Intraoperative Brainstem Auditory Evoked Potentials and Postoperative Nausea and Vomiting After Microvascular Decompression.

BACKGROUND: We performed this study to investigate the effect of intraoperative brainstem auditory evoked potential (IBAEP) changes on the development of postoperative nausea and vomiting (PONV) after microvascular decompression (MVD) for neurovascular cross compression. METHODS: A total of 373 consecutive cases were treated with MVD. The use of rescue antiemetics after surgery was used as an objective indicator of PONV. IBAEP monitoring was routinely performed in all. RESULTS: The use of rescue antiemetics was significantly associated with female sex (OR = 3.427; 95% CI, 2.077-5.654; P < 0.001), PCA use (OR = 3.333; 95% CI, 1.861-5.104; P < 0.001), and operation time (OR = 1.017; 95% CI, 1.008-1.026; P < 0.001). A Wave V peak delay of more than 1.0 milliseconds showed a significant relation with the use of rescue antiemetics (OR = 1.787; 95% CI, 1.114-2.867; P = 0.016) and a strong significant relation with the use of rescue antiemetics more than 5 times (OR = 2.426; 95% CI, 1.372-4.290; P = 0.002). CONCLUSIONS: A wave V peak delay of more than 1.0 milliseconds might have value as a predictor of PONV after MVD. More detailed neurophysiological studies will identify the exact pathophysiology underlying PONV after MVD.

The Korean Society for Neuro-Oncology (KSNO) Guideline for the Management of Brain Tumor Patients During the Crisis Period: A Consensus Recommendation Using the Delphi Method (Version 2023.1).

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, the need for appropriate treatment guidelines for patients with brain tumors was indispensable due to the lack and limitations of medical resources. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. METHODS: The KSNO Guideline Working Group was composed of 22 multidisciplinary experts on neuro-oncology in Korea. In order to reach consensus among the experts, the Delphi method was used to build up the final recommendations. RESULTS: All participating experts completed the series of surveys, and the results of final survey were used to draft the current consensus recommendations. Priority levels of surgery and radiotherapy during crises were proposed using appropriate time window-based criteria for management outcome. The highest priority for surgery is assigned to patients who are life-threatening or have a risk of significant impact on a patient's prognosis unless immediate intervention is given within 24-48 hours. As for the radiotherapy, patients who are at risk of compromising their overall survival or neurological status within 4-6 weeks are assigned to the highest priority. Curative-intent chemotherapy has the highest priority, followed by neoadjuvant/adjuvant and palliative chemotherapy during a crisis period. Telemedicine should be actively considered as a management tool for brain tumor patients during the mass infection crises such as the COVID-19 pandemic. CONCLUSION: It is crucial that adequate medical care for patients with brain tumors is maintained and provided, even during times of crisis. This guideline will serve as a valuable resource, assisting in the delivery of treatment to brain tumor patients in the event of any future crisis.

The Korean Society for Neuro-Oncology (KSNO) Guideline for the Management of Brain Tumor Patients During the Crisis Period: A Consensus Survey About Specific Clinical Scenarios (Version 2023.1).

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, there was a shortage of medical resources and the need for proper treatment guidelines for brain tumor patients became more pressing. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. As part II of the guideline, this consensus survey is to suggest management options in specific clinical scenarios during the crisis period. METHODS: The KSNO Guideline Working Group consisted of 22 multidisciplinary experts on neuro-oncology in Korea. In order to confirm a consensus reached by the experts, opinions on 5 specific clinical scenarios about the management of brain tumor patients during the crisis period were devised and asked. To build-up the consensus process, Delphi method was employed. RESULTS: The summary of the final consensus from each scenario are as follows. For patients with newly diagnosed astrocytoma with isocitrate dehydrogenase (IDH)-mutant and oligodendroglioma with IDH-mutant/1p19q codeleted, observation was preferred for patients with low-risk, World Health Organization (WHO) grade 2, and Karnofsky Performance Scale (KPS) ≥60, while adjuvant radiotherapy alone was preferred for patients with high-risk, WHO grade 2, and KPS ≥60. For newly diagnosed patients with glioblastoma, the most preferred adjuvant treatment strategy after surgery was radiotherapy plus temozolomide except for patients aged ≥70 years with KPS of 60 and unmethylated MGMT promoters. In patients with symptomatic brain metastasis, the preferred treatment differed according to the number of brain metastasis and performance status. For patients with newly diagnosed atypical meningioma, adjuvant radiation was deferred in patients with older age, poor performance status, complete resection, or low mitotic count. CONCLUSION: It is imperative that proper medical care for brain tumor patients be sustained and provided, even during the crisis period. The findings of this consensus survey will be a useful reference in determining appropriate treatment options for brain tumor patients in the specific clinical scenarios covered by the survey during the future crisis.

Brain Invasion and Trends in Molecular Research on Meningioma.

Meningiomas are the most common primary brain tumors in adults. The treatment of non-benign meningiomas remains a challenging task, and after the publication of the 2021 World Health Organization classification, the importance of molecular biological classification is emerging. In this article, we introduce the mechanisms of brain invasion in atypical meningioma and review the genetic factors involved along with epigenetic regulation. First, it is important to understand the three major steps for brain invasion of meningeal cells: 1) degradation of extracellular matrix by proteases, 2) promotion of tumor cell migration to resident cells by adhesion molecules, and 3) neovascularization and supporting cells by growth factors. Second, the genomic landscape of meningiomas should be analyzed by major categories, such as germline mutations in NF2 and somatic mutations in non-NF2 genes (TRAF7, KLF4, AKT1, SMO, and POLR2A). Finally, epigenetic alterations in meningiomas are being studied, with a focus on DNA methylation, histone modification, and RNA interference. Increasing knowledge of the molecular landscape of meningiomas has allowed the identification of prognostic and predictive markers that can guide therapeutic decision-making processes and the timing of follow-up.

Venous outflow-targeted coil embolization of direct carotid-cavernous fistulas.

BACKGROUND: Coil embolization is the mainstay treatment for carotid-cavernous fistulas (CCFs). However, few studies have reported entire occlusion of engorged veins to interrupt venous outflow. We report our experience with venous outflow-targeted coil embolization of direct CCFs. METHODS: We retrospectively reviewed all the patients diagnosed with direct CCFs treated with venous outflow-targeted coil embolization between November 2013 and February 2020. Venous outflow-targeted coil embolization of the CCFs was performed as follows. First, transarterial stent-assisted coil embolization of CCFs was performed. If the venous outflow to the engorged veins persisted after transarterial stent-assisted coil embolization, entire occlusion of the engorged veins and additional coil packing within the cavernous sinus were performed to interrupt the venous outflow. RESULTS: Ten patients had undergone venous outflow-targeted coil embolization, 6 women (60%) and 4 men (40%). Transfemoral cerebral angiography showed high-flow, direct CCFs in all the patients. Venous outflow occurred through the superior ophthalmic vein (SOV) in all the patients and was completely interrupted by the entire occlusion of the engorged veins with fibered coils. Three patients (30%) had undergone additional treatment in a supplementary manner because of recurrent symptoms (chemosis in 1 patient, faint tinnitus in 2 patients) in the early postprocedural period (1 to 4 weeks). All the symptoms were resolved on follow-up. No additional recurrence was found during follow-up (1-75 months). No peri-procedural complications were encountered. CONCLUSIONS: Venous outflow-targeted coil embolization of CCFs would be a safe and effective treatment method.

The novel prognostic value of postoperative follow-up lateral spread response after microvascular decompression for hemifacial spasm.

OBJECTIVE: The lateral spread response (LSR) is an aberrant electrophysiological response in which a stimulus on one branch of the facial nerve spills over to other branches of the nerve, which can be captured by electrodes near each branch. The authors performed this study to evaluate the prognostic value of the follow-up LSR with a sufficient time interval from intraoperative LSR (IO-LSR) after microvascular decompression (MVD) for hemifacial spasm (HFS), excluding the interference of various intraoperative situations. METHODS: A total of 247 patients treated with MVD for HFS between June 2011 and March 2019 were enrolled in this study. The IO-LSR was routinely evaluated in all patients. The LSR was checked again on postoperative day (POD) 2 after surgery (POD2-LSR). A total of 228 patients (92.3%) were considered cured at the last clinical follow-up. RESULTS: The IO-LSR disappeared in 189 patients (76.5%), and among them, 181 patients (95.8%) were cured 1 year after surgery. The POD2-LSR disappeared in 193 patients (78.1%), and 185 patients (95.9%) among them were cured. Among the 189 patients in which the IO-LSR disappeared, the POD2-LSR reappeared in 26 patients (13.8%). In contrast, the POD2-LSR disappeared in 30 (51.7%) of 58 patients for whom the IO-LSR continued at the end of surgery. When classified into groups according to the status of the IO-LSR and POD2-LSR, in the group of patients in whom both LSRs disappeared, the cure rate was 98.2%, which was significantly higher than that of the other 3 groups (p < 0.05, Cochran-Armitage trend test). The use of both LSRs was found to be significantly associated with better predictability (p < 0.05, McNemar's test). CONCLUSIONS: Postoperative follow-up LSR examination may be beneficial in predicting clinical outcomes after MVD for HFS, especially when considered together with IO-LSR.

The Combination PARP Inhibitor Olaparib With Temozolomide in an Experimental Glioblastoma Model.

BACKGROUND/AIM: Poly (ADP-ribose) polymerase (PARP) inhibition could enhance the efficacy of temozolomide and prolong survival in patients with glioblastoma. The aim of this study was to evaluate the combination of the PARP inhibitor olaparib with temozolomide in the treatment of glioblastoma. MATERIALS AND METHODS: The in vitro and in vivo antitumor effects of the PARP inhibitor olaparib together with temozolomide were evaluated. The in vitro experimental glioblastoma model involved O6-methylguanine methyltransferase (MGMT) promoter-methylated (U87MG, U251MG) and MGMT promoter-unmethylated (T98G) glioblastoma cell lines using In this model cell viability and apoptosis were assessed. For the in vivo studies, nude mice bearing orthotopically xenografted glioblastoma cell lines (U87MG) were randomized to four experimental groups: i) the untreated, ii) temozolomide alone, iii) olaparib alone and iv) olaparib and temozolomide combination groups. Mice were treated daily for 4 weeks and monitored for tumor growth and survival. RESULTS: In vitro we found that the combination of olaparib with temozolomide enhanced temozolomide-induced cytotoxicity in all glioblastoma cell lines regardless of the status of MGMT promoter methylation. In vivo, mice treated with temozolomide alone or in combination with olaparib showed greater survival than those untreated or with the olaparib monotherapy, as well as significantly decreased tumor volume. There was no significant difference in survival and tumor volume between temozolomide alone and the combination treatment. CONCLUSION: The combination of the PARP inhibitor olaparib with temozolomide could be promising candidates for combination therapy of glioblastoma regardless of the MGMT promoter methylation status.

A rare case of intraparenchymal subependymoma in a child.

Subependymoma is a slow-growing, exophytic, intraventricular glial neoplasm that commonly arises in the ventricular system. However, a report found that the frequency of intracerebral subependymoma was 0.4% in 1000 routine autopsies. To the best of our knowledge, only seven cases of intracerebral subependymoma have been reported. We report a rare case of intracerebral subependymoma in a child. An 11-year-old girl with generalized tonic-clonic seizures visited the emergency room and had an intraparenchymal tumor on the left frontal lobe on magnetic resonance imaging (MRI). Craniotomy with gross total removal was performed without any perioperative morbidities. The tumor was finally histopathologically diagnosed as a subependymoma.

Clinical Characteristics of High-Grade Glioma with Primary Leptomeningeal Seeding at Initial Diagnosis in a Single Center Study.

BACKGROUND: High-grade glioma (HGG) with primary leptomeningeal seeding (PLS) at initial diagnosis is rare. The purpose of this study was to identify its clinical features and to describe the clinical treatment outcomes. METHODS: We retrospectively reviewed the medical records of patients with HGG (World Health Organization grade III or IV) at our institution between 2004 and 2019, and patients with PLS at the initial diagnosis were enrolled in the study. Clinical features, such as the location of leptomeningeal seeding, surgical methods, and degree of resection, were sorted based on electronic medical records also containing performance scale, and hematological and serological evaluations. Radiological findings and immunohistochemical categories were confirmed. Furthermore, we sought to determine whether controlling intracranial pressure (ICP) via early cerebrospinal fluid (CSF) diversion increases overall survival (OS) after the initial diagnosis. RESULTS: Of the 469 patients with HGG in our institution, less than 2% had PLS at the initial diagnosis. Most patients suffered from headache, diplopia, and dizziness. Pathological findings included 7 glioblastomas and 2 anaplastic astrocytomas. Seven of the 9 patients underwent CSF diversion. All patients were administered concurrent chemoradiotherapy (CCRT) with temozolomide, 89% of which started adjuvant temozolomide and 33% of which completed the six cycles of adjuvant temozolomide. The OS of patients with HGG and PLS was 8.7 months (range, 4-37), an extremely poor result compared to that of other studies. Also, the 1-year and 2-year OS rates were 44.4% and 16.7%, respectively. CONCLUSION: Diagnosis and treatment of HGG with PLS are challenging. Aggressive control of ICP followed by early initiation of standard CCRT seems to be helpful in improving symptoms. However, despite aggressive treatment, the prognosis is poor. A multicenter trial and research may be necessary to create a standardized protocol for this disease.

Surgical Nuances to Reduce and Manage Cerebrospinal Fluid Leaks after Microvascular Decompression.

BACKGROUND: No dural substitute has proven to be complication-free in a large clinical trial, even suggesting some benefit during watertight closure. However, primary dural closure is not always possible due to dural shrinkage from electrocautery for dural bleeding. OBJECTIVE: This study is performed to analyze the clinical outcomes related to cerebrospinal fluid (CSF) leakage after microvascular decompression (MVD) using a simple surgical technique. METHODS: Three hundred and sixty consecutive cases were treated with MVD and followed up for more than one month after surgery. Bleeding from the cut veins during dural incision was controlled by pulling stay sutures instead of electrocautery to avoid dural shrinkage. Additionally, a wet cottonoid was placed on the cerebellar side dural flap to prevent dural dehydration. During dural closure, primary dural closure was always attempted. If not possible, a "plugging muscle" method was used for watertight dural closure. RESULTS: The mean age was 54.1 ± 10.8 years (range, 24-85 years), and 238 (66.1%) were female. Primary MVD was performed in 345 (95.8%) patients. The mean operation time (from skin incision to skin closure) was 96.7 ± 33.0 min (range, 38-301 min). Primary dural closure was possible in 344 (95.6%) patients. The "plugging muscle method" was performed more frequently in patients older than 60 years (8 of 99 cases, 8.08%) than in younger cases (8 of 261 cases, 3.07%) (p = 0.039; chi-squared test). After surgery, 5 (1.4%) patients were treated for middle ear effusion, and another 5 (1.4%) patients experienced transient CSF rhinorrhea, which was spontaneously resolved within 1 to 7 days. No patients required additional treatments for CSF leakage. CONCLUSION: A simple technique using pulling stay sutures to stop bleeding from the dural edges and placing a wet cottonoid on the exposed dura can make primary dural closure easier.

Solitary intraventricular hemorrhage without subarachnoid hemorrhage due to aneurysmal rupture: a case report.

The presence of primary intraventricular hemorrhage (IVH) without vascular lesion is very rare. We experienced solitary IVH without subarachnoid hemorrhage due to aneurysmal rupture in a 58-year-old man treated with coil embolization, which contributed to his good prognosis. After 33 days of hospitalization, he had mild right hemiplegic symptoms remaining, and he was transferred to a rehabilitation institute for further treatment. In cases of primary IVH, computed tomography angiography seems worthwhile for making a differential diagnosis, although the possibility of IVH due to cerebral aneurysmal rupture is very low. Endovascular intervention is a good option for diagnosis and treatment.

Cystic Meningiomas: Correlation between Radiologic and Histopathologic Features.

BACKGROUND: Tumors with cysts often correlate with gliomas, metastatic tumors, or hemangioblastomas, which require differentiation. METHODS: Thirty-eight cases of cyst associated-meningioma based on preoperative radiologic studies and histologic confirmations were reviewed from November 1998 to July 2017. RESULTS: A total of 395 cases of meningioma were observed in the 20 years, and surgical treatment of intracranial meningioma was performed in 120 cases. Thirty-eight (9.6%) cases of cyst associated meningiomas were analyzed. Nauta type I was the most common type of cyst (39.5%) and the most frequent histopathological subtype was meningothelial type (36.8%). CONCLUSION: Statistically there were no significant associations between meningioma histopathological type and associated cysts; however, the rate of World Health Organization grade II was higher in cyst associated meningiomas than in unrelated meningiomas. This correlation was weak, in accordance with the meningioma grade.