Carlson, Matthew L.

Objective: To present a single-institution experience and supportive systematic literature review examining outcomes after repeat microsurgery for recurrent vestibular schwannoma (VS) following previous gross total resection (GTR). Study Design: Retrospective review of prospectively maintained VS database. Systematic literature review. Setting: Tertiary referral center. Patients: Six proven VS recurrences after primary GTR, treated via repeat microsurgery. Intervention: Repeat microsurgery. Main Outcome Measures: Facial nerve function, extent-of-resection, time-to-repeat surgery, same versus alternate approach at repeat surgery (relative to primary operation). Results: GTR was achieved in four (67%). House–Brackmann (HB) grade I–II facial nerve function was achieved in five (87%), including one that improved from preoperative HB grade V. An alternate surgical approach was chosen in four (67%). Systematic review identified four studies documenting 50 cases with patient-specific outcomes after repeat microsurgery for recurrent VS. Our cohort had significantly longer mean time-to-repeat surgery (117 vs. 64 months, p = 0.03), was significantly less likely to have HB III–VI function postrepeat (17% vs. 68%, p = 0.04), and was significantly less likely to undergo same approach surgery (33% vs. 90%, p = 0.0002); rates of GTR were nonsignificant (67% vs. 94%, p = 0.1). Conclusion: We report a six-patient series of microsurgery for recurrent VS after GTR, and the first systematic review of this rare and challenging entity. Anecdotally, our findings suggest that an alternate surgical approach may facilitate easier access to the tumor, with less scar encountered during the approach. Our results confirm that repeat microsurgery for recurrent VS is safe and effective, even for larger tumors not typically amenable to stereotactic radiosurgery.

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.

Objective: To describe a unique case of an asymptomatic arteriovenous lesion of the internal auditory canal (IAC) and present the associated imaging findings. Methods: Retrospective case report and review of the literature. Results: A 55-year-old man presented for further evaluation of a left-sided sudden sensorineural hearing loss that occurred 8 years earlier. Careful review of outside serial magnetic resonance (MR) imaging revealed a contralateral, ill-defined right-sided IAC mass with low T2 signal and subtle peripheral enhancement on postcontrast T1-weighted sequencing. The patient had no history of right-sided otologic symptoms. Subsequent dedicated IAC MR imaging confirmed the presence of a space-occupying lesion adjacent to a complexity of vasculature. The presence of prominent flow voids, paucity of avid enhancement on previous studies, and marked signal within the lesion on time-of-flight MR angiography and MR venography was consistent with the diagnosis of a solitary arteriovenous lesion of the IAC. There was no radiological evidence of recent or remote parenchymal or subarachnoid hemorrhage or stroke. Conclusion: We report a novel case of an occult asymptomatic IAC arteriovenous lesion. Vascular anomalies confined to the IAC are rare. To date, there have been only four reports in the literature of IAC arteriovenous lesions and our case is the first to present asymptomatically. A high index of suspicion and dedicated imaging is required to identify and accurately diagnose these lesions to guide appropriate counseling and potential intervention.

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.

OBJECTIVEThe aim of this study was to evaluate the incidence, presentation, and treatment outcomes of trigeminal nerve–mediated symptoms secondary to large vestibular schwannomas (VSs) with trigeminal nerve contact. Specifically, the symptomatic results of pain, paresthesias, and numbness after microsurgical resection or stereotactic radiosurgery (SRS) were examined.METHODSThe authors conducted a retrospective review of a database for concomitant diagnosis of trigeminal neuralgia (TN) or trigeminal neuropathy and VS between 1994 and 2014 at a tertiary academic center. All patients with VS with TN or neuropathy were included, with the exception of those patients with neurofibromatosis Type 2 and patients who elected observation. Patient demographic data, symptom evolution, and treatment outcomes were collected. Population data were summarized, and outcome comparisons between microsurgery and SRS were analyzed at last follow-up.RESULTSSixty (2.2%) of 2771 total patients who had large VSs and either TN or neuropathy symptoms met inclusion criteria. The average age of trigeminal symptom onset was 53.6 years (range 24–79 years), the average age at VS diagnosis was 54.4 years (range 25–79 years), and the average follow-up for the microsurgery and SRS groups was 30 and 59 months, respectively (range 3–132 months). Of these patients, 50 (83%) had facial numbness, 16 (27%) had TN pain, and 13 (22%) had paresthesias (i.e., burning or tingling). Subsequently, 50 (83%) patients underwent resection and 10 (17%) patients received SRS.Treatment of VS with SRS did not improve trigeminal symptoms in any patient. This included 2 subjects with unimproved facial numbness and 4 patients with worsened numbness. Similarly, SRS worsened TN pain and paresthesias in 5 patients and failed to improve pain in 2 additional patients. The Barrow Neurological Institute neuralgia and hypesthesia scale scores were significantly worse for patients undergoing SRS compared with microsurgery.Resection alleviated facial numbness in 22 (50%) patients, paresthesias in 5 (42%) patients, and TN in 7 (70%) patients. In several patients, surgery was not successful in relieving facial numbness, which failed to improve in 17 (39%) cases and became worse in 5 (11%) cases. Also, surgery did not change the intensity of facial paresthesias or neuralgia in 6 (50%) and 3 (25%) patients, respectively. Microsurgery exacerbated facial paresthesias in 1 (8%) patient but, notably, did not aggravate TN in any patient.CONCLUSIONSOverall, resection of large VSs provided improved outcomes for patients with concomitant TN, facial paresthesia, and numbness compared with SRS. However, caution should be used when counseling surgical candidates because a number of patients did not experience improvement. This was especially true in patients with preoperative facial numbness and paresthesias, who frequently reported that these symptoms were unchanged following surgery.

Objectives: To describe the clinical presentation, radiological features, and outcome of patients with plasmacytoma of the temporal bone. Methods: Multicenter retrospective case series of all patients diagnosed with plasmacytoma of the temporal bone between 1990 and 2015. Comprehensive literature review of all previously published cases. Results: A total of seven patients (average age, 57.3 yr; 57% women) met inclusion criteria. Three (43%) had a known history of multiple myeloma (MM). The most common symptoms at presentation included otalgia, headache, and dizziness (43%, each). Five (71%) presented with a vascular appearing middle ear mass visible on otoscopy. Four of these patients did not have an established history of MM and were referred with presumptive diagnoses of paraganglioma or endolymphatic sac tumor (ELST). The average maximum tumor diameter was 3.7 cm (median, 3.5 cm; range, 0.9–6.6 cm) and the most commonly involved temporal bone subsites were the middle ear and mastoid (71% each). MM was ultimately diagnosed in six cases (86%). In addition to the new cases presented herein, 18 previously published reports were analyzed. In the 25 aggregate cases, 44% of cases were associated with MM, and the mastoid (72%) and middle ear (53%) were the most commonly involved temporal bone subsites. Conclusion: Plasmacytoma of the temporal bone is rare, and the clinical presentation can closely mimic that of other primary temporal bone tumors. In patients with an established history of MM, it is imperative to have a high index of suspicion for temporal bone plasmacytoma, even when radiological features suggest an alternate diagnosis.

Objectives: This study characterizes primary petroclival meningioma growth rates, before intervention, using volumetric analysis. In addition, predictors of growth are analyzed. Methods: Patients with previously untreated petroclival meningiomas were retrospectively reviewed (1999–2015). Image analysis software was used to perform volumetric analyses of tumor size and growth. Three-dimensional segmentation volumetric analyses were compared with volumes estimated utilizing three orthogonal dimensions. Tumor growth was defined as a 15% increase in volume. Results: Thirty-four patients who underwent at least two magnetic resonance imaging (MRI) studies before intervention were included. The mean age was 55.2 years, and 65.7% were women. The mean tumor volume at presentation was 5.6 cm 3 (range, 0.1–25.8 cm 3 ) as determined from segmentation volumetric analysis. At a mean follow-up of 44.5 months (range, 3.7–125.1 mo), 88.2% of tumors grew. The mean annual volumetric growth rate was 2.38 cm 3 /yr (−0.63 to 25.9 cm 3 /yr). Tumor volume, T2 hyperintensity within the tumor, peritumoral edema, and ataxia and/or cerebellar symptoms at presentation were all significantly associated with greater rates of tumor growth. Ultimately, 10 (29.4%) patients underwent treatment during the follow-up period. Conclusion: Our experience demonstrates that the vast majority (88%) of untreated petroclival meningiomas grow; the mean volumetric growth rate was noted to be 2.38 cm 3 /yr. We found a significant association between increased growth rate and larger tumor size at diagnosis, T2 hyperintensity within the tumor, peritumoral edema, and the presence of ataxia and/or cerebellar symptoms.