Impact of superior semicircular canal dehiscence on cochlear implant audiologic outcomes.

PURPOSE: Determine whether adult cochlear implant users with radiographic superior semicircular canal dehiscence experience clinically significant differences in audiological outcomes when compared to cochlear implant users with normal temporal bone anatomy. MATERIALS AND METHODS: Retrospective, single institution review. Adult, post-lingual deaf patients implanted between 2010 and 2020. Inclusion criteria included age 18 years or older, available preoperative computed tomography imaging, and preoperative and postoperative AzBio audiological data for at least 6 months of cochlear implant use. Preoperative and postoperative AzBio Sentence Test scores were compared between patients with normal temporal bone anatomy and those with radiographic superior semicircular canal dehiscence or near dehiscence. RESULTS: 110 patients met inclusion criteria. Mean AzBio score for normal temporal bone anatomy group improved from 35.2 % (SD 28.2) preoperatively to 70.3 % (SD 25.7) postoperatively, an improvement of 35.1 % (SD 28.6). Mean AzBio score for near dehiscent temporal bone anatomy group improved from 26.6 % (SD 28.9) preoperatively to 64.5 % (SD 30.6) postoperatively, an improvement of 37.9 % (SD 27.9). Mean AzBio score for dehiscent temporal bone anatomy group improved from 26.3 % (SD 20.4) preoperatively to 65.1 % (SD 27.6) postoperatively, an improvement of 38.7 % (SD 26.9). Utilizing the one-way analysis of variance test, there was no significant difference in audiologic outcomes between the three groups. CONCLUSIONS: Patients with complete or near complete radiographic superior canal dehiscence at the time of cochlear implantation achieve similar improvements in speech perception scores compared to normal anatomy adult cochlear implant users.

Educational Benefit of the Three-Dimensional Exoscope Versus Operating Microscope in Otologic Surgery.

OBJECTIVE: To compare observation of otologic surgery using a traditional operating microscope (OM) and a three-dimensional exoscope. STUDY DESIGN: Prospective, nonrandomized, noncontrolled study. SETTING: Tertiary care center. METHODS: Senior medical students and otolaryngology trainees observing otologic surgery performed with OM and exoscope were asked to complete a questionnaire comparing the two experiences. The key variables were image clarity, depth perception, observer's level of motion sickness during the surgery, the participant's understanding of middle ear anatomy, and their overall preference between OM and exoscope. RESULTS: Twenty-two observers participated in the study. Subjective clarity of the image was significantly better with the exoscope compared with the OM (9.7 ± 0.6 versus 6.9 ± 1.7, p = 0.0004) as well as the depth perception (9.25 ± 0.87 versus 5 ± 2.69, p = 0.0007). Observers subjectively had an improved understanding of middle ear anatomy after observing an exoscopic surgery, but not a microscopic surgery. All but one observer preferred the exoscope. CONCLUSION: The three-dimensional exoscope may be a valuable educational tool for teaching trainees otologic surgery. More objective studies are needed in the future to assess the degree of improvement.

Preoperative Evaluation of Otosclerosis: A National Survey of Otologists.

OBJECTIVE: Describe practice patterns in preoperative assessment for stapedectomy. STUDY DESIGN: Survey. SETTING: Tertiary referral center. SUBJECTS: Active members of the American Neurotologic Society and American Otologic Society. INTERVENTION: Survey. MAIN OUTCOME MEASURES: Percent of respondents performing preoperative testing with acoustic reflexes (ARs), electrocochleography, vestibular evoked myogenic potentials, and computed tomography (CT). Further analysis of those not ordering routine CT to determine whether imaging would be ordered for previous ear surgery, vestibular complaints, childhood hearing loss, AR inconsistent with otosclerosis, possible advanced otosclerosis, or atypical complaints, including autophony. Further subgroup analysis based on years in practice and practice setting (private versus academic). RESULTS: Most respondents (56.5%) had practiced more than 15 years and worked in academic settings (69.4%). Rates of routine use of preoperative AR, vestibular evoked myogenic potential, and electrocochleography were 80, 4.7, and 0%, respectively. There were no significant differences based on time in practice or practice settings. For CT, 35.3% reported routine use with a statistically significant difference between academic and private practice respondents (42.4% versus 19.2%, p = 0.040). For CT contingent on specific clinical factors, only AR inconsistent with otosclerosis showed a statistically significant difference between academic and private practice providers (85.3% versus 57.1%, p = 0.020). CONCLUSION: Most otologists routinely obtain AR before stapedectomy. Academic providers more commonly order CT routinely and for AR inconsistent with otosclerosis. Most respondents not ordering routine CT ordered imaging in specific clinical scenarios. Overall, there is a high level of consistency in preoperative testing regardless of practice setting or time in practice.

Audiologic comparison of classification systems of advanced otosclerosis.

OBJECTIVE: To identify which patients with advanced otosclerosis may have the greatest audiologic improvement with stapedotomy based on different classifications of advanced otosclerosis. STUDY DESIGN: Retrospective chart review. SETTING: Single tertiary neurotology center. METHODS: Patients were divided into different classifications of advanced otosclerosis based on either a bone conduction threshold of greater than 60 dB HL (Bone Conduction (BC) Group), a word recognition score of less than 70% (Word Recognition (WRS) Group), or pure tone average of greater than 85 dB HL (Pure Tone Average (PTA) Group). Audiologic outcomes and complication profiles were compared between these groups. RESULTS: Nineteen patients met criteria for one or more group. There were 18 patients in the PTA group, 11 in the BC group, and 12 in the WRS group. There was no significant difference in the pre- or postoperative audiologic status between the different groups. CONCLUSIONS: Patients with advanced otosclerosis have significant improvements in pure tone averages and air-bone gaps following stapedotomy regardless of the classification criteria used. Stapedotomy remains a reasonable primary intervention for the majority of patients with advanced otosclerosis.

Outcomes of Stapedotomy in Patients With Concomitant Otosclerosis and Superior Semicircular Canal Dehiscence: Should a Radiographic Third-Window Be a Contraindication to Stapes Surgery?

OBJECTIVE: Review surgical outcomes of stapedotomy in patients with concomitant otosclerosis and superior semicircular canal dehiscence. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients with otosclerosis and radiographic superior semicircular canal dehiscence undergoing stapedotomy between 2008 and 2020. INTERVENTION: Stapedotomy. MAIN OUTCOME MEASURES: Pre- and postoperative hearing and unmasking of third-window symptoms. Hearing was measured by air conduction (AC) and bone conduction (BC) pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). Third-window symptoms included hyperacusis, autophony, sound- or pressure-induced vertigo, imbalance, or oscillopsia. RESULTS: Twenty patients with otosclerosis and radiographic superior semicircular canal dehiscence underwent stapedotomy, 13 primary and 7 revision. Mean AC PTA was 49.3 dB preoperatively and 35.6 dB postoperatively (p = 0.0077), while the ABG improved on average from 23.9 to 9.68 dB (p < 0.0001). The ABG improved to ≤10 dB in 12/20 patients (60%), and ≤20 dB in 18/20 patients (90%). There was no significant difference in BC PTA or WRS postoperatively. Two patients (10%) experienced potential transient unmasking of third-window symptoms-hyperacusis and prolonged imbalance-which both resolved. There were no other complications. There was no significant difference in audiologic outcomes or unmasking of third window symptoms between primary or revision cases. CONCLUSIONS: Persistent conductive hearing loss is common following stapedotomy for otosclerosis in patients with concomitant superior semicircular canal dehiscence. However, a majority of patients can achieve excellent hearing outcomes, while unmasking of third window symptoms appears to be rare. Radiographic superior semicircular canal dehiscence may not be an absolute contraindication to stapes surgery for otosclerosis.

Audiologic Outcomes of Footplate Drillout for Obliterative Otosclerosis.

OBJECTIVE: To evaluate the audiologic outcomes of microdrill fenestration for obliterative otosclerosis compared to traditional stapedotomy technique. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into groups that underwent either microdrill or laser fenestration based on intraoperative severity of disease. Audiologic outcomes and complications were compared between the two groups. RESULTS: There were 588 ears in 519 patients that were evaluated. There was a significant postoperative improvement in pure tone average, air-bone gap, and mean bone conduction thresholds for both the obliterative and nonobliterative group (p < 0.001). There was no significant difference in the pre- or postoperative hearing status between the two groups. There was no significant difference in complications between the two groups, including no cases of postoperative profound hearing loss in the drill fenestration group. CONCLUSIONS: Audiologic outcomes are similar between microdrill fenestration and laser fenestration for otosclerosis. Pure tone average, air-bone gap, and mean bone conduction thresholds all improved postoperatively and were similar between groups.

Comparison of Cranioplasty Techniques Following Translabyrinthine Surgery: Implications for Postoperative Pain and Opioid Usage.

OBJECTIVE: To assess differences in postoperative pain, opioid usage, and surgical outcomes between cranioplasty using abdominal fat graft (AFG) versus hydroxyapatite cement (HAC) following translabyrinthine surgery. STUDY DESIGN: Retrospective case control. SETTING: Tertiary referral center. PATIENTS: Sixty translabyrinthine procedures were evaluated, including 30 consecutive HAC patients and 30 matched AFG patients. Patients were matched by age, gender, body mass index, and tumor size. INTERVENTION: Cranioplasty using HAC or AFG following translabyrinthine resection of vestibular schwannoma. MAIN OUTCOME MEASURES: Postoperative patient pain ratings, narcotic usage, inpatient length of stay, and complication rates. RESULTS: Patients who underwent HAC cranioplasty had lower postoperative pain scores on several measures (p < 0.05) and less postoperative narcotic usage (mean difference of 36.7 morphine equivalents, p = 0.0025) when compared to those that underwent AFG closure. HAC cranioplasty patients had shorter average length of hospital stay (2.2 vs 3.4 days, p = 0.0441). Postoperative cerebrospinal fluid leaks (one in HAC group, two in AFG group) and skin reactions in AFG closure patients (n = 1) were infrequent. CONCLUSION: HAC cranioplasty is a safe technique comparable to AFG closure following translabyrinthine surgery which can decrease postoperative pain, narcotic usage, and hospital length of stay.

Effect of Surgical Start Time on Stapedotomy Outcomes.

OBJECTIVE: To examine if performing stapedotomy as the first case of the day provides improved outcomes compared with those performed later in the day. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into either a first case group or a later case group based on surgical start time. Audiologic outcomes and complications were compared between the two groups. RESULTS: The first case group had a smaller postoperative air-bone gap (ABG) compared with the later case group of 9.81 dB HL compared with 11.73dB HL and 3.79 dB HL compared with 6.29 dB HL at 1000 and 2000 Hz, respectively (p = 0.03, p < 0.01). The mean postoperative ABG was 10.63 dB HL for the first start group compared with 12.12 dB HL for the later start group, which was statistically significant (p = 0.05). CONCLUSIONS: First start stapedotomy is associated with slightly improved audiologic outcomes compared with those starting later in the day, although both groups had significantly improved postoperative outcomes overall. There was no significant difference in complications when comparing stapedotomy by case start time.

Early Outcomes of Simultaneous Translabyrinthine Resection and Cochlear Implantation.

OBJECTIVES/HYPOTHESIS: Hearing rehabilitation after translabyrinthine resection of a vestibular schwannoma (VS) has largely been based on the transfer of acoustic stimulus to the contralateral ear, typically through a contralateral routing of signal hearing aid or bone-anchored hearing aid (BAHA). Cochlear implant, either as a subsequent surgery or simultaneously, has become a more common treatment option; however, there is still relatively limited data available on its success. The purpose of this study is to evaluate the early outcomes of simultaneous cochlear implantation in patients with sporadic VS undergoing translabyrinthine resection. STUDY DESIGN: Prospective, nonrandomized study. METHODS: A prospective study of nonrandomized patients was completed at a tertiary care neurotology center. Audiologic outcomes, primarily based on AzBIO in quiet and background noise, as well as consonant-nucleus-consonant (CNC) testing of the affected ears were utilized. Tinnitus, dizziness, and spatial hearing questionnaries were also completed. Audiologic outcomes and questionnaires were compared between the pre- and postoperative groups. RESULTS: Ten patients were included in the study with 3 month follow-up data. There was statistically significant improvement in AzBO with +10 and +5 signal to noise ratio and in quiet, as well as in CNC testing (P < .05). There was a significant improvement in Tinnitus Handicap Inventory between the two groups. CONCLUSIONS: Simultaneous cochlear implantation is a viable treatment for hearing loss after translabyrinthine approach to VS. These patients have improved hearing in background noise and tinnitus compared to their preoperative state. Further prognostic data are required to determine which patients are the best candidates. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2312-E2317, 2021.

Network-Related Changes in Neurotransmitters and Seizure Propagation During Rodent Epileptogenesis.

OBJECTIVE: To test the hypothesis that glutamate and GABA are linked to the formation of epilepsy networks and the triggering of spontaneous seizures, we examined seizure initiation/propagation characteristics and neurotransmitter levels during epileptogenesis in a translationally relevant rodent model of mesial temporal lobe epilepsy. METHODS: The glutamine synthetase (GS) inhibitor methionine sulfoximine was infused into one of the hippocampi in laboratory rats to create a seizure focus. Long-term video-intracranial EEG recordings and brain microdialysis combined with mass spectrometry were used to examine seizure initiation, seizure propagation, and extracellular brain levels of glutamate and GABA. RESULTS: All seizures (n = 78 seizures, n = 3 rats) appeared first in the GS-inhibited hippocampus of all animals, followed by propagation to the contralateral hippocampus. Propagation time decreased significantly from 11.65 seconds early in epileptogenesis (weeks 1-2) to 6.82 seconds late in epileptogenesis (weeks 3-4, paired t test, p = 0.025). Baseline extracellular glutamate levels were 11.6-fold higher in the hippocampus of seizure propagation (7.3 µM) vs the hippocampus of seizure onset (0.63 µM, analysis of variance/Fisher least significant difference, p = 0.01), even though the concentrations of the major glutamate transporter proteins excitatory amino acid transporter subtypes 1 and 2 and xCT were unchanged between the brain regions. Finally, extracellular GABA in the seizure focus decreased significantly from baseline several hours before a spontaneous seizure (paired t test/false discovery rate). CONCLUSION: The changes in glutamate and GABA suggest novel and potentially important roles of the amino acids in epilepsy network formation and in the initiation and propagation of spontaneous seizures.

Audiologic Outcomes After Oval and Round Window Reinforcement Surgery.

INTRODUCTION: Oval window (OW) and round window (RW) reinforcement surgery has been used for symptomatic treatment of multiple clinical entities, most commonly perilymphatic fistula and superior semicircular canal dehiscence. Owing to the theoretical acoustically negative effect of stiffening the windows, there has been concern of an unfavorable effect on audiologic outcomes due to the procedure. The purpose of this study is to specifically evaluate audiologic outcomes after OW and RW reinforcement. METHODS: A retrospective review of patients undergoing transcanal OW or RW reinforcement was completed. Patients were evaluated both as a total group and as two groups separated into "third window" and "two-window" groups based on their specific diagnosis. Primary outcomes included changes in individual pure-tone thresholds, pure-tone average (PTA), air-bone gap, speech reception threshold (SRT), and word recognition scores (WRS) between the preoperative and postoperative groups. RESULTS: Seventy-one patients were included in the study. The combined cohort demonstrated a significant postoperative 2.75 dB increase in the air conduction hearing level at 4000 Hz (p < 0.05). This was almost entirely accounted for by a 2.18 dB increase in the air-bone gap at this frequency (p < 0.05). There were no significant changes in PTA, SRT, or WRS between in the combined group or in the subgroup analysis. CONCLUSION: OW and RW tissue reinforcement resulted in a statistically significant but likely clinically insignificant decrease in hearing at the 4000 Hz frequency. There was no worsening of PTA, WRS, or SRT.

Hydroxyapatite cement cranioplasty in the setting of simultaneous translabyrinthine resection of cerebellopontine angle tumors and cochlear implantation.

Cochlear implantation (CI) has become an option for the treatment of hearing loss after translabyrinthine resection of vestibular schwannomas. The surgical video presents the case of a 67-year-old male who had translabyrinthine resection of vestibular schwannoma with simultaneous CI and closure with a hydroxyapatite (HA) cement cranioplasty. HA cement cranioplasty can be utilized in place of abdominal fat graft for the closure of translabyrinthine approaches with similar efficacy and complication profile. To the authors' knowledge, this is the first reported case of a simultaneous CI and translabyrinthine resection of vestibular schwannoma with HA cement cranioplasty. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID211.

Exoscope-assisted Otologic Surgery During the COVID-19 Pandemic.

OBJECTIVE: The recent COVID-19 pandemic has required careful reconsideration of safe operating room practices. We describe our initial experiences performing otologic surgery with the exoscope during the COVID-19 pandemic. METHOD: The exoscope was used for several semiurgent otologic surgeries in combination with complete eye protection, a "tent" drape, a smoke evacuator with ultra-low particulate air filter, and betadine irrigation. These techniques are demonstrated in the accompanying video. This was compared with our experiences using the microscope. RESULTS: The described modified goggles allowed complete eye protection while providing a fully three-dimensional view of the surgical site. The other safety measures described are simple and efficient techniques which can easily be adopted for otologic surgery using the microscope. CONCLUSION: Use of the exoscope for otologic surgery during the COVID-19 pandemic allows full three-dimensional visualization of the surgical field while simultaneously providing complete eye protection. Use of the "tent" drape, ultra-low particulate air filter, and betadine irrigation are also options that otologic surgeons may consider for additional safety.

Current imaging tools for vestibular schwannoma.

PURPOSE OF REVIEW: Of the tumors found in the cerebellopontine angle (CPA), vestibular schwannomas are by far the most common. Modern diagnostic imaging enables excellent visualization of the CPA and detection of very small tumors while optimizing patient comfort and time. This review addresses the current imaging tools available for diagnosis of vestibular schwannomas. RECENT FINDINGS: The current gold-standard imaging study for vestibular schwannomas is a gadolinium-enhanced T1-weighted MRI. The yield of this expensive study is only about 3-4% given the low incidence of vestibular schwannomas, thus there is utility in screening with noncontrast T2-weighted MRI, which is a quicker and more economical study. SUMMARY: Vestibular schwannomas are best evaluated with gadolinium-enhanced T1-weighted MRI, which can detect tumors as small as 2-3 mm. Recent studies have found that the reported sensitivity and specificity of noncontrast MRI is almost equivalent to that of gadolinium-enhanced T1-weighted MRI. As such, this modality is increasingly being adopted by institutions for both diagnosis and surveillance of vestibular schwannomas and shows promise for broader implementation. Newer protocols, such as FLAIR and DTI may provide additional information and further aid preoperative counseling and surgical planning in the future.

What Genes Can Tell: A Closer Look at Vestibular Schwannoma.

OBJECTIVE: Comprehensive molecular profiling of radioresistant and cystic vestibular schwannoma (VS) subtypes. STUDY DESIGN: Our study utilized whole-exome sequencing (WES), RNA-sequencing (RNAseq), and correlated clinical data from 12 samples (2 samples of solid sporadic subtype, 8 with cystic changes, and 2 previously irradiated). SETTING: Academic medical center. PATIENTS: Patients diagnosed with VS who required surgical treatment. Inclusion: Cystic and radioresistant tumors matched to age and tumor volume, with solid sporadic VS samples as control; Exclusion: NF-2 patients. INTERVENTION(S): WES using custom probes for copy number analysis. A modified version of the Agilent Human Whole Exome sequencing hybrid capture system was used to process samples. Recurrent variants were identified and compared between groups. Leukocyte-derived DNA was utilized as internal control to reduce false-positives. MAIN OUTCOME MEASURE(S): Analysis of genetic landscape of VS subtypes (naive solid VS, cystic VS, and previously irradiated VS) by performing deep next-generation sequencing. RESULTS: WES data achieved a mean coverage of 202X and RNAseq generated an average of 74 million total reads. As a group, 25% of samples had 22q loss. Somatic analysis identified previously reported genes and multiple novel mutations across samples. Differential expression analysis of RNAseq data found significantly mutated genes such as COL6A3, CLMP, ART4, Lumican that were shared by both cystic VS and irradiated VS, but not seen in sporadic VS. CONCLUSIONS: Using WES we were able to demonstrate that cystic and irradiated samples are subtypes of VS with an increased mutation burden and a unique genetic fingerprint. We identified differences between the genomic and molecular profile of cystic VS and radioresistant VS. Our results help advance the understanding of the pathophysiology of these tumor subtypes and suggest possible molecular targets for novel treatment strategies.

Cochlear FLAIR Signal Changes in Hearing Preservation Vestibular Schwannoma Surgery.

OBJECTIVE: Cochlear fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) signal intensity has been shown to be elevated in patients with vestibular schwannomas (VS). This study evaluated the preoperative and postoperative cochlear signal on FLAIR sequences in patients undergoing hearing preservation surgery. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: All patients undergoing middle cranial fossa or retrosigmoid craniotomy for VS at a single institution from September 2013 to January 2017 were screened.Hearing was graded according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification. Inclusion criteria included preoperative AAO-HNS class A or B hearing and available preoperative and postoperative FLAIR sequences. MAIN OUTCOME MEASURE: Signal intensity of cochlear FLAIR signal was measured in the affected cochlea and normalized to the contralateral cochlea. Hearing preservation was defined as AAO-HNS class A or B postoperatively. RESULTS: Eighteen patients met all inclusion criteria, and 12/18 experienced hearing preservation. There was no difference in preoperative FLAIR ratio between hearing preserved and nonpreserved groups (2.02 vs 2.32, p = 0.52). Postoperatively, FLAIR ratio was lower in the hearing preserved group compared to the nonpreserved group (1.19 vs 1.87, p = 0.033). CONCLUSIONS: The current study is the first to examine postoperative cochlear FLAIR changes in VS patients undergoing hearing preservation surgery. In our study population, abnormal hyperintense FLAIR signal normalized in patients experiencing successful hearing preservation, while those who lost hearing maintained abnormal signal. Future studies may investigate the role of FLAIR in guiding optimal timing of operative intervention in VS patients.

Age-related hearing loss: Unraveling the pieces.

Age-related hearing loss (ARHL) is the most common cause of hearing loss in the world. The development of ARHL in each individual is multifactorial, involving both intrinsic and extrinsic factors. This review highlights several of the key findings in the ARHL literature and discusses future directions. LEVEL OF EVIDENCE: NA.

Paraganglioma Presenting as a Nasal Septal Mass: Case Report and Literature Review.

OBJECTIVES: To describe a rare case of a paraganglioma arising from the nasal septum and review the diagnosis and management of paragangliomas in the nasal cavity and paranasal sinuses. METHODS: We present a case of a 70-year-old female presenting with persistent nasal congestion and obstruction. Nasal endoscopy revealed a posterior septal mass approaching the sphenoid sinuses and partially obstructing the nasopharynx. A biopsy of the mass was taken, and histologic analysis confirmed a diagnosis of paraganglioma. RESULTS: The patient underwent an endoscopic resection of the tumor. There has been no evidence of disease recurrence after 3 months of follow-up. CONCLUSIONS: Paragangliomas arising from the nasal septum are exceedingly rare, but should be considered in the differential diagnosis in patients presenting with nasal septal masses. These tumors are typically benign, although few cases of malignant sinonasal paragangliomas have been reported. Treatment requires surgical excision with close follow-up as several cases of tumor recurrence have been reported.