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OBJECTIVE Surgery is a treatment option for medically intractable epileptic spasms (ESs). However, outcomes of ES after surgery are not well understood, especially when surgeries aimed at seizure palliation are included. The purpose of the present study was to 1) investigate the proportion of favorable postoperative ES outcomes, 2) explore the preoperative factors related to favorable postoperative ES outcomes, and 3) examine the timing of ES recurrence after disconnection surgeries, including both curative and palliative indications. METHODS This retrospective study included patients who underwent disconnection surgery for medically intractable ES at the authors’ institution between May 2015 and April 2021. Patients with suggested focal-onset ES based on preoperative evaluations initially underwent lobar disconnection. Patients with suggested generalized or unknown-onset ES underwent corpus callosotomy (CC). If evaluations after initial CC showed focalized or lateralized change, they were considered secondarily revealed focal-onset ES, and lobar disconnection was performed. ES outcomes were evaluated using the International League Against Epilepsy classification. ES outcomes were divided into classes 1–4 as favorable outcomes and classes 5 and 6 as unfavorable outcomes. The relationship between the favorable postoperative ES outcomes and the following preoperative factors was analyzed: sex, age at onset (< or > 1 year), duration between seizure onset and initial surgery (< or > 2 years), type of seizure at onset (ES or others), presence of other types of seizures, substrate, hypsarrhythmia, and MRI abnormalities. The period between the last surgery and ES recurrence was also analyzed. RESULTS A total of 41 patients were included, of whom 75.6% achieved favorable ES outcomes. A longer seizure duration between seizure onset and initial surgery, presence of hypsarrhythmia, and positive MRI findings led to poorer postoperative ES outcomes (p = 0.0028, p = 0.0041, and p = 0.0241, respectively). A total of 60.9% of patients had ES recurrence during the follow-up period, and their ES recurred within 13 months after the last surgery. CONCLUSIONS Disconnection surgery is an effective treatment option for medically intractable ES, even when the preoperative evaluation suggests a generalized or unknown onset.

A 253 J with 26 ns at 0.2 Hz laser performance was demonstrated using a LD pumped cryogenically cooled Yb:YAG ceramics laser amplifier. A high energy storage of 344 J was achieved with a stored energy density of 0.58 J/cm3 using a 1 kJ output multidirectional-pumping system. High energy-extraction efficiency of 56.5% was achieved with high energy fluence of 4.63 J /cm2. To the best of our knowledge, this is the highest output energy obtained with a repetitive nanosecond pulse by LD pumped solid-state laser. This paper presented a design of 1 kJ amplifier based on experimentally proven numerical data.

Background The relationship between uptake of amino acid tracer with positron emission tomography (PET) and glioma subtypes/gene status is still unclear. Objective To assess the relationship between uptake of [11C]methionine using PET and pathology, IDH (isocitrate dehydrogenase) mutation, 1p/19q codeletion, and TERT (telomerase reverse transcriptase) promoter status in gliomas. Methods The participants were 68 patients with newly diagnosed and untreated glioma who underwent surgical excision and preoperative [11C]methionine PET examination at Osaka City University Hospital between July 2011 and March 2018. Clinical and imaging studies were reviewed retrospectively based on the medical records at our institution. Results The mean lesion/contralateral normal brain tissue (L/N) ratio of diffuse astrocytomas was significantly lower than that of anaplastic astrocytomas (P = 0.00155), glioblastoma (P Conclusions Distinguishing glioma subtypes based on the revised 2016 World Health Organization classification of the central nervous system tumors on the basis of [11C]methionine PET alone seems to be difficult. However, [11C]methionine PET might be useful for predicting the IDH mutation status in newly diagnosed and untreated gliomas noninvasively before tumor resection.

Background Meningioma is a common intracranial tumor originating from arachnoid cap cells. Meningiomas are generally benign tumors curable by one-time resection. However, some meningiomas regrow and invade into the dura mater, and thus frequently require additional treatment. A useful marker to predict the regrowth of meningioma is desired. This study aimed to clarify the significance of p53 and Ki67 for postoperative recurrence of meningioma. Materials and methods The expression of p53 and Ki67 in 215 intracranial or intraspinal meningiomas was investigated by immunohistochemistry. Results Of the 215 meningiomas, 35 cases (16.3%) were p53-positive and 49 cases (22.8%) were Ki67-positive. Multivariate analysis revealed Ki67 and p53 status as being significantly correlated with recurrence. Positivity for either Ki67- or p53 was significantly associated with poor recurrence-free survival. Conclusion Combined p53 and Ki67 status might represent a useful independent predictive marker for recurrence of meningioma.

Several approach routes exist for selective amygdalohippocampectomy (SAH); however, previous reports regarding a comparison of these routes are limited. Here, we compared trans-middle temporal gyrus (T2) SAH and transsylvian (TS) SAH in terms of seizure outcome, visual-field defect, memory function, and operation time in our institution. This retrospective study examined the data of 16 patients with medically intractable mesial temporal lobe epilepsy. Six patients underwent trans-T2 SAH and 10 patients underwent TS SAH between July 2014 and February 2019 in Osaka City University Hospital. In trans-T2 SAH, we performed a keyhole temporal craniotomy and a small corticotomy on T2. In TS SAH, we performed a 1.5 cm corticotomy along the inferior periinsular sulcus after opening the sylvian fissure. Amygdalohippocampectomy after reaching the inferior horn of the lateral ventricle was performed in the same manner in both procedures. The seizure outcome, visual-field defect, memory function, and operation time were retrospectively compared between the procedures. Seizure-free outcomes were achieved for six patients in the trans-T2 SAH and eight patients in the TS SAH group. There were no significant differences in the seizure outcome, visual-field defect, and memory function. The operation time was significantly shorter for trans-T2 SAH than TS SAH. The postoperative scar was less conspicuous for trans-T2 SAH. Trans-T2 SAH and TS SAH were comparable in terms of the seizure outcome, visual-field defect, and memory function. The operation time and length of the skin incision were shorter for trans-T2 SAH, suggesting that it may be preferable for general epilepsy surgeons.

Anterior callosotomy to about 20 mm has been considered relatively safe empirically. The present study aimed to compare cognitive function before and after resection of tumors in the anterior part of the lateral ventricle. We analyzed 6 patients with intraventricular tumors located in the anterior horn or body of the lateral ventricle who underwent surgical excision via interhemispheric transcallosal approach at Osaka City University Hospital between March 2015 and August 2018. And clinical and imaging studies, neuropsychological function using MMSE, WAIS-III and WMS-R and surgical complications were retrospectively reviewed based on the medical records at our institution. As a result, 4 patients achieved gross total resection of the tumor and 2 patients achieved subtotal resection. 4 patients showed hydrocephalus, which disappeared in each case within 6 months after tumor resection. Mean length of callosotomy was 16.9 mm (range, 15.5–26.1 mm). One patient showed postoperative transient deficits including aphasia, microphonia, ballism in all extremities and hemiplegia, and another patient experienced subjective difficulty when talking. These symptoms disappeared within 3 months after tumor resection. Scores from the MMSE and WAIS-III showed no significant postoperative deterioration. Performance intelligence quotient (P = 0.04), full intelligence quotient (P = 0.04) and perceptual organization (P = 0.03) of WAIS-III were significantly improved after surgery compared with preoperatively. In conclusion, anterior corpus callosotomy of about 20 mm for intraventricular tumor in the anterior horn or body of the lateral ventricle might have little effect on cognitive function in the chronic phase, although the influence of hydrocephalus cannot be ignored.

Purpose: This study aimed whether the uptake of amino tracer positron emissiontomography (PET) can be used as an additional imaging biomarker to estimatethe prognosis of glioma.Methods: Participants comprised 56 adult patients with newly diagnosed and untreated World Health Organization (WHO) gradeⅡ-Ⅳ astrocytic glioma who underwent surgical excision and were evaluated by 11C-methionine PET prior to the surgical excision at Osaka City University Hospital from July 2011 to March 2018. Clinical and imaging studies were retrospectively reviewed based on medical records at our institution.Results: Preoperative Karnofsky Performance Status (KPS) only influenced progression-free survival (PFS) (hazard ratio [HR] 0.20; 95% confidence interval [CI] 0.10-0.41, pp=0.025; glioblastoma: HR 11.52, 95%CI 2.27-58.47, p=0.0032), preoperative KPS≥80 (HR 0.23, 95%CI 0.09-0.62, p=0.004), maximum lesion-to-contralateral normal brain tissue (LN max)≥4.03 (HR 0.24, 95%CI 0.08-0.71, p=0.01), and isocitrate dehydrogenase (IDH) status (HR 14.06, 95%CI 1.81-109.2, p=0.011) were factors influencing overall survival (OS) in multivariate Cox regression. OS was shorter in patients with LN max≥ 4.03 (29.3 months) than in patients with LN maxp=0.03). OS differed significantly between patients with IDH mutant/LN maxIDH mutant/LN max ≥4.03.Conclusions: LN max using 11C-methionine PET may be used in prognostic markers for newly identified and untreated WHO gradeⅡ-Ⅳ astrocytic glioma.

AIM To investigate clinicopathological significance of autophagy and its association with genetic alterations in gliomas. MATERIALS AND METHODS The expression of three autophagy-related proteins, light chain-3 (LC3), beclin 1, and p62 was immunohistochemically analyzed in 32 low-grade gliomas and 65 high-grade gliomas. RESULTS LC3, beclin 1, and p62 expression was positive in 70/94 (74%), 51/94 (54%) and 55/96 (57%) gliomas, respectively. High expression of LC3, beclin 1 and p62 was significantly more frequent in high-grade gliomas than in low-grade. Positive expression of LC3, beclin 1 and p62 were significantly positively correlated with overall survival, methylation of O6-methylyguanine-DNA methyltransferase (MGMT) promoter, mutations of isocitrate dehydrogenase 1 (IDH1) and telomerase reverse transcriptase (TERT) promoter, and 1p/19q co-deletion. Kaplan-Meier analyses revealed that LC3, p62 and autophagy status (positivity for at least two of the three proteins) were significantly associated with poorer survival. CONCLUSION Autophagy might be associated with the progression of glioma, particularly high-grade, and thus might be a useful prognostic factor in patients with glioma.

Background/aim Glioblastoma (GBM) is one of the most lethal solid cancers due to its highly invasive nature. The malignant potential of GBM cells might be partially regulated by surrounding normal cells, such as oligodendrocytes or fibroblasts. The aim of this study was to examine the interaction between stromal cells and GBM cells. Materials and methods Two GBM cell lines were used. The effect of stromal cells, oligodendrocytes or fibroblasts, on the invasive ability of GBM cells was examined by wound-healing assay and invasion assay. Results Oligodendrocytes, in contrast to fibroblasts, significantly increased the migration and invasive ability of GBM cells. Angiopoietin-2 levels were high in the conditioned medium obtained from oligodendrocytes. Angiopoietin-2 significantly increased the motility of GBM, and the motility-stimulating activity of the oligodendrocytes-derived conditioned medium was significantly decreased by anti-angiopoietin-2-neutralizing antibody. Conclusion Glioma stromal cells, oligodendrocytes, might up-regulate the invasiveness of GBM cells via angiopoietin-2 signaling.

Long-term proliferating tumorsphere-forming glioma derived cells (LTP-TS-GDCs) and patient derived xenografts (PDXs) are essential tools for translational research for glioma. However, only small subsets of glioma samples are established as LTP-TS and/or PDXs and little is known about the genetics and molecular properties of LTP-TS -forming GDCs and PDX. In this study, we aim to analyze the characteristics of LTP-TS -forming GDCs and PDXs. We tried primary sphere cultures from 56 glioma patient-derived samples and established 11 LTP-TS-GDCs out of 45 glioblastoma samples and no long-term sphere culture was isolated from grade3 and grade 2 gliomas. LTP-TS-GDCs had self-renewal ability and possessed certain multipotency. However, they significantly less expressed SOX1 FOXG1 and TUBB3, whereas they expressed LGALS1 and EN1 significantly higher than normal neural stem/progenitor cells. In addition, we found that LTP-TS-GDCs shared the same genetic profiles with original patients’ tumors. Furthermore, we investigated the genetic differences between the glioma tissues which were successfully established as LTP-TS-GDCs and those which were not. We found that glioma tissues with TERT promotor mutations and triple copy number alteration (CNA) [EGFR, CDKN2A, and PTEN loci] are significantly established as LTP-TS-GDCs. Lastly, we next investigated in vivo characteristics of glioma PDXs. We have injected glioma PDXs lines into immunodeficient mice brains and histopathologically analyzed the characteristics of xenografts. Each xenograft well recapitulated histological features of original patients’ tumors and tumor cells remarkably invade through subventricular zone. In conclusion, each LTP-TS-GDCs and PDXs had various gene expression profiles, reflecting intratumoral and interpatient heterogeneities of glioma. In addition, TERT promotor mutations and triple CNA significantly correlated with success rate of LTP-TS-GDCs. These findings will be of use and advance the preclinical and translational researches of glioma.

Thrombolytic therapy in the treatment of cardiogenic acute cerebral embolism caused by coagulated blood carries the risk of hemorrhagic complications, and there is a need to develop safer and more reliable treatment methods. Laser thrombolysis therapy, which utilizes the difference in energy absorption between the thrombus and the arterial wall, has shown promise as a new treatment method because it can selectively act only on the thrombus. It has not been applied clinically, however, and one of the main reasons for this is that its underlying mechanism has not been elucidated. We developed a pulse laser thrombolysis system for treating cerebral blood vessels that consists of a diode-pumped solid-state neodymium-yttrium aluminum garnet laser, which has excellent stability and maintainability and is suitable for clinical applications coupled to a small-diameter optical fiber. Moreover, we analyzed the mechanisms that occur during pulsed laser irradiation of transparent glass tubes and gelatin phantoms. We found that bubbles form as a thermal effect in addition to ablation of the pulsed laser irradiation. Furthermore, we detected no shock waves or water jets associated with the bubbles. We analyzed the bubbles’ dynamics and growth rate, and their effect on a rabbit blood clot phantom. We concluded that the bubbles generated by the laser irradiation physically cut the thrombus and thereby had a thrombectomy effect. We believe that this study will clarify the mechanism of laser thrombolysis therapy and contribute greatly to the realization of its clinical application.

In this chapter, we report our latest work on the technical development of the cryogenically cooled Yb:YAG-ceramics laser as scalable technology toward achievement of repetitive kilo-joule-class lasers. In our first trial, we obtain a high small signal gain of 20.4 with a high stored energy of 149.0 J using a conductively side-cooled Yb:YAG ceramic multi-disk laser amplifier operating at 100-K cooling temperature. In the second trial, we obtain 117-J nanosecond pulsed laser output with a cryogenic-helium-gas face-cooled Yb:YAG ceramic multi-disk laser amplifier. In this study, we obtain 42.3% energy-extraction efficiency from the energy stored in the Yb:YAG ceramic disks. We also determined the specifications of the face-cooled laser amplifier designed for repetitive operation by flowing helium gas on the end faces of the Yb:YAG ceramic disks. The feasibility of a practical design for kilo-joule-class diode pumped solid state lasers with a cryogenically cooled Yb:YAG ceramic disks was demonstrated by the developed high-gain and high-efficiency laser technologies.

The relationship between uptake of amino acid tracer with positron emission tomography (PET) and glioma subtypes/gene status is still unclear.To assess the relationship between uptake of [The participants were 68 patients with newly diagnosed and untreated glioma who underwent surgical excision and preoperative [The mean lesion/contralateral normal brain tissue (L/N) ratio of diffuse astrocytomas was significantly lower than that of anaplastic astrocytomas (P = 0.00155), glioblastoma (P0.001), and oligodendrogliomas (P = 0.0157). The mean L/N ratio of IDH mutant gliomas was significantly lower than that of IDH wild-type gliomas (median 1.75 vs. 2.61; P = 0.00162). A mean L/N ratio of 2.05 provided the best sensitivity and specificity for distinguishing between IDH mutant and IDH wild-type gliomas (69.2% and 76.2%, respectively). The mean L/N ratio of TERT promoter mutant gliomas was significantly higher than that of TERT promoter wild-type gliomas (P = 0.0147). Multiple regression analysis showed that pathologic diagnosis was the only influential factor on L/N ratio.Distinguishing glioma subtypes based on the revised 2016 World Health Organization classification of the central nervous system tumors on the basis of [

OBJECTIVE Epileptic spasms (ESs) are classified as focal, generalized, or unknown onset ESs. The classification of ESs and surgery in patients without lesions apparent on MRI is challenging. Total corpus callosotomy (TCC) is a surgical option for diagnosis of the lateralization and possible treatment for ESs. This study investigated phase-amplitude coupling (PAC) of fast activity modulated by slow waves on scalp electroencephalography (EEG) to evaluate the strength of the modulation index (MI) before and after disconnection surgery in children with intractable nonlesional ESs. The authors hypothesize that a decreased MI due to surgery correlates with good seizure outcomes. METHODS The authors studied 10 children with ESs without lesions on MRI who underwent disconnection surgeries. Scalp EEG was obtained before and after surgery. The authors collected 20 epochs of 3 minutes each during non–rapid eye movement sleep. The MI of the gamma (30–70 Hz) amplitude and delta (0.5–4 Hz) phase was obtained in each electrode. MIs for each electrode were averaged in 4 brain areas (left/right, anterior/posterior quadrants) and evaluated to determine the correlation with seizure outcomes. RESULTS The median age at first surgery was 2.3 years (range 10 months–9.1 years). Two patients with focal onset ESs underwent anterior quadrant disconnection (AQD). TCC alone was performed in 5 patients with generalized or unknown onset ESs. Two patients achieved seizure freedom. Three patients had residual generalized onset ESs. Disconnection surgeries in addition to TCC consisted of TCC + posterior quadrant disconnection (PQD) (1 patient); TCC + AQD + PQD (1 patient); and TCC + AQD + hemispherotomy (1 patient). Seven patients became seizure free with a mean follow-up period of 28 months (range 5–54 months). After TCC, MIs in 4 quadrants were significantly lower in the 2 seizure-free patients than in the 6 patients with residual ESs (p < 0.001). After all 15 disconnection surgeries in 10 patients, MIs in the 13 target quadrants for each disconnection surgery that resulted in freedom from seizures were significantly lower than in the 26 target quadrants in patients with residual ESs (p < 0.001). CONCLUSIONS In children with nonlesional ESs, PAC for scalp EEG before and after disconnection surgery may be a surrogate marker for control of ESs. The MI may indicate epileptogenic neuronal modulation of the interhemispheric corpus callosum and intrahemispheric subcortical network for ESs. TCC may be a therapeutic option to disconnect the interhemispheric modulation of epileptic networks.

The injection and engagement of pellets using laser beam irradiation is one of the key technologies to realize a laser-driven inertial fusion energy (IFE) reactor. We irradiated ultra-intense laser...

Long-term proliferating tumorsphere (LTP-TS)-forming glioma derived cells (GDCs) and patient derived xenografts (PDXs) are essential tools for translational research for glioma. However, only small subsets of glioma samples are established as LTP-TS and/or PDXs and little is known about the genetics and molecular properties of LTP-TS -forming GDCs and PDX. In this study, we aim to analyze the characteristics of LTP-TS -forming GDCs and PDXs. We tried primary sphere cultures from 56 glioma patient-derived samples and established 14 LTP-TS -forming GDCs out of 48 glioblastoma samples and no long-term sphere culture was isolated from grade3 and grade 2 gliomas. LTP-TS -forming GDCs had self-renewal ability and possessed certain multipotency. However, they significantly less expressed SOX1 FOXG1 and TUBB3, whereas they expressed LGALS1 significantly higher than normal neural stem/progenitor cells. In addition, we found that LTP-TS -forming GDCs shared the same genetic profiles with original patients’ tumors. Furthermore, we investigated the genetic differences between the glioma tissues which were successfully established as LTP-TS -forming GDCs and those which were not. We found that glioma tissues with TERT promotor mutations and triple CNA (EGFR, CDKN2A, and PTEN loci) are significantly established as LTP-TS -forming GDCs. Lastly, we next investigated in vivo characteristics of glioma PDXs. We have injected glioma PDXs lines into immunodeficient mice and histopathologically analyzed the characteristics of xenografts. Each xenograft well recapitulated histological features of original patients’ tumors and tumor cells remarkably invade through subventricular zone. In conclusion, each LTP-TS -forming GDCs and PDXs had various gene expression profiles, reflecting intratumoral and interpatient heterogeneities of glioma. In addition, TERT promotor mutations and triple CNA significantly correlated with success rate of LTP-TS -forming GDCs. These findings will be of use and advance the preclinical and translational researches of glioma.

This surgical video shows a 19-yr-old woman with focal impaired awareness seizures. Seizure semiology showed no lateralizing signs. Ictal electroencephalography (EEG) failed to determine the seizure origin. Interictal EEG showed bilateral spike-and-waves at the temporal electrodes. Magnetic resonance imaging (MRI) showed suspected hippocampal sclerosis on the right side. To determine the side of the focus, depth electrodes were implanted in both hippocampi. Invasive video EEG identified the seizure origin on the right. The decision was made to perform selective amygdalohippocampectomy (SelAH) via the middle temporal gyrus (MTG). An endoscope was used to minimize the craniotomy and shorten the skin incision. A 5-cm linear skin incision and 2.5-cm craniotomy were made. A thin tube was inserted to the inferior horn of the lateral ventricle (Inf-H) under neuronavigation to guide the route to the Inf-H. The endoscope was introduced. A 1.5-cm corticotomy was made at the MTG, and white matter was aspirated until opening the Inf-H. The hippocampus and parahippocampal gyrus were removed with the usual steps in microsurgical SelAH. The surgical time was 4 h 20 min. The patient was discharged without complications and has remained seizure free. In addition to the preoperative objectives, using an endoscope widens the surgical view in the Inf-H compared with microsurgical procedures. Although seizure and cognitive outcomes are expected to be comparable to those from other methods of SelAH, invasiveness might be reduced. This appears to represent the first video report of endoscopic SelAH. The patient consented to the procedure and publication of her images and surgical video.

Background Vertical hemispherotomy is performed in hemispheric epilepsy to disconnect commissural fibers, projecting fibers, and limbic system from the affected side of the brain with minimal parenchyma removal. However, anatomic understanding of this surgery is generally difficult. Objective To present the vertical hemispherotomy procedures using cadaveric brains and intraoperative photographs. Methods Two formalin-fixed adult cadaveric brains were used to demonstrate vertical hemispherotomy. Intraoperative photographs were taken of a 19-year-old man with intractable epilepsy due to head trauma in infancy. Results After coronal skin incision along the coronal suture, bifrontal craniotomy and a C-shaped dural incision from lateral to medial to the midline are performed. The interhemispheric fissure is dissected from anterior to posterior. Interhemispheric total corpus callosotomy is performed to disconnect commissural fibers. Corticotomy on the cingulate gyrus is performed to approach the lateral ventricle. The lateral border of the thalamus is cut from posterior to anterior until exposing the inferior horn of the lateral ventricle and hippocampal head to disconnect projecting fibers. At the anteromedial side of the hippocampus, the inferior part of the amygdala and uncal gyrus is removed, exposing the basal cistern to disconnect the hippocampus and amygdala. The posterior column of the fornix at the trigone of the lateral ventricle is resected to disconnect the limbic system. Projecting fibers from the anterior frontal lobe are disconnected. Conclusion A step-by-step procedure using cadaveric brains and intraoperative photographs provide a better anatomic understanding of vertical hemispherotomy.

Glioblastoma (GBM) is one of the most lethal solid cancers due to its highly invasive nature. The malignant potential of GBM cells might be partially regulated by surrounding normal cells, such as oligodendrocytes or fibroblasts. The aim of this study was to examine the interaction between stromal cells and GBM cells.Two GBM cell lines were used. The effect of stromal cells, oligodendrocytes or fibroblasts, on the invasive ability of GBM cells was examined by wound-healing assay and invasion assay.Oligodendrocytes, in contrast to fibroblasts, significantly increased the migration and invasive ability of GBM cells. Angiopoietin-2 levels were high in the conditioned medium obtained from oligodendrocytes. Angiopoietin-2 significantly increased the motility of GBM, and the motility-stimulating activity of the oligodendrocytes-derived conditioned medium was significantly decreased by anti-angiopoietin-2-neutralizing antibody.Glioma stromal cells, oligodendrocytes, might up-regulate the invasiveness of GBM cells via angiopoietin-2 signaling.

Optic canal invasion by tuberculum sellae meningiomas (TSMs) has been reported, but the characteristics of invasion remain unclear. This study was performed to clarify the incidence and characteristics of optic canal invasion by TSM and to determine whether optic canal invasion could be predicted preoperatively by magnetic resonance imaging (MRI). Between February 2002 and August 2014, 31 patients with TSM underwent tumor resection in our institute. In all cases, the optic canal was explored to identify any tumor invasion. We classified the characteristics of optic canal invasion from intraoperative findings. Invasion was classified into four types: type 1: no invasion; type 2: secondary invasion; type 3: partial wall invasion (two subtypes); and type 4: invasion into the supero-medial-inferior walls of the optic canal. Thirty of 31 cases showed optic canal invasion. Of these 30 cases, 9 (30 %) showed bilateral optic canal invasion. The most common finding was type 1 (23 sides). Among cases with optic canal invasion (39 sides), type 4 was the most common pattern (17 sides), followed by type 3-infero-medial (13 sides), type 2 (5 sides), and type 3-supero-medial (4 sides). Blinded prediction of tumor invasion was accurate in 61 % of cases, but characteristics of tumor invasion were undeterminable from preoperative MRI. In conclusion, optic canal invasion was frequently seen in our consecutive series of TSM, characteristics of which were unpredictable preoperatively. Neurosurgeons should be aware of the high incidence and variety of optic canal invasion in planning strategies for TSM treatment.

We demonstrated 117-J laser output in a nanosecond regime with a diode-pumped Yb:YAG ceramic laser amplifier. The repetition rate was 0.05 Hz, and the pulse duration was around 40 ns. 5-J input energy was amplified by two cryogenically cooled Yb:YAG ceramic laser heads. Six Yb:YAG ceramic disks in each laser head were cooled by cryogenic helium gas with a temperature of 175 K. The output energy of the first and second laser heads was about 28 and 117 J.

Patient-derived xenografts (PDXs) are essential tools for translational research for brain tumors. However, it is sometimes difficult for each institution to establish PDXs because it needs experiences and techniques and it also takes a lot of works to establish them. Thus we aim to establish patient derived xenograft’s biobank among institutions of Kansai Molecular Diagnosis Network for Central Nervous System (CNS) Tumors, Osaka, Japan. We have already began sharing two anaplastic astrocytoma PDXs, twelve glioblastoma IDH wild type PDXs, two medulloblastoma Shh subgroup PDXs, one atypical teratoid/rhabdoid tumor (AT/RT) PDX, and three metastatic brain tumor PDXs. Furthermore these PDXs can also be cultured in vitro, except 2 medulloblastoma SHH subgroup PDXs, 1 AT/RT PDX. However, we have not yet established any PDXs from low grade glioma, ependymoma, primary central nervous system lymphoma (PCNSL), diffuse intrinsic pontine glioma (DIPG). We began sharing these PDXs among the institutions of Kansai Molecular Diagnosis Network for CNS Tumors, Osaka, Japan. However, further improvement is necessary to succeed in establishing PDX from low grade glioma, PCSNL, DIPG, etc. and get enough number of PDXs so we can share PDXs from almost all of the brain tumors.

Background and importance: Malignant transformation of vestibular schwannoma (VS) after Gamma Knife Surgery (GKS) was extremely rare, but potentially serious complication leading to poor prognosis. Small number cases have been reported but they are limited to single case report. Clinical presentation: This article presents a case of a cerebellopontine angle tumor in a 54-year-old man who had right-sided hearing disturbance which lasted for 11 years. The patient underwent tumor resection via retrosigmoid approach in May 2004 at another hospital, and subtotal removal was achieved. Pathological diagnosis was vestibular schwannoma (VS). One year later, Gamma Knife Surgery (GKS) was performed for residual tumor control. Two years after GKS, the patient was referred to our hospital and second surgical resection was performed, subtotal tumor removal was achieved and pathology showed VS. Clinical and radiological follow up were performed every 6 months. In April 2014, deterioration on clinical symptom appeared and the tumor had grown, and therefore third tumor resection via retrosigmoid approach was performed. Conclusion: Subtotal removal was achieved and pathology showed malignant peripheral nerve sheath tumor (MPNST). Although this case is rare, malignant transformation of VS after GKS should keep in mind when treating VS. Keywords: Vestibular schwannoma, Malignant transformation, Gamma Knife Surgery

Background Posterior quadrant disconnection is a surgery for refractory unilateral temporoparieto-occipital epilepsy to limit propagation of epileptic discharges. As incomplete disconnection can lead to residual seizures, detailed procedures are presented using a cadaveric brain, three-dimensional (3D) reconstruction and simulation models, and intraoperative photographs. Methods A formalin-fixed adult cadaveric brain was dissected to show each step in posterior quadrant disconnection. Using 3D preoperative planning software, we reconstructed 3D models of operative views from computed tomography and magnetic resonance imaging. Intraoperative photographs were taken from the case of a 7-year-old girl with temporoparieto-occipital epilepsy. Results Frontotemporoparietal craniotomy was performed. The Sylvian fissure was widely dissected, and the insular cortex was exposed. The temporal stem was disconnected along the inferior peri-insular sulcus. The disconnection was extended from the limen insulae to the atrium of the lateral ventricle. The fibers between the head of the hippocampus and the amygdala were disconnected. The parietal lobe was disconnected along the postcentral sulcus, and the disconnection was connected to the atrium of the lateral ventricle. At the medial surface of the parietal lobe, the disconnection was continued to the corpus callosum. The splenium of the corpus callosum was disconnected via the medial wall of the lateral ventricle. The fornix was divided in the atrium of the lateral ventricle. After these steps, disconnection of the unilateral tempoparieto-occipital lobe was achieved while preserving the arteries and veins. Conclusions Inclusion of views from cadaveric brain, 3D reconstruction and simulation models, and intraoperative photographs facilitates a clearer anatomic understanding of posterior quadrant disconnection.

Surgery of arteriovenous malformation (AVM) is sometimes challenging and carries a high risk of morbidity, especially when the AVM is located in an eloquent area of the brain. Unlike gliomas, awake craniotomy has not been widely used for resection of AVM. The authors present a case of an AVM in the left frontal lobe which was successfully removed with the aid of awake craniotomy with cortical language mapping. In conclusion, awake craniotomy for functional cortical mapping is beneficial for AVM resection, especially when the lesion is located in or adjacent to eloquent areas of the brain. A hybrid approach with functional mapping in the awake condition and AVM resection under general anesthesia may be useful in selected cases. Furthermore, en bloc resection with the nidus embedded in the brain parenchyma may be a useful means of removal to reduce operation time and intraoperative blood loss if there is no apparent functional cortex surrounding the AVM, as in the present case.