Brian A. Neff

Implications of minimizing trauma during conventional cochlear implantation.

Objective: To describe the relationship between implantation-associated trauma and postoperative speech perception scores among adult and pediatric patients undergoing cochlear implantation using conventional length electrodes and minimally traumatic surgical techniques. Study Design: Retrospective chart review (2002-2010). Setting: Tertiary academic referral center. Patients: All subjects with significant preoperative low-frequency hearing (≤70 dB HL at 250 Hz) who underwent cochlear implantation with a newer generation implant electrode (Nucleus Contour Advance, Advanced Bionics HR90K [1J and Helix], and Med El Sonata standard H array) were reviewed. Intervention(s): Preimplant and postimplant audiometric thresholds and speech recognition scores were recorded using the electronic medical record. Main Outcome Measure(s): Postimplantation pure tone threshold shifts were used as a surrogate measure for extent of intracochlear injury and correlated with postoperative speech perception scores. Results: Between 2002 and 2010, 703 cochlear implant (CI) operations were performed. Data from 126 implants were included in the analysis. The mean preoperative low-frequency pure-tone average was 55.4 dB HL. Hearing preservation was observed in 55% of patients. Patients with hearing preservation were found to have significantly higher postoperative speech perception performance in the CI-only condition than those who lost all residual hearing. Conclusion: Conservation of acoustic hearing after conventional length cochlear implantation is unpredictable but remains a realistic goal. The combination of improved technology and refined surgical technique may allow for conservation of some residual hearing in more than 50% of patients. Germane to the conventional length CI recipient with substantial hearing loss, minimizing trauma allows for improved speech perception in the electric condition. These findings support the use of minimally traumatic techniques in all CI recipients, even those destined for electric-only stimulation.

Chondrosarcoma of the Skull Base

Objectives Sarcomas of the skull base are challenging, potentially lethal tumors. Prognosis is considered poor. The present report reviews treatment options and presents a case of treatment with en bloc resection of the temporal bone and adjacent skull base.

Auditory and vestibular symptoms and chronic subjective dizziness in patients with Ménière's disease, vestibular migraine, and Ménière's disease with concomitant vestibular migraine

Objective To compare presentations of Ménière’s disease (MD), vestibular migraine (VM), and Ménière’s disease plus vestibular migraine (MDVM), with and without comorbid chronic subjective dizziness (CSD). Study Design Retrospective review with diagnosis confirmed by consensus conference of investigators using published criteria for MD, VM, and CSD. Setting Ambulatory, tertiary dizziness clinic. Patients Approximately 147 consecutive patients with diagnoses of MD, VM, or MDVM, with/without comorbid CSD. Interventions Diagnostic consultation. Main Outcome Measures Similarities and differences between diagnostic groups in demographics; symptoms; and results of neurotologic, audiometric, and vestibular laboratory assessments. Results Seventy-six patients had MD, 55 MD alone. Ninety-two patients had VM, 71 VM alone. Twenty-one patients had MDVM, representing about one-quarter of those diagnosed with MD or VM. Clinical features thought to differentiate VM from MD were found in all groups. Twenty-seven patients with VM (38%) had ear complaints (subjective hearing loss, aural pressure, and tinnitus) during episodes of vestibular symptoms and headache, including 10 (37%) with unilateral symptoms. Conversely, 27 patients with MD alone (49%) had headaches with migraine features that did not meet full IHS diagnostic criteria, migrainous symptoms (photophobia, headache with vomiting), or first-degree relative with migraine. Including MDVM patients, 59% (45/76) of all patients with MD had migrainous features. Thirty-two patients had CSD; most (29; 91%) were in the VM group. Conclusion Comorbidity was common between MD and VM, and their symptoms overlapped. More specific diagnostic criteria are needed to differentiate these diseases and address their coexistence. CSD co-occurred with VM but was rarely seen with MD.

Long-term hearing outcomes following stereotactic radiosurgery for vestibular schwannoma: patterns of hearing loss and variables influencing audiometric decline

OBJECT The goals of this retrospective cohort study were as follows: 1) to describe the long-term prevalence and timing of hearing deterioration following low-dose (12- to 13-Gy marginal dose) stereotactic radiosurgery (SRS) for vestibular schwannoma (VS); and 2) to identify clinical variables associated with long-term preservation of useful hearing following treatment. METHODS Patients with serviceable hearing who underwent SRS for VS between 1997 and 2002 were studied. Data including radiosurgery treatment plans, tumor characteristics, pre- and posttreatment pure tone average, speech discrimination scores, and American Academy of Otolaryngology-Head and Neck Surgery hearing class were collected. Time to nonserviceable hearing was estimated using the Kaplan-Meier method. Univariate and multivariate associations with time to nonserviceable hearing were evaluated using Cox proportional hazards regression models. RESULTS Forty-four patients met the study criteria and were included. The median duration of audiometric follow-up was 9.3 years. Thirty-six patients developed nonserviceable hearing at a mean of 4.2 years following SRS. The Kaplan-Meier estimated rates of serviceable hearing at 1, 3, 5, 7, and 10 years following SRS were 80%, 55%, 48%, 38%, and 23%, respectively. Multivariate analysis revealed that pretreatment ipsilateral pure tone average (p < 0.001) and tumor size (p = 0.009) were statistically significantly associated with time to nonserviceable hearing. CONCLUSIONS Durable hearing preservation a decade after low-dose SRS for VS occurs in less than one-fourth of patients. Variables including preoperative hearing capacity and tumor size may be used to predict hearing outcomes following treatment. These findings may assist in pretreatment risk disclosure. Furthermore, these data demonstrate the importance of long-term follow-up when reporting audiometric outcomes following SRS for VS.

Cochlear implantation in the neurofibromatosis type 2 patient: long-term follow-up.

Objective: To evaluate the long‐term hearing outcomes of neurofibromatosis type 2 (NF2) patients with cochlear implants.

Long-term quality of life in patients with vestibular schwannoma: an international multicenter cross-sectional study comparing microsurgery, stereotactic radiosurgery, observation, and nontumor controls

OBJECT The optimal treatment for sporadic vestibular schwannoma (VS) is highly controversial. To date, the majority of studies comparing treatment modalities have focused on a narrow scope of technical outcomes including facial function, hearing status, and tumor control. Very few publications have investigated health-related quality of life (HRQOL) differences between individual treatment groups, and none have used a disease-specific HRQOL instrument. METHODS All patients with sporadic small- to medium-sized VSs who underwent primary microsurgery, stereotactic radiosurgery (SRS), or observation between 1998 and 2008 were identified. Subjects were surveyed via postal questionnaire using the 36-Item Short Form Health Survey (SF-36), the 10-item Patient-Reported Outcomes Measurement Information System short form (PROMIS-10), the Glasgow Benefit Inventory (GBI), and the Penn Acoustic Neuroma Quality-of-Life (PANQOL) scale. Additionally, a pool of general population adults was surveyed, providing a nontumor control group for comparison. RESULTS A total of 642 respondents were analyzed. The overall response rate for patients with VS was 79%, and the mean time interval between treatment and survey was 7.7 years. Using multivariate regression, there were no statistically significant differences between management groups with respect to the PROMIS-10 physical or mental health dimensions, the SF-36 Physical or Mental Component Summary scores, or the PANQOL general, anxiety, hearing, or energy subdomains. Patients who underwent SRS or observation reported a better total PANQOL score and higher PANQOL facial, balance, and pain subdomain scores than the microsurgical cohort (p < 0.02). The differences in scores between the nontumor control group and patients with VS were greater than differences observed between individual treatment groups for the majority of measures. CONCLUSIONS The differences in HRQOL outcomes following SRS, observation, and microsurgery for VS are small. Notably, the diagnosis of VS rather than treatment strategy most significantly impacts quality of life. Understanding that a large number of VSs do not grow following discovery, and that intervention does not confer a long-term HRQOL advantage, small- and medium-sized VS should be initially observed, while intervention should be reserved for patients with unequivocal tumor growth or intractable symptoms that are amenable to treatment. Future studies assessing HRQOL in VS patients should prioritize use of validated disease-specific measures, such as the PANQOL, given the significant limitations of generic instruments in distinguishing between treatment groups and tumor versus nontumor subjects.

Cochlear implantation in the octogenarian and nonagenarian.

Objective: Previous studies have shown that cochlear implant outcomes with respect to surgical morbidity and speech perception may be poorer in elderly patients as compared with younger adults. However, recent anecdotal reports suggest that elderly cochlear implant recipients are achieving increasingly higher speech perception performance and fewer surgical complications than previously noted. Our objective is to review cochlear implant outcomes using newer generation implants and minimally traumatic cochleostomy techniques in patients 80 years and older compared with younger adult recipients. Study Design: Retrospective chart review. Setting: Tertiary referral center. Patients: All adult cochlear implant recipients (232 patients, 258 implants) who underwent implantation with a Nucleus Freedom, Advanced Bionics HR90k, or Med El Sonata device at a tertiary academic institution. Intervention(s): Postoperative speech perception scores and clinical data extraction using the electronic medical record. Main Outcome Measure(s): Anesthetic and surgical complications, device malfunction, operative time, admission status, length of hospital stay, and postoperative speech perception scores were collected after 50 cochlear implant procedures in patients who were implanted beyond the eighth decade and 208 among younger adults (18-79 yr). Results: Patients 80 years or older were more likely to have anesthetic complications and require hospital admission (p < 0.05). There was no statistical difference between groups with respect to surgical complications or device malfunction. Speech perception analysis revealed similar outcomes for older and younger patients. Conclusion: Cochlear implantation is well tolerated across all adult age groups with a relatively low risk for adverse surgical events or device malfunction. Given the favorable safety profile and high levels of speech perception achieved by older patients, routine implantation of octogenarian and nonagenarians seems warranted. These results also stress the need for thorough preoperative evaluation of elderly patients, given the increased likelihood for perioperative anesthetic complications.

The molecular biology of vestibular schwannomas: dissecting the pathogenic process at the molecular level.

Objective: The goal of this article was to review concisely what is currently known about the tumorigenesis of vestibular schwannomas. Background: Recent advances in molecular biology have led to a better understanding of the cause of vestibular schwannomas. Mutations in the neurofibromatosis type 2 tumor suppressor gene (NF2) have been identified in these tumors. In addition, the interactions of merlin, the protein product of the NF2 gene, and other cellular proteins are beginning to give us a better idea of NF2 function and the pathogenesis of vestibular schwannomas. Methods: Review of the relevant basic science studies at our institution as well as the basic science and clinical literature. Results: The clinical characteristics of vestibular schwannomas and neurofibromatosis type 2 syndromes are reviewed and related to alterations in the NF2 gene. Studies demonstrating our current understanding of tumor developmental pathways are highlighted. In addition, methods of clinical and genetic screening for neurofibromatosis type 2 disease are outlined. Avenues for the development of potential future research and therapies are discussed. Conclusion: Great strides have been made to identify why vestibular schwannomas develop at the molecular level. Continued research is needed to find targeted therapies with which to treat these tumors.

Temporal bone hemangiomas involving the facial nerve.

Objective Hemangiomas of the facial nerve are rare tumors that can mimic more common temporal bone tumors such as vestibular schwannomas and facial nerve schwannomas. This article reviews the diagnostic challenges in the surgical treatment of facial nerve hemangiomas. Study Design Two case reports and literature review. Results Early diagnosis and surgical excision of facial nerve hemangiomas can sometimes allow tumor removal with facial nerve preservation. In patients in whom the facial nerve needs to be resected to remove the hemangioma, primary anastomosis or cable nerve grafting can yield House-Brackmann Grade III/VI postoperative facial nerve function. Conclusion Complete surgical excision of facial nerve hemangiomas with primary facial nerve repair (when necessary) is the treatment of choice for these lesions.

Phosphatidylinositol 3-kinase/AKT pathway activation in human vestibular schwannoma.

Hypothesis: The neurofibromatosis 2 gene, which encodes the tumor suppressor protein merlin, is frequently mutated in vestibular schwannomas (VS). Merlin can inhibit phosphatidylinositol 3 kinase (PI3 kinase) by binding to PI3 kinase enhancer long isoform. Therefore, we hypothesized that the PI3 kinase/AKT pathway is activated in VS. Background: Despite advances in diagnosis and treatment, VS continue to cause patient morbidity. A more thorough understanding of the signaling pathways deregulated in VS will aid in the development of novel medical therapeutics. Activation of the PI3 kinase/AKT pathway increases cell survival and cell proliferation and has been observed in a variety of human cancers. However, whether the PI3 kinase/AKT pathway is activated in human VS has not been reported. Methods: Complementary deoxyribonucleic acid microarrays were performed using cultured Schwann cells, 4 VS specimens, and 2 paired normal vestibular nerves. Immunohistochemical analysis using antibodies to activated phosphorylated-AKT was performed on 14 VS tissue sections. Western blots using various antibodies to components of the PI3 kinase/AKT pathways were conducted. Results: Microarray analysis demonstrated that total AKT gene expression was upregulated in VS, compared with normal vestibular nerves. Immunohistochemical analysis of 14 VS tissue sections detected positive staining for activated AKT phosphorylated at both serine-473 and threonine-308 in all tumors. Western blots comparing VS specimens with normal vestibular nerves showed that the AKT pathway was activated in VS but not in normal nerve. Total AKT, phosphorylated-AKT, PI3-kinase, phosphorylated-phosphatase and tensin homologue deleted on chromosome 10, phosphorylated-phosphoinositide-dependent protein kinase 1, phosphorylated-forkhead box O, phosphorylated-glycogen synthase kinase 3&bgr;, and phosphorylated-mammalian target of rapamycin were upregulated in VS. Conclusion: The PI3 kinase/AKT pathway is activated in VS. Using our recently reported quantifiable VS xenograft model, novel inhibitors of the PI3 kinase/AKT pathway may be tested for VS growth inhibition in vivo.