Application of intraoperative ultrasound in the resection of high-grade gliomas.

The incidence of gliomas is approximately 3-5/100,000, with high-grade gliomas accounting for approximately 30-40% of these tumors. Surgery is a confirmed positive factor in prolonging the survival of these patients, and a larger resection range means a longer survival time. Therefore, surgery for high-grade glioma patients should aim to maximize the extent of resection while preserving neurological function to achieve a better quality of life. There is consensus regarding the need to lengthen progression-free survival (PFS) and overall survival (OS) times. In glioma surgery, methods such as intraoperative computed tomography (ICT), intraoperative magnetic resonance imaging (IMRI), navigation, 5-aminolevulinic acid (5-ALA), and intraoperative ultrasound (IOUS) are used to achieve an expanded resection during the surgical procedure. IOUS has been increasingly used in the surgery of high-grade gliomas and various tumors due to its convenient intraoperative use, its flexible repeatability, and the relatively low cost of operating room construction. With the continuous upgrading of ultrasound equipment, IOUS has been able to better assist surgeons in achieving an increased extent of resection. This review aims to summarize the application of ultrasound in the surgery of high-grade gliomas in the past decade, its improvement in patient prognosis, and its prospects.

A Condition Evaluation Simplified Method for Traction Converter Power Module Based on Operating Interval Segmentation.

In the actual operation of urban rail vehicles, it is essential to evaluate the condition of the traction converter IGBT modules. Considering the fixed line and the similarity of operation conditions between adjacent stations, this paper proposes an efficient and accurate simplified simulation method to evaluate IGBT conditions based on operating interval segmentation (OIS). Firstly, this paper proposes the framework for a condition evaluation method by segmenting operating intervals based on the similarity of average power loss between neighboring stations. The framework makes it possible to reduce the number of simulations to shorten the simulation time while ensuring the state trend estimation accuracy. Secondly, this paper proposes a basic interval segmentation model that uses the operating conditions as inputs to implement the segmentation of the line and is able to simplify the operation conditions of entire line. Finally, the simulation and analysis of the temperature and stress fields of IGBT modules based on segmented intervals completes the IGBT module condition evaluation and realizes the combination of lifetime calculation with actual operating conditions and internal stresses. The validity of the method is verified by comparing the interval segmentation simulation with actual test results. The results show that the method can effectively characterize the temperature and stress trends of traction converter IGBT modules in the whole line, which could support the fatigue mechanism and lifetime assessment reliability study of IGBT modules.

Study on the relationship between obesity and complications of Pediatric Epilepsy surgery.

OBJECTIVE: Studies have shown that obesity has a significant impact on poor surgical outcomes. However, the relationship between obesity and pediatric epilepsy surgery has not been reported. This study aimed to explore the relationship between obesity and complications of pediatric epilepsy surgery and the effect of obesity on the outcome of pediatric epilepsy surgery, and to provide a reference for weight management of children with epilepsy. METHODS: A single-center retrospective analysis of complications in children undergoing epilepsy surgery was conducted. Body mass index (BMI) percentiles were adjusted by age and used as a criterion for assessing obesity in children. According to the adjusted BMI value, the children were divided into the obese group (n = 16) and nonobese group (n = 20). The intraoperative blood loss, operation time, and postoperative fever were compared between the two groups. RESULTS: A total of 36 children were included in the study, including 20 girls and 16 boys. The mean age of the children was 8.0 years old, ranging from 0.8 to 16.9 years old. The mean BMI was 18.1 kg/m2, ranging from 12.4 kg/m2 to 28.3 kg/m2. Sixteen of them were overweight or obese (44.4%). Obesity was associated with higher intraoperative blood loss in children with epilepsy (p = 0.04), and there was no correlation between obesity and operation time (p = 0.21). Obese children had a greater risk of postoperative fever (56.3%) than nonobese children (55.0%), but this was statistically nonsignificant (p = 0.61). The long-term follow-up outcomes showed that 23 patients (63.9%) were seizure-free (Engel grade I), 6 patients (16.7%) had Engel grade II, and 7 patients (19.4%) had Engel grade III. There was no difference in long-term seizure control outcomes between obese and nonobese groups (p = 0.682). There were no permanent neurological complications after surgery. CONCLUSION: Compared with nonobese children with epilepsy, obese children with epilepsy had a higher intraoperative blood loss. It is necessary to conduct early weight management of children with epilepsy as long as possible.

Case report and literature review: Treatment of multiple meningiomas combined with multiple unruptured aneurysms in a single operation.

Background: Although the incidence of a single meningioma or a single aneurysm is common, cases of multiple meningiomas combined with multiple aneurysms are rarely reported, and surgical treatment of the coexisting situation is also relatively uncommon. Case presentation: A 38-year-old male patient presented to the neurosurgery department of our center with a headache. Examination revealed only symptoms of headache. Laboratory tests showed only decreased total protein and albumin. Magnetic resonance imaging showed preoccupation with the frontal lobe and the right temple bone. Magnetic resonance angiography and digital subtraction angiography showed two aneurysms in the anterior communicating artery and right anterior cerebral artery. Based on a combination of the patient's history and imaging, we hypothesized that the patient was simultaneously suffering from meningioma and an aneurysm, and both of them are multiple. The patient underwent tumor resection and clipping procedure based on this hypothesis in one surgery. Intraoperative biopsy proved to be a meningioma. The patient was discharged on the 10th postoperative day, and a postoperative follow-up suggested no complications. Conclusion: Multiple meningiomas combined with multiple aneurysms are rare to be reported in the same patient. For those unruptured intracranial aneurysms (UIAs) located in the visual field of craniotomy prepared for brain tumorlike meningioma, it is possible to do the clipping as well. When the meningiomas are multiple, fitted with the surgical indication, and located in a position that cannot be treated in one surgery, this may lead to a two-stage operation, no matter where the UIAs are located.

Preconditioning with Trehalose Protects the Bone Marrow-Derived Mesenchymal Stem Cells Under Oxidative Stress and Enhances the Stem Cell-Based Therapy for Cerebral Ischemic Stroke.

Bone marrow-derived mesenchymal stem cell (BMSC) transplantation has emerged as a potential treatment for ischemic stroke. Preconditioning with pharmacological agents before cell transplantation has been shown to increase the efficiency of cell therapy. In this study, trehalose (Tre), an autophagy inducer, was used as a pharmacological agent to treat BMSCs, and the neuroprotective effect of BMSCs preconditioned with Tre on cerebral ischemia was assessed. BMSCs were treated in vitro with different concentrations of Tre. Immunofluorescence staining of LC3B was performed to detect autophagy, and Western blotting for LC3, Beclin1, p-AMPK, and p-mTOR was performed. Flow cytometry and Western blotting analysis were performed to measure cell apoptosis in the presence of hydrogen peroxide (H2O2). Enzyme-linked immunosorbent assay was used to test the secretion levels of neurotrophic factors. An in vivo ischemia/reperfusion model was generated by middle cerebral artery occlusion in male Sprague Dawley rats, and Tre-preconditioned BMSCs were administered intralesionally 24 hours after ischemic injury. Histopathological examination and neurological function studies were conducted. In vitro, Tre promotes autophagy of BMSCs through the activation of the AMPK signal pathway. Tre protected BMSCs from H2O2-induced cell viability reduction and apoptosis. Moreover, Tre pretreatment increased the secretion of brain-derived neurotrophic factor, vascular endothelial growth factor, and hepatocyte growth factor. In vivo, preconditioning with Tre could further enhance the survival of BMSCs, reduce infarct size, alleviate cell apoptosis, abate vessel decrease, and ultimately improve functional recovery. Our study indicates that Tre can enhance the survival of BMSCs under oxidative stress and enhance BMSC-based treatment of ischemia/reperfusion injury.

Distinct Effects of Ca2+ Sparks on Cerebral Artery and Airway Smooth Muscle Cell Tone in Mice and Humans.

The effects of Ca2+ sparks on cerebral artery smooth muscle cells (CASMCs) and airway smooth muscle cells (ASMCs) tone, as well as the underlying mechanisms, are not clear. In this investigation, we elucidated the underlying mechanisms of the distinct effects of Ca2+ sparks on cerebral artery smooth muscle cells (CASMCs) and airway smooth muscle cells (ASMCs) tone. In CASMCs, owing to the functional loss of Ca2+-activated Cl- (Clca) channels, Ca2+ sparks activated large-conductance Ca2+-activated K+ channels (BKs), resulting in a decreases in tone against a spontaneous depolarization-caused high tone in the resting state. In ASMCs, Ca2+ sparks induced relaxation through BKs and contraction via Clca channels. However, the integrated result was contraction because Ca2+ sparks activated BKs prior to Clca channels and Clca channels-induced depolarization was larger than BKs-caused hyperpolarization. However, the effects of Ca2+ sparks on both cell types were determined by L-type voltage-dependent Ca2+ channels (LVDCCs). In addition, compared with ASMCs, CASMCs had great and higher amplitude Ca2+ sparks, a higher density of BKs, and higher Ca2+ and voltage sensitivity of BKs. These differences enhanced the ability of Ca2+ sparks to decrease CASMC and to increase ASMC tone. The higher Ca2+ and voltage sensitivity of BKs in CASMCs than ASMCs were determined by the ß1 subunits. Moreover, Ca2+ sparks showed the similar effects on human CASMC and ASMC tone. In conclusions, Ca2+ sparks decrease CASMC tone and increase ASMC tone, mediated by BKs and Clca channels, respectively, and finally determined by LVDCCs.

Views on Careers in Clinical Neurosciences Among Neurosurgeons and Neurologists in China.

BACKGROUND: China has a large and aging population. The need for physicians with training in clinical neurosciences will grow. There is little known regarding the factors that lead physicians in China to pursue careers in clinical neurosciences. The objective of this study was to garner a clearer understanding of factors that influence physicians to pursue careers in neurosurgery and neurology in China. METHODS: We surveyed attendees at a national neuroscience conference on the factors that influence their pursuit of careers in clinical neurosciences. Responses were quantified on a Likert scale. One-way analysis of variance was used to compare different groups of respondents. RESULTS: Factors associated with the intellectual elements of the specialties were rated most highly. Differences were noted between respondents, with trainees rating lifestyle-related factors more highly compared with attending physicians. CONCLUSIONS: The intellectual challenges are important factors for physicians in China influencing the pursuit of careers in the clinical neurosciences. This finding echoes results found elsewhere in the world. However, differences with trainees elsewhere in the world emerge when evaluating additional factors influencing trainees pursuing careers in the clinical neurosciences. Trainees in China rate educational experiences and mentorship more highly, whereas U.S. trainees rate altruistic goals more highly. This study provides a clearer understanding of factors influencing career choice among clinical neuroscientists in China.

Intraoperative neuromonitoring for removal of large vestibular schwannoma: Facial nerve outcome and predictive factors.

BACKGROUND: Preservation of facial nerve (FN) function is one of the major goals for resection of large vestibular schwannoma (VS) (≥ 30 mm). Little is known about the FN outcome and its predictive factors due to limited data. OBJECTIVE: To explore the predictive factors affecting FN outcome following resection of large VS. METHODS: 106 Large VS patients underwent surgical resection from 2010 to 2012 via intraoperative neuromonitoring for FN preservation approach. Postoperative FN function evaluation was conducted at the time points of 3-7th day, 3rd month and at the end of the 2nd year. Correlation between tumor size, intraoperative parameters and FN function were examined. RESULTS: The ratios of total and subtotal resection were 82.1% and 14.2%, respectively. Acceptable FN function was achieved in 78% patients. Patients with good FN function showed much smaller (P < 0.01) VS size than those of poor-FN function patients at 3-7th day, 3rd month and 2nd year. There was a significant correlation between facial motor evoked potential (FMEP) ratios and postoperative FN function at 3-7th day (r = -0.709, P < 0.001) 3rd month (r = -0.709, P< 0.001) and 2nd year (r = -0.750, P < 0.001). Maximal response amplitude (MRA) ratio was a supplementary indicator for train time in predicting both immediate and long-term FN function in patients with large VS. CONCLUSION: Indicative factors of both immediate and long-term postoperative FN function in large VSs include tumor size, intraoperative train time, start to final FMEP ratios and proximal to distal MRA ratios.

Clinical characteristics of patients with asymptomatic intracranial meningiomas and results of their surgical management.

Surgery performed during the asymptomatic phase of meningioma remains controversial. The effects of surgery and the factors associated with postsurgical complications and patient prognosis were studied to optimize surgical decisions for clinicians who treat asymptomatic patients. The medical records of 513 patients with meningiomas (112 patients were asymptomatic) treated at our hospital from May 2007 to April 2012 were retrospectively reviewed. The results were analyzed with univariate and multivariate analyses. Asymptomatic meningiomas were characterized by a more common cerebral hemispheric location, a smaller size, and a lack of peritumoral edema. A significantly higher Simpson I resection rate of 95.2 % was achieved in tumors located in the cerebral hemisphere; in contrast, a rate of 66.7 % was obtained in tumors located at the skull base (P = 0.003). The overall postsurgical complication rate was 13.6 %, which was lower than the rate of 21.7 % in the symptomatic patients. Hemiplegia was the most common complication, which occurred most often in the patients with tumors in parietal locations (P = 0.015). Ninety-two percent of the asymptomatic patients achieved a Glasgow Outcome Scale (GOS) score of 5 1 year after the operation, and significantly more patients younger than 60 years of age obtained a GOS score of 5 compared with patients older than 60 years of age (P = 0.006). To achieve maximal tumor resection and good patient recovery, tumor location and patient age should be carefully considered prior to choosing to perform surgery in asymptomatic patients.

DCPIB, a potent volume-regulated anion channel antagonist, attenuates microglia-mediated inflammatory response and neuronal injury following focal cerebral ischemia.

Accumulating evidence indicates that extensive microglia activation-mediated local inflammation contributes to neuronal injury in cerebral ischemia. We have previously shown that 4-(2-butyl-6, 7-dichloro-2-cyclopentyl-indan-1-on-5-yl) oxobutyric acid (DCPIB), a potent volume-regulated anion channel (VRAC) inhibitor, suppresses pathological glutamate release and excitatory neurotoxicity in reversible middle cerebral artery occlusion (rMCAO) model in vivo. In the present study, we sought to determine whether DCPIB also attenuates microglia activation that could contribute to neuronal injury in the cerebral ischemia/reperfusion pathology. We show that oxygen-glucose deprivation (OGD) induced microglia proliferation, migration, and secretion of cytokines and all these pathological changes were effectively inhibited by DCPIB in vitro. In the microglia/neuron co-cultures, OGD induced neuronal damage was reduced markedly in the presence of DCPIB. In rat rMCAO animal model, DCPIB significantly attenuated microglia activation and neuronal death. Activation of mitogen-activated protein kinase (MAPK) signaling pathway is known to be a critical signaling pathway for microglia activation. We further explored a potential involvement of DCPIB in this pathway by western blot analysis. Under the conditions that MAPK pathway was activated either by lipopolysaccharides (LPS) or OGD, the levels of phosphorylated ERK1/2, JNK and p38 were reduced significantly in the presence of DCPIB. Altogether, our study demonstrated that DCPIB inhibits microglia activation potently under ischemic conditions both in vitro and in vivo. The DCPIB effect is likely attributable to both direct inhibition VRAC and indirect inhibition of MAPK pathway in microglia that are beneficial for the survival of neurons in cerebral ischemic conditions.

Conus medullaris schistosomiasis.

OBJECT: The authors performed a study to investigate the clinical manifestations, treatment strategies, and possible pathogenesis of conus medullaris schistosomiasis. METHODS: Six cases collected from the authors' experience and four cases reported in the literature were studied retrospectively for clinical manifestations, treatment outcomes, and prognosis. All patients experienced progressive lower-extremity weakness and functional bowel and bladder impairment. Although the magnetic resonance (MR) imaging results suggested the presence of a conus medullaris tumor, schistosomiasis was diagnosed based on pathological results obtained in the 10 patients. The results of surgery followed by pyquiton and hormone treatment confirmed the diagnosis, and the patients' prognoses were good. CONCLUSIONS: This pathological entity is predominantly found in adults, and the clinical manifestations have no specificity, although the MR imaging may provide some clues. As a form of ectopic schistosomiasis, conus medullaris schistosomiasis deserves special consideration and further exploration. If an early diagnosis can be made and pyquiton and hormone therapy is given, surgery can be avoided and the prognosis will remain good.