Faculty Bibliography

OBJECTIVE:To describe our institutional experience with cochlear implantation (CI) for rehabilitation of hearing loss in Neurofibromatosis type 2 (NF2) patients. STUDY DESIGN/METHODS:Retrospective review between 1989 and 2019. SETTING/METHODS:Tertiary-care center. PATIENTS/METHODS:Twenty-four patients (67% female, mean age 45.6years) with NF2. Management of their ipsilateral vestibular schwannoma included microsurgery (n=12), stereotactic radiation (n=5), and observation (n=7). INTERVENTIONS/METHODS:Cochlear implantation. MAIN OUTCOME MEASURES/METHODS:Ability to obtain open-set speech, daily device usage and long-term device benefit. RESULTS:All patients achieved some degree of sound awareness with CI. Nineteen patients (79%) achieved open-set speech understanding with a mean word-recognition score of 43% (range 0-88%). Patients with tumors 1.5 cm or less demonstrated the better speech understanding, without significant differences among treatment modalities. For tumors greater than 1.5 cm, patients who underwent microsurgery had a lower rate of open-set speech understanding compared to those treated with radiation or observation. Regular daily device use in 83% of patients was found. Long-term use (>10years) was observed in several patients, though some ultimately required reimplantation with an auditory brainstem implant due to progressive tumor growth. Mean follow-up duration was 4.1 years (range 0.4-15). CONCLUSIONS:Cochlear implantation can be an effective treatment for hearing loss in NF2 patients provided the cochlear nerve is intact, regardless of prior management for the ipsilateral tumor. The degree of benefit varies and is influenced by tumor size. Management strategies that preserve the cochlear nerve maximize the interval during which a CI could be of benefit to NF2 patients.

OBJECTIVE:To evaluate the performance changes after sequential bilateral cochlear implantation in a pediatric population of bimodal cochlear implant (CI) users. To evaluate the factors which influence the parental and recipient decision to discontinue hearing aid use and seek a second implant. STUDY DESIGN/METHODS:Retrospective case review, within-subject comparison. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:Thirty-one pediatric (<18 yr) bimodal CI users who underwent sequential bilateral CI. INTERVENTIONS/METHODS:Sequential bilateral CI. MAIN OUTCOME MEASURES/METHODS:Parental and/or recipient's reasons for discontinuing their hearing aid and pursuing a second implant, device usage from datalogs, speech understanding in the bimodal and bilateral CI condition. RESULTS:Parents/patients were motivated to pursue sequential bilateral CI based on their positive performance with CI1, the expectation of further improvement with a second CI, and the prospect of having a second independently functional ear. In the bimodal condition, mean word recognition score (WRS), sentence recognition in quiet (SIQ), and sentence recognition in noise (SIN) scores were 87.4, 97.3, and 92.9% respectively. At 1-year post-sequential bilateral CI, the mean WRS, SIQ, and SIN score were 92.7, 98.7, and 97.7%, respectively. The improvement in bilateral CI speech scores compared with bimodal scores was statistically significant for WRS (p = 0.015). A ceiling effect limited the ability to detect further meaningful differences on speech perception testing. CONCLUSIONS:The bilateral CI condition demonstrates equivalent or slightly superior performance compared with the bimodal condition. Several non-speech benefits were elicited from parents as reasons for pursuing a second implant. Close monitoring of the residual acoustic hearing, inquiring about the perceived benefits provided by the HA, and early counseling regarding the potential for sequential bilateral CI are important aspects in determining if and when a second implant is indicated.

Objective: To describe cochlear implantation (CI) outcomes for rehabilitation of hearing loss due to retrocochlear pathology and/or its treatment.
Method(s): Retrospective review between 1995 and 2019 from a single tertiary care center of all patients with retrocochlear pathology who underwent CI. Demographics, clinical history, and audiometric data were reviewed. Study endpoints include (1) logged device use, (2) ability to achieve auditory perception, and (3) word recognition score (WRS) in the CI-only condition.
Result(s): Thirty-two patients (63% of females) with retrocochlear pathology were implanted at our center. The average age at implantation was 46.9 years (SD: 19, range: 13-80). Mean duration of deafness was 4.5 years (SD: 5.0, range: 0.4-19.0). Etiology of hearing loss included VS in 24 (75%), CNS malignancy treated with radiation in 4 (13%), intralabyrinthine schwannoma in 2 (6%), head and neck malignancy treated with radiation in 1 (3%), and superficial siderosis in 1 (3%). The mean preoperative PTA was 95.8 dBHL (SD 24.7) and WRS was 7.2% (SD 13.1). Of the 24 VSs, 21 were NF2-associated and 3 were sporadic. The mean tumor size was 1.64 cm (SD: 0.6, range: 0.5-2.6 cm). At the time of CI, 11 patients had prior microsurgery, 6 patients had prior radiation to the ipsilateral tumor, and 7 patients had stable tumors without prior surgery or radiation. Device use was classified as regular (>7 hours/day) in 15 (47%), limited (<7 hours/day) in 12 (38%), and nonuse is 5 (16%). The audiometric outcomes of 26 patients are reported, as the other 6 patients have been implanted too recently for review. Auditory perception was achieved in 24/26 patients. The two patients who failed to achieve auditory perception underwent prior surgery. Open-set speech recognition (WRS > 20%) was achieved in 18 patients. Meaningful sound perception but without significant open-set speech (WRS < 20%) was seen in six patients. Altogether, the mean WRS at most recent follow-up (mean: 3.4 years, SD: 1.8) for the observation, microsurgery, and radiation cohorts was 51% (SD: 15), 36% (SD: 28), and 39% (SD: 26), respectively. Over long-term follow-up, two patients experienced decline in CI performance associated with tumor regrowth and necessitated additional surgery; both underwent explantation of the CI and successful auditory brainstem implantation. The remaining patients have demonstrated durable benefit. A multivariate analysis is presented to evaluate the effects of the following variables: duration of deafness, time interval between treatment and CI, diagnosis of NF2, treatment cohort, pathology, and status of hearing in the contralateral ear.
Conclusion(s): In appropriately selected patients, cochlear implantation is feasible for the rehabilitation of hearing loss due to retrocochlear pathology and/or its treatment. Given the heterogeneity inherent to this population, outcomes are variable. In most cases, auditory percept was achieved and over half of the patients obtained open-set speech perception, irrespective of prior management and treatment

OBJECTIVECerebral venous sinus thrombosis (CVST) is a known complication of surgeries near the major dural venous sinuses. While the majority of CVSTs are asymptomatic, severe sinus thromboses can have devastating consequences. The objective of this study was to prospectively evaluate the true incidence and risk factors associated with postoperative CVST and comment on management strategies.METHODSA prospective study of 74 patients who underwent a retrosigmoid, translabyrinthine, or suboccipital approach for posterior fossa tumors, or a supratentorial craniotomy for parasagittal/falcine tumors, was performed. All patients underwent pre- and postoperative imaging to evaluate sinus patency. Demographic, clinical, and operative data were collected. Statistical analysis was performed to identify incidence and risk factors.RESULTSTwenty-four (32.4%) of 74 patients had postoperative MR venograms confirming CVST, and all were asymptomatic. No risk factors, including age (p = 0.352), BMI (p = 0.454), sex (p = 0.955), surgical approach (p = 0.909), length of surgery (p = 0.785), fluid balance (p = 0.943), mannitol use (p = 0.136), tumor type (p = 0.46, p = 0.321), or extent of resection (p = 0.253), were statistically correlated with thrombosis. All patients were treated conservatively, with only 1 patient receiving intravenous fluids. There were no instances of venous infarctions, hemorrhages, or neurological deficits. The rate of CSF leakage was significantly higher in the thrombosis group than in the nonthrombosis group (p = 0.01).CONCLUSIONSThis prospective study shows that the radiographic incidence of postoperative CVST is higher than that previously reported in retrospective studies. In the absence of symptoms, these thromboses can be treated conservatively. While no risk factors were identified, there may be an association between postoperative CVST and CSF leak.

OBJECTIVE: To describe our initial operative experience and hearing preservation results with the Advanced Bionics (AB) Mid Scala Electrode (MSE). STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: Sixty-three MSE implants in pediatric and adult patients were compared with age- and sex-matched 1j electrode implants from the same manufacturer. All patients were severe to profoundly deaf. INTERVENTION: Cochlear implantation with either the AB 1j electrode or the AB MSE. MAIN OUTCOME MEASURES: The MSE and 1j electrodes were compared in their angular depth of insertion and pre to postoperative change in hearing thresholds. Hearing preservation was analyzed as a function of angular depth of insertion. Secondary outcome measures included operative time, incidence of abnormal intraoperative impedance and telemetry values, and incidence of postsurgical complications. RESULTS: Depth of insertion was similar for both electrodes, but was more consistent for the MSE array and more variable for the 1j array. Patients with MSE electrodes had better hearing preservation. Thresholds shifts at four audiometric frequencies ranging from 250 to 2000 Hz were 10, 7, 2, and 6 dB smaller for the MSE electrode than for the 1j (p < 0.05). Hearing preservation at low frequencies was worse with deeper insertion, regardless of array. Secondary outcome measures were similar for both electrodes. CONCLUSION: The MSE electrode resulted in more consistent insertion depth and somewhat better hearing preservation than the 1j electrode. Differences in other surgical outcome measures were small or unlikely to have a meaningful effect.

Objective: Cerebral venous sinus thrombosis (CVST) is a rare but potentially dangerous complication following craniotomies involving the posterior fossa, the skull base, and craniotomies involving the superior sagittal sinus. Surgical manipulation of the sinuses has been shown to cause sinus thromboses of varying degrees. This phenomenon is often clinically silent, with only a small number of patients becoming symptomatic. Recent advances in neuroimaging provide higher resolution evaluation of cerebral sinuses pre and postoperatively, often revealing clinically silent filling defects. Although sinus thrombosis can be a major cause of morbidity and mortality, its incidence and factors that contribute to its formation in the postoperative population remain unclear. In addition, current guidelines advise to anticoagulate with Heparin upon diagnosis, which can be contraindicated for immediate post craniotomy patients. The goal of this study is to evaluate retrospective data of patient outcomes and factors that might contribute to sinus thrombus formation. Methods: A retrospective chart review was conducted at NYU Langone Medical Center. Ninety-seven patients were included who underwent either a retrosigmoid/translabrynthine/suboccipital resection of a posterior fossa tumor or a supratentorial craniotomy for resection of parasagittal/falcine tumor between July 1, 2014 and July 1, 2015. Pre operative Magnetic Resonance Venography (MRV) was obtained per the attending surgeon's discretion. Based on intraoperative findings, clinical symptoms, and surgeon's preference, a postoperative MRV was obtained. Decision to treat a thrombosis was made based on the results of the MRV and clinical symptoms. Treatments included observation, intravenous fluids (IVF) alone, anti-platelet therapy with Aspirin alone, or a combination of the two. Results: A total of 7 of 97 patients (7.22%) had postoperative sinus thrombosis. Of those patients, 5 had occlusion of the venous sinuses. In the occlusion group, 4 had preoperative imaging documenting patency of the sinuses. An additional 2 patients had postoperative MRVs revealing partial thrombosis of the sinus, 1 that was new and 1 that did not have a preoperative MRV for comparison. Compared with the cohort of patients without postoperative thromboses, there was no significant difference in age, BMI, length of surgery, or surgical approach. Of the 5 patients with postoperative thrombotic occlusion, 4 underwent intervention (1 with IVF alone, 2 with IVF and aspirin, and 1 with aspirin alone). Two patients with thromboses also developed CSF leaks requiring lumbar drainage and operative repair. One patient had a persistent CSF leak requiring a shunt. Of the 2 patients with partial thrombosis, 1 was placed on IVF and aspirin. At 3 months follow up, 1 out of 5 patients in the occlusion group had recanalization of the previously thrombosed sinus. Conclusions: MRV is a non-invasive method to evaluate the caliber and patency of dural venous sinuses in post craniotomy patients. Symptomatic thrombosis is rare and can be managed either conservatively or with IVF and/or anti platelet therapy, both which are safer than anticoagulation with heparin in post craniotomy patients. A larger prospective trial is necessary to further characterize the incidence of postoperative venous sinus thrombosis, identify risk factors, and to devise recommendations for therapy

Background: The transcochlear approach extends the anterior exposure afforded by the translabyrinthine technique. Although this wider exposure allows improved access to cranial nerves and the brainstem with less retraction on the cerebellum, the classical description involving facial nerve transposition often results in permanent facial paresis. This study discusses the role of the transcochlear approach in resection of cerebellopontine angle tumors including patient selection, surgical technique, and outcomes. Study Design: Retrospective review. Methods: This is a retrospective review conducted at a single academic institution. Cases performed by our skull base team (neurotologist and neurosurgeon) between 2000 and 2015 were reviewed. All cases utilizing the transcochlear approach were included. Factors including tumor size, completeness of resection, facial nerve function, post-operative complications, and length of stay were analyzed. Results: Fourteen cases were included. All of these patients had pre-operative severe hearing loss except for two in which surgery was performed urgently in the setting of hydrocephalus and brainstem compression. Eight out of 14 patients had pre-operative facial paresis. Tumor size ranged from 2.2-7 cm in greatest dimension (mean = 4.56 cm). All patients underwent a transcochlear approach to and removal of tumor with blind sac of the external auditory canal. In addition, 3 patients underwent an immediate facial nerve to hypoglossal anastomosis. Post-operatively, patients remained in the hospital for 3-5 days (mean = 4). Of the patients who started out with normal facial nerve function (n = 6), 3 recovered to House-Brackmann scores II or greater. There were no reported CSF leaks requiring hospitalization and 1 abdominal hematoma from fat graft harvest. There was a single mortality reported in the peri-operative period; however, on autopsy the cause of death was unrelated to the surgery itself or any subsequent intracranial event. Conclusions: As in other surgical approaches destructive to the labyrinth, patients were selected with consideration of their pre-operative hearing status and/or their candidacy for hearing preservation surgery. Patients with pre-operative facial nerve paralysis and hearing loss were deemed particularly appropriate candidates for the transcochlear technique given the additional exposure and the lack of added morbidity. In these cases the surgeon also has the option to perform dynamic facial nerve reanimation at the time of tumor resection

OBJECTIVES: Although there are various available treatment options for unilateral severe-to-profound hearing loss, these options do not provide the benefits of binaural hearing since sound is directed from the poorer ear to the better ear. The purpose of this investigation was to review our center's experience with cochlear implantation in such patients in providing improved auditory benefits and useful binaural hearing. STUDY DESIGN: Retrospective chart review. METHODS: Twelve adult patients and four pediatric patients with unilateral severe-to-profound hearing loss received an implant in the poorer ear. Outcome measures performed preoperatively on each ear and binaurally included consonant-nucleus-consonant (CNC) monosyllabic words and sentences in noise. The mean pure-tune average in the better ear was within normal range. RESULTS: Test scores revealed a significant improvement in CNC and sentence in noise test scores from the preoperative to most recent postoperative evaluation in the isolated implant ear. All adult subjects use the device full-time. CONCLUSIONS: The data reveal significant improvement in speech perception performance in quiet and in noise in patients with single-sided deafness after implantation. Performance might depend on factors including length of hearing loss, age at implantation, and device usage.

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.