Cochlear Implant Outcomes in Neurofibromatosis Type 2: Implications for Management
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.
Cochlear Implantation in Sporadic Vestibular Schwannoma and Other Retrocochlear Pathology: A Case Series
OBJECTIVE:To describe outcomes with cochlear implantation (CI) for rehabilitation of hearing loss in patients with sporadic vestibular schwannomas (VS) and other retrocochlear pathologies. STUDY DESIGN/METHODS:Retrospective review. SETTING/METHODS:Tertiary-care center. PATIENTS/METHODS:Twenty three cases in 19 patients (53% men, mean age 55.8 yr) with non-neurofibromatosis type 2 related retrocochlear pathology. INTERVENTIONS/METHODS:Unilateral or bilateral CI. MAIN OUTCOME MEASURES/METHODS:Word recognition score, device usage. RESULTS:Etiology of deafness included sporadic VS (nâ€Š=â€Š9, 39%), radiation after head and neck or central nervous system (CNS) malignancy (nâ€Š=â€Š8, 35%), superficial siderosis (nâ€Š=â€Š3, 13%), neurosarcoidosis (nâ€Š=â€Š2, 9%), and pontine stroke (nâ€Š=â€Š1, 4%). Mean follow-up duration was 2.3 years (standard deviation [SD] 3.0; range, 0.2-9.4). Auditory perception was achieved in 20 out of 22 patients (91%) who have been activated. Mean WRS in patients with sporadic VS was 18% (SD 20; range, 0-44). Mean WRS in patients with non-VS retrocochlear pathology was 55% (SD 30; range, 0-94). Data logs showed 7.0â€Šh/d of average use (SD 4.3; range, 0-13). CONCLUSIONS:Appropriately selected patients with retrocochlear pathology may benefit from CI so long as the patient has a cochlear fluid signal and an intact cochlear nerve. Patients with sporadic VS patients and normal contralateral hearing exhibited guarded outcomes with CI, whereas most patients with non-VS retrocochlear pathologies demonstrated open-set speech understanding scores comparable to or slightly worse than conventional CI candidates. Since variable performance benefit is observed with CI in patients with retrocochlear pathology, counseling is imperative to align patient expectations with realistic outcomes.
Skull Base Aerosol Generating Cases Amidst the COVID-19 Pandemic: An Experience from the Epicenter
Soon after the World Health Organization declared the severe acute respiratory syndrome coronavirus 2 a global health emergency on January 30, 2020, New York City was plagued by the virus and its health system and economy pushed to their limits. The majority of the limited neurosurgical data in relation to COVID-19 is anecdotal and the higher theoretical risk of transmission of the virus among skull base aerosol generating (SBAG) cases has not been investigated or discussed in a neurosurgical population. We discuss a series of 13 patients who underwent 15 SBAG surgical procedures during the peak of COVID-19 in our hospital system and the protocols use perioperatively for their procedures. Our data support that with proper preoperative testing, a well-delineated surgical algorithm, and appropriate personal protective equipment, emergent/urgent cases can be done safely in hospitals that are currently experiencing high volumes of COVID-19 cases as we did in March to May of 2020.
Outcomes of Salvage Resection and Radiosurgery Following Failed Primary Treatment of Vestibular Schwannomas
Objective: To evaluate outcomes following salvage microsurgery (MS) and salvage stereotactic radiosurgery (SRS) after failure of primary treatment for vestibular schwannomas (VS). Study Design: Retrospective chart review. Setting: Tertiary referral center. Methods: Patients with more than 1 intervention for their VS were divided into 4 groups: MS followed by SRS (n = 61), MS followed by MS (n = 9), SRS followed by MS (n = 7), and SRS followed by SRS (n = 7), and outcomes were evaluated. Results: A total of 77 patients were included (84 procedures). In group 1 (MS then SRS), 3% developed a decline in facial function, 3% developed trigeminal sensory loss, and 13% patients had gradual improvement of facial nerve function following SRS. Group 2 (MS then MS) had the highest rates of facial nerve deterioration, although all but 1 patient achieved a House-Brackmann score of II or III. Gross-total resection (GTR) was achieved in 56% of patients. When a different approach was used for salvage resection, GTR occurred more commonly, and facial nerve outcomes were similar. In group 3 (SRS then MS), GTR occurred in 43% of cases, and 2 of 7 patients developed worsened facial function. In group 4 (SRS then SRS), no patient developed facial weakness after reirradiation, and 1 developed a trigeminal nerve deficit. Conclusions: For MS recurrences/residuals, SRS is the mainstay of treatment and does not preclude facial function recovery. If salvage microsurgery is required, an alternate approach should be considered. For SRS failures, when MS is required, less-than GTR may be preferable, and reirradiation is a potential safe alternative.
From Bimodal Hearing to Sequential Bilateral Cochlear Implantation in Children-A Within-Subject Comparison
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 (pâ€Š=â€Š0.015). 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.
Cochlear implantation in patients with neurofibromatosis type 2 and other retrocochlear pathology: A review of 32 cases over 25 years [Meeting Abstract]
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
Postoperative cerebral venous sinus thrombosis in the setting of surgery adjacent to the major dural venous sinuses
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.
Other lateral approaches to the posterior fossa
Initial Operative Experience and Short-term Hearing Preservation Results With a Mid-scala Cochlear Implant Electrode Array
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.
Single-sided Deafness Cochlear Implantation: Candidacy, Evaluation, and Outcomes in Children and Adults
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.