Citations

OBJECTIVE The morbidity of gross-total resection of jugular paraganglioma (JP) is often unacceptable due to the potential for irreversible lower cranial neuropathy. Stereotactic radiosurgery (SRS) has been used at the authors’ institution since 1990 for the treatment of JP and other benign intracranial tumors. Conventional means of assessing tumor progression using linear measurements or elliptical approximations are imprecise due to the irregular shape and insinuating growth pattern of JP. The objective of this study was to assess long-term tumor control in these patients by using slice-by-slice 3D volumetric segmentation of serial MRI data. METHODS Radiographic data and clinical records were reviewed retrospectively at a single, tertiary-care academic referral center for patients treated from 1990 to 2017. Volumetric analyses by integration of consecutive tumor cross-sectional areas (tumor segmentation) of serial MRI data were performed. Tumor progression was defined as volumetric growth of 15% or greater over the imaging interval. Primary outcomes analyzed included survival free of radiographic and clinical progression. Secondary outcomes included new or worsened cranial neuropathy. RESULTS A total of 85 patients were treated with Gamma Knife radiosurgery (GKRS) for JP at the authors’ institution over the last 27 years. Sixty patients had pretreatment and serial posttreatment contrast-enhanced MRI follow-up suitable for volumetric analysis. A total of 214 MR images were analyzed to segment tumor images in a slice-by-slice fashion to calculate integral tumor volume. The median follow-up duration was 66 months (range 7–202 months). At 5 years the tumor progression-free survival rate was 98%. Three tumors exhibited progression more than 10 years after GKRS. Estimated survival free of radiographic progression rates (95% confidence interval [CI]; n = number still at risk) at 5, 10, and 15 years following radiosurgery were 98% (95% CI 94%–100%; n = 34), 94% (95% CI 85%–100%; n = 16), and 74% (95% CI 56%–98%; n = 6), respectively. One patient with tumor progression required treatment intervention using external beam radiation therapy, constituting the only case of clinical progression. Two patients (3%) without preexisting lower cranial nerve dysfunction developed new ipsilateral vocal fold paralysis following radiosurgery. CONCLUSIONS SRS achieves excellent long-term tumor control for JP without a high risk for new or worsened cranial neuropathy when used in primary, combined modality, or recurrent settings. Long-term follow-up is critical due to the potential for late radiographic progression (i.e., more than 10 years after SRS). As none of the patients with late progression have required salvage therapy, the clinical implications of this degree of tumor growth have yet to be determined.

Objectives To describe transnasal Eustachian tube (ET) occlusion with a liquid embolic solution for lateral skull base cerebrospinal fluid (CSF) leaks. Design A lateral skull base CSF fistula model was developed by the authors using fresh cadaveric heads. Using a transtympanic needle, regulated pressurized pigmented saline was continuously instilled into the middle ear space and visualized endoscopically in the nasopharynx. An angioembolization catheter was then placed through the cartilaginous ET orifice just medial to the bony ET. Under endoscopic and fluoroscopic guidance, a column of liquid embolic agent was deployed into the bony ET segment up to the middle ear space. Setting Tertiary care academic center. Participants Cadaveric specimens. Main Outcome Measures Cessation of CSF flow after occlusion at supraphysiologic pressures. Results In two cadavers, a CSF fistula model was developed and endoscopic visualization of irrigant flow into the nasopharynx was confirmed. Fluoroscopy provided adequate anatomic views of the ET and middle ear, in addition to dynamic views of embolization. Cessation of flow after occlusion was successfully achieved with pressures up to 25 mm Hg, which exceeds normal physiological intracranial pressure. Conclusion Eustachian tube occlusion with a liquid embolic solution is feasible in a novel cadaveric CSF leak model. In the future, this relatively short, straightforward procedure may become an outpatient alternative to manage intermittent or low-flow CSF fistulae following lateral skull base surgery.

Objective: To describe audiometric outcomes following stereotactic radiosurgery (SRS) for jugular paraganglioma (JP). Study Design: Retrospective review. Setting: Tertiary referral center. Patients: Patients with pretreatment serviceable hearing (American Academy of Otolaryngology—Head and Neck Surgery [AAO-HNS] Class A or B) and serial post-SRS audiometric follow-up who underwent Gamma Knife SRS for JP between 1990 and 2017. Intervention(s): Gamma Knife SRS. Main Outcome Measures: Progression to nonserviceable hearing; correlation between baseline hearing and treatment parameters with audiometric outcomes. Results: Of 85 patients with JP who underwent SRS during the study period, 35 (66% female, median age 53) had pretreatment serviceable hearing and serial post-treatment audiometry available for review. Median tumor volume at the time of treatment was 7,080 mm3, median cochlear point dose was 5.8 Gy (interquartile range [IQR] 4.1 to 7.3 Gy), and median marginal and maximum tumor doses were 16 and 32 Gy, respectively. After a median follow-up of 37 months (IQR 16 to 77 mo), the median change in pure-tone average and speech discrimination score in the treated ear was −1.2 dB HL/yr (IQR −4.5 to 0.3) and 0%/yr (IQR 0–3.5%), compared with 0.07 dB HL/yr (IQR −0.03 to 0.12) and 0 %/yr (IQR 0 to 0%) in the contralateral untreated ear. Seven patients developed nonserviceable hearing (AAO-HNS Class C or D) at a median of 13.2 months following SRS (IQR 4.8 to 24 mo). Among those who maintained serviceable hearing, median audiometric follow-up was 42 months (IQR 18 to 77 mo). The Kaplan–Meier estimated rates of serviceable hearing at 1, 3, and 5 years following SRS were 91%, 80%, and 80%, respectively. Sixty percent of patients with pulsatile tinnitus who underwent SRS experienced varying levels of symptomatic improvement following treatment. Conclusion: The short- and intermediate-term risk of progression to nonserviceable hearing following SRS for JP is low. Data regarding the impact of cochlear dose from the vestibular schwannoma literature should not be freely applied to JP, since the impact of SRS parameters on hearing preservation seems to be less significant.

ObjectiveTo define relationships between the frontal sinus opening, ostia of other frontal recess cells, and endoscopic landmarks and to develop a clinically useful framework to guide frontal sinus surgery.Study DesignRetrospective review.SettingTertiary care academic referral center.MethodsAdult patients with computed tomography (CT) without sinonasal pathology were included. Virtual endoscopy (using OsiriX) and corresponding CT reconstructions were used to identify all visible ostia in the frontal recess and characterize their positions in spaces between the uncinate/agger nasi (U), bulla ethmoidalis (EB), and middle turbinate (MT).ResultsTwo hundred sides in 100 patients (median age 51 years, 62% female) were analyzed. The “center” of each map was defined as the intersection of spaces between U, EB, and MT. The frontal sinus opening was in the “center” in 53% of frontal recesses, lateral to this position in 29%, and anterior in 11%. When the frontal sinus opening was at the “center,” anterior ostia drained frontal Kuhn T cells in 51% and intersinus septal cells in 23%. The skull base attachment of the apical strut of the uncinate process demarcated medial and lateral within the space between U and EB, with the opening to the frontal sinus medial in 68% and lateral in 31%. Left‐right asymmetry in frontal sinus openings was noted in 46% of patients.ConclusionCombining preoperative imaging and knowledge of these anatomic relationships may facilitate more efficient frontal outflow tract identification and instrumentation. This represents the first and largest description of ostial configurations relative to endoscopic structural landmarks.Level of Evidence:4

Objective: To describe a novel case of congenital profound bilateral sensorineural hearing loss in a patient with bilateral nodular internal auditory canal and labyrinthine enhancement and temporal bone dysplasia. Patients: A 76-day-old female was referred to the authors’ center for evaluation of congenital deafness. Behavioral observations and objective audiometric evaluation demonstrated bilateral profound sensorineural hearing loss and a comprehensive multidisciplinary evaluation identified compound heterozygous pathogenic variants in MYO7A , a gene associated with Usher Syndrome Type 1B or DFNB2. Computed tomography and contrast-enhanced magnetic resonance imaging studies demonstrated bilateral temporal bone anomalies with unique middle and inner ear malformations, as well as unique contrast enhancement in the membranous labyrinth, internal auditory canals, and cranial nerves, which have not been previously described with MYO7A variants. Interventions: Given the potential risk for progressive bilateral labyrinthitis ossificans, bilateral simultaneous cochlear implantation was performed at 4 months of age. Main Outcome Measures: Subsequent audiologic follow up after implantation shows significantly improved access to auditory information and increased vocalizations. At last testing, speech and language skills for both receptive and expressive language abilities were found to be commensurate with her chronological age. Conclusion: We report a novel presentation and imaging findings of congenital bilateral profound sensorineural hearing loss in a patient with nodular internal auditory canal and labyrinthine enhancement and coexisting inner ear dysplasia. Despite the multiple radiologic abnormalities, the patient has demonstrated good benefit from cochlear implantation. Future study of rare variants of congenital deafness, such as this, is critical toward defining new disease processes and determining optimal treatment.

ObjectiveTo determine the sensitivity and specificity of ocular and cervical vestibular evoked myogenic potentials (VEMPs) in the diagnosis of superior semicircular canal dehiscence (SCD) and to describe the VEMP response characteristics that are most sensitive to SCD and compare the findings to previous reports.Study DesignCase series with chart review.SettingTwo tertiary neurotologic referral centers.Subjects and MethodsCervical and ocular VEMP peak‐to‐peak amplitudes and thresholds from 39 adult patients older than 18 years with surgically confirmed SCD were compared with 84 age‐matched controls.ResultsUsing receiver operating characteristic (ROC) curves, cervical VEMP (cVEMP) amplitudes, cVEMP thresholds, and ocular VEMP (oVEMP) amplitudes had areas under the curve of 0.731, 0.912, and 0.856, respectively, all of which were statistically significant (P <. 0001). For cVEMP thresholds, at the clinical equivalent ≤85‐dB normalized hearing level (nHL) threshold, the sensitivity and specificity were 97.3% and 31.3%, respectively. At the ≤70‐dB nHL threshold, the sensitivity and specificity were 73.0% and 94.0%, respectively. For oVEMP amplitudes >12.0 µV, the sensitivity and specificity were 78.6% and 81.7%, respectively.ConclusionData from this multicenter study suggest that both cVEMP thresholds and oVEMP amplitudes remain good diagnostic tests for identifying SCD, with each test dependent on a number of factors. The sensitivity and specificity of these individual tests may vary slightly between centers depending on testing parameters used.

ObjectivePatients with incidental or minimally symptomatic superior semicircular canal dehiscence (SSCD) are usually observed, without surgical repair. However, it remains unknown whether a labyrinthine fistula of the superior semicircular canal is associated with progressive conductive or sensorineural hearing loss over time.Study DesignRetrospective review at two tertiary care academic referral centers.MethodsAdults analyzed were diagnosed with SSCD by high‐resolution temporal bone computed tomography and vestibular evoked myogenic potential testing and observed with a minimum of two sequential audiograms. Patients with other potential causes of hearing impairment were excluded.ResultsA total of 40 ears in 30 adult patients (median age: 59 years; 63% female) were analyzed. Median audiometric follow‐up was 23 months (range 1–136 months). None experienced a sudden hearing loss over the follow‐up period. In patients with audiometric follow‐up of at least 20 months (median 34 months), the median change in air‐conduction pure tone average and air–bone gap was 0.9 decibels (dB) per year (interquartile range [IQR] 0–2.1) and 0.7 dB per year (IQR 0–2.0), respectively. Speech discrimination scores did not differ when comparing median initial (100%) and median final (98%) scores (P = 0.77). There was no statistically significant change in bone‐conduction thresholds at 0.5, 1, 2, and 4 kHz over the period of observation.ConclusionThe risk of progressive hearing loss with observed SSCD is low during short‐ and intermediate‐term follow‐up. Further studies are necessary to determine whether late hearing loss occurs. Such information may be critical toward patient counseling regarding the need for and timing of surgery.Level of Evidence4. Laryngoscope, 127:1181–1186, 2017

ObjectiveDemonstrate the association of radiographic dural enhancement with increased tumor adherence at the porus acusticus, which may influence completeness of resection and facial nerve outcome.Study DesignCase series with chart review.SettingAcademic referral center.Subjects and MethodsA total of 205 consecutive patients with histopathologically confirmed vestibular schwannoma (VS) were evaluated. Patients with tumors exhibiting dural enhancement on postgadolinium T1‐weighted magnetic resonance imaging were identified and compared with matched controls. Completeness of resection, intraoperative details, and facial nerve outcomes were analyzed.ResultsExcluding strictly intracanalicular tumors (n = 32, 16%) and those with NF2 (n = 10, 4.9%), the presence of dural enhancement was radiographically confirmed in 16 (9.8%) cases. Paired analysis did not reveal significant baseline differences between cases and controls. Subtotal resection was performed in 5 (31%) of the 16 patients with tumors exhibiting dural enhancement, in contrast to 1 (3%) of the matched controls (P =. 01). Four (25%) demonstrated increased tumor adherence at the porus acusticus intraoperatively, compared with 1 control (3%, P =. 04). Long‐term facial nerve function was similar between cases and controls (81% vs 84% House‐Brackmann I‐II function, P = 1.00).ConclusionDural enhancement is present in approximately 10% of extracanalicular VS. Dural enhancement at the porus acusticus may represent hypervascularity, dural reaction, or infiltration, and portends increased tumor adherence and greater likelihood of subtotal resection to preserve facial nerve function. To our knowledge, this is the first series that reports the prevalence of this phenomenon in VS and the potential surgical implications. Recognition preoperatively may be valuable toward patient counseling.