Resection of meningiomas in octogenarians: a comparison with a younger geriatric population.

OBJECTIVE: Intracranial meningiomas (ICMs) may be diagnosed in octogenarians. Since the lesions are rarely life-threatening, surgery is a questionable choice in this age group. The authors' aim in this study was to analyze factors associated with the extent of resection (EOR), overall survival (OS), and postoperative complications in octogenarians undergoing ICM surgery, by using a cohort of septuagenarians as a reference. METHODS: All patients ≥ 70 years of age who underwent surgery at Oslo University Hospital for an ICM between 1990 and 2010 were included in this study. Data on these cases were retrospectively (1990-2002) and prospectively (2003-2010) acquired from a databank belonging to Oslo University Hospital. All related preoperative imaging studies or reports (earlier cases) were reviewed to confirm tumor location, the presence of bone invasion, and the postoperative EOR. RESULTS: In this study, 49 octogenarians (29 females [59.2%], mean age 83.3 ± 2.5 years) were compared with 272 septuagenarians (173 females [63.6%], mean age 74.3 ± 2.7 years). Forty octogenarians (81.6%) and 217 septuagenarians (79.8%) underwent gross-total resection. Simpson grade IV resection was achieved in 9 octogenarians (18.4%) and 4 septuagenarians (1.4%), while Simpson grade V resection was obtained in 4 septuagenarians (1.4%). Postoperative complications were similar in both groups, and 4 octogenarians (8.2%) and 11 septuagenarians (4.1%) died within 30 days after surgery (p = 0.25). No octogenarian underwent adjuvant radiotherapy. The OS was 4.2 ± 2.8 years in the octogenarians and 5.8 ± 4.4 years in the septuagenarians (p < 0.001). Female sex (OR 0.36, 95% CI 0.14-0.93; p = 0.03) and a preoperative Karnofsky Performance Scale score ≥ 70 (OR 0.27, 95% CI 0.10-0.72; p = 0.009) were correlated to the OS. CONCLUSIONS: Octogenarians undergoing surgery for ICMs had an overall reduced OS compared to septuagenarians. However, the clinical relevance of this difference in OS is debatable and has to be put in perspective with expected survival without surgery. Data on symptoms upon admission, EOR, invasive tumor features, and postoperative complications in octogenarians are similar to those observed in septuagenarians. Therefore, the decision concerning whether surgery should be performed must be based on a case-by-case discussion, and surgery should not be immediately dismissed when it comes to ICMs in octogenarians.

Prevalence of osteoporosis and osteopenia diagnosed using quantitative CT in 296 consecutive lumbar fusion patients.

OBJECTIVE: Osteoporosis is a metabolic bone disease that increases the risk for fragility fractures. Screening and diagnosis can be achieved by measuring bone mineral density (BMD) using quantitative CT tomography (QCT) in the lumbar spine. QCT-derived BMD measurements can be used to diagnose osteopenia or osteoporosis based on American College of Radiology (ACR) thresholds. Many reports exist regarding the disease prevalence in asymptomatic and disease-specific populations; however, osteoporosis/osteopenia prevalence rates in lumbar spine fusion patients without fracture have not been reported. The purpose of this study was to define osteoporosis and osteopenia prevalence in lumbar fusion patients using QCT. METHODS: A retrospective review of prospective data was performed. All patients undergoing lumbar fusion surgery who had preoperative fine-cut CT scans were eligible. QCT-derived BMD measurements were performed at L1 and L2. The L1-2 average BMD was used to classify patients as having normal findings, osteopenia, or osteoporosis based on ACR criteria. Disease prevalence was calculated. Subgroup analyses based on age, sex, ethnicity, and history of abnormal BMD were performed. Differences between categorical groups were calculated with Fisher's exact test. RESULTS: Overall, 296 consecutive patients (55.4% female) were studied. The mean age was 63 years (range 21-89 years). There were 248 (83.8%) patients with ages ≥ 50 years. No previous clinical history of abnormal BMD was seen in 212 (71.6%) patients. Osteopenia was present in 129 (43.6%) patients and osteoporosis in 44 (14.9%). There were no prevalence differences between sex or race. Patients ≥ 50 years of age had a significantly higher frequency of osteopenia/osteoporosis than those who were < 50 years of age. CONCLUSIONS: In 296 consecutive patients undergoing lumbar fusion surgery, the prevalence of osteoporosis was 14.9% and that for osteopenia was 43.6% diagnosed by QCT. This is the first report of osteoporosis disease prevalence in lumbar fusion patients without vertebral fragility fractures diagnosed by QCT.

Efficacy and toxicity of particle radiotherapy in WHO grade II and grade III meningiomas: a systematic review.

OBJECTIVEAdjuvant radiotherapy has become a common addition to the management of high-grade meningiomas, as immediate treatment with radiation following resection has been associated with significantly improved outcomes. Recent investigations into particle therapy have expanded into the management of high-risk meningiomas. Here, the authors systematically review studies on the efficacy and utility of particle-based radiotherapy in the management of high-grade meningioma.METHODSA literature search was developed by first defining the population, intervention, comparison, outcomes, and study design (PICOS). A search strategy was designed for each of three electronic databases: PubMed, Embase, and Scopus. Data extraction was conducted in accordance with the PRISMA guidelines. Outcomes of interest included local disease control, overall survival, and toxicity, which were compared with historical data on photon-based therapies.RESULTSEleven retrospective studies including 240 patients with atypical (WHO grade II) and anaplastic (WHO grade III) meningioma undergoing particle radiation therapy were identified. Five of the 11 studies included in this systematic review focused specifically on WHO grade II and III meningiomas; the others also included WHO grade I meningioma. Across all of the studies, the median follow-up ranged from 6 to 145 months. Local control rates for high-grade meningiomas ranged from 46.7% to 86% by the last follow-up or at 5 years. Overall survival rates ranged from 0% to 100% with better prognoses for atypical than for malignant meningiomas. Radiation necrosis was the most common adverse effect of treatment, occurring in 3.9% of specified cases.CONCLUSIONSDespite the lack of randomized prospective trials, this review of existing retrospective studies suggests that particle therapy, whether an adjuvant or a stand-alone treatment, confers survival benefit with a relatively low risk for severe treatment-derived toxicity compared to standard photon-based therapy. However, additional controlled studies are needed.

Global neurosurgery: current and potential impact of neurosurgeons at the World Health Organization and the World Health Assembly. Executive summary of the World Federation of Neurosurgical Societies-World Health Organization Liaison Committee at the 71st World Health Assembly.

Since the creation of the World Health Organization (WHO) in 1948, the annual World Health Assembly (WHA) has been the major forum for discussion, debate, and approval of the global health agenda. As such, it informs the framework for the policies and budgets of many of its Member States. For most of its history, a significant portion of the attention of health ministers and Member States has been given to issues of clean water, vaccination, and communicable diseases. For neurosurgeons, the adoption of WHA Resolution 68.15 changed the global health landscape because the importance of surgical care for universal health coverage was highlighted in the document. This resolution was adopted in 2015, shortly after the publication of The Lancet Commission on Global Surgery Report titled "Global Surgery 2030: evidence and solutions for achieving health, welfare and economic development." Mandating global strengthening of emergency and essential surgical care and anesthesia, this resolution has led to the formation of surgical and anesthesia collaborations that center on WHO and can be facilitated via the WHA. Participation by neurosurgeons has grown dramatically, in part due to the official relations between WHO and the World Federation of Neurosurgical Societies, with the result that global neurosurgery is gaining momentum.

Clinical potential of meningioma genomic insights: a practical review for neurosurgeons.

Meningiomas are among the most common intracranial pathological conditions, accounting for 36% of intracranial lesions treated by neurosurgeons. Although the majority of these lesions are benign, the classical categorization of tumors by histological type or World Health Organization (WHO) grade has not fully captured the potential for meningioma progression and recurrence. Many targeted treatments have failed to generate a long-lasting effect on these tumors. Recently, several seminal studies evaluating the genomics of intracranial meningiomas have rapidly changed the understanding of the disease. The importance of NF2 (neurofibromin 2), TRAF7 (tumor necrosis factor [TNF] receptor-associated factor 7), KLF4 (Kruppel-like factor 4), AKT1, SMO (smoothened), PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha), and POLR2 (RNA polymerase II subunit A) demonstrates that there are at least 6 distinct mutational classes of meningiomas. In addition, 6 methylation classes of meningioma have been appreciated, enabling improved prediction of prognosis compared with traditional WHO grades. Genomic studies have shed light on the nature of recurrent meningioma, distinct intracranial locations and mutational patterns, and a potential embryonic cancer stem cell-like origin. However, despite these exciting findings, the clinical relevance of these findings remains elusive. The authors review the key findings from recent genomic studies in meningiomas, specifically focusing on how these findings relate to clinical insights for the practicing neurosurgeon.

The estimated cost of surgically managed isolated traumatic head injury secondary to road traffic accidents.

OBJECTIVE Traumatic brain injury due to road traffic accidents occurs mainly in the younger age group in which injury-related disability leads to long-term impact on employment and economic and social consequences across the lifespan. This study was designed to assign a monetary cost (in Malaysian ringgits [RM]) to the treatment of patients with surgically treated isolated traumatic head injury as determined up to 1 year after injury. METHODS Relevant resource items used were identified and valued using the direct measurement of costs method, cost accounting methods, standard unit costs method, fees, charges and/or market prices method. These values were then tabulated to generate the total costs for each patient, via a combination of macro-costing and micro-costing methods. Malaysian currency values were converted to US dollars according to the average conversion rate for the period from January to May 2016: RM1 = US$0.2452. RESULTS This costing study analyzed data from 49 patients. The estimated cost for the 1st year of care for all patients was RM1,471,919.80 (US$360,914.735), with a mean (± SD) cost per case of RM30,039.18 ± 22,986.25 or $7365.61 ± $5636.23. The mean cost of care per case was RM11,041.35 ± 10,936.88 or $2707.34 ± $2681.72 for mild head injury, RM32,550.00 ± 20,998.76 or $7981.26 ± $5148.90 for moderate head injury, and RM36,917.86 ± 23,697.34 or $9052.26 ± $5810.59 for severe head injury. Severe head injury (p = 0.001), sustaining 2 or more intracranial pathologies (p = 0.01), having a poor Glasgow Outcome Scale (GOS) score (GOS score 1-3) (p = 0.02), requiring a tracheostomy (p < 0.001), and contracting pneumonia (p < 0.001) were significantly associated with higher cost. Logistic regression analysis revealed that cost of care increased by RM591.60 or $145.06 per year increment of age (ß = RM591.60, p = 0.05). CONCLUSIONS The mean cost of treatment for traumatic head injury is high compared to the per capita income of RM37,900 in 2016. The cost values generated in this study provide baseline cost estimates that the authors hope will be used as a guide to determine where adequate funding should be allocated to provide timely and appropriate delivery of care.

The challenges and opportunities of global neurosurgery in East Africa: the Neurosurgery Education and Development model.

OBJECTIVE: The objective of this study was to describe the experience of a volunteering neurosurgeon during an 18-week stay at the Neurosurgery Education and Development (NED) Institute and to report the general situation regarding the development of neurosurgery in Zanzibar, identifying the challenges and opportunities and explaining the NED Foundation's model for safe practice and sustainability. METHODS: The NED Foundation deployed the volunteer neurosurgeon coordinator (NC) for an 18-week stay at the NED Institute at the Mnazi Mmoja Hospital, Stonetown, Zanzibar. The main roles of the NC were as follows: management of patients, reinforcement of weekly academic activities, coordination of international surgical camps, and identification of opportunities for improvement. The improvement opportunities were categorized as clinical, administrative, and sociocultural and were based on observations made by the NC as well as on interviews with local doctors, administrators, and government officials. RESULTS: During the 18-week period, the NC visited 460 patients and performed 85 surgical procedures. Four surgical camps were coordinated on-site. Academic activities were conducted weekly. The most significant challenges encountered were an intense workload, deficient infrastructure, lack of self-confidence among local physicians, deficiencies in technical support and repairs of broken equipment, and lack of guidelines. Through a series of interviews, the sociocultural factors influencing the NED Foundation's intervention were determined. Factors identified for success were the activity of neurosurgical societies in East Africa; structured pan-African neurosurgical training; the support of the Foundation for International Education in Neurological Surgery (FIENS) and the College of Surgeons of East, Central and Southern Africa (COSECSA); motivated personnel; and the Revolutionary Government of Zanzibar's willingness to collaborate with the NED Foundation. CONCLUSIONS: International collaboration programs should balance local challenges and opportunities in order to effectively promote the development of neurosurgery in East Africa. Support and endorsement should be sought to harness shared resources and experience. Determining the caregiving and educational objectives within the logistic, administrative, social, and cultural framework of the target hospital is paramount to success.

Cost-effectiveness of preoperative motor mapping with navigated transcranial magnetic brain stimulation in patients with high-grade glioma.

OBJECTIVE Navigated transcranial magnetic stimulation (nTMS) is used to identify the motor cortex prior to surgery. Yet, there has, until now, been no published evidence on the economic impact of nTMS. This study aims to analyze the cost-effectiveness of nTMS, evaluating the incremental costs of nTMS motor mapping per additional quality-adjusted life year (QALY). By doing so, this study also provides a model allowing for future analysis of general cost-effectiveness of new neuro-oncological treatment options. METHODS The authors used a microsimulation model based on their cohort population sampled for 1000 patients over the time horizon of 2 years. A health care provider perspective was used to assemble direct costs of total treatment. Transition probabilities and health utilities were based on published literature. Effects were stated in QALYs and established for health state subgroups. RESULTS In all scenarios, preoperative mapping was considered cost-effective with a willingness-to-pay threshold < 3*per capita GDP (gross domestic product). The incremental cost-effectiveness ratio (ICER) of nTMS versus no nTMS was 45,086 Euros/QALY. Sensitivity analyses showed robust results with a high impact of total treatment costs and utility of progression-free survival. Comparing the incremental costs caused by nTMS implementation only, the ICER decreased to 1967 Euros/QALY. CONCLUSIONS Motor mapping prior to surgery provides a cost-effective tool to improve the clinical outcome and overall survival of high-grade glioma patients in a resource-limited setting. Moreover, the model used in this study can be used in the future to analyze new treatment options in neuro-oncology in terms of their general cost-effectiveness.

Prospective evaluation of the utility of intraoperative confocal laser endomicroscopy in patients with brain neoplasms using fluorescein sodium: experience with 74 cases.

OBJECTIVE: This study evaluated the utility, specificity, and sensitivity of intraoperative confocal laser endomicroscopy (CLE) to provide diagnostic information during resection of human brain tumors. METHODS: CLE imaging was used in the resection of intracranial neoplasms in 74 consecutive patients (31 male; mean age 47.5 years; sequential 10-month study period). Intraoperative in vivo and ex vivo CLE was performed after intravenous injection of fluorescein sodium (FNa). Tissue samples from CLE imaging-matched areas were acquired for comparison with routine histological analysis (frozen and permanent sections). CLE images were classified as diagnostic or nondiagnostic. The specificities and sensitivities of CLE and frozen sections for gliomas and meningiomas were calculated using permanent histological sections as the standard. RESULTS: CLE images were obtained for each patient. The mean duration of intraoperative CLE system use was 15.7 minutes (range 3-73 minutes). A total of 20,734 CLE images were correlated with 267 biopsy specimens (mean number of images/biopsy location, in vivo 84, ex vivo 70). CLE images were diagnostic for 45.98% in vivo and 52.97% ex vivo specimens. After initiation of CLE, an average of 14 in vivo images and 7 ex vivo images were acquired before identification of a first diagnostic image. CLE specificity and sensitivity were, respectively, 94% and 91% for gliomas and 93% and 97% for meningiomas. CONCLUSIONS: CLE with FNa provided intraoperative histological information during brain tumor removal. Specificities and sensitivities of CLE for gliomas and meningiomas were comparable to those for frozen sections. These data suggest that CLE could allow the interactive identification of tumor areas, substantially improving intraoperative decisions during the resection of brain tumors.

Human prion diseases: surgical lessons learned from iatrogenic prion transmission.

The human prion diseases, or transmissible spongiform encephalopathies, have captivated our imaginations since their discovery in the Fore linguistic group in Papua New Guinea in the 1950s. The mysterious and poorly understood "infectious protein" has become somewhat of a household name in many regions across the globe. From bovine spongiform encephalopathy (BSE), commonly identified as mad cow disease, to endocannibalism, media outlets have capitalized on these devastatingly fatal neurological conditions. Interestingly, since their discovery, there have been more than 492 incidents of iatrogenic transmission of prion diseases, largely resulting from prion-contaminated growth hormone and dura mater grafts. Although fewer than 9 cases of probable iatrogenic neurosurgical cases of Creutzfeldt-Jakob disease (CJD) have been reported worldwide, the likelihood of some missed cases and the potential for prion transmission by neurosurgery create considerable concern. Laboratory studies indicate that standard decontamination and sterilization procedures may be insufficient to completely remove infectivity from prion-contaminated instruments. In this unfortunate event, the instruments may transmit the prion disease to others. Much caution therefore should be taken in the absence of strong evidence against the presence of a prion disease in a neurosurgical patient. While the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have devised risk assessment and decontamination protocols for the prevention of iatrogenic transmission of the prion diseases, incidents of possible exposure to prions have unfortunately occurred in the United States. In this article, the authors outline the historical discoveries that led from kuru to the identification and isolation of the pathological prion proteins in addition to providing a brief description of human prion diseases and iatrogenic forms of CJD, a brief history of prion disease nosocomial transmission, and a summary of the CDC and WHO guidelines for prevention of prion disease transmission and decontamination of prion-contaminated neurosurgical instruments.

Durability of an endoscopic management strategy for recurrent choroid plexus carcinoma with a comprehensive molecular characterization: illustrative case.

OBJECTIVE: Choroid plexus carcinoma (CPC) is a rare, primarily intraventricular neoplasm. Extent of resection correlates with improved outcomes but is limited due to tumor vascularity and size. Evidence on optimal surgical management and molecular drivers of recurrence remains limited. Here the authors characterize a case of multiply recurrent CPC treated with sequential endoscopic removals over 10 years and highlight its genomic properties. OBSERVATIONS: Five years after standard treatment, a 16-year-old female presented with a distant intraventricular recurrence of CPC. Whole exome sequencing revealed NF1, PER1, and SLC12A2 mutations, FGFR3 gain, and no TP53 alterations. Repeat sequencing on recurrences 4 and 5 years later showed persistent NF1 and FGFR3 alterations. Methylation profiling was consistent with plexus tumor, subclass pediatric B. Short-term magnetic resonance imaging detected four total isolated recurrences, all treated with complete endoscopic resections at 5, 6.5, 9, and 10 years after initial diagnosis. Mean hospital stay for all recurrences was 1 day with no complications. LESSONS: The authors describe a patient with four isolated recurrences of CPC over a decade, each treated with complete endoscopic removal, and identify unique molecular alterations that persisted without TP53 alterations. These outcomes support frequent neuroimaging to facilitate endoscopic surgical removal following early detection of CPC recurrence.

True anaplastic oligoastrocytoma with dual genotype: illustrative case.

BACKGROUND: The revised fourth edition of the World Health Organization classification of central nervous system tumors was published in 2016. Based on this classification, one of the infiltrating glioma entities named "oligoastrocytoma/anaplastic oligoastrocytoma" is discouraged. It is proposed that these mixed gliomas should be classified as diffuse astrocytoma/anaplastic astrocytoma or oligodendroglioma/anaplastic oligodendroglioma when analyzing their genetic alteration. OBSERVATIONS: A 78-year-old female underwent brain computed tomography (CT) because of a traffic accident. Cranial CT revealed a brain tumor in the left temporoparietal lobe; therefore, she was hospitalized. She underwent awake craniotomy. After the operation, she was treated with only local radiotherapy; the authors could not prescribe temozolomide, because she had had levetiracetam-induced pancytopenia. The remaining tumor neuroradiologically disappeared, and she was alive 40 months after the operation without tumor recurrence. LESSONS: Histopathologically, this tumor was diagnosed as an anaplastic oligoastrocytoma with a distinct dual phenotype of astrocytoma and oligodendroglioma components. Genetically, these two components revealed astrocytoma and oligodendroglioma genotypes, respectively. Therefore, the authors considered the integrated diagnosis of the temporal tumor as a true anaplastic oligoastrocytoma with a dual genotype. Interestingly, this case also included an area composed of spindle to oval neoplastic cells that revealed intermediate genetic alterations between astrocytomas and oligodendrogliomas.

Cerebellar high-grade glioma with H3 K27M mutation: illustrative case.

BACKGROUND: Diffuse midline glioma H3 K27M-mutant is a distinct subtype of glial tumors newly introduced in the revised fourth edition of the World Health Organization Classification of Tumours of the Central Nervous System. They are aggressive pediatric tumors with a poor prognosis but have also been reported in adults. OBSERVATIONS: The authors present the case of a man in his 60s who presented with rotatory vertigo, taste disorder, and right facial paralysis. Magnetic resonance imaging showed a tumor expanding from the cerebellum to the pons, which was histologically identified as glioblastoma, grade IV, IDH wild type. After tumor resection, the patient received chemoradiotherapy but showed only a partial response. His condition gradually worsened, and he died of progressive disease 12 months postoperation, after which an autopsy was performed. Tumor cells with a high nuclear-to-cytoplasm ratio were immunohistochemically analyzed and found to test positive for H3 K27M and negative for H3 K27me3. Furthermore, mutational analysis revealed HIST1H3B K27M mutation, and the tumor was finally identified as a high-grade glioma H3 K27M-mutant. The tumor invaded widely along the cerebral ventricle and disseminated to the spinal cord. LESSONS: When a glioblastoma shows localization or dissemination patterns different from those of typical glioblastoma, an H3 K27M-mutant glioma should be suspected.

Primary meningeal melanoma masquerading as neurofibromatosis type 2: illustrative case.

BACKGROUND: Primary meningeal melanocytic neoplasms are exceedingly rare tumors, representing only 0.06% to 0.1% of all primary brain tumors and ranging in spectrum from benign localized tumors to highly aggressive malignant lesions. The diagnosis of these tumors is often challenging from clinical, radiological, and pathologic standpoints. Equally challenging is the distinction between primary meningeal melanocytic neoplasm and metastatic melanoma. OBSERVATIONS: The authors reported the case of a 41-year-old man with imaging findings diagnostic of neurofibromatosis type 2: bilateral internal auditory canal lesions (most consistent with bilateral vestibular schwannomas), two dura-based lesions presumed to be meningiomas, multiple spinal lesions consistent with peripheral nerve sheath tumors, and one intramedullary spinal lesion consistent with an ependymoma. Biopsy of these lesions revealed melanocytic neoplasms with mild to moderate atypia and a mildly elevated proliferation index, which made the distinction between benign and malignant challenging. In addition, the disseminated nature of these tumors made it difficult to determinate whether they arose from the meninges or represented metastases from an occult primary melanoma. LESSONS: This case illustrated the challenges presented by the diagnosis of meningeal melanocytic neoplasms and highlighted the importance of integrating the clinical and radiographic findings with histologic appearance and molecular studies.

Adult isocitrate dehydrogenase-mutant brainstem glioma: illustrative case.

BACKGROUND: Adult brainstem gliomas are rare entities that demonstrate heterogeneous biology and appear to be distinct from both their pediatric counterparts and adult supratentorial gliomas. Although the role of histone 3 mutations is being increasingly understood in this disease, the effect of isocitrate dehydrogenase (IDH) mutations remains unclear, largely because of limited data. OBSERVATIONS: The authors present the case of a 29-year-old male with an IDH1-mutant, World Health Organization grade III anaplastic astrocytoma in the dorsal medulla, and they provide a review of the available literature on adult IDH-mutant brainstem glioma. The authors have amassed a cohort of 15 such patients, 7 of whom have survival data available. Median survival is 56 months in this small cohort, which is similar to that for IDH wild-type adult brainstem gliomas. LESSONS: The authors' work reenforces previous literature suggesting that the role of IDH mutation in glioma differs between brainstem and supratentorial lesions. Therefore, the authors advocate that adult brainstem gliomas be studied in terms of major molecular subgroups (including IDH mutant) because these gliomas may exhibit fundamental differences from each other, from pediatric brainstem gliomas, and from adult supratentorial gliomas.

Long-term survival in patients with long-segment complex meningiomas occluding the dural venous sinuses: illustrative cases.

BACKGROUND: Invasive sagittal sinus meningiomas are difficult tumors to cure by resection alone. Stereotactic radiosurgery (SRS) can be used as an adjuvant management strategy to improve tumor control after incomplete resection. OBSERVATIONS: The authors reported the long-term retrospective follow-up of two patients whose recurrent parasagittal meningiomas eventually occluded their superior sagittal sinus. Both patients underwent staged radiosurgery and fractionated radiation therapy to achieve tumor control that extended to 20 years after their initial surgery. After initial subtotal resection of meningiomas that had invaded major cerebral venous sinuses, adjuvant radiosurgery was performed to enhance local tumor control. Over time, adjacent tumor progression required repeat SRS and fractionated radiation therapy to boost long-term tumor response. Staged multimodality intervention led to extended survival in these patients with otherwise unresectable meningiomas. LESSONS: Multimodality management with radiosurgery and fractionated radiation therapy was associated with long-term survival of two patients with otherwise surgically incurable and invasive meningiomas of the dural venous sinuses.

Primary intraosseous meningioma of the vertebra: illustrative case.

BACKGROUND: Primary intraosseous meningiomas (PIMs) are rare, and PIMs of the vertebrae have not yet been reported. The authors report a case of primary meningioma arising from the vertebrae. OBSERVATIONS: A 49-year-old man presented with lower back pain and numbness in both lower extremities. Lumbar spine magnetic resonance imaging revealed an L2 pathological fracture with epidural and paraspinal invasion. The patient had undergone a first palliative decompression and fixation surgery, and the diagnosis turned out to be a World Health Organization grade III anaplastic meningioma based on histopathology. The tumor had progressed after first operation and radiation therapy, and the patient was referred to the authors' institute for excision. The patient had an uneventful postoperative course after a revisional total en bloc spondylectomy of L2. LESSONS: The authors present a rare case of PIM of the vertebrae with epidural and paraspinal invasion. Careful preoperative assessment and surgical planning is crucial for successful patient management.

A case of brain metastasis with pathological transformation of long-surviving malignant pleural mesothelioma: illustrative case.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare cancer, and in 80% of cases the cause is asbestos exposure. In 1972, the World Health Organization (WHO) declared asbestos is a carcinogenic substance. Since then, every developed country has restricted and banned the product. Because of its high heat resistance, asbestos had been widely used as building material for decades. The WHO estimated that approximately 125 million people are exposed to asbestos, and more than 107,000 die from asbestos-related diseases annually. Because of its long incubation period, the number of patients is estimated to keep increasing in the near future. OBSERVATIONS: The authors report a case of long-surviving MPM with a rushed clinical course after brain metastasis. A 69-year-old woman diagnosed with MPM (epithelial type) 6 years earlier presented with a brain metastasis. The pathological result of the brain metastasis was the sarcomatoid type. This case showed the possibility of subtype transition after long survival. LESSONS: This article aids in understanding the long-term natural history of MPM and the possibility of epithelial-mesenchymal transition. Neurosurgeons have to be aware of its the natural history and the possibility of brain metastasis.

Leber's hereditary optic neuropathy with diffuse white matter changes mimicking gliomatosis cerebri: illustrative case.

BACKGROUIND: Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by bilateral severe subacute central vision loss and a mutation in the mitochondrial DNA (mtDNA). The findings on cranial magnetic resonance imaging of patients with LHON vary from subtle to multiple white matter changes. However, they rarely present with diffuse infiltrative white matter changes. OBSERVATIONS: The authors reported a case with diffuse white matter changes mimicking gliomatosis cerebri (GC). The histological findings included only mild glial hyperplasia without immunohistochemical positivity, supporting the diagnosis of glial tumors. Analysis of mtDNA obtained from the blood and brain tissue revealed mutation of m.11778G>A in the NADH dehydrogenase 4 gene, which confirmed the case as LHON. Immunohistochemistry of the brain tissue revealed 8-hydroxy-2'-deoxyguanosine positivity, suggesting the presence of oxidative stress. LESSONS: LHON is extremely difficult to diagnose unless one suspects or knows the disease. The present case brings attention not only to LHON but also to other mtDNA-mutated diseases that need to be considered with diffuse white matter changes or GC.

Intraoperative MRI for the microsurgical resection of meningiomas close to eloquent areas or dural sinuses: patient series.

BACKGROUND: Meningiomas are the most commonly encountered nonglial primary intracranial tumors. The authors report on the usefulness of intraoperative magnetic resonance imaging (iMRI) during microsurgical resection of meningiomas located close to eloquent areas or dural sinuses and on the feasibility of further radiation therapy. OBSERVATIONS: Six patients benefited from this approach. The mean follow-up period after surgery was 3.3 (median 3.2, range 2.1-4.6) years. Five patients had no postoperative neurological deficit, of whom two with preoperative motor deficit completely recovered. One patient with preoperative left inferior limb deficit partially recovered. The mean interval between surgery and radiation therapy was 15.8 (median 16.9, range 1.4-40.5) months. Additional radiation therapy was required in five cases after surgery. The mean preoperative tumor volume was 38.7 (median 27.5, range 8.6-75.6) mL. The mean postoperative tumor volume was 1.2 (median 0.8, range 0-4.3) mL. At the last follow-up, all tumors were controlled. LESSONS: The use of iMRI was particularly helpful to (1) decide on additional tumor resection according to iMRI findings during the surgical procedure; (2) evaluate the residual tumor volume at the end of the surgery; and (3) judge the need for further radiation and, in particular, the feasibility of single-fraction radiosurgery.