Citations

Objectives/HypothesisTo evaluate outcomes of salvage surgery for vestibular schwannoma (VS) that failed primary stereotactic radiosurgery (SRS).MethodsCase‐control study of 37 patients who underwent surgical resection of sporadic VS following prior SRS at two tertiary academic referral centers between 2003 and 2015. A cohort of nonirradiated control subjects, matched according to tumor size, age, and treatment center, were used as comparison.ResultsThirty‐seven patients were included. The median time from radiation to surgical salvage was 36 months (range 9.6–153 months). Following tumor progression after SRS, 18 (49%) patients underwent gross total resection, 10 (27%) underwent near‐total resection, and nine (24%) underwent subtotal resection. Postoperative complications following salvage surgery included one (3%) case of stroke, four (11%) cases of cerebrospinal fluid leak, and two (5%) cases of meningitis. Twenty‐seven (73%) patients had good postoperative facial nerve outcome (House‐Brackmann Score I–II) at long‐term follow‐up. There were no cases of tumor recurrence or regrowth after a median length of 26 months following microsurgical salvage (range 3–114 months). The rate of satisfactory postoperative facial nerve function was not different between study and control subjects (73% vs. 76%; P = 0.8); however, less‐than‐complete resection was utilized more frequently among previously radiated patients (P = 0.01).ConclusionMicrosurgical salvage of VS following primary radiation therapy is challenging. Less‐than‐complete resection is required in a greater percentage of patients to preserve facial nerve integrity and prevent neurological complications. Long‐term follow‐up is needed to determine the risk of delayed progression following incomplete tumor removal.Level of Evidence3b. Laryngoscope, 126:2580–2586, 2016

OBJECTIVE Vagus nerve and sympathetic chain cervical schwannomas (VNCSs and SCCSs) are benign nerve sheath tumors that arise in the head and neck. Despite similar presentations that make accurate preoperative diagnosis more difficult, the potential for morbidity following resection is significantly higher for patients with VNCS. Therefore, the authors analyzed a retrospective case series and performed a comparative analysis of the literature to establish diagnostic criteria to facilitate more accurate preoperative diagnoses. METHODS The authors conducted a blinded review of imaging studies from retrospectively collected, operatively confirmed cases of VNCS and SCCS. They also performed a systematic review of published series that reported patient-specific preoperative imaging findings in VNCS or SCCS. RESULTS Nine patients with VNCS and 11 with SCCS were identified. In the study cohort, splaying of the internal carotid artery (ICA) and internal jugular vein (IJV) did not significantly predict the nerve of origin (p = 0.06); however, medial and lateral ICA displacement were significantly associated with VNCS and SCCS, respectively (p = 0.01 and p = 0.003, respectively). Multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carried an 86% probability of VNCS (p = 0.001), while the absence of splaying with lateral ICA displacement carried a 91% probability of SCCS (p = 0.006). The presence of vocal cord symptoms or peripheral enhancement significantly augmented the predictive probability of VNCS, as did Horner's syndrome or homogeneous enhancement for SCCS. A review of the literature produced 25 publications that incorporated a total of 106 patients, including the present series. Splaying of the ICA and IJV was significantly, but not uniquely, associated with VNCS (p < 0.0001); multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carries a 75% probability of VNCS (p < 0.0001), while the absence of such splaying with lateral ICA displacement carries an 87% probability of SCCS (p = 0.0003). CONCLUSIONS ICA and IJV splaying frequently predicts VNCS; however, this finding is also commonly observed in SCCS and, among the 9 cases in the present study, was observed more often than previously reported. When congruent with splaying, medial or lateral ICA displacement significantly enhances the reliability of preoperative predictions, empowering more accurate prognostication.

Abstract BACKGROUND: Studies examining patient-reported outcomes in subjects with vestibular schwannoma (VS) and “excellent” hearing are lacking. OBJECTIVE: To assess patient-reported audiovestibular handicap and overall quality of life (QoL) in VS patients with class A hearing in both ears. METHODS: Among 539 VS patients treated during 1998 to 2008, we identified 296 patients with either bilateral class A (AA) hearing or 1 good ear and 1 deaf ear (AD) according to the American Academy of Otolaryngology–Head and Neck Surgery classification. Patients responded to validated hearing, tinnitus, and dizziness handicap inventories and 2 QoL questionnaires, and the 2 groups were compared. A reference group of 103 adults filled out the same questionnaires. RESULTS: Forty-nine patients (16.6%) had class AA and 247 patients (83.4%) had class AD hearing. AA patients scored poorer than control subjects without tumor on all handicap questionnaires ( P < .001) and a VS-specific QoL instrument ( P = .006). Con-versely, AA patients scored significantly better than patients with AD on the hearing inventory and the disease-specific QoL instrument ( P < .001), but no difference was found between these groups with regard to tinnitus and dizziness. The hearing disability score was approximately 3 times poorer for AA patients compared with control subjects without tumor; a third of AA patients reported a hearing handicap. CONCLUSION: Patients with VS and bilateral class A hearing report significantly poorer hearing handicap than control subjects without tumor but better hearing than those with unilateral deafness. When patients with bilateral class A hearing are counseled, it should be noted that one-third of patients experience self-perceived hearing handicap.

OBJECTIVE Successful stereotactic radiosurgery (SRS) for the treatment of arteriovenous malformations (AVMs) results in nidus obliteration without new neurological deficits related to either intracranial hemorrhage (ICH) or radiation-induced complications (RICs). In this study the authors compared 5 AVM grading scales (Spetzler-Martin grading scale, radiosurgery-based AVM score [RBAS], Heidelberg score, Virginia Radiosurgery AVM Scale [VRAS], and proton radiosurgery AVM scale [PRAS]) at predicting outcomes after SRS. METHODS The study group consisted of 381 patients with sporadic AVMs who underwent Gamma Knife SRS between January 1990 and December 2009; none of the patients underwent prior radiation therapy. The primary end point was AVM obliteration without a decline in modified Rankin Scale (mRS) score (excellent outcome). Comparison of the area under the receiver operating characteristic curve (AUC) and accuracy was performed between the AVM grading scales and the best linear regression model (generalized linear model, elastic net [GLMnet]). RESULTS The median radiological follow-up after initial SRS was 77 months; the median clinical follow-up was 93 months. AVM obliteration was documented in 297 patients (78.0%). Obliteration was 59% at 4 years and 85% at 8 years. Fifty-five patients (14.4%) had a decline in mRS score secondary to RICs (n = 29, 7.6%) or ICH (n = 26, 6.8%). The mRS score declined by 10% at 4 years and 15% at 8 years. Overall, 274 patients (71.9%) had excellent outcomes. There was no difference between the AUC for the GLMnet (0.69 [95% CI 0.64–0.75]), RBAS (0.68 [95% CI 0.62–0.74]), or PRAS (0.69 [95% CI 0.62–0.74]). Pairwise comparison for accuracy showed no difference between the GLMnet and the RBAS (p = 0.08) or PRAS (p = 0.16), but it did show a significant difference between the GLMnet and the Spetzler-Martin grading system (p < 0.001), Heidelberg score (p < 0.001), and the VRAS (p < 0.001). The RBAS and the PRAS were more accurate when compared with the Spetzler-Martin grading scale (p = 0.03 and p = 0.01), Heidelberg score (p = 0.02 and p = 0.02), and VRAS (p = 0.03 and p = 0.02). CONCLUSIONS SRS provides AVM obliteration without functional decline in the majority of treated patients. AVM grading scales having continuous scores (RBAS and PRAS) outperformed integer-based grading systems in the prediction of AVM obliteration without mRS score decline after SRS.

OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) of the eighth cranial nerve (CN) are exceedingly rare. To date the literature has focused on MPNSTs occurring after radiation therapy for presumed benign vestibular schwannomas (VSs), while MPNSTs arising without prior irradiation have received little attention. The objectives of the current study are to characterize the epidemiology, clinical presentation, disease course, and outcome using a large national cancer registry database and a systematic review of the English literature. Additionally, a previously unreported case is presented. METHODS The authors conducted an analysis of the Surveillance, Epidemiology, and End Results (SEER) database, a systematic review of the literature, and present a case report. Data from all patients identified in the SEER database with a diagnosis of MPNST involving the eighth CN, without a history of prior radiation, were analyzed. Additionally, all cases reported in the English literature between January 1980 and March 2015 were reviewed. Finally, 1 previously unreported case is presented. RESULTS The SEER registries identified 30 cases between 1992 and 2012. The average incidence was 0.017 per 1 million persons per year (range 0.000–0.0687 per year). The median age at diagnosis was 55 years, and 16 (53%) were women. Thirteen cases were diagnosed upon autopsy. Of the 17 cases diagnosed while alive, the median follow-up was 118 days, with 3 deaths (18%) observed. When compared with the incidence of benign VS, 1041 VSs present for every 1 MPNST arising from the eighth CN. Including a previously unreported case from the authors' center, a systematic review of the English literature yielded 24 reports. The median age at diagnosis was 44 years, 50% were women, and the median tumor size at diagnosis was 3 cm. Eleven patients (46%) reported isolated audiovestibular complaints typical for VS while 13 (54%) exhibited facial paresis or other signs of a more aggressive process. Treatment included microsurgery alone, microsurgery with adjuvant radiation, or microsurgery with chemoradiation. Sixty-one percent of patients receiving treatment experienced recurrence, 22% of which were diagnosed with drop metastases to the spine. Ultimately, 13 patients (54%) died of progressive disease at a median of 3 months following diagnosis. The ability to achieve gross-total resection was the only feature that was associated with improved disease-specific survival. CONCLUSIONS MPNSTs of the eighth CN are extremely rare and portend a poor prognosis. Nearly half of patients initially present with findings consistent with a benign VS, often making an early diagnosis challenging. In light of these data, early radiological and clinical follow-up should be considered in those who elect nonoperative treatment, particularly in patients with a short duration of symptoms or atypical presentation. These data also provide a baseline rate of malignancy that should be considered when estimating the risk of malignant transformation following stereotactic radiosurgery for VS.

Objectives/HypothesisThe primary goals of microsurgery for vestibular schwannoma (VS) include preservation of neural function and complete tumor removal. In a subset of patients, adherent tumor remnant may be intentionally left behind in order to minimize risk of new neurologic deficits. It is not well established if residual tumor volume predicts likelihood of tumor remnant growth.MethodsPatients with sporadic VS who underwent near‐total (NTR) or subtotal (STR) VS resection between 2000 and 2014 were reviewed. Postoperative tumor remnants were volumetrically contoured using T1‐weighted gadolinium‐enhanced magnetic resonance imaging obtained within 3 months of surgery.ResultsA total of 103 patients met study criteria, and the median duration of radiographic follow‐up was 41 months (mean 56.1 months, range 12–150 months). Fifty patients underwent NTR and 53 received STR. Overall 14 (13.6%) tumors recurred at a median of 41.0 months. Patients who underwent STR were over 13 times more likely to recur compared with those treated with NTR (hazard ratio 13.31; 95% confidence interval 1.71–103.91; P = 0.014). The median time to recurrence following NTR was 124 months compared to 32 months after STR (P < 0.001).ConclusionsLong‐term follow‐up in patients undergoing incomplete resection is essential. Near‐total resection has a significantly lower rate of recurrence compared to STR. Maximal surgical resection should be the goal in VS microsurgery. The decision to pursue less than complete resection should be based on intraoperative impression, when it is felt that continued dissection of adherent disease would compromise neurologic outcome.Level of Evidence4. Laryngoscope, 126:1877–1882, 2016

ObjectiveTo characterize the evolving management of vestibular schwannoma (VS) in the United States.Study DesignRetrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database.SettingSEER database.Subjects and MethodsAll patients with a diagnosis of VS were analyzed. Data were described and compared using trend analyses and univariate and multivariable logistic regression.ResultsA total of 8330 patients (average age 54.7 years, 51.9% female) were analyzed. The mean incidence was approximately 1.1 per 100,000 per year and did not vary significantly across time; however, from 2004 to 2011, there was a statistically significant decrease in tumor size category at time of diagnosis (P <. 01). Overall, 3982 patients (48%) received primary microsurgery, 1978 (24%) radiation therapy alone, and 2370 (29%) observation. Within the microsurgical cohort, 732 (18%) underwent subtotal resection, and of those, 98 (13.4%) received postoperative radiation therapy. Multivariable regression revealed that surgical treatment was more common in younger patients and larger tumor size categories (P <. 05). Management trend analysis revealed that microsurgery was used less frequently over time (P <. 0001), observation was used more frequently (P <. 0001), and the pattern of radiation therapy remained unchanged. Linear regression was used to create an equation that was applied to predict future management practices. These data predict that by 2026, half of all cases of VS will be managed initially with observation.ConclusionWhile the incidence of VS has remained steady, tumor size at time of diagnosis has decreased over time. Within the United States there has been a clear, recent evolution in management toward observation.

OBJECT The primary goals of this study were: 1) to examine the influence of disease and treatment on headache in patients with sporadic vestibular schwannoma (VS); and 2) to identify clinical predictors of long-term headache disability. METHODS This was a cross-sectional observational study with international multicenter enrollment. Patients included those with primary sporadic < 3-cm VS and a separate group of general population control subjects without tumors. Interventions included a postal survey incorporating the Headache Disability Inventory (HDI), the Hospital Anxiety and Depression Scale, and a VS symptom questionnaire. The main outcome measures were univariate and multivariable associations with HDI total score. RESULTS The overall survey response rate was 79%. Data from 538 patients with VS were analyzed. The mean age at time of survey was 64 years, 56% of patients were female, and the average duration between treatment and survey was 7.7 years. Twenty-seven percent of patients received microsurgery, 46% stereotactic radiosurgery, and 28% observation. Patients with VS who were managed with observation were more than twice as likely to have severe headache disability compared with 103 control subjects without VS. When accounting for baseline differences, there was no statistically significant difference in HDI outcome between treatment modalities at time of survey. Similarly, among the microsurgery cohort, the long-term risk of severe headache disability was not different between surgical approaches. Multivariable regression demonstrated that younger age, greater anxiety and depression, and a preexisting diagnosis of headache were the primary predictors of severe long-term headache disability, while tumor size and treatment modality had little influence. CONCLUSIONS At a mean of almost 8 years following treatment, approximately half of patients with VS experience headaches of varying frequency and severity. Patient-driven factors including age, sex, mental health, and preexisting headache syndrome are the strongest predictors of long-term severe headache disability. Tumor size and treatment modality have less impact. These data may assist with patient counseling regarding long-term expectations following diagnosis and treatment.