Maximal Resection of Gliomas Adjacent to the Corticospinal Tract Using 3-T Intraoperative Magnetic Resonance Imaging.

BACKGROUND: Gliomas adjacent to the corticospinal tract (CST) should be carefully resected to preserve motor function while achieving maximal surgical resection. Modern high-field intraoperative magnetic resonance imaging (iMRI) enables precise visualization of the residual tumor and intraoperative tractography. We prospectively evaluated the extent of resection and distance between the tumor resection cavity and CST using 3-T iMRI combined with motor evoked potentials (MEP) in glioma surgery. METHODS: Participants comprised patients who underwent surgery for solitary supratentorial glioma located within 10 mm of the CST. All cases underwent surgery using neuronavigation with overlaid CST under MEP monitoring. The correlation between distance from CST and transcortical MEP amplitude was calculated using Spearman rank correlation. RESULTS: Among the 63 patients who underwent surgery, 27 patients were enrolled in the study. Gross total resections were achieved in 26 of the 27 cases. Volumetric analysis showed the extent of resection was 98.6%. Motor function was stable or improved in 24 patients (Stable/Improved group) and deteriorated in 3 patients (Deteriorated group). All patients in the Deteriorated group showed motor deficit before surgery. Mean intraoperative minimal distance was significantly longer in the Stable/Improved group (7.3 mm) than in the Deteriorated group (1.1 mm; P < 0.05). MEP amplitude correlated with minimal distance between the resection cavity and CST (R = 0.64). CONCLUSIONS: Resection of gliomas adjacent to CST with a navigation system using 3-T iMRI could result in an ultimate EOR >98%. The combination of intraoperative tractography and MEP contributes to maximal removal of motor-eloquent gliomas.

Soluble C-type lectin-like receptor 2 in stroke (CLECSTRO) study: protocol of a multicentre, prospective cohort of a novel platelet activation marker in acute ischaemic stroke and transient ischaemic attack.

INTRODUCTION: Soluble C-type lectin-like receptor 2 (sCLEC-2) is a new biomarker for platelet activation, which can be easily measured by usual blood collection. We conducted the CLECSTRO, a prospective, observational cohort study, to evaluate the clinical implications of sCLEC-2 in patients with acute ischaemic stroke (AIS) and transient ischaemic attack (TIA). METHODS AND ANALYSIS: The participants are patients with AIS/TIA and control patients required for differentiation from AIS/TIA. The target population is 600, including the patients and controls, who would be recruited from eight stroke centres across Japan. The inclusion criteria are AIS within 24 hours of onset and a modified Rankin Scale (mRS) score of 0-2, TIA within 7 days of onset, and contemporary patients required for differentiation from AIS/TIA. Plasma sCLEC-2 will be measured by high-sensitive chemiluminescent enzyme immunoassay using residual blood samples from routine laboratory examinations at the first visit in all patients and 7 days later or at discharge in patients with AIS/TIA. The outcomes include plasma levels of sCLEC-2 in patients with AIS/TIA and controls, sCLEC-2/D-dimer ratio in non-cardioembolic and cardioembolic AIS/TIA, correlation of sCLEC-2 with recurrence or worsening of stroke, severity of stroke, infarct size, ABCD2 score in TIA and outcome (mRS) at 7 days and 3 months. ETHICS AND DISSEMINATION: This study was approved by the Ethical Committee of the University of Yamanashi as the central ethical committee in agreement with the ethical committees of all collaborative stroke centres. Informed consent will be obtained by an opt-out form from the patients at each stroke centre according to the Ethical Guidelines for Medical and Biological Research Involving Human Subjects by the Japanese Ministry of Health, Labour and Welfare. TRIAL REGISTRATION NUMBERS: NCT05579405, UMIN000048954.

Chronological Change of the Clinical Features and Treatment Outcomes for Subarachnoid Hemorrhage in Japan: A Multicenter Retrospective Study.

Aneurysmal subarachnoid hemorrhage (SAH) treatment has progressed, and patients are rapidly aging in Japan. Consequently, dynamic changes must have emerged in the clinical practice of SAH. This study aimed to elucidate chronological changes of aneurysmal SAH and the prognostic factors in the previous quarter century in Japan. We conducted a retrospective survey regarding aneurysmal SAH in eight institutions in Japan. The study included 848, 863, and 781 patients in the first (1989-1993), second (1999-2003), and third (2009-2013) periods, respectively. The chronological changes of factors that influenced the poor outcomes and differences between the nonelderly (<75 years) and elderly patients were investigated. Mean age was significantly higher in patients in the third period (61.4 years) than in those in the other two periods (first, 57.8 years; second, 59.5 years). During these periods, the proportion of good outcomes did not change; however, the mortality rate significantly decreased from 19% in the first period to 11% and 9.2% in the second and third periods, respectively. The poor outcome was mainly caused by the significantly higher incidence of systemic complication and procedural complication in the first period and the significantly lower incidence of delayed ischemic neurological deficit in the third period. The elderly patients had significantly poorer clinical outcomes than the nonelderly ones. During the last 25 years, the age of patients with aneurysmal SAH has rapidly increased. The study results may contribute to the improvement of the treatment strategy of SAH in advanced countries with a rapidly aging population.

A Novel Staged Revascularization Strategy for Bilateral Severe Internal Carotid Artery Stenosis at High Risk for Hyperperfusion Syndrome.

OBJECTIVE: Since bilateral severe internal carotid artery stenosis often is associated with severely decreased cerebrovascular reactivity (CVR) due to poor collateral blood flow, revascularization carries a high risk for development of hyperperfusion syndrome. In this study, we report a new staged strategy to prevent postoperative hyperperfusion syndrome in such patients. METHODS: Bilateral severe cervical internal carotid artery stenosis patients with decreased CVR to 10% or less on one side were prospectively enrolled in this study. We first performed carotid artery stenting on the side with the milder CVR decrease (lower-risk side), aiming to improve hemodynamics associated with the severe CVR decrease on the greater-risk side. Then, carotid endarterectomy or carotid artery stenting was performed on the contralateral side after an interval of 4-8 weeks. RESULTS: In all 3 cases enrolled in this study, CVR on the greater-risk side improved to 10% or more 1 month after the first treatment. The ratio of regional cerebral blood flow on the contralateral greater-risk side was 114% 1 day after the second treatment, and HPS did not develop in any of the cases. CONCLUSIONS: Our treatment strategy, in which revascularization on the lower-risk side precedes that on the greater-risk side, is effective for the prevention of HPS in bilateral ICA stenosis patients.

Hemorrhagic cervical juxta-facet cyst presenting with Brown-Séquard syndrome: illustrative case.

BACKGROUND: Intraspinal juxta-facet cysts of the spine are known to predominate at the lumbar level and is relatively rare at the cervical level. Most cervical spinal lesions are found incidentally, but they sometimes cause myelopathy or radiculopathy in a chronic course. OBSERVATIONS: The authors present a rare case of hemorrhagic cervical juxta-facet cyst presenting with Brown-Séquard syndrome. An 86-year-old woman presented with acute-onset right hemiparesis following neck pain and was admitted to the local hospital. She was started on antithrombotic therapy with a suspected diagnosis of cerebral infarction, but quadriplegia progressed 2 days later. Cervical magnetic resonance imaging revealed an intraspinal mass at the C4-5 level and she was referred to the authors' hospital. Her neurological findings on admission revealed right Brown-Séquard syndrome. In emergency surgery, the mass was resected with a posterior approach. Pathological findings showed hemosiderin deposition and fibroblast proliferation, consistent with a juxta-facet cyst with intracystic hemorrhage. The patient recovered well and returned to an independent daily life. LESSONS: Rarely, juxta-facet cyst of the cervical spine can cause acute Brown-Séquard syndrome due to intraspinal hemorrhage. In a case of hemiparesis that develops following neck pain, hemorrhagic cervical juxta-facet cyst should be taken into consideration as a differentiation.

Analysis of vascular perfusion territory using selective intraarterial injection CT angiography before and after revascularization surgery in patients with moyamoya disease.

OBJECTIVE: In moyamoya disease (MMD), blood flow to the internal carotid artery (ICA) system is supplied via the basal fine vascular network, leptomeningeal anastomoses, and transdural collateral vessels from the external carotid artery (ECA). After revascularization, there is a dramatic change in cerebral perfusion to the ECA system. Understanding this shift in blood supply is important for evaluating treatment efficacy and elucidating the postoperative pathophysiology. However, anatomical and quantitative methods for doing so have not yet been established. In the present study, selective intraarterial injection CT angiography (iaCTA) was performed in patients with MMD, and blood supply changes in each arterial system before and after revascularization surgery were evaluated. METHODS: This study included 10 hemispheres in 10 patients who underwent combined revascularization surgery for adult MMD. Digital subtraction angiography was performed before and 3 months after surgery, and selective iaCTA was performed from the ICA, ECA, and vertebral artery (VA) at the same times in a hybrid CT/digital subtraction angiography suite. The anatomical distribution of each vessel was determined and perfusion volume was measured quantitatively on contrast-enhanced axial CT images. RESULTS: Selective iaCTA clearly depicted the anatomical distribution of perfusion for each vessel. Conversion of blood supply from the ICA and VA to the ECA system was observed in the cerebral cortices and insulae but not in the basal ganglia. The mean volume of perfusion territories of the ECA (preoperative 0.9 cm3, postoperative 98.8 cm3); ICA (preoperative 225.7 cm3, postoperative 159.3 cm3); and VA (preoperative 244.0 cm3, postoperative 163.6 cm3) in the cerebral hemispheres changed significantly after revascularization. There was a correlation between increase in the ECA territory volume and decrease in the VA territory volume due to revascularization (R = -0.84, p < 0.005). CONCLUSIONS: Selective iaCTA enabled clear visualization of anatomical changes in each vascular perfusion territory and quantitative measurement of each perfusion volume. Perfusion conversion to the ECA system after bypass surgery was observed in the cortical regions and in the insulae on the bypass operation sides, but not in the basal ganglia. Combined revascularization promoted the development of ECA-perfused territory, which correlated with a decrease in hemodynamic burden of the posterior cerebral artery.

Blood Blister-Like Aneurysms at the Junction of the Internal Carotid and Posterior Communicating Artery: Characteristics and Treatment Strategies.

BACKGROUND: Blood blister-like aneurysms (BBAs) usually arise from the anterior walls of the internal carotid artery, and such lesions at the junction of the internal carotid artery and posterior communicating artery (PCoA) have not been reported to date. Here, we report our experiences of BBAs at PCoA. We studied their clinical and angiographical characteristics including the internal carotid-PCoA angle, an indicator of hemodynamic stress at the bifurcation. METHODS: Three patients with BBAs located at the origin of PCoA were studied. Wrap-clipping was adopted as the first-line therapy, but direct clipping was conducted when difficult. RESULTS: All patients were elderly females (mean age 81.3 years), and BBAs were small in size (mean maximum diameter 1.5 mm), which arose at the origins of wide-angled fetal-type PCoAs (mean internal carotid-PCoA angle 37.8 degrees). All the lesions were treated by surgery (direct clipping 2, wrap-clipping 1), and severe atherosclerotic changes were observed at adjacent arterial walls in all cases. Ordinary wrap-clipping using a polytetrafluoroethylene membrane via the transsylvian approach was difficult because of the limited working space, requiring some special techniques such as usage of fenestrated clips, polyglycolic acid sheets, and combined approach with subtemporal craniotomy. Good clinical outcomes were achieved in 2 patients. CONCLUSION: BBAs at PCoA were predominantly occurred as the small bulges at the origins of wide-angled fetal-type PCoAs in elderly females. Hemodynamic stress and atherosclerosis would contribute to the aneurysmal formation. Wrap-clipping or direct clipping with additional techniques would be useful for this rare condition.

Neuronal dysfunction and hemodynamic disturbance due to venous congestion in dural arteriovenous fistula revealed by 123I-iomazenil SPECT.

OBJECTIVE: Retrograde leptomeningeal venous drainage (RLVD) of a dural arteriovenous fistula (dAVF) is associated with neurological morbidity and unfavorable outcomes. However, the direct damage to cortical neurons by dAVF with RLVD has not been elucidated. 123I-iomazenil (123I-IMZ) SPECT can reveal cerebral blood flow and cortical neuronal damage in early and late images, respectively. This study aimed to assess the cerebral venous congestive encephalopathy caused by dAVF using 123I-IMZ SPECT. METHODS: Based on the pre- and posttreatment MRI findings, patients were divided into three groups: a normal group, an edema group, and an infarction group. Radioactive counts in the early and late images of 123I-IMZ SPECT were investigated using the affected-to-contralateral side asymmetry ratio (ACR). RESULTS: None of the patients in the normal group showed any symptoms related to venous congestion. In contrast, all the patients in the edema and infarction groups developed neurological symptoms. The ACR in early images in the edema group was significantly lower than that in the normal group and significantly higher than that in the infarction group. The ACR in the late images of the infarction group was significantly lower than those of the normal and edema groups. After treatment, the neurological signs disappeared in the edema group, but only partial improvement was observed in the infarction group. The ACR in early images significantly improved after treatment in the edema group, but the ACR in late images did not change in any groups. CONCLUSIONS: 123I-IMZ SPECT is useful for evaluating hemodynamic disturbances and neuronal damage in dAVFs. The reduction in early images was correlated with the severity of venous congestive encephalopathy, and the significant reduction in late images is a reliable indicator of irreversible venous infarction caused by RLVD.

Recurring cervical internal carotid artery vasospasm elicited by head rotation: illustrative case.

BACKGROUND: Idiopathic extracranial internal carotid artery vasospasm (IEICAV) is a rare cerebrovascular disorder causing transient or permanent cerebral ischemia. The pathophysiology underlying this disorder is not well understood. Although various medical treatments have been tried, complete remission of vasospasm is difficult to achieve. The first case of bilateral IEICAV induced by head rotation, which was successfully treated by carotid artery stenting (CAS), was presented. OBSERVATIONS: A 40-year-old woman with bilateral IEICAV had been conservatively treated for 13 years. However, transient ischemic attacks (TIAs) were not suppressed. She eventually presented with a large brain infarction in the left hemisphere and was referred to our department. Digital subtraction angiography clearly demonstrated the triggering of internal carotid artery (ICA) vasospasm by head rotation. After CAS treatment, the TIAs disappeared completely. LESSONS: Clinicians should recognize that ordinary mechanical stimulation to the ICA by head rotation can induce vasospasm, and CAS should be performed for refractory IEICAV at the appropriate time to avoid cerebral infarction causing severe neurological deficits.

Nonconvulsive status epilepticus due to pneumocephalus after suprasellar arachnoid cyst fenestration with transsphenoidal surgery: illustrative case.

BACKGROUND: Nonconvulsive status epilepticus (NCSE) requires prompt diagnosis and treatment, particularly after neurosurgical procedures for cerebral damage. Here, the authors reported an extremely rare case of suprasellar arachnoid cyst presenting with NCSE after cyst fenestration with transsphenoidal surgery, which was associated with pneumocephalus. OBSERVATIONS: A 61-year-old man presented with visual impairment and was diagnosed with a suprasellar arachnoid cyst on magnetic resonance imaging (MRI). The patient received cyst fenestration with endonasal transsphenoidal surgery. His visual symptoms improved immediately after the operation; however, on postoperative day 3, semicoma appeared and was prolonged. The patient was diagnosed with NCSE due to pneumocephalus based on MRI and electroencephalography (EEG) findings. The administration of antiepileptic drugs (AEDs) improved his clinical symptoms and the abnormal findings on MRI and EEG. LESSONS: This is the first case of NCSE with pneumocephalus after transsphenoidal surgery for a suprasellar arachnoid cyst. Pneumocephalus due to cerebrospinal fluid leakage can cause NCSE. Arterial spin labeling perfusion imaging and diffusion-weighted imaging are as useful for differentially diagnosing NCSE as EEG and AED tests.

Spinal glomus AVM presenting solely with groin pain: illustrative case.

BACKGROUND: Spinal glomus arteriovenous malformations (AVMs) are rare and can cause neurological morbidity due to spinal hemorrhage, venous hypertension, or mass effect. OBSERVATIONS: The authors presented a rare case of spinal glomus AVM presenting with groin pain due to nerve root compression by a feeder aneurysm. A 41-year-old woman was referred to the hospital with initial right groin pain that had worsened over 2 months. Magnetic resonance imaging showed intra- and extramedullary abnormal flow voids at the T11-12 level, and spinal angiography revealed an intramedullary AVM, with extramedullary protrusion of an aneurysm on the feeder vessel, which arose from the sulcal artery of the anterior spinal artery. Because compression of the right L1 nerve root by the aneurysm was the likely cause of the patient's pain, endovascular embolization was performed. The feeder aneurysm disappeared after partial n-butyl 2-cyanoacrylate embolization, and the groin pain disappeared immediately after treatment. Her clinical status has been stable with no recurrence during 1 year of follow-up. LESSONS: This is the first report of glomus-type AVM presenting with radiculopathy alone. One should not overlook the possibility of spinal AVM among patients with groin pain.

P2X7 Receptors in Astrocytes: A Switch for Ischemic Tolerance.

A sub-lethal ischemic episode (preconditioning [PC]) protects neurons against a subsequent lethal ischemic injury. This phenomenon is known as ischemic tolerance. PC itself does not cause brain damage, but affects glial responses, especially astrocytes, and transforms them into an ischemia-resistant phenotype. P2X7 receptors (P2X7Rs) in astrocytes play essential roles in PC. Although P2X7Rs trigger inflammatory and toxic responses, PC-induced P2X7Rs in astrocytes function as a switch to protect the brain against ischemia. In this review, we focus on P2X7Rs and summarize recent developments on how astrocytes control P2X7Rs and what molecular mechanisms they use to induce ischemic tolerance.

Japan Stroke Society Guideline 2021 for the Treatment of Stroke.

The revised Japan Stroke Society Guidelines for the Treatment of Stroke were published in Japanese in July 2021. In this article, the extracted recommendation statements are published. The revision keeps pace with the great progress in stroke control based on the recently enacted Basic Act on Stroke and Cardiovascular Disease in Japan. The guideline covers the following areas: primary prevention, general acute management of stroke, ischemic stroke and transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, asymptomatic cerebrovascular disease, other cerebrovascular disease, and rehabilitation.

The Japan Neurosurgical Database: Statistics Update 2018 and 2019.

Each year, the Japan Neurosurgical Society (JNS) reports up-to-date statistics from the Japan Neurosurgical Database regarding case volume, patient demographics, and in-hospital outcomes of the overall cohort and neurosurgical subgroup according to the major classifications of main diagnosis. We hereby report patient demographics, in-hospital mortality, length of hospital stay, purpose of admission, number of medical management, direct surgery, endovascular treatment, and radiosurgery of the patients based on the major classifications and/or main diagnosis registered in 2018 and 2019 in the overall cohort (523283 and 571143 patients, respectively) and neurosurgical subgroup (177184 and 191595 patients, respectively). The patient demographics, disease severity, proportion of purpose of admission (e.g., operation, 33.9-33.5%) and emergent admission (68.4-67.8%), and in-hospital mortality (e.g., cerebrovascular diseases, 6.3-6.5%; brain tumor, 3.1-3%; and neurotrauma, 4.3%) in the overall cohort were comparable between 2018 and 2019. In total, 207783 and 225217 neurosurgical procedures were performed in the neurosurgical subgroup in 2018 and 2019, respectively, of which endovascular treatment comprised 19.1% and 20.3%, respectively. Neurosurgical management of chronic subdural hematoma (19.4-18.9%) and cerebral aneurysm (15.4-14.8%) was most common. Notably, the proportion of management of ischemic stroke/transient ischemic attack, including recombinant tissue plasminogen activator infusion and endovascular acute reperfusion therapy, increased from 7.5% in 2018 to 8.8% in 2019. The JNS statistical update represents a critical resource for the lay public, policy makers, media professionals, neurosurgeons, healthcare administrators, researchers, health advocates, and others seeking the best available data on neurosurgical practice.

[A patient with recurrent multiloculated hydrocephalus after Cryptococcal ventriculitis].

We report here a rare case of adult-onset multiloculated hydrocephalus (MLH) after Cryptococcal meningitis. A 63-year-old man had Cryptococcal ventriculitis in 2011, and he recovered with treatment of antimycotic drugs. However, he was admitted again because of disorientation and amnesia, and brain MRI showed dilation of the inferior horn of the left lateral ventricle. He underwent a ventriculoperitoneal shunt (VPS) for noncommunicating hydrocephalus in 2019, and the disorientation and amnesia improved. One year after the VPS, he was admitted because of urinary dysfunction and gait disturbance. Brain MRI showed dilation of the bilateral anterior horns of the lateral ventricles. He underwent an additional VPS into the space in 2020, and urinary dysfunction and gait disturbance improved. This case was supposed that the symptom in agreement with the dilated ventricle by MLH was shown.

Small Unruptured Aneurysm Verification-prevention Effect against Growth of Cerebral Aneurysm Study Using Statin.

Several basic experimental studies have demonstrated that statins have beneficial effects for intracranial aneurysm (IA). Clinical studies on unruptured IAs, however, remain limited to four retrospective studies that have reached different conclusions. This study was the first open-label, multicenter, randomized controlled trial to assess the preventive effects of atorvastatin. Patients with unruptured small saccular IAs were randomly assigned to statin and control groups. The primary endpoint was a composite of aneurysm growth of ≥0.5 mm, new bleb formation confirmed from magnetic resonance (MR) angiography, and rupture. Enrollment was prematurely terminated due to unexpectedly slow enrollment. Of 231 patients (275 target IAs), 110 patients (128 IAs) were randomly assigned to the statin group and 121 patients (147 IAs) to the control group. After excluding 22 dropout patients, 107 IAs in the 93 statin group patients and 140 IAs in the 116 control group patients were finally analyzed. No significant differences of basic characteristics were evident between groups, except for significantly higher systolic pressure in the statin group (P = 0.03). The primary endpoint occurred in 28 IAs (20.0%) in the control group and in 17 IAs (15.9%) in the statin group. No aneurysm rupture was confirmed in either group. Significant beneficial effects of statin for IAs were not demonstrated for the primary endpoint (log-rank P = 0.359). This randomized trial did not establish any preventive effects of atorvastatin for unruptured small IAs. Further studies of larger cohorts are required to clarify the efficacy of statins for patients with unruptured IAs. Clinical trial registration: UMIN000005135.

Neuroprotective roles of HAX-1 in ischemic neuronal injury.

Hematopoietic cell-specific protein 1 associated protein X-1 (HAX-1) is a novel mitochondrial protein that regulates oxidative stress-induced apoptosis. However, the roles of HAX-1 in ischemic neuronal injury have not been thoroughly elucidated. In this study, the expression and roles of HAX-1 after ischemic stress were investigated using in vivo and in vitro models. The effect of oxidative stress on the regulation of HAX-1 was examined using knockout mice lacking nicotinamide-adenine dinucleotide phosphate oxidase 2 (NOX2), which is a major source of reactive oxygen species (ROS) after cerebral ischemia. Male C57BL/6 J mice were subjected to transient forebrain ischemia induced by 22-min occlusion of the bilateral common carotid arteries, and striatum samples were analyzed. For in vitro ischemic experiments, oxygen and glucose deprivation (OGD) in a rat pheochromocytoma cell line was utilized. Western blotting and immunofluorescence analysis revealed HAX-1 expression in neuronal mitochondria, which was significantly decreased after ischemia in vivo and in vitro. In NOX2 knockout mice, ischemia-induced decrease in HAX-1 expression and ischemic neuronal injury was significantly alleviated compared to those in wild-type mice. Inhibition of HAX-1 using small interfering RNA significantly increased injury in cultured cells after OGD. These findings suggest that HAX-1 has a neuroprotective effect against ischemic neuronal injury, and downregulation of HAX-1 by NOX2-produced ROS induces apoptosis after cerebral ischemia.

A Study of the Patient Acceptance Capacity of the Yamanashi Prefecture Medical System amid the Coronavirus Disease 2019 Pandemic.

INTRODUCTION: Whether healthcare providers can secure the number of beds that may be required during the coronavirus disease 2019 (COVID-19) pandemic remains unclear. This study aimed to determine the sufficiency of the hospital beds available to the healthcare system of Yamanashi, Japan, in accommodating hospitalized and severely ill patients during the COVID-19 pandemic. METHODS: In total, 60 hospitals, with > 20 beds each, were included in this study (n = 10,684). However, beds in the psychiatric and tuberculosis wards (n = 2,295), nonoperational beds (n = 376), and beds for patients in the recovery and chronic phases (n = 3,494) were excluded. The projected occupancy rate was calculated based on the estimated number of patients, including severely ill patients requiring hospitalization during the COVID-19 pandemic. Based on the number of hospitalized patients, we created an adjusted model to calculate the mean occupancy rate of beds for each medical area in the prefecture (Model 1), which is free of areal occupancy rate biases. Moreover, we created an adjusted model that places severely ill patients in the two advanced acute hospitals in Yamanashi, thereby calculating the bed occupancy rates in other hospitals with > 200 beds (Model 2). RESULTS: A total of 4,519 beds were analyzed. Although the existing infectious disease beds may not be able to accommodate the projected number of severely ill patients, the existing capacity can accommodate all patients projected to require hospitalization during the pandemic. In Model 1, the mean bed occupancy rate was 50%. Conversely, in Model 2, advanced acute hospital beds were insufficient for the projected number of severely ill patients, and the mean bed occupancy rate was 72.5%. CONCLUSIONS: Adjustment of patients across the medical area borders enables the existing hospital beds to accommodate the estimated number of patients requiring hospitalization or those who are severely ill.

An Adult Case of Sellar Atypical Teratoid/Rhabdoid Tumor Presenting with Lung Metastasis, Harboring a Compound Heterozygous Mutation in INI1.

A typical teratoid/rhabdoid tumors (AT/RT) are highly malignant embryonal tumors in children that are associated with inactivation of the integrase interactor 1 (INI1) gene. Several adult cases of AT/RT have been reported, which were characterized by the sellar occurrence and predominantly occurred in females with INI1 mutation variants. However, clinical and genetic features are poorly understood in this unusual entity. We experienced a case of a 45-year-old female with sellar AT/RT presenting diplopia, who underwent subtotal removal of the tumor by the endoscopic endonasal transsphenoidal approach. Pathological diagnosis was AT/RT with INI1 inactivation on immunohistochemistry. Subsequently, multiple lung metastases were confirmed on fluorodeoxyglucose positron emission tomography (FDG-PET). Although she received postoperative chemoradiotherapy, she died of cerebrospinal fluid dissemination. Autopsy revealed cerebrospinal dissemination and lung metastasis of AT/RT. Biallelic alterations in the INI1 gene were identified by direct sequencing, harboring on different alleles (compound heterozygous mutations) was observed, which is the potential genetic pattern in adult AT/RT. Literature review indicated that lung metastasis frequently occurs in sellar AT/RTs, which is accompanied by cavernous sinus invasion. These observations suggested that cavernous sinus invasion causes haematogenous metastasis to the lung in sellar AT/RT. We discuss clinical and pathological features in adult sellar AT/RT to improve understanding of this unique entity.

Primary Spinal Intradural Extramedullary Mesenchymal Chondrosarcoma.

BACKGROUND: Among chondrosarcomas arising from bones and soft tissues, mesenchymal chondrosarcoma (MCS), especially primary spinal intradural extramedullary MCS, is extremely rare, and only 18 cases have been reported to date. We report an adult case of this rare condition mimicking meningioma. CASE DESCRIPTION: A 42-year-old woman presented with paraplegia and sensory disturbance associated with right-sided Brown-Séquard syndrome following back pain. Magnetic resonance imaging showed an intradural mass in the right dorsal spinal canal with homogeneous enhancement and dural tail sign at the T8 level. Computed tomography demonstrated a calcified portion in the mass. Following T7-8 laminectomies, an intradural extramedullary tumor was completely removed after detaching the tumor from the dura mater. The histopathologic diagnosis was MCS, and positron emission tomography showed no metastatic lesions at other sites. The patient did not receive adjuvant therapy, and magnetic resonance imaging revealed no evidence of recurrence during 2-year follow-up. CONCLUSIONS: Primary spinal intradural extramedullary MCS has been reported to have a better prognosis than MCS occurring in other regions. In a case with early complete surgical resection, adjuvant therapy should be considered at the time of recurrence.