Citations

Abstract BACKGROUND AND IMPORTANCE Laser interstitial thermal therapy (LiTT) has increasingly been used as a treatment option for medically refractory epilepsy, tumors, and radiation necrosis. The use of LiTT requires intraoperative magnetic resonance (MR) thermography. This can become an issue in patients with other implanted therapeutic devices such as pacemakers and vagal nerve stimulators due to concerns regarding increases in the specific absorption rate (SAR). This is a technical case report demonstrating a successfully and safely performed LiTT in a 1.5-T magnetic resonance imaging (MRI) in a patient with a pacemaker for mesial temporal sclerosis. CLINICAL PRESENTATION An 83-yr-old gentleman who had an implanted cardiac pacemaker presented with medically intractable epilepsy and was confirmed to have mesial temporal sclerosis on imaging. Video electroencephalography demonstrated concordant ipsilateral seizures and semiology. He underwent LiTT for ablation of the mesial temporal lobe. This was performed with the below described protocol with a cardiology nurse monitoring the patient's cardiac condition and a physicist monitoring SAR, and MR imaging quality without any adverse events. CONCLUSION This study reports on a protocol of cardiac and MR SAR to safely perform MR-guided LiTT in the setting of traditional pacemakers in patients who are not pacemaker dependent.

Introduction Vestibular schwannoma (VS) behavior following subtotal resection (STR) is highly variable. Overall progression rates have been reported as high as 44%, and optimal treatment is controversial. Correspondingly, identification of a reliable clinical or pathologic marker associated with progression after STR would help guide decision-making. Methods A prospectively maintained institutional VS registry from 1999 to 2014 was retrospectively reviewed for sporadic VS patients who underwent primary STR without preceding stereotactic radiosurgery (SRS) by a single neurosurgery-neurotology team. Primary endpoints included tumor progression and postoperative facial nerve function. Pathologic specimens were stained for Ki67, CD68, S100, and SOX10 and were quantitated by digital imaging analysis. Macrophage density was defined as the ratio of CD68+ macrophages to S100+ macrophages and Schwannian tumor cells. Clinical outcomes were correlated with pathologic markers. Results Forty-six patients met the study inclusion criteria. Thirteen (28%) progressed during a mean 57 months of follow-up (range 15–149). Favorable postoperative facial nerve function (House–Brackmann I–II) was achieved in 37 (80%). CD68+ cells were present at significantly higher concentrations in tumors that progressed (p = 0.03). Higher macrophage density was significantly associated with both tumor progression (p = 0.02) and unfavorable facial nerve function (p = 0.02). Ki67 percent positivity was not significantly associated with either primary endpoint (p = 0.83; p = 0.58). Conclusions Macrophage density may provide an important marker for individuals at the highest risk for progression of VS after STR, potentially prompting closer surveillance or consideration for upfront SRS following STR. This finding supports preceding conclusions that an intratumoral macrophage-predominant inflammatory response may be a marker for tumor growth and a potential therapeutic target.

Objective Few studies have compared transsphenoidal endoscopic (TE) and transsphenoidal microscopic (TM) techniques for the treatment of craniopharyngiomas. Design We performed a systematic review of published series. The results were stratified in two time periods from 1995 to 2016. Results A total of 48 articles and 1,186 patients met the inclusion criteria. Overall, 60% of endoscopic cases were supradiaphragmatic, and 76% of microsurgical cases were infradiaphragmatic. Mean tumor size was 3 cm and 2.4 cm in the TE and TM series, respectively (p = 0.008). Total resection rate was similar (66%) between TE and TM. Considering the surgical outcome for different tumor locations, total resection rate was slightly higher in the TE for supradiaphragmatic lesions (59% versus 42.5%; p = 0.26). Recurrence rate was higher in the endoscopic series (21.7% versus 12%). Mortality and the overall complication rates were similar (p = 0.84). However, hydrocephalus (7.6%) and cognitive dysfunction (15.8%) were more common in TE, and meningitis (6%) and endocrinologic complications were more common in the TM series. In the past 6 years, the rate of cerebrospinal fluid leak in TE was significantly lower (13%) and was comparable between TE and TM. Conclusion Both techniques appear comparable for infradiaphragmatic lesions; however, TE seems to yield better results for supradiaphragmatic tumors. In conclusion, more complex lesions with difficult locations can be effectively treated with endoscopic surgery.

Background Very few studies have examined vestibular schwannoma (VS) management trends across centers and between providers. The objective of this study is to examine current practice trends, variance in treatment philosophies, and nuanced or controversial aspects of VS care across North America. Methods This is a cross-sectional survey of North American Skull Base Society (NASBS) members who report regular involvement in VS care. Results A total of 57 completed surveys were returned. Most respondents claimed to have over 20 years of experience and the majority reported working in an academic practice with an affiliated otolaryngology and/or neurosurgery residency program. Sixty-three percent of respondents claimed to evaluate VS patients in clinic with both an otolaryngologist and neurosurgeon involved. Eighty-six percent of respondents claimed to operate on VS with both an otolaryngologist and neurosurgeon involved, while only 18% of neurosurgeons and 9% of otolaryngologists performed surgery alone. There was a wide range in the number of cases evaluated at each center annually. Similarly, there was wide variation in the number of patients treated with microsurgery and radiation at each center. Additional details regarding management preferences for microsurgery, stereotactic radiosurgery, stereotactic radiotherapy, and conservative observation are presented. Conclusion VS management practices vary between providers and centers. Overall, most centers employ a multidisciplinary approach to management with collaboration between otolaryngology and neurosurgery. Overall, survey responses concur with previous studies suggesting a shift toward conservatism in management.

Introduction Perioperative care of vestibular schwannoma (VS) patients is extremely variable across surgeons and institutions making practice patterns difficult to standardize. No data currently exist detailing this practice variability. Methods The North American Skull Base Society membership was electronically surveyed regarding perioperative care of surgically operated VS patients. Results There were 87 respondents to the survey. Surgical positioning, surgical approach utilized, and perioperative medical adjuncts are quite variable. However, of those performing retrosigmoid approaches, 49% perform this in the supine position, while 33% use a park-bench position with only 2% using the sitting position. In those performing translabyrinthine approaches, 86% perform this in supine position. Although the use of neuromonitoring appears to be standard of care (98%), other than the seventh nerve, there is substantial variability between respondents regarding monitoring of additional cranial nerves. Postoperative antibiotics are used by 65%, postoperative steroids 81%, and postoperative chemical deep vein thrombosis prophylaxis in 68% of survey respondents. Conclusion Although the perioperative adjuncts to VS surgery are variable, there does appear to be a trend in common practice. Therefore, making surgeons aware of these trends may lead to standardized practice or alternatively trials of these variances to instruct which truly improve patient outcomes.

Abstract MEDICAL THERAPY Target Population Adults with histologically proven or suspected vestibular schwannomas with neurofibromatosis type 2 (NF2). Question What is the role of bevacizumab in the treatment of patients with vestibular schwannomas? Recommendations Level 3: It is recommended that bevacizumab be administered in order to radiographically reduce the size or prolong tumor stability in patients with NF2 without surgical options. Level 3: It is recommended that bevacizumab be administered to improve hearing or prolong time to hearing loss in patients with NF2 without surgical options. Question Is there a role for lapatinib, erlotinib, or everolimus in the treatment of patients with vestibular schwannomas? Recommendations Level 3: Lapatinib may be considered for use in reducing vestibular schwannoma size and improvement in hearing in NF2. Level 3: Erlotinib is not recommended for use in reducing vestibular schwannoma size or improvement in hearing in patients with NF2. Level 3: Everolimus is not recommended for use in reducing vestibular schwannoma size or improvement in hearing in NF2. Question What is the role of aspirin, to augment inflammatory response, in the treatment of patients with vestibular schwannomas? Target Population Any patient with a vestibular schwannoma undergoing observation. Recommendation Level 3: It is recommended that aspirin administration may be considered for use in patients undergoing observation of their vestibular schwannomas. Question Is there a role for treatment of vasospasm, ie, nimodipine or hydroxyethyl starch, perioperatively to improve facial nerve outcomes in patients with vestibular schwannomas? Target Population Adults with histologically proven or suspected vestibular schwannomas. Recommendation Level 3: Perioperative treatment with nimodipine (or with the addition of hydroxyethyl starch) should be considered to improve postoperative facial nerve outcomes and may improve hearing outcomes. PREHABILITATION Question Is there a role for preoperative vestibular rehab or vestibular ablation with gentamicin for patients surgically treated for vestibular schwannomas? Target Population Adults with histologically proven or suspected vestibular schwannomas. Recommendations Level 3: Preoperative vestibular rehabilitation is recommended to aid in postoperative mobility after vestibular schwannoma surgery. Level 3: Preoperative gentamicin ablation of the vestibular apparatus should be considered to improve postoperative mobility after vestibular schwannoma surgery. SURGICAL THERAPY Question Does endoscopic assistance make a difference in resection or outcomes in patients with vestibular schwannomas? Target Population Vestibular schwannoma patients, who are surgical candidates. Inclusion in this analysis required resection utilizing the endoscope, either as the primary operative visualization or microscopic assistance with more than 20 patients treated. Recommendation Level 3: Endoscopic assistance is a surgical technique that the surgeon may choose to use in order to aid in visualization. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_9.

Abstract TARGET POPULATION Adults diagnosed with vestibular schwannomas. QUESTION 1 What is the prognostic significance of Antoni A vs B histologic patterns in vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 2 What is the prognostic significance of mitotic figures seen in vestibular schwannoma specimens? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 3 Are there other light microscopic features that predict clinical behavior of vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 4 Does the KI-67 labeling index predict clinical behavior of vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 5 Does the proliferating cell nuclear antigen labeling index predict clinical behavior of vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 6 Does degree of vascular endothelial growth factor expression predict clinical behavior of vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_6.

Abstract Please see the full-text version of this guideline (https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_8) for the target population of each recommendation listed below. QUESTION 1 What surgical approaches for vestibular schwannomas (VS) are best for complete resection and facial nerve (FN) preservation when serviceable hearing is present? RECOMMENDATION There is insufficient evidence to support the superiority of either the middle fossa (MF) or the retrosigmoid (RS) approach for complete VS resection and FN preservation when serviceable hearing is present. QUESTION 2 Which surgical approach (RS or translabyrinthine [TL]) for VS is best for complete resection and FN preservation when serviceable hearing is not present? RECOMMENDATION There is insufficient evidence to support the superiority of either the RS or the TL approach for complete VS resection and FN preservation when serviceable hearing is not present. QUESTION 3 Does VS size matter for facial and vestibulocochlear nerve preservation with surgical resection? RECOMMENDATION Level 3: Patients with larger VS tumor size should be counseled about the greater than average risk of loss of serviceable hearing. QUESTION 4 Should small intracanalicular tumors (<1.5 cm) be surgically resected? RECOMMENDATION There are insufficient data to support a firm recommendation that surgery be the primary treatment for this subclass of VSs. QUESTION 5 Is hearing preservation routinely possible with VS surgical resection when serviceable hearing is present? RECOMMENDATION Level 3: Hearing preservation surgery via the MF or the RS approach may be attempted in patients with small tumor size (<1.5 cm) and good preoperative hearing. QUESTION 6 When should surgical resection be the initial treatment in patients with neurofibromatosis type 2 (NF2)? RECOMMENDATION There is insufficient evidence that surgical resection should be the initial treatment in patients with NF2. QUESTION 7 Does a multidisciplinary team, consisting of neurosurgery and neurotology, provides the best outcomes of complete resection and facial/vestibulocochlear nerve preservation for patients undergoing resection of VSs? RECOMMENDATION There is insufficient evidence to support stating that a multidisciplinary team, usually consisting of a neurosurgeon and a neurotologist, provides superior outcomes compared to either subspecialist working alone. QUESTION 8 Does a subtotal surgical resection of a VS followed by stereotactic radiosurgery (SRS) to the residual tumor provide comparable hearing and FN preservation to patients who undergo a complete surgical resection? RECOMMENDATION There is insufficient evidence to support subtotal resection (STR) followed by SRS provides comparable hearing and FN preservation to patients who undergo a complete surgical resection. QUESTION 9 Does surgical resection of VS treat preoperative balance problems more effectively than SRS? RECOMMENDATION There is insufficient evidence to support either surgical resection or SRS for treatment of preoperative balance problems. QUESTION 10 Does surgical resection of VS treat preoperative trigeminal neuralgia more effectively than SRS? RECOMMENDATION Level 3: Surgical resection of VSs may be used to better relieve symptoms of trigeminal neuralgia than SRS. QUESTION 11 Is surgical resection of VSs more difficult (associated with higher facial neuropathies and STR rates) after initial treatment with SRS? RECOMMENDATION Level 3: If microsurgical resection is necessary after SRS, it is recommended that patients be counseled that there is an increased likelihood of a STR and decreased FN function. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_8.

Abstract BACKGROUND When clinical presentation, laboratory studies, or imaging cannot diagnose cavernous sinus (CS) and/or Meckel's cave (MC) lesions, biopsy may be necessary. OBJECTIVE To review our institutional series of biopsies of indeterminate CS and MC lesions. METHODS Records from January 1994 to June 2016 were searched for biopsied indeterminate CS and MC lesions. We defined indeterminate as having an atypical imaging appearance or a broad differential and the need for tissue for definitive diagnosis. We defined primary tumors as originating from cells inherent or near the CS and MC. RESULTS Eighty-five patients were included (median age 59 [2-85] yr); 22 (28%) had a cancer history. Approaches included frontotemporal craniotomy (n = 48, 56%), endoscopic endonasal (n = 20, 24%), percutaneous transforamen ovale (n = 12, 14%), or retrosigmoid craniotomy (n = 5, 6%). Final diagnosis was metastatic in 27 (32%), primary in 21 (25%), inflammatory in 13 (15%), hematologic in 11 (13%), fungal in 5 (5%), and nondefinitive or nondiagnostic in 8 (10%) patients. Thirteen (59%) patients with a cancer history (n = 22) had a diagnosis consistent with their prior cancer; the remaining had a second pathology (n = 6, 27%) or nondiagnostic biopsy (n = 3, 14%). Two patients had surgical complications resulting in death. CONCLUSION In this patient cohort, metastatic tumors were the most likely pathology. The biopsy threshold should be lower in patients with a cancer history if clinical or radiographic diagnosis is uncertain as 27% had a second disease. However, we consider biopsy as a last resort because the risk of major morbidity/mortality, while low, is not zero.