinical outcomes following microsurgery (MS) or stereotactic radiosurgery (SRS) for patients with small- and medium-sized vestibular schwannomas (VSs) is impractical, but would have important implications for clinical decision making. A matched cohort analysis was conducted to evaluate clinical outcomes in patients treated with MS or SRS.

METHODS

The records of 399 VS patients who were cared for by 2 neurosurgeons and 1 neurotologist between 2001 and 2014 were evaluated. From this data set, 3 retrospective matched cohorts were created to compare hearing preservation (21 matched pairs), facial nerve preservation (83 matched pairs), intervention-free survival, and complication rates (85 matched pairs) between cases managed with SRS and patients managed with MS. Cases were matched for age at surgery (± 10 years) and lesion size (± 0.1 cm). To compare hearing outcomes, cases were additionally matched for preoperative Class A hearing according to the American Academy of Otolaryngology-Head and Neck Surgery guidelines. To compare facial nerve (i.e., cranial nerve [CN] VII) outcomes, cases were additionally matched for preoperative House-Brackmann (HB) score. Investigators who were not involved with patient care reviewed the clinical and imaging records. The reported outcomes were as assessed at the time of the last follow-up, unless otherwise stated.

RESULTS

The preservation of preoperative Class A hearing status was achieved in 14.3% of MS cases compared with 42.9% of SRS cases (OR 4.5; p < 0.05) after an average follow-up interval of 43.7 months and 30.3 months, respectively. Serviceable hearing was preserved in 42.8% of MS cases compared with 85.7% of SRS cases (OR 8.0; p < 0.01). The rates of postoperative CN VII dysfunction were low for both groups, although significantly higher in the MS group (HB III–IV 11% vs 0% for SRS; OR 21.3; p < 0.01) at a median follow-up interval of 35.7 and 19.0 months for MS and SRS, respectively. There was no difference in the need for subsequent intervention (2 MS patients and 2 SRS patients).

CONCLUSIONS

At this high-volume center, VS resection or radiosurgery for tumors ≤ 2.8 cm in diameter was associated with low overall morbidity. The need for subsequent intervention was the same in both groups. SRS was associated with improved hearing and facial preservation rates and reduced morbidity, but with a shorter average follow-up period. Facial function was excellent in both groups. Since patients were not randomly selected for surgery, different clinical outcomes may be of different value to individual patients. Both anticipated medical outcomes and patient goals remain the drivers of treatment decisions.

The Relationship Between Insertion Angles, Default Frequency Allocations, and Spiral Ganglion Place Pitch in Cochlear Implants

OBJECTIVES

Commercially available cochlear implant systems attempt to deliver frequency information going down to a few hundred Hertz, but the electrode arrays are not designed to reach the most apical regions of the cochlea, which correspond to these low frequencies. This may cause a mismatch between the frequencies presented by a cochlear implant electrode array and the frequencies represented at the corresponding location in a normal-hearing cochlea. In the following study, the mismatch between the frequency presented at a given cochlear angle and the frequency expected by an acoustic hearing ear at the corresponding angle is examined for the cochlear implant systems that are most commonly used in the United States.

DESIGN

The angular insertion of each of the electrodes on four different electrode arrays (MED-EL Standard, MED-EL Flex28, Advanced Bionics HiFocus 1J, and Cochlear Contour Advance) was estimated from X-ray. For the angular location of each electrode on each electrode array, the predicted spiral ganglion frequency was estimated. The predicted spiral ganglion frequency was compared with the center frequency provided by the corresponding electrode using the manufacturer's default frequency-to-electrode allocation.

RESULTS

Differences across devices were observed for the place of stimulation for frequencies below 650 Hz. Longer electrode arrays (i.e., the MED-EL Standard and Flex28) demonstrated smaller deviations from the spiral ganglion map than the other electrode arrays. For insertion angles up to approximately 270°, the frequencies presented at a given location were typically approximately an octave below what would be expected by a spiral ganglion frequency map, while the deviations were larger for angles deeper than 270°. For frequencies above 650 Hz, the frequency to angle relationship was consistent across all four electrode models.

CONCLUSIONS

A mismatch was observed between the predicted frequency and the default frequency provided by every electrode on all electrode arrays. The mismatch can be reduced by changing the default frequency allocations, inserting electrodes deeper into the cochlea, or allowing cochlear implant users to adapt to the mismatch. Further studies are required to fully assess the clinical significance of the frequency mismatch.

A physiological and behavioral system for hearing restoration with cochlear implants

Cochlear implants are neuroprosthetic devices that provide hearing to deaf patients, although outcomes are highly variable even with prolonged training and use. The central auditory system must process cochlear implant signals, but it is unclear how neural circuits adapt-or fail to adapt-to such inputs. The knowledge of these mechanisms is required for development of next-generation neuroprosthetics that interface with existing neural circuits and enable synaptic plasticity to improve perceptual outcomes. Here, we describe a new system for cochlear implant insertion, stimulation, and behavioral training in rats. Animals were first ensured to have significant hearing loss via physiological and behavioral criteria. We developed a surgical approach for multichannel (2- or 8-channel) array insertion, comparable with implantation procedures and depth in humans. Peripheral and cortical responses to stimulation were used to program the implant objectively. Animals fitted with implants learned to use them for an auditory-dependent task that assesses frequency detection and recognition in a background of environmentally and self-generated noise and ceased responding appropriately to sounds when the implant was temporarily inactivated. This physiologically calibrated and behaviorally validated system provides a powerful opportunity to study the neural basis of neuroprosthetic device use and plasticity.

Neurocognitive testing and cochlear implantation: insights into performance in older adults

OBJECTIVE

The aim of this case series was to assess the impact of auditory rehabilitation with cochlear implantation on the cognitive function of elderly patients over time.

DESIGN

This is a longitudinal case series of prospective data assessing neurocognitive function and speech perception in an elderly cohort pre- and post-implantation.

SETTING

University cochlear implant center.

PARTICIPANTS

The patients were post-lingually deafened elderly female (mean, 73.6 years; SD, 5.82; range, 67-81 years) cochlear implant recipients (n=7).

MEASUREMENTS

A neurocognitive battery of 20 tests assessing intellectual function, learning, short- and long-term memory, verbal fluency, attention, mental flexibility, and processing speed was performed prior to and 2-4.1 years (mean, 3.7) after cochlear implant (CI). Speech perception testing using Consonant-Nucleus-Consonant words was performed prior to implantation and at regular intervals postoperatively. Individual and aggregate differences in cognitive function pre- and post-CI were estimated. Logistic regression with cluster adjustment was used to estimate the association (%improvement or %decline) between speech understanding and years from implantation at 1 year, 2 years, and 3 years post-CI.

RESULTS

Improvements after CI were observed in 14 (70%) of all subtests administered. Declines occurred in five (25%) subtests. In 55 individual tests (43%), post-CI performance improved compared to a patient's own performance before implantation. Of these, nine (45%) showed moderate or pronounced improvement. Overall, improvements were largest in the verbal and memory domains. Logistic regression demonstrated a significant relationship between speech perception and cognitive function over time. Five neurocognitive tests were predictive of improved speech perception following implantation.

CONCLUSION

Comprehensive neurocognitive testing of elderly women demonstrated areas of improvement in cognitive function and auditory perception following cochlear implantation. Multiple neurocognitive tests were strongly associated with current speech perception measures. While these data shed light on the complex relationship between hearing and cognition by showing that CI may slow the expected age-related cognitive decline, further research is needed to examine the impact of hearing rehabilitation on cognitive decline.

A case report: the first successful cochlear implant in Uganda

Hearing impairment is a significant disability. According to the World Health Organization (WHO), more than 80% of the world's approximately 120 million people with hearing impairment live in developing countries. Cochlear implant is the only therapeutic intervention for those with severe-profound sensorineural hearing loss. We are reporting an interesting case of the very first cochlear implant operation carried out in Uganda. The patient was a 23 year old male whose presenting complaint was inability to hear in the left ear for three and a half years and in the right ear for one year. He had been treated for TB(Tuberculosis) mastoiditis. After the 8 months of treatment, the otorrhea persisted and he underwent a tympanomastoidectomy on the same ear. He reported no familial history of hearing loss. On examination, ENT examination revealed a small pars flaccida retration pocket of the right tympanic membrane with cholesteatoma. The left ear had an intact tympanic membrane. Pure tone audiometry revealed profound sensorineural hearing loss in both ears (see attached PTA results), CT scan of the temporal bone showed normal inner ear anatomy bilaterally and mild sclerotic changes in both mastoid bones. He then had surgery on his right ear which included cochlear implantation. The cochlear implant (CI) was activated on the first postoperative day remotely via internet with the help of the cochlear implant team at New York University Cochlear Implant Center and the patient was immediately able to appreciate some sounds. He received a pneumococcal vaccine on the first postoperative day and was discharged the following day.

Surgical techniques and outcomes of cochlear implantation in patients with radiographic findings consistent with X-linked deafness

OBJECTIVES

X-linked deafness is a potential etiology of sensorineural hearing loss characterized by bulbous dilatation of the fundus of the internal auditory canal (IAC) and the absence of the bony plates separating the basal turn of the cochlea and IAC. These malformations predispose patients to IAC insertion during cochlear implantation (CI). Our objective is to describe the surgical technique, audiometric and speech performance outcomes in a group of patients with this unique cochlear malformation.

METHODS

A retrospective chart review was performed of all patients at a tertiary care facility who underwent CI between January 2006 and July 2011.

RESULTS

A total of five patients were identified with radiographic findings characteristic of X-linked deafness, specifically a deficient modiolous, absent lamina cribrosa and bulbous IAC. A modified cochleostomy was utilized to ensure electrode insertion within the scala tympani avoiding the IAC. In each case, fluoroscopy was utilized to visual electrode progression during insertion and complete insertion was accomplished. All patients demonstrated improved speech performance following implantation.

CONCLUSIONS

Utilizing the techniques described, patients with these unique radiographic findings consistent with X-linked deafness may successfully undergo CI with excellent potential for auditory rehabilitation.

United States multicenter clinical trial of the cochlear nucleus hybrid implant system

Objectives/Hypothesis

To evaluate the safety and efficacy of acoustic and electric sound processing for individuals with significant residual low‐frequency hearing and severe‐to‐profound high‐frequency sensorineural hearing loss.

Study Design

Prospective, single‐arm repeated measures, single‐subject design.

Methods

Fifty individuals, ≥ 18 years old, with low‐frequency hearing and severe high‐frequency loss were implanted with the Cochlear Nucleus Hybrid L24 implant at 10 investigational sites. Preoperatively, subjects demonstrated consonant‐nucleus‐consonant word scores of 10% through 60% in the ear to be implanted. Subjects were assessed prospectively, preoperatively, and postoperatively on coprimary endpoints of consonant‐nucleus‐consonant words, AzBio sentences in noise, and self‐assessment measures.

Results

Significant mean improvements were observed for coprimary endpoints: consonant‐nucleus‐consonant words (35.8 percentage points) and AzBio sentences in noise (32.0 percentage points), both at P < 0.001. Ninety‐six percent of subjects performed equal or better on speech in quiet and 90% in noise. Eighty‐two percent of subjects showed improved performance on speech in quiet and 74% in noise. Self‐assessments were positive, corroborating speech perception results.

Conclusion

The Nucleus Hybrid System provides significant improvements in speech intelligibility in quiet and noise for individuals with severe high‐frequency loss and some low‐frequency hearing. This device expands indications to hearing‐impaired individuals who perform poorly with amplification due to bilateral high‐frequency hearing loss and who previously were not implant candidates.

Level of Evidence

2b. Laryngoscope, 126:175–181, 2016

Sequential bilateral cochlear implantation in the adolescent population

OBJECTIVES

To examine the variables affecting outcomes for sequential bilateral cochlear implantation patients in the adolescent population.

STUDY DESIGN

Retrospective chart review at tertiary care center.

METHODS

Main outcome measures were open set speech recognition tests at the word (Consonant-Nucleus-Consonant/Phonetically Balanced Kindergarten List Test [CNC/PBK]) and sentence levels in noise (Hearing in Noise Test-Noise [HINT-N]) in different test conditions with respect to the age at first and sequential implantation, as well as the interval between implants.

RESULTS

Despite a mean age at sequential implantation of 13.5 years, sequential bilateral implanted adolescents revealed significant improvement in the sequential cochlear implant (CI2) ear. The mean time interval between implants was 8.2 years. A wide range of performance was noted, and age at implantation and interval between first cochlear implant (CI1) and CI2 did not predict outcome. Mean CNC/PBK score with CI1 alone was 83.0%, with the CI2 alone was 56.5%, and with bilateral implants was 86.8%. Sentence scores (HINT-N) were 89.5% for CI1, 74.2% for CI2, and 94.4% for bilateral CI condition. The clinical relevance of these enhanced perception abilities requires attention to individual device use, performance with the first implant, and subjective benefits reported by patients.

CONCLUSIONS

Bilateral sequential cochlear implantation leads to improved speech perception in the adolescent population and should be considered in this population, even after a long period of deafness and despite a prolonged interval between implants. Numerous factors affect the ability to predict performance, but age at implantation and interimplant interval were not correlated with performance measures. Extensive preoperative counseling and individualized evaluation are critical to ensure that patients and families understand the range of possible outcomes.

LEVEL OF EVIDENCE

4

Effects of loss of residual hearing on speech performance with the CI422 and the Hybrid-L electrode

OBJECTIVE

Preservation of residual low-frequency hearing has become a priority in cochlear implantation. The purpose of this study was to compare rates of hearing preservation and effects on performance of loss of low-frequency acoustic hearing with two different length electrodes.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary Care Hospital.

PATIENTS

Twelve patients were implanted with the CI422 a slim-straight electrode; the second group consisted of 10 patients implanted with the Hybrid-L, a shorter hearing preservation electrode.

MAIN OUTCOME MEASURE

Audiometric thresholds and speech perception measures.

RESULTS

At 1 year, 3/10 (30%) patients with the Hybrid-L and 7/12 (58%) patients with the CI422 lost residual acoustic hearing resulting in a profound hearing loss in the implanted ear. In comparing these patients in particular, mean CNC words in the implanted ear were 72% in the CI422 electrode group and 15% in the Hybrid-L electrode group at 1 year (P = 0.03). While hearing preservation rates with the Hybrid-L tended to be better, among recipients who lost residual hearing, speech perception was better in those with the longer CI422 electrode.

CONCLUSIONS

With emphasis on preservation of residual hearing, patients need to be counseled regarding possible outcomes and options should loss of residual hearing occur following implantation. While shorter electrodes may have better rates of hearing preservation, the patients with the longer straight electrode in our study had significantly better speech understanding following the loss of residual hearing.

Quality of Life (QoL) Assessment in Patients with Neurofibromatosis Type 2 (NF2)

OBJECTIVE

The aim of this study was to develop a multidimensional metric for assessing quality of life (QoL) in patients with neurofibromatosis type 2 (NF2).

STUDY DESIGN

Electronically distributed questionnaire.

SETTING

University tertiary care hospital, NF2 support groups.

SUBJECTS AND METHODS

Structured interviews with NF2 providers and patients identified relevant domains. Items in each domain were extracted from validated QoL modules, then combined with items unique to NF2 and pretested on NF2 providers and patients. The final 61-item questionnaire was administered electronically to patients with NF2 (N = 118). The form assessed overall QoL and 11 additional domains, including hearing, balance, facial function, vision, oral intake, future uncertainty, psychosocial, cognition, sexual activity, pain, and vocal communication. Responses were compared with reference values for the general population, patients with head and neck cancer, and patients with brain cancer.

RESULTS

Overall, QoL in patients with NF2 was lower than that of the general population (P < .01) and similar to that of patients with cancer. Patients with more facial weakness, hearing loss, and imbalance reported significantly lower QoL. However, domains most predictive of overall QoL were psychosocial, future uncertainty, and pain. Compared with patients with head and neck and brain cancer, patients with NF2 demonstrated significantly higher levels of psychosocial stressors, including disease-related anxiety, personal and financial stress, and lack of social support (P < .01).

CONCLUSION

Psychosocial stress and pain significantly affect QoL in NF2, indicating that mental health, pain management, and financial counseling could have an important impact on QoL in this population.

[Fluoroscopic assisted cochlear implantation in children with inner ear malformations]

BACKGROUND

Cochlear implants are the treatment of choice for individuals with severe to profound sensorineural hearing loss. In most cases, the anatomy is normal and the insertion of the electrode-array is straightforward, complete and in the correct position. In the presence of inner-ear malformations, the risk of an intra or extra-cochlear malpositioned electrode-array increases.

OBJECTIVES

To describe the technique of fluoroscopic assisted cochlear implantation in children with severe inner-ear malformations and present the results with respect to the number of active electrodes and function.

METHODS

Fifteen fluoroscopy assisted implantations in 9 children were conducted at the Shaare Zedek Cochlear Implant Center between 2009-1014. All implanted ears had severe anatomic malformations. Mean implantation age was 3.5 years (range 1-11). Six children underwent sequential bilateral implantation. Two children underwent revision surgery due to a malpositioned electrode initially implanted without fluoroscopy at other centers.

RESULTS

There was no radiologic or electro-physiologic evidence of kinking, bending or electrode damage in all 15 implantations. Complete insertion was achieved in all ears except one with partial insertion. There were no extra-cochlear or intrameatal placements. In 9 ears, all electrodes were active at switch-on and in the remaining, 15-20 were active. In all ears the Ling-6 sounds were detected and in 13 they were also identified.

CONCLUSION

Fluoroscopy is an effective tool in complex cochlear implant surgeries and its use is simple and safe. As demonstrated in this study, with fluoroscopy assistance, good results are achieved in children with inner-ear malformations.

Quality of Life Assessment in Patients with Neurofibromatosis Type II

Objectives:

(1) Develop a multidimensional metric for assessing quality of life (QoL) in patients with NF2. (2) Compare NF2 results with reference values for the general population and patients with head and neck or brain cancer.

Methods:

Structured interviews with NF2 providers and patients identified relevant domains. Items in these domains were extracted from validated EORTC modules, combined with items unique to NF2 and pre-tested on NF2 providers and patients (N = 118). The questionnaire included 61 items assessing overall QoL and 10 additional domains including hearing, balance, facial function, vision, oral intake, future uncertainty, psychosocial, cognition, sexual activity, pain and vocal communication. Responses were compared to reference values for the general population and head and neck cancer and brain cancer patients.

Results:

QoL in NF2 patients was lower than that of the general population ( P < .01) and similar to that of patients with cancer. NF2 patients whose treatment included radiation therapy had worse overall QoL than patients who did not undergo radiation. Patients with more facial weakness, hearing loss and imbalance reported significantly lower QoL. However, domains most predictive of overall QoL were psychosocial, future uncertainty and pain. When compared to patients with head and neck and brain cancer, NF2 patients demonstrated significantly higher levels of psychosocial stressors, including disease-related anxiety, personal and financial stress, and lack of social support ( P < .01).

Conclusions:

Psychosocial stress and pain significantly impact QoL in NF2 indicating that mental health, pain management, and financial counseling could have an important impact on QoL in this population.

Revision Cochlear Implantation Using a Double-Array Device in the Post-meningitis Ossified Cochlea

Objectives:

Describe the surgical technique and outcome in a series of patients who underwent revision cochlear implantation using a double-array or split electrode device. All patients had an ossified cochlea due to meningitis and were functioning poorly with a standard electrode cochlear implant.

Methods:

Four patients between the ages of 4-15 years underwent revision with 5 double-array cochlear implant devices in our center during the years 2010-2012. One patient underwent bilateral revision surgery. All patients suffered from meningitis with computed tomography and magnetic resonance imaging studies that demonstrated an ossified cochlea. The time interval between the disease and initial cochlear implantation was 4 months to 4 years. Patients data were retrospectively analyzed with emphasis on the surgical technique, number of electrodes inserted, and number of active electrodes at follow-up. In addition, pre and post revision surgery function was compared.

Results:

The revision surgery was carried out 4 to 10 years after the initial surgery. Two tunnels, basal and apical, were drilled in the ossified cochlea. In each of the tunnels 5 to 12 electrodes were inserted. While the number of active electrodes before revision was 0-5, after revision with the double array it increased to 8-16. This resulted in increased auditory and speech function.

Conclusions:

The double-array device can provide good outcome in the post-meningitis ossified cochlea. In many of these cases function can be better than with a single electrode device.

Current and Developing Management of Single-Sided Deafness

Program Description:

The single-sided deafness (SSD) handicap has been underestimated. The purpose of this miniseminar is to present the latest research on the benefits of binaural hearing (Sig Soli, PhD), and the impact of SSD on childhood development and school performance (Nancy Young, MD). The different rehabilitation methods available will be presented, including osseointegrated bone conduction technologies (Jack J. Wazen, MD) and nonsurgical options (John Goddard, MD). Future trends and clinical research on the use of cochlear implants in SSD will be presented (Bruce Gantz, MD, and Tom Roland, MD). Open discussion, questions, and audience participation will follow the presentations.

Educational Objectives:

(1) Recognize the benefits of binaural hearing in children and adults and the potential deficits imposed by SSD. (2) Differentiate between surgical and nonsurgical options in the rehabilitation of SSD. (3) Use developing technologies and clinical research in the rehabilitation of SSD, including the use of cochlear implants.

Phase II study of everolimus in children and adults with neurofibromatosis type 2 and progressive vestibular schwannomas

BACKGROUND

Activation of the mammalian target of rapamycin (mTOR) signaling pathway is thought to be a key driver of tumor growth in Merlin (NF2)-deficient tumors. Everolimus is an oral inhibitor of mTOR complex 1 (mTORC1) with antitumor activity in a variety of cancers.

METHODS

We conducted a single-institution, prospective, 2-stage, open-label phase II study to estimate the response rate to everolimus in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Ten eligible patients were enrolled, including 2 pediatric patients. Everolimus was administered at a daily dose of 10 mg (adults) or 5 mg/m(2)/day (children <18 y) orally in continuous 28-day courses, for up to 12 courses. Response was assessed every 3 months with MRI, using 3-dimensional volumetric tumor analysis, and audiograms. Nine patients were evaluable for the primary response, defined as ≥15% decrease in VS volume. Hearing response was evaluable as a secondary endpoint in 8 patients.

RESULTS

None of the 9 patients with evaluable disease experienced a clinical or MRI response. No objective imaging or hearing responses were observed in stage 1 of the trial, and the study was closed according to predefined stopping rules.

CONCLUSION

Everolimus is ineffective for the treatment of progressive VS in NF2 patients. We are currently conducting a pharmacokinetic/pharmacodynamic ("phase 0") study of everolimus in presurgical VS patients to elucidate the biological basis for apparent treatment resistance to mTORC1 inhibition in these tumors.

Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection

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.

Revision cochlear implantation following internal auditory canal insertion

OBJECTIVES/HYPOTHESIS

In pediatric patients with congenital malformations of the inner ear, anomalies within the anatomy may facilitate unintentional insertion of the cochlear implant electrode into the internal auditory canal. Revision procedures for removal and replacement of cochlear implant electrodes following internal auditory canal insertion are fraught with potential danger, including the theoretical risk of injury to vasculature within the internal auditory canal, repeat insertion within the internal auditory canal, and cerebrospinal fluid leak. The objective of this presentation is to describe a technique for revision cochlear implantation following internal auditory canal insertion to minimize the potential associated risks.

STUDY DESIGN

Case series.

METHODS

A retrospective chart review was performed on all patients at a tertiary care facility who underwent revision cochlear implantation for internal auditory canal insertion between January 1999 and July 2011.

RESULTS

A total of four patients referred from outside institutions have undergone revision cochlear implantation for internal auditory canal insertion. The records from these patients were reviewed. Electrodes were safely removed in all cases without injury to the anterior inferior cerebellar artery or its branches (i.e., labyrinthine artery). Complete insertion was accomplished on reimplantation. Neural response telemetry was performed in all cases, and responses were noted. Fluoroscopy was utilized to visualize electrode progression during insertion. A detailed description of the operative technique is provided.

CONCLUSIONS

This case series describes a technique for revision cochlear implantation that appears to be safe and effective in preventing potential associated complications.

Hearing Loss 2013: Expanded Technology, Expanded Criteria

Program Description:

The purpose of this course is to educate our otolaryngology community about how best to provide the widest array of surgical technologies to the largest populations of patients with hearing loss. Traditionally, technologic advancement has driven the field forward, though recent attention has also focused on expanding eligibility criteria for existing technology. The format will be a panel of experts with proposed topics organized by patient population (rather than by technology), including patients with moderate to severe hearing loss and significant residual hearing, single sided-deafness, tinnitus, children, age extremes, the multi-handicapped, cochlear nerve deficiency, and others.

Educational Objectives:

1) Recognize the most current surgical technologies available to patients with hearing loss. 2) Articulate the rationale for expanding inclusion criteria for existing technologies to patients previously considered ineligible. 3) Evaluate how promising preliminary outcomes data support the continued expansion of both technology and criteria for patients with hearing loss.

Real-time measurement of electrode impedance during intracochlear electrode insertion

OBJECTIVES/HYPOTHESIS

This pilot study details the use of a software tool that uses continuous impedance measurement during electrode insertion, with the eventual potential to assess and optimize electrode position and reduce insertional trauma.

STUDY DESIGN

Software development and experimental study with human cadaveric cochleae and two live surgeries.

METHODS

A prototype program to measure intracochlear electrode impedance and display it graphically in real time has been developed. The software was evaluated in human cadaveric temporal bones while simultaneously making real-time fluoroscopic recordings and in two live surgeries during intracochlear electrode insertion.

RESULTS

Impedance changes were observed with various scalar positions, and values were consistent with those obtained using clinically available software. Using Contour Advance electrodes, impedance values increased after stylet removal, particularly when using the monopolar mode.

CONCLUSIONS

Impedance values seem systematically affected by electrode position, with higher values being associated with proximity to the cochlear wall. The new software is capable of acquiring impedance measurements during electrode insertion, and these data may be useful to guide surgeons to achieve optimal and atraumatic electrode insertion, to guide robotic electrode insertion, and to provide insights about electrode position in the cochlea.

Outcomes of Direct Facial-to-Hypoglossal Neurorrhaphy with Parotid Release

Lesions of the temporal bone and cerebellopontine angle and their management can result in facial nerve paralysis. When the nerve deficit is not amenable to primary end-to-end repair or interpositional grafting, nerve transposition can be used to accomplish the goals of restoring facial tone, symmetry, and voluntary movement. The most widely used nerve transposition is the hypoglossal-facial nerve anastamosis, of which there are several technical variations. Previously we described a technique of single end-to-side anastamosis using intratemporal facial nerve mobilization and parotid release. This study further characterizes the results of this technique with a larger patient cohort and longer-term follow-up. The design of this study is a retrospective chart review and the setting is an academic tertiary care referral center. Twenty-one patients with facial nerve paralysis from proximal nerve injury at the cerebellopontine angle underwent facial-hypoglossal neurorraphy with parotid release. Outcomes were assessed using the Repaired Facial Nerve Recovery Scale, questionnaires, and patient photographs. Of the 21 patients, 18 were successfully reinnervated to a score of a B or C on the recovery scale, which equates to good oral and ocular sphincter closure with minimal mass movement. The mean duration of paralysis between injury and repair was 12.1 months (range 0 to 36 months) with a mean follow-up of 55 months. There were no cases of hemiglossal atrophy, paralysis, or subjective dysfunction. Direct facial-hypoglossal neurorrhaphy with parotid release achieved a functional reinnervation and good clinical outcome in the majority of patients, with minimal lingual morbidity. This technique is a viable option for facial reanimation and should be strongly considered as a surgical option for the paralyzed face.

Phase II trial of lapatinib in adult and pediatric patients with neurofibromatosis type 2 and progressive vestibular schwannomas

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.

Flat-panel computed tomography versus multislice computed tomography to evaluate cochlear implant positioning

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.

Pediatric cochlear implantation: candidacy evaluation, medical and surgical considerations, and expanding criteria

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.

Implantation of the common cavity malformation may prevent meningitis

OBJECTIVES AND IMPORTANCE: Children with certain congenital malformations of the inner ear, including those with a common cavity defect, have a higher incidence of spontaneous cerebrospinal fluid (CSF) leak and resulting meningitis. However, they may also benefit from cochlear implantation. We suggest that surgical management may be possible that both prevents meningitis and provides hearing rehabilitation during the same procedure.

CLINICAL PRESENTATION

A 2-year-old girl with bilateral common cavity defects who had previously undergone cochlear implantation developed contralateral CSF leak resulting in meningitis.

INTERVENTION

After resolution of the infection, cochlear implantation was performed at the same time as definitive CSF leak repair. Simultaneous cochlear implantation and repair of the CSF leak successfully decreased the chance of recurrent meningitis in this case. She has been deriving hearing benefit from the bilateral implants.

CONCLUSION

This case suggests a role for cochlear implantation to be combined with simultaneous CSF leak repair in children with a cochlear malformation. Furthermore, bilateral cochlear implantation at an early age may be warranted in these patients before CSF leaks and meningitis have occurred.

Cochlear implantation in prelingually deafened adolescents

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.

Development and evaluation of the modiolar research array--multi-centre collaborative study in human temporal bones

OBJECTIVE

Multi-centre collaborative study to develop and refine the design of a prototype thin perimodiolar cochlear implant electrode array and to assess feasibility for use in human subjects.

STUDY DESIGN

Multi-centre temporal bone insertion studies.

MATERIALS AND METHODS

The modiolar research array (MRA) is a thin pre-curved electrode that is held straight for initial insertion with an external sheath rather than an internal stylet. Between November 2006 and February 2009, six iterations of electrode design were studied in 21 separate insertion studies in which 140 electrode insertions were performed in 85 human temporal bones by 12 surgeons. These studies aimed at addressing four fundamental questions related to the electrode concept, being: (1) Could a sheath result in additional intra-cochlear trauma? (2) Could a sheath accommodate variations in cochlea size and anatomies? (3) Could a sheath be inserted via the round window? and (4) Could a sheath be safely removed once the electrode had been inserted? These questions were investigated within these studies using a number of evaluation techniques, including X-ray and microfluoroscopy, acrylic fixation and temporal bone histologic sectioning, temporal bone microdissection of cochlear structures with electrode visualization, rotational tomography, and insertion force analysis.

RESULTS

Frequent examples of electrode rotation and tip fold-over were demonstrated with the initial designs. This was typically caused by excessive curvature of the electrode tip, and also difficulty in handling of the electrode and sheath. The degree of tip curvature was progressively relaxed in subsequent versions with a corresponding reduction in the frequency of tip fold-over. Modifications to the sheath facilitated electrode insertion and sheath removal. Insertion studies with the final MRA design demonstrated minimal trauma, excellent perimodiolar placement, and very small electrode dimensions within scala tympani. Force measurements in temporal bones demonstrated negligible force on cochlear structures with angular insertion depths of between 390 and 450°.

CONCLUSION

The MRA is a novel, very thin perimodiolar prototype electrode array that has been developed using a systematic collaborative approach. The different evaluation techniques employed by the investigators contributed to the early identification of issues and generation of solutions. Regarding the four fundamental questions related to the electrode concept, the studies demonstrated that (1) the sheath did not result in additional intra-cochlear trauma; (2) the sheath could accommodate variations in cochlea size and anatomies; (3) the sheath was more successfully inserted via a cochleostomy than via the round window; and (4) the sheath could be safely removed once the electrode had been inserted.

Managing Cochlear Implant Complications

Program Description: This miniseminar is designed for otolaryngologists who include cochlear implants in the scope of their practice and would like to learn more about managing various intraoperative and postoperative complications, and special considerations as they inevitably arise. Particularly useful for otologic surgeons who have small to moderate cochlear implant case volumes, this seminar will address common as well as less common complications and provide a framework for systematically and effectively managing them. A panel of experts consists of four otologists who run busy, mature cochlear implant programs and have extensive experience in managing various implant-related issues. During the first hour, each panelist will give a brief presentation. Topics include: analyzing suspected device failures, evaluation and revision of inappropriate electrode placement, management of CSF gushers and leaks, management of skin ulceration, skin breakdown and device exposure, management of wound infection and device infection. The following half hour will be reserved for discussion of individual case scenarios. The moderator will present cases to the expert panel for discussion. Members of the audience are encouraged to participate in the discussion, ask questions, and present their own cases to the panel. Attendees will learn how to avoid common intraoperative complications and how to better manage complications when they do occur. The aim of this miniseminar is to allow the attendees to benefit from the experience of our panelists and provide them with “tried and true” techniques that can be implemented in their own cochlear implant programs, ultimately improving the scope and quality of cochlear implant services available nationally and internationally.

Educational Objectives: 1) Identify and manage a variety of complications related to cochlear implants with more confidence. 2) Learn to evaluate suspected cochlear implant device failures and need for revisions. 3) Learn an operative technique for managing a CSF gusher.

Emerging Technologies in Implantable Auditory Prostheses

Program Description: Current prosthetic auditory implants have achieved a high level of success, however, it would be fair to say that performance gains over the past decade have reached a stable plateau. The latest phase of development has centered primarily on increasing stimulus resolution, preserving residual auditory ultrastructure and function, and implanting higher order neural pathways. To serve these objectives, electrodes have been designed to more closely approximate the spiral ganglion and be inserted virtually atraumatically. Implantation of the higher order pathways has already been performed with combinations of penetrating needles or electrode paddles at the brainstem. Prototypes even exist for stimulation as high up as the auditory cortex. We are now also witnessing the development of highly focused fiberoptic delivery systems for infrared laser energy as the stimulus source. A panel of surgeons and scientists, all of whom have been involved in both clinical and basic science of auditory implants, will debate the strategies being developed to foster the next leap in performance gains. The seminar will begin with a candid appraisal of the successes of currently marketed achievements including modiolar hugging electrodes, hearing preservation hybrid implants, compressed and split arrays for severely malformed and obstructed cochleae, and bilateral implantation. Minimally invasive surgical techniques will be examined with the questions posed: What truly constitutes a minimally invasive procedure? What technical features need to be retained in order to maintain necessary safeguards and precautions? The variable successes of auditory brainstem implantation will be reviewed with an eye toward future improvement. The panelists will then present their collective experience with emerging technologies aiming to push the envelope of performance higher into the future. The constant gains in microprocessor speeds will offer opportunities for development of novel processing strategies including current steering. The emerging concept of integrated drug delivery systems will require a careful re-exploration of the well-known design problems of hermeticity, durability, and ultrastructural trauma induction. Changes in stimulus energy source (eg, infrared laser) will undoubtedly require radical changes in device designs and coding strategies. It is the hope of the organizers that this miniseminar will benefit both the attendees and the panelists through the process of evaluative debate and exploration of new ideas.

Educational Objectives: 1) Understand the current status and future direction of hybrid “hearing preservation” cochlear implantation. 2) Understand the newest device and coding strategies including infrared laser optical based devices. 3) Be familiar with the current systems under development including vestibular prostheses, DACS and ABI.

Auditory rehabilitation of patients with neurofibromatosis Type 2 by using cochlear implants

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.

Direct Facial-to-Hypoglossal Neurorrhaphy with Parotid Release

OBJECTIVE

Facial nerve paralysis or compromise can be caused by lesions of the temporal bone and cerebellopontine angle and their treatment. When the facial nerve is transected or severely compromised and primary end-to-end repair is not possible, hypoglossal-facial nerve anastomosis remains the most popular method for accomplishing three main goals: restoring facial tone, restoring facial symmetry, and facilitating return of voluntary facial movement. Our objectives are to evaluate the surgical feasibility and long-term outcomes of our technique of direct facial-to-hypoglossal neurorrhaphy with a parotid-release maneuver.

DESIGN

Prospective cohort.

SETTING

Academic tertiary care referral center.

PATIENTS

Ten patients with facial paralysis from proximal nerve injury underwent the facial-hypoglossal neurorrhaphy with a parotid-release maneuver.

MAIN OUTCOME MEASURES

The Repaired Facial Nerve Recovery Scale, questionnaires, and photographs.

RESULTS

Facial-hypoglossal neurorrhaphy with parotid release was technically feasible in all cases, and anastomosis was performed distal to the origin of the ansa hypoglossi. All patients had good return of facial nerve function. Nine patients had scores of C or better, indicating strong eyelid and oral sphincter closure and mass motion. There was no hemilingual atrophy and no subjective tongue dysfunction.

CONCLUSIONS

The parotid-release maneuver mobilizes additional length to the facial nerve, facilitating a tensionless communication distal to the ansa hypoglossi. The technique is a viable option for facial reanimation, and our patients achieved good clinical outcomes with continual improvement.

Sphenoid cranial base defects in siblings presenting with cerebrospinal fluid leak

Two sisters presented to our medical center with nontraumatic cerebrospinal fluid (CSF) fistulas from left sphenoid sinocranial junction defects. One sister had recurrent meningitis over a 20-year period that prompted a skull base evaluation. Four years later, her younger sister presented with profuse CSF rhinorrhea. Transethmoid sphenoidotomy with sinus obliteration and lumbar-subarachnoid temporary CSF diversion successfully treated one sister, while the other required reoperation and permanent lumbar-peritoneal shunting. In both cases the skull base defect was identically located in the posterolateral left sphenoid sinus. Embryological considerations, evaluation and management are presented.

Processed allograft: novel use in facial nerve repair after resection of a rare racial nerve paraganglioma

OBJECTIVES

To present a rare case of facial nerve paraganglioma and novel use of a processed allograft for facial nerve reconstruction.

STUDY DESIGN

Case report and review of the literature.

METHODS

A 34 year old female presented with progressive onset right sided facial palsy for 5 months. CT and MRI demonstrated an irregular mass in the right facial nerve canal from the intratympanic segment to the stylomastoid foramen.

RESULTS

Following transmastoid resection, the defect was repaired using processed allograft. Pathologic analysis was consistent with a paraganglioma. Facial nerve paraganglioma is a rare entity that has been reported only 10 times in the literature.

CONCLUSIONS

Traditional methods of facial nerve reconstruction, including autologous and cadaveric grafting, can lead to significant patient morbidity. Autologous nerve grafts are the "gold standard" for superior regenerative capability, but are limited by the length and potential neuroma formation at the donor site. Allogenic grafts from donors or cadavers have shown some efficacy, but can require immunosuppression. The Avance nerve graft is a cadaveric graft, processed and decellularized to maintain an extracellular matrix with laminin and intact endoneural tubes, thus providing support for the growing axon without generating an immune response. Initial studies of the Avance graft in animals and humans have examined repair of peripheral nerves, but this is the first reported case of human facial nerve reconstruction.