Usefulness of synthetic MRI for differentiation of IDH-mutant diffuse gliomas and its comparison with the T2-FLAIR mismatch sign.

INTRODUCTION: The T2-FLAIR mismatch sign is a characteristic imaging biomarker for astrocytoma, isocitrate dehydrogenase (IDH)-mutant. However, investigators have provided varying interpretations of the positivity/negativity of this sign given for individual cases the nature of qualitative visual assessment. Moreover, MR sequence parameters also influence the appearance of the T2-FLAIR mismatch sign. To resolve these issues, we used synthetic MR technique to quantitatively evaluate and differentiate astrocytoma from oligodendroglioma. METHODS: This study included 20 patients with newly diagnosed non-enhanced IDH-mutant diffuse glioma who underwent preoperative synthetic MRI using the Quantification of Relaxation Times and Proton Density by Multiecho acquisition of a saturation-recovery using Turbo spin-Echo Readout (QRAPMASTER) sequence at our institution. Two independent reviewers evaluated preoperative conventional MR images to determine the presence or absence of the T2-FLAIR mismatch sign. Synthetic MRI was used to measure T1, T2 and proton density (PD) values in the tumor lesion. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance. RESULTS: The pathological diagnoses included astrocytoma, IDH-mutant (n = 12) and oligodendroglioma, IDH-mutant and 1p/19q-codeleted (n = 8). The sensitivity and specificity of T2-FLAIR mismatch sign for astrocytoma were 66.7% and 100% [area under the ROC curve (AUC) = 0.833], respectively. Astrocytoma had significantly higher T1, T2, and PD values than did oligodendroglioma (p < 0.0001, < 0.0001, and 0.0154, respectively). A cutoff lesion T1 value of 1580 ms completely differentiated astrocytoma from oligodendroglioma (AUC = 1.00). CONCLUSION: Quantitative evaluation of non-enhanced IDH-mutant diffuse glioma using synthetic MRI allowed for better differentiation between astrocytoma and oligodendroglioma than did conventional T2-FLAIR mismatch sign. Measurement of T1 and T2 value by synthetic MRI could improve the differentiation of IDH-mutant diffuse gliomas.

Super T2-FLAIR mismatch sign: a prognostic imaging biomarker for non-enhancing astrocytoma, IDH-mutant.

PURPOSE: The T2-FLAIR mismatch sign is a highly specific diagnostic imaging biomarker for astrocytoma, IDH-mutant. However, a definitive prognostic imaging biomarker has yet to be identified. This study investigated imaging prognostic markers, specifically analyzing T2-weighted and FLAIR images of this tumor. METHODS: We retrospectively analyzed 31 cases of non-enhancing astrocytoma, IDH-mutant treated at our institution, and 30 cases from The Cancer Genome Atlas (TCGA)/The Cancer Imaging Archive (TCIA). We defined "super T2-FLAIR mismatch sign" as having a significantly strong low signal comparable to cerebrospinal fluid at non-cystic lesions rather than just a pale FLAIR low-signal tumor lesion as in conventional T2-FLAIR mismatch sign. Cysts were defined as having a round or oval shape and were excluded from the criteria for the super T2-FLAIR mismatch sign. We evaluated the presence or absence of the T2-FLAIR mismatch sign and super T2-FLAIR mismatch sign using preoperative MRI and analyzed the progression-free survival (PFS) and overall survival (OS) by log-rank test. RESULTS: The T2-FLAIR mismatch sign was present in 17 cases (55%) in our institution and 9 cases (30%) within the TCGA-LGG dataset without any correlation with PFS or OS. However, the super T2-FLAIR mismatch sign was detected in 8 cases (26%) at our institution and 13 cases (43%) in the TCGA-LGG dataset. At our institution, patients displaying the super T2-FLAIR mismatch sign showed significantly extended PFS (122.7 vs. 35.9 months, p = 0.0491) and OS (not reached vs. 116.7 months, p = 0.0232). Similarly, in the TCGA-LGG dataset, those with the super T2-FLAIR mismatch sign exhibited notably longer OS (not reached vs. 44.0 months, p = 0.0177). CONCLUSION: The super T2-FLAIR mismatch is a promising prognostic imaging biomarker for non-enhancing astrocytoma, IDH-mutant.

Declining trend in the estimated annual rupture rate of unruptured cerebral aneurysms in Japan: a nationwide study.

The incidence of subarachnoid hemorrhages (SAHs) in Japan has recently decreased. However, trends in the annual rates of unruptured cerebral aneurysms (UCAs) are unclear because calculations based on follow-up periods are limited to patients with ruptured cerebral aneurysms. We aimed to clarify current trends in the estimated annual rupture rates of UCAs in Japan and to identify the most relevant contributing factors. We analyzed data from the Japanese Ministry of Health, Labour and Welfare and records of the Japan Neurosurgical Society. The estimated annual rupture rates of UCAs between 2003 and 2018 were calculated according to age-adjusted mortality rates of SAH and number of treated ruptured cerebral aneurysms (RCAs). We estimated trends in annual rupture rates using sensitivity analysis and assessed associations between estimated annual rupture rates and the prevalences of hypertension and current smoking. The estimated annual rupture rate of UCAs significantly decreased from 1.44 to 0.87% and from 0.92 to 0.76%, respectively, in terms of age-adjusted mortality rates of SAH and number of treated RCAs (p < 0.001). The range of changes in estimated annual rupture rates of UCAs was - 1.13%‒0.83%, representing a declining UCA trend of 88%. The estimated annual rupture rates of UCAs declined by 0.02-0.10% and 0.01-0.05% with every percent decrease in hypertension and current smoking prevalence, respectively. The estimated annual rupture rate of UCAs has recently decreased in Japan, possibly due to a decrease in the prevalence of hypertension rather than smoking.

T2-FLAIR mismatch sign, an imaging biomarker for CDKN2A-intact in non-enhancing astrocytoma, IDH-mutant.

INTRODUCTION: The WHO classification of central nervous system tumors (5th edition) classified astrocytoma, IDH-mutant accompanied with CDKN2A/B homozygous deletion as WHO grade 4. Loss of immunohistochemical (IHC) staining for methylthioadenosine phosphorylase (MTAP) was developed as a surrogate marker for CDKN2A-HD. Identification of imaging biomarkers for CDKN2A status is of immense clinical relevance. In this study, we explored the association between radiological characteristics of non-enhancing astrocytoma, IDH-mutant to the CDKN2A/B status. METHODS: Thirty-one cases of astrocytoma, IDH-mutant with MTAP results by IHC were included in this study. The status of CDKN2A was diagnosed by IHC staining for MTAP in all cases, which was further confirmed by comprehensive genomic analysis in 12 cases. The T2-FLAIR mismatch sign, cystic component, calcification, and intratumoral microbleeding were evaluated. The relationship between the radiological features and molecular pathological diagnosis was analyzed. RESULTS: Twenty-six cases were identified as CDKN2A-intact while 5 cases were CDKN2A-HD. The presence of > 33% and > 50% T2-FLAIR mismatch was observed in 23 cases (74.2%) and 14 cases (45.2%), respectively, and was associated with CDKN2A-intact astrocytoma (p = 0.0001, 0.0482). None of the astrocytoma, IDH-mutant with CDKN2A-HD showed T2-FLAIR mismatch sign. Cystic component, calcification, and intratumoral microbleeding were not associated with CDKN2A status. CONCLUSION: In patients with non-enhancing astrocytoma, IDH-mutant, the T2-FLAIR mismatch sign is a potential imaging biomarker for the CDKN2A-intact subtype. This imaging biomarker may enable preoperative prediction of CDKN2A status among astrocytoma, IDH-mutant.

[Training of Academic Neurosurgeons: Current Status and Challenges in Japan].

The concept of translational research, which emphasizes the importance of applying research findings to clinical practice, was first introduced in the early 21st century. Since then, Japan has actively promoted translational research through government and academic institutions, fostering collaboration between basic scientists and clinicians. Despite this, Japan's academic competitiveness has declined globally, particularly in fields such as neurosurgery, due to unique training systems and reduced time for research and education amidst physician work reforms. Herein, we discuss the significance of academic pursuits among clinicians, particularly in Japan's neurosurgery landscape, alongside future challenges.

[Thrombectomy].

Endovascular procedures have become the standard treatment for acute stroke caused by large vessel occlusion. Various strategies are available, including stent retrieval, aspiration catheter placement, and combined techniques. However, the first-pass effect can be maximized using the technique most familiar to each surgeon and institution. Therefore, it is necessary to understand the characteristics of each device and develop case-specific treatment strategies.

[Carotid Artery Stenting].

Currently, stricter indications for carotid artery stenosis are required owing to improvements in multifaceted medical treatment, including the intensive management of risk factors for atherosclerosis and lifestyle changes. High-risk factors for carotid artery stenting, such as vulnerable plaques, severe calcification, pseudo-occlusion, and difficult access, should be evaluated before endovascular intervention. Therefore, we need to understand the characteristics of each device to achieve maximum risk reduction for carotid artery stenting.

[Preoperative Simulation in Epilepsy Surgery].

In patients with intractable epilepsy, seizure focus resection can yield favorable seizure outcomes. First, the localization of the seizure focus is estimated by noninvasive methods such as magnetic resonance imaging(MRI), video-electroencephalography(EEG)monitoring, nuclear medicine examinations, magnetoencephalography, and neuropsychological tests. A subgroup of patients may require additional information obtained from the intracranial EEG. There are two major methods for intracranial EEG: intracranial EEG with subdural grid electrodes(SDG)and stereotactic electroencephalography. If the estimated seizure focus overlaps with the eloquent area in noninvasive studies, the margin and extent of the resection are determined by the results of intracranial EEG and functional mapping by electrical cortical stimulation. Herein, we present a case of lobe epilepsy with subtle MRI lesions in the superior temporal sulcus of the language-dominant hemisphere. The results of the SDG and functional mapping showed that the seizure onset zone overlapped with the language area. Resection of the middle and inferior temporal gyri and multiple transections of the language area resulted in Engel IIB seizure outcomes. In such cases, a thorough preoperative simulation is required to determine the best resection margin for seizure control and functional preservation.

Arterial Spin Labeling-Based MR Angiography for Cerebrovascular Diseases: Principles and Clinical Applications.

Arterial spin labeling (ASL) is a noninvasive imaging technique that labels the proton spins in arterial blood and uses them as endogenous tracers. Brain perfusion imaging with ASL is becoming increasingly common in clinical practice, and clinical applications of ASL for intracranial magnetic resonance angiography (MRA) have also been demonstrated. Unlike computed tomography (CT) angiography and cerebral angiography, ASL-based MRA does not require contrast agents. ASL-based MRA overcomes most of the disadvantages of time-of-flight (TOF) MRA. Several schemes have been developed for ASL-based MRA; the most common method has been pulsed ASL, but more recently pseudo-continuous ASL, which provides a higher signal-to-noise ratio (SNR), has been used more frequently. New methods that have been developed include direct intracranial labeling methods such as velocity-selective ASL and acceleration-selective ASL. MRA using an extremely short echo time (eg, silent MRA) or ultrashort echo-time (TE) MRA can suppress metal susceptibility artifacts and is ideal for patients with a metallic device implanted in a cerebral vessel. Vessel-selective 4D ASL MRA can provide digital subtraction angiography (DSA)-like images. This review highlights the principles, clinical applications, and characteristics of various ASL-based MRA techniques. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Residual diffusion-weighted imaging hyperintense signal in primary central nervous system lymphoma can predict early recurrence.

BACKGROUND: The treatment response of primary central nervous system lymphomas (PCNSLs) is mainly evaluated using postcontrast T1-weighted imaging (T1WI). Because poorly enhanced lesions may contain residual tumors, the combination of evaluation methods will potentially improve the accuracy of determining treatment effectiveness. In this study, we evaluated the usefulness of diffusion-weighted imaging (DWI) in predicting recurrence among patients with PCNSL who achieved complete response (CR)/unconfirmed CR (CRu). METHODS: Fifty-four patients newly diagnosed with PCNSL who were treated at our institution and achieved CR/CRu at the end of treatment were included in this study. The patients were divided into two groups according to the presence or absence of residual DWI hyperintense signal at the tumor site at the end of treatment. Kaplan-Meier analysis was performed to analyze the median overall survival (OS) and progression-free survival (PFS). RESULTS: The mean age of the 54 patients was 66.4 ± 13.3 years. The induction therapies were HD-MTX in 20 patients, R-MPV in 29 patients, and other chemotherapies in five patients. Radiotherapy was performed in 35 patients, high-dose cytarabine therapy in 14 patients, and autologous hematopoietic stem cell transplantation in one patient, and of the 54 patients, 10 had no consolidation therapy. The residual DWI hyperintense signal sign was observed in 18 patients. The R-MPV regimen was statistically associated with a lower rate of residual DWI hyperintense signal (p = 0.0453). The median PFS was statistically shorter in the residual DWI hyperintense signal group than in the non-residual DWI hyperintense signal group (14.0 months vs. 85.1 months) (p < 0.0001, log-rank test). CONCLUSION: A residual DWI hyperintense signal at the end of treatment was statistically associated with shorter PFS. Among patients who achieved CR/CRu evaluated based on postcontrast T1WI, DWI could be a valuable additional sequence to predict the early recurrence of PCNSL.

Headache characteristics to screen for cervicocerebral artery dissection in patients with acute onset unusual headache.

OBJECTIVES: The aim of this preplanned primary analysis was to investigate the clinical manifestations of headache to screen for CAD patients with acute onset headache only. BACKGROUND: Spontaneous cervicocerebral artery dissection (CAD) with acute onset headache is not rare in clinical practice; however, it is underdiagnosed. On the other hand, subsequent infarction or subarachnoid hemorrhage mainly occurs within 1 week of headache onset. METHODS: Between April 2017 and January 2022, we conducted a single-center, cross-sectional retrospective study on 197 consecutive referred patients from neurosurgical outpatient clinics with acute onset unusual headache (stronger or longer headache than usual). All patients underwent magnetic resonance imaging to screen for secondary headache and were diagnosed based on the diagnostic protocol. We examined patient background data and the following headache characteristics: distribution, condition at the onset of headache, accompanying vomiting or nausea, worsening headache, and analgesic effects against headache. These factors were analyzed to identify independent diagnostic predictors of CAD. In this study, the rate of missing data was 41% for improvement of headache by analgesia and multiple imputation by chained equations was performed. RESULTS: A total of 93 patients (46 men and 47 women; mean age: 48 years, range: 25-73 years) were diagnosed with CAD. Univariate logistic regression analysis showed CAD was associated with current smoking, systolic blood pressure >140 mmHg, unilateral headache, worsening headache, and no headache improvement by analgesia. Unilateral, worsening headache and no headache improvement by analgesia remained independent diagnostic predictors in multivariable logistic regression after multiple imputation. No headache improvement by analgesia had the highest sensitivity (86%), while worsening headache had the highest specificity (84%). CONCLUSIONS: CAD needs to be considered in patients with unilateral, worsening headache and no headache improvement by analgesia.

Secondary meningioma after cranial irradiation: case series and comprehensive literature review.

BACKGROUND: Secondary meningioma after cranial irradiation, so-called radiation-induced meningioma, is one of the important late effects after cranial radiation therapy. In this report, we analyzed our case series of secondary meningioma after cranial irradiation and conducted a critical review of literature to reveal the characteristics of secondary meningioma. MATERIALS AND METHODS: We performed a comprehensive literature review by using Pubmed, MEDLINE and Google scholar databases and investigated pathologically confirmed individual cases. In our institute, we found pathologically diagnosed seven cases with secondary meningioma between 2000 and 2018. Totally, 364 cases were analyzed based on gender, WHO grade, radiation dose, chemotherapy. The latency years from irradiation to development of secondary meningioma were analyzed with Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between age at irradiation and the latency years. RESULTS: The mean age at secondary meningioma development was 35.6 ± 15.7 years and the mean latency periods were 22.6 ± 12.1 years. The latency periods from irradiation to the development of secondary meningioma are significantly shorter in higher WHO grade group (P = 0.0026, generalized Wilcoxon test), higher radiation dose group (P < 0.0001) and concomitant systemic chemotherapy group (P = 0.0003). Age at irradiation was negatively associated with the latency periods (r = -0.23231, P < 0.0001, Spearman's correlation test). CONCLUSION: Cranial irradiation at older ages, at higher doses and concomitant chemotherapy was associated with a shorter latency period to develop secondary meningiomas. However, even low-dose irradiation can cause secondary meningiomas after a long latency period. Long-term follow-up is necessary to minimize the morbidity and mortality caused by secondary meningioma after cranial irradiation.

Optic tract edema in craniopharyngioma as a predictor of BRAFV600E mutation presence.

OBJECTIVE: the advent of BRAF inhibitors for preoperative treatment of craniopharyngioma has necessitated the identification of BRAFV600E status. Hence, we investigated predictors of BRAFV600E mutation in craniopharyngiomas. METHODS: this retrospective study utilized data from 30 patients who were newly diagnosed with craniopharyngioma between 2011 and 2021. Magnetic resonance imaging (MRI) and computed tomography were performed within 1 week prior to surgery. Genetic analysis for BRAF mutation was performed using the Oncomine next-generation sequencing panel or Sanger sequencing. The relationship between BRAF mutation and demographic data, endocrinological function and tumour characteristics on imaging was assessed. RESULTS: tumour tissue carried the BRAFV600E mutation in nine patients. There was no significant difference in age, sex, or presence of hormonal dysfunction amongst patients with and without the BRAFV600E mutation in the tumour. Most tumours with the BRAFV600E mutation were histologically categorized as papillary craniopharyngioma (P = 0.0005), and were solid (P = 0.0002) and supra-diaphragmatic (P = 0.0033) on MRI. BRAFV600E tumours were more frequently associated with optic tract edema than wild-type tumour s (55.6 vs. 0%, P = 0.0009) and all tumour s with optic tract edema carried the BRAFV600E mutation. Optic tract edema was not associated with tumour volume, cysts, or preoperative pituitary function. CONCLUSIONS: in craniopharyngiomas, the presence of optic tract edema can predict the presence of BRAFV600E mutation with a positive predictive value of 100%. The finding should be verified in larger prospective cohorts and multivariate regression analysis.

Characteristics and therapeutic strategies of brain and cranial radiation-induced sarcoma: analysis of 165 cases from our case experience and comprehensive review.

BACKGROUND: Radiation-induced sarcoma (RIS) is among the neoplasms potentially caused by radiation therapy (RT) for brain tumors. However, the clinical characteristics of and ideal treatment for RIS are unclear. We analysed our case experience and conducted a comprehensive literature review to reveal the characteristics of brain and cranial RIS. METHODS: We analysed 165 cases of RIS from the literature together with the RIS case treated at our institution. In each case, the latency period from irradiation to the development of each RIS and the median overall survival (OS) of the patients was analysed by Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between the latency period and radiation dose or age at irradiation. RESULTS: The mean age at the development of RIS was 39.63 ± 17.84 years. The mean latency period was 11.79 ± 8.09 years. No factors associated with early development of RIS were detected. The median OS was 11 months, with fibrosarcoma showing significantly shorter OS compared with osteosarcoma and other sarcomas (p = 0.0021), and intracranial RIS showing a worse prognosis than extracranial RIS (p < 0.0001). Patients treated with surgery (p < 0.0001) and postoperative chemotherapy (p = 0.0157) for RIS presented significantly longer OS, whereas RT for RIS was not associated with a survival benefit. CONCLUSIONS: Although prognosis for RIS is universally poor, pathological characteristics and locations are associated with worse prognosis. Surgery and chemotherapy may be the ideal treatment strategies for RIS.

Association of the body mass index with poor outcome at discharge in patients with aneurysmal subarachnoid hemorrhage: a registry study.

Although several studies have reported on the impact of the body mass index (BMI) on functional outcome of aneurysmal subarachnoid hemorrhage (aSAH), the relationship remains unclear. This study aimed to investigate the risk factors of poor outcome of aSAH, with particular attention to BMI. A total of 860 patients with aSAH were enrolled in our registry at Shimane Prefectural Central Hospital between 2000 and 2017, of whom 393 were included in the analysis. Basic patient characteristics, including BMI, and data related to aSAH were recorded. We conducted a univariable analysis, followed by a multivariable analysis to identify the risk factors of poor outcome, defined as a modified Rankin Scale score > 2 at discharge. We also compared our study with previous studies that reported a relationship between BMI and aSAH. Multivariable analysis revealed that age (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.07-1.12), underweight (OR, 2.36; 95% CI, 1.13-4.90), overweight (OR, 2.22; 95% CI, 1.06-4.64), World Federation of Neurosurgical Societies grade (III vs I: OR, 3.10; 95% CI, 1.03-9.35; IV vs I: OR, 8.02; 95% CI, 3.54-18.19; V vs I: OR, 13.37; 95% CI, 5.33-33.54), and symptomatic vasospasm (OR, 3.40; 95% CI, 1.73-6.70) were risk factors for poor outcome at discharge. This study showed the association of underweight (BMI < 18.5 kg/m2) and overweight (≥ 25 kg/m2) with poor outcome; therefore, both high and low BMI are associated with a poor outcome at discharge for patients with aSAH. Clinical trial registry: University Hospital Medical Information Network (UMIN000035160; date of registration: December 6, 2018).

Flow volume mismatch dramatically affects transient neurologic symptoms after direct bypass in Moyamoya disease.

Transient neurological events (TNEs) occur after bypass surgery in Moyamoya disease (MMD); however, their pathology remains unknown. To elucidate the pathophysiology of TNEs, we investigated their relationship with perioperative superficial temporal artery (STA) blood flow volume, which was evaluated using ultrasonography. Forty-nine patients with MMD, who underwent direct bypass surgery, were included and stratified into TNE and non-TNE groups, respectively. The STA blood flow volume was evaluated at four time points (preoperatively and 2-4, 7, and 10-14 days postoperatively), and a change in volume during the postoperative period was defined as a flow volume mismatch. We investigated the association between ultrasonographic findings of flow volume mismatch and TNEs and magnetic resonance imaging findings, such as the cortical hyperintensity belt (CHB) sign, using univariate and path analyses. The STA blood flow volume increased immediately postoperatively, gradually decreasing over time, in both groups. The TNE group showed a significant increase in blood flow volume 2-4 days postoperatively (P = 0.042). Flow volume mismatch was significantly larger in the TNE group than in the non-TNE group (P = 0.020). In the path analysis, STA flow volume mismatch showed a positive association with the CHB sign (P = 0.023) and TNEs (P = 0.000). Additionally, the CHB sign partially mediated the association between STA flow volume mismatch and TNEs. These results suggest that significantly high STA blood flow volume changes occurring during the acute postoperative period after direct bypass surgery in MMD are correlated with TNEs and the CHB sign, suggesting involvement in the pathophysiology of TNEs.

Differences in invasiveness and recurrence rate among nonfunctioning pituitary neuroendocrine tumors depending on tumor subtype.

PURPOSE: To clarify the invasiveness to surrounding structures and recurrence rate of each subtype of nonfunctioning pituitary neuroendocrine tumor (Pit-NETs) according to the WHO 2022 classification. METHODS: This retrospective study utilized data from 292 patients with nonfunctioning Pit-NETs treated with initial transsphenoidal surgery. Recurrence was evaluated on 113 patients who were available for a magnetic resonance imaging follow-up ≥ 60 months. All tumors were assessed by immunohistochemical staining for Pit-1, T-PIT, and GATA3. Invasiveness to surrounding structures was evaluated based on intraoperative findings. RESULTS: Cavernous sinus invasion was found in 47.5% of null cell tumors, 50.0% of Pit-1 lineage tumors, 31.8% of corticotroph tumors, and 18.3% of gonadotroph tumors. Dura mater defects in the floor of sellar turcica, indicating dural invasion, were found in 44.3% of null cell tumors, 36.4% of corticotroph tumors, 16.7% of Pit-1 lineage tumors, and 17.3% of gonadotroph tumors. In logistic regression analysis, Pit-1 (OR 5.90, 95% CI 1.71-20.4, P = 0.0050) and null tumors (OR 4.14, 95% CI 1.86-9.23, P = 0.0005) were associated with cavernous sinus invasion. Recurrence was found in 8 (4.9%) patients, but without significant differences between tumor subtypes. The presence of cavernous sinus invasion was correlated with recurrence (HR = 1.95, 95% CI 1.10-3.46, P = 0.0227). CONCLUSION: Among nonfunctioning Pit-NETs, Pit-1 lineage tumors tend to invade the cavernous sinus, corticotroph tumors may produce dura mater defects, and null cell tumors tend to cause both. Pit-NETs with cavernous sinus invasion require a careful attention to recurrence.

Impact of immediate general anesthesia in the emergency room on prevention of rebleeding after subarachnoid hemorrhage.

BACKGROUND: Aneurysm rebleeding is fatal in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to investigate whether immediate general anesthesia (iGA) management in the emergency room, upon arrival, prevents rebleeding after admission and reduces mortality following aSAH. METHODS: The clinical data of 3033 patients with World Federation of Neurosurgical Societies (WFNS) grade 1, 2, or 3 aSAH from the Nagasaki SAH Registry Study between 2001 and 2018 were retrospectively analyzed. iGA was defined as sedation and analgesia using intravenous anesthetics and opioids combined with intubation induction. We calculated crude and adjusted odds ratios to evaluate the associations between iGA and the risk of rebleeding/death using multivariable logistic regression models with fully conditional specification for multiple imputations. In the analysis of the relationship between iGA and death, we excluded patients with aSAH who died within 3 days after the onset of symptoms. RESULTS: Of the 3033 patients with aSAH who met the eligibility criteria, 175 patients (5.8%) received iGA (mean age, 62.4 years; 49 were male). Heart disease, WFNS grade, and lack of iGA were independently associated with rebleeding in the multivariable analysis with multiple imputations. Among the 3033 patients, 15 were excluded due to death within 3 days after the onset of symptoms. After excluding these cases, our analysis revealed that age, diabetes mellitus, history of cerebrovascular disease, WFNS grade, Fisher grade, lack of iGA, rebleeding, postoperative rebleeding, no shunt operation, and symptomatic spasm were independently associated with mortality. CONCLUSIONS: Management by iGA was associated with a 0.28-fold decrease in the risks of both rebleeding and mortality in patients with aSAH, even after adjusting for the patient's history of diseases, comorbidities, and aSAH status. Thus, iGA can be a treatment for the prevention of rebleeding before aneurysmal obliteration treatment.

Pulsatility index of superficial temporal artery was associated with cerebral infarction after direct bypass surgery for moyamoya disease.

OBJECTIVE: Direct bypass surgery by superficial temporal artery (STA) - middle cerebral artery anastomosis is an established procedure for moyamoya disease (MMD). However, some patients may develop cerebral infarction (CI) due to the watershed shift phenomenon after the surgery. This study sought to investigate the correlation between the postoperative changes of STA flow as well as cerebral blood flow (CBF) and the incidence of CI after direct bypass surgery for MMD. METHODS: We conducted a retrospective study of 62 hemispheres in 50 subjects who underwent direct bypass surgery for MMD. All subjects underwent pre- and post-operative MR imaging, ultrasound evaluation of STA, and single-photon emission computed tomography. The presence of CI was correlated with preoperative CBF, the delta difference of each value of the STA between before and after the surgery, and the postoperative increase ratio of CBF. RESULTS: All bypass procedures were patent, and CI was observed in 4 cases (6.4%). There was no significant association between the incidence of CI and both pre- and post-operative CBF. However, there was a significant difference in delta pulsatility index (PI) of the STA between cases with or without CI (-0.38±0.22 and -0.87±0.63, respectively, p=0.03). Whereas, other factors did not show any significant differences between those with or without CI. CONCLUSIONS: A relatively high postoperative PI of the STA was significantly associated with the incidence of CI after direct bypass surgery for MMD. A larger study is needed to confirm these findings.

Characteristics and therapeutic strategies of radiation-induced glioma: case series and comprehensive literature review.

INTRODUCTION: The so-called radiation-induced glioma (RIG, a secondary glioma after cranial irradiation), is a serious late effect after cranial radiation therapy. The clinical characteristics of and ideal treatment for these tumors are unclear. We analyzed our case series and conducted a comprehensive literature review to reveal the precise characteristics of RIGs. METHODS: We analyzed the cases of six patients with RIGs treated at our institution and 354 patients with RIGs from the literature. The latency period from irradiation to the development of each RIG and the median overall survival of the patients were subjected to Kaplan-Meier analyses. Spearman's correlation test was used to determine the relationship between age at irradiation and the latency period. RESULTS: The mean age of the 360 patients at the development of RIG was 27.42 ± 17.87 years. The mean latency period was 11.35 ± 8.58 years. Multiple gliomas were observed in 28.4%. WHO grade 3 and 4 RIGs accounted for 93.3%. The latency periods were significant shorter in the higher WHO grade group (p = 0.0366) and the concomitant systemic chemotherapy group (p < 0.0001). Age at irradiation was negatively associated with the latency period (r =- 0.2287, p = 0.0219). The patients treated with radiotherapy achieved significantly longer survival compared to those treated without radiotherapy (p = 0.0011). CONCLUSIONS: Development in younger age, multiplicity, and high incidence of grade 3 and 4 are the clinical characteristics of RIGs. Cranial irradiation at older ages and concomitant chemotherapy were associated with shorter latency for the development of RIG. Radiation therapy may be the feasible treatment option despite radiation-induced gliomas.