Link, Michael J.

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.

ObjectiveSeveral studies have demonstrated small but statistically significant differences in quality‐of‐life (QOL) scores among vestibular schwannoma (VS) treatment modalities. However, does a several‐point difference on a 100‐point scale really matter? The minimal clinically important difference (MCID)—defined as the smallest difference in scores that patients perceive as important and that could lead to a change in management—was developed to answer this important question. While the MCID has been determined for QOL measures used in other diseases, it remains undefined in the VS literature.Study DesignDistribution‐ and anchor‐based techniques were utilized to define the MCID for the Penn Acoustic Neuroma Quality of Life (PANQOL) and 36‐Item Short Form Health Survey (SF‐36).SettingTwo academic referral centers.PatientsPatients with VS (N = 538).InterventionCross‐sectional postal survey.Main Outcome MeasuresMCID for PANQOL domains and total score and SF‐36 Physical and Mental Health Component Summary scores.ResultsThe MCID (median, interquartile range) for the PANQOL total score was 11 points (10‐12); the MCIDs for individual domains were as follows: hearing, 6 (5‐8); balance, 16 (14‐19); facial, 10 (no interquartile range); pain, 11 (10‐13); energy, 13 (10‐17); anxiety, 11 (5‐22); and general, 15 (11‐19). The MCID was 7 points (6‐11) for the SF‐36 Mental Health Component Summary score and 8 points (6‐10) for the Physical Health Component Summary score.ConclusionsThe MCIDs determined in the current study generally exceed differences reported in previous prospective studies, in which conclusions about QOL benefit (or harm) among VS treatment modalities were based on statistical significance alone. Moving forward, these MCIDs should be considered when interpreting results of VS QOL studies.

Unruptured intracranial aneurysms (UIAs) are a major public health issue. These lesions have become increasingly recognized in recent years with the advent of advanced cerebral imaging techniques. Epidemiological evidence from multiple sources suggests that most intracranial aneurysms do not rupture. Therefore, it is desirable to identify which UIAs are at greatest risk of rupture when considering which to repair. It is important to compare size-, site-, and group-specific natural history rates with size-, site-, and age-specific morbidity and mortality associated with UIA repair because increased natural history risk often is associated with increased risk of aneurysm repair. Patient age is crucial in decision making because of its major effect on operative morbidity and mortality; however, it does not substantially affect natural history. The effect of age is most notable in patients about 50 years of age and older for open surgery and about 70 years of age and older for endovascular procedures. In general, rupture risk is lowest for patients in asymptomatic group 1 (no history of subarachnoid hemorrhage) with UIAs less than 7 mm in diameter in the anterior circulation. Surgical morbidity and mortality are most favorable for asymptomatic patients younger than 50 years who have UIAs less than 24 mm in diameter in the anterior circulation and no history of ischemic cerebrovascular disease. Endovascular morbidity and mortality may be less age dependent, and this could favor endovascular procedures, particularly in patients aged 50 to 70 years. An important issue is determining immediate vs long-term risk regarding treatment effectiveness and durability. This issue emphasizes the importance of long-term follow-up in patients after surgical and endovascular procedures.

OBJECT The objective of this study was to characterize the clinical features of radiation-induced cavernous malformations (RICMs). METHODS The authors retrospectively reviewed the clinical and radiological characteristics of patients with RICMs. The features of these RICMs were then compared with features of nonradiation cavernous malformations (CMs) in 270 patients. RESULTS Thirty-two patients with RICMs were identified (56.2% men), with a median age of 31.1 years at RICM diagnosis. The median latency from radiation treatment to RICM diagnosis was 12.0 years (interquartile range 5.0–19.6 years). RICMs were always within the previous radiation port. RICMs were symptomatic at diagnosis in 46.9%, and were associated with symptomatic intracranial hemorrhage at any time in 43.8%. Older age at the time of radiation treatment and higher radiation dose were associated with shorter latency. RICMs tended to be diagnosed at a younger age than nonradiation CMs (median 31.1 vs 42.4 years, respectively; p = 0.054) but were significantly less likely to be symptomatic at the time of diagnosis (46.9% vs 65.8%, respectively; p = 0.036). RICMs were more likely to be multiple CMs than nonradiation CMs (p = 0.0002). Prospectively, the risk of symptomatic hemorrhage was 4.2% for RICMs and 2.3% for nonradiation CMs per person-year (p = 0.556). In the absence of symptoms at presentation, the risk of hemorrhage for RICMs was higher than for nonradiation CMs (4.2% vs 0.35%, respectively; p = 0.118). CONCLUSIONS In this patient population, RICMs occurred within the radiation port approximately 12 years after radiation treatment. Compared with nonradiation CMs, RICMs were more likely to occur as multiple CMs, to present at a younger age, and were at least as likely to cause symptomatic hemorrhage.

OBJECT The optimal treatment for sporadic vestibular schwannoma (VS) is highly controversial. To date, the majority of studies comparing treatment modalities have focused on a narrow scope of technical outcomes including facial function, hearing status, and tumor control. Very few publications have investigated health-related quality of life (HRQOL) differences between individual treatment groups, and none have used a disease-specific HRQOL instrument. METHODS All patients with sporadic small- to medium-sized VSs who underwent primary microsurgery, stereotactic radiosurgery (SRS), or observation between 1998 and 2008 were identified. Subjects were surveyed via postal questionnaire using the 36-Item Short Form Health Survey (SF-36), the 10-item Patient-Reported Outcomes Measurement Information System short form (PROMIS-10), the Glasgow Benefit Inventory (GBI), and the Penn Acoustic Neuroma Quality-of-Life (PANQOL) scale. Additionally, a pool of general population adults was surveyed, providing a nontumor control group for comparison. RESULTS A total of 642 respondents were analyzed. The overall response rate for patients with VS was 79%, and the mean time interval between treatment and survey was 7.7 years. Using multivariate regression, there were no statistically significant differences between management groups with respect to the PROMIS-10 physical or mental health dimensions, the SF-36 Physical or Mental Component Summary scores, or the PANQOL general, anxiety, hearing, or energy subdomains. Patients who underwent SRS or observation reported a better total PANQOL score and higher PANQOL facial, balance, and pain subdomain scores than the microsurgical cohort (p < 0.02). The differences in scores between the nontumor control group and patients with VS were greater than differences observed between individual treatment groups for the majority of measures. CONCLUSIONS The differences in HRQOL outcomes following SRS, observation, and microsurgery for VS are small. Notably, the diagnosis of VS rather than treatment strategy most significantly impacts quality of life. Understanding that a large number of VSs do not grow following discovery, and that intervention does not confer a long-term HRQOL advantage, small- and medium-sized VS should be initially observed, while intervention should be reserved for patients with unequivocal tumor growth or intractable symptoms that are amenable to treatment. Future studies assessing HRQOL in VS patients should prioritize use of validated disease-specific measures, such as the PANQOL, given the significant limitations of generic instruments in distinguishing between treatment groups and tumor versus nontumor subjects.

Objectives/HypothesisTo investigate the influence of posttreatment audiovestibular symptoms, facial neuropathy, and headache on long‐term quality‐of‐life outcomes in patients with sporadic vestibular schwannoma (VS) utilizing the Short Form 36 (SF‐36) Health Survey and the Penn Acoustic Neuroma Quality of Life (PANQOL) scale.Study DesignCross‐sectional observation study.MethodsPatients with sporadic small‐ or medium‐sized VS (< 3.0 cm) who were evaluated between 1998 and 2008 at two independent tertiary academic referral centers were surveyed. Multivariable associations with the PANQOL total score and the SF‐36 physical and mental component scores evaluated using regression analysis.ResultsA total of 538 surveyed patients returned a completed questionnaire, providing a response rate of 79%. Two hundred forty‐seven (46%) patients underwent stereotactic radiosurgery, 143 (27%) microsurgery, and 148 (28%) observation. Multivariable regression analysis revealed that ongoing dizziness was associated with the greatest reduction in PANQOL total score, followed by headache. After adjusting for all examined features, ongoing dizziness and ongoing headache were the only two variables that were associated with both the SF‐36 physical and mental component scores. Patient sex and treatment modality did not significantly influence PANQOL or SF‐36 scores.ConclusionsOngoing dizziness and headache are the strongest predictors of long‐term quality‐of‐life reduction in patients with sporadic VS, while the impact of hearing loss, facial nerve function, and tinnitus are less by comparison. This information may be valuable for patient counseling, refinement of VS quality‐of‐life assessment instruments, and determining high‐yield targets for therapy in efforts to further improve patient outcomes.Level of Evidence4. Laryngoscope, 125:1697–1702, 2015

Objectives/HypothesisFibrous dysplasia is a condition of nonmalignant osseous change and may occur in a monostotic or polyostotic pattern, the latter potentially being associated with McCune‐Albright syndrome. Symptoms are highly variable and dependent upon lesion location and size.Study DesignRetrospective review.MethodsConsecutive subjects with fibrous dysplasia of the temporal bone were evaluated between 2000 and 2013 at two tertiary academic referral centers. Main outcome measures included disease presentation, diagnostic evaluation, management strategy, and outcome.ResultsSixty‐six patients with fibrous dysplasia of the skull were found to have involvement of the temporal bone. The mean age at diagnosis was 25 years, 39 (59%) were female, and the mean duration of follow‐up was 48 months. Six (11%) patients had monostotic disease, with the remaining 60 (89%) patients having the polyostotic form; 16 (24%) patients had McCune‐Albright syndrome. The most common presenting complaint was headache (59%), followed by hearing loss (29%). The most common exam finding was cosmetic deformity (50%). Cholesteatoma (3%) and spontaneous cerebrospinal fluid fistula (1.5%) were found in a small percentage. No patients had evidence of motor cranial neuropathy by history or physical examination.ConclusionsThe clinical presentation of fibrous dysplasia involving the temporal bone is variable. A growing number of patients are diagnosed incidentally through imaging, and since most patients experience a benign course, the majority can be followed clinically without need for intervention.Level of Evidence4. Laryngoscope, 125:1438–1443, 2015

OBJECT The following study was conducted to identify risk factors for a postoperative CSF leak after vestibular schwannoma (VS) surgery. METHODS The authors reviewed a prospectively maintained database of all patients who had undergone resection of a VS at the Mayo Clinic between September 1999 and May 2013. Patients who developed a postoperative CSF leak within 30 days of surgery were compared with those who did not. Data collected included patient age, sex, body mass index (BMI), tumor size, tumor side, history of prior tumor treatment, operative time, surgical approach, and extent of resection. Both univariate and multivariate regression analyses were performed to evaluate all variables as risk factors of a postoperative CSF leak. RESULTS A total of 457 patients were included in the study, with 45 patients (9.8%) developing a postoperative CSF leak. A significant association existed between increasing BMI and a CSF leak, with those classified as overweight (BMI 25–29.9), obese (BMI 30–39.9), or morbidly obese (BMI ≥ 40) having a 2.5-, 3-, and 6-fold increased risk, respectively. Patients undergoing a translabyrinthine (TL) approach experienced a higher rate of CSF leaks (OR 2.5, 95% CI 1.3–4.6; p = 0.005), as did those who had longer operative times (OR 1.04, 95% CI 1.02–1.07; p = 0.0006). The BMI, a TL approach, and operative time remained independent risk factors on multivariate modeling. CONCLUSIONS Elevated BMI is a risk factor for the development of a postoperative CSF leak following VS surgery. Recognizing this preoperatively can allow surgeons to better counsel patients regarding the risks of surgery as well as perhaps to alter perioperative management in an attempt to decrease the likelihood of a leak. Patients undergoing a TL approach or having longer operative times are also at increased risk of developing a postoperative CSF leak.