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Various grading systems and surgical techniques have been developed for the treatment of intraventricular hemorrhage (IVH); however, little attention has been paid to the fourth ventricle hematoma. Nonetheless, hemorrhagic dilation of the fourth ventricle may lead to catastrophic consequences for patients with massive IVH. We present two cases of massive IVH accompanied by massive fourth ventricle hematoma which was successfully removed with combination of suboccipital craniotomy for fourth ventricle hematoma and intraventricular fibrinolysis for supratentorial hematoma.

The incidence of acute subdural hemorrhage (ASDH), which is often caused by head trauma, is steadily increasing due to an increase in the elderly population and the use of anticoagulants. Urgent surgical treatment is recommended if the patient has impaired consciousness, worsening neurological symptoms, or brain midline shift (MLS) due to large hematomas on brain computed tomography (CT). Although large craniotomy is traditionally recommended for ASDH removal, old age, comorbidities, and antiplatelet drugs are considered risk factors for surgical complications, many neurosurgeons hesitate to perform aggressive surgical procedures in these patients. In this study, we introduced a method that can quickly and effectively remove ASDH without general anesthesia. We retrospectively reviewed 11 cases of patients with ASDH who underwent hematoma drainage between June 2019 and December 2020. We measured the maximum subdural hematoma thickness and MLS on brain CT of patients and recorded the Glasgow Coma Scale scores before and after the surgical procedure. All patients had multiple comorbidities, and seven patients received anticoagulant or antiplatelet therapy. On initial brain CT, the median subdural hemorrhage thickness was 21.36 mm, median MLS was 10.09 mm, and mean volume of the subdural hematoma was 163.64 mL. The mean evacuation rate of the subdural hematoma after drainage was 83.57%. There was no rebleeding or operation-related infection during the aspiration procedure, and the median MLS correction after the procedure was 7.0 mm. Our treatment strategies can be a reliable, less invasive, and alternative treatment option for patients at high risk of complications due to general anesthesia or patients who are reluctant to undergo a large craniotomy due to a high bleeding tendency.

본 연구에서는 송전선 결빙으로 인한 피해를 최소화하고자 상온 경화형 실리콘 고무에 입자 크기와 혼합 배열을 달리한 알루미늄 안료를 첨가하여 결빙 방지 코팅재를 제조하였다. 접촉각과 표면에너지 측정을 통해 표면 거칠기가 높은 코팅재가 뛰어난 발수성을 가짐을 확인하였다. 하지만, 결빙 방지 성능은 표면 거칠기와 경도가 낮을수록 우수하였다. 연속허용전류 인가 실험 결과, 실리콘 고무 코팅재의 방열성능이 가장 우수하였으며, 이는 실리콘고무의 복사율이 가장 컸기 때문이다. 또한 가속 열화 시험과 얼음 탈착/부착 반복 시험을 통하여 실리콘 고무 코팅재는 장기간 물성 변화 없이 우수한 결빙 방지 성능이 유지됨을 알 수 있었다. 본 연구를 통하여 개발된 코팅재는 송전선의 결빙 방지를 위해 충분히 사용될 수 있는 가능성을 보여주었으며, 특히 우수한 방열특성으로 인하여 송전선의 온도도 낮추어 주기 때문에 여름철 전력 효율을 높이는데도 크게 기여를 할 수 있을 것으로 생각된다.

In this study, we manufactured a non-equiatomic (CoNi)

Background In patients with intracerebral hemorrhage (ICH), brain volume loss can occur in the hemisphere ipsilateral to the hematoma. However, contralateral hemispheric volume change after ICH is not well known. The present study aimed to investigate contralateral brain volume changes in patients with ICH who had not undergone surgery. Methods Of the 2213 patients with ICH admitted to our hospital between January 2010 and December 2017, 46 patients without surgical intervention were included in the present study. We measured contralateral hemispheric brain volume in the axial images of brain computed tomography at the time of ICH onset and after 12 months. We analyzed the relationship between various factors and volume changes in the contralateral hemisphere. Results The mean change percentage between the initial and follow-up contralateral parenchyma volume was 96.84%. The average volume decreased by 3.16% (P = 0.001). Univariate and multivariate logistic regression models revealed no significant factors associated with contralateral brain volume loss. Kruskal–Wallis test and Mann–Whitney U test showed no statistical significance (P = 0.824, P = 0.122) between ICH volume groups. Conclusions Contralateral parenchymal volumes were significantly decreased at follow-up brain computed tomography scanning; these changes may provide important clinical information on the remote effect of focal lesion and symptoms in the course of ICH treatment. However, further investigation is required to determine the mechanisms underlying these volume changes.

Background Microsurgical management of blood blister aneurysms of the internal carotid artery is challenging because of the special characteristics of these aneurysms. We reviewed our diverse surgical methods with long-term clinical and radiologic follow-up. Methods We retrospectively reviewed all patients with blood blister aneurysms presenting with subarachnoid hemorrhage that were treated with microsurgical obliteration between 1993 and 2017. Baseline characteristics of patients and aneurysms, surgical methods, and clinical and radiologic outcomes were analyzed. Results This study included 36 patients. The patients were treated using microsurgery with direct clipping (2 patients; 5.6%), cotton-assisted clipping (24 patients; 66.7%), wrapping-clipping (5 patients; 13.9%), or wrapping-clipping with suturing (5 patients; 13.9%). Complete occlusion of aneurysm was achieved in 34 of 36 patients (94.4%). Severe vasospasm developed in 18 of 36 patients (50%). Ischemic events occurred in 8 patients (22.2%), 2 of whom remained with severe disability. Regrowth or recurrence occurred in 1 patient (0.28%), which required additional stent-assisted coil embolization. Mean modified Rankin Scale score was 2.0 (median, 1.0; range, 0–4) at discharge and 1.3 (median, 1.0; range, 0–4) at the last follow-up. Conclusions Direct clipping is ideal if possible; however, direct clipping is challenging in most blood blister aneurysms. Assisted clipping with cotton is mainly used and could be an effective technique for reinforcement of the friable wall, with good clinical outcomes in our series. Moreover, suturing followed by wrapping-clipping is also useful for managing intraoperative rupture.

Objective: Macrophages have been shown to play important roles in various pathophysiological processes of the central nervous system via neuroinflammation, leading to an increased interest in macrophage biology. Circulating blood monocytes are among the first cells to infiltrate the brain after ischemic stroke; however, the role of innate immune cells such as monocytes and macrophages remains to be elucidated. Here, we investigated the association between blood monocytes and infarct size following ischemic stroke.Methods: We induced stroke using a focal ischemia mouse model through middle cerebral artery suture occlusion. To deplete circulating blood monocytes, clodronate was injected intraperitoneally 24 h before the surgery. Animals were sacrificed at specified time points, and the infarct size and mRNA expression were then measured.Results: The clodronate-injected mice showed significantly smaller infarct size than the control mice. Immunohistochemical staining revealed that monocyte depletion significantly blocked the infiltration of macrophages and microglia. The mRNA expression levels of macrophage and microglia markers were higher in the left infarcted brain than in the right non-infarcted brain.Conclusions: In summary, monocyte depletion reduced the infarct size and mitigated neurological deficits in mice following ischemic stroke, likely by blocking the infiltration of inflammatory cells such as macrophages and microglia.

Rationale: Bevacizumab has shown good efficacy in radiation necrosis (RN) following gamma knife radiosurgery (GKRS) and associated peritumoral edema. However, few studies have reported bevacizumab failure. Moreover, the pathologic transformation of benign meningioma following GKRS has never been reported. Patients concerns: A 41-year-old man was admitted with focal seizure on the right arm. Diagnoses: Magnetic resonance imaging (MRI) demonstrated a 4.7 cm-sized convexity meningioma involving left motor cortex. Interventions: Subtotally resected tumor was confirmed as a meningothelial meningioma and subsequently treated by GKRS. During 4-year follow-up after GKRS, seizure and hemiparesis had persisted with progressively worsened peritumoral edema regardless of steroid and bevacizumab treatment. Radical debulking of tumor was achieved and immunohistopathological examination revealed angiomatous meningioma with necrotic core presenting scanty VEGF expression. Outcomes: A follow-up MRI at 4 months after debulking surgery showed a marked reduction of peritumoral edema with improvement of symptoms. Lessons: This is the first report of pathologically confirmed angiomatous transformation following GKRS. Although the pathogenesis is not fully understood, this rare pathologic transformation may be closely related to RN. Also, if bevacizumab is resistant, debulking surgery for reducing tumor burden could be an effective treatment option to control the RN.

Objective Carotid endarterectomy (CEA) is an effective surgical procedure for treating symptomatic or asymptomatic patients with carotid stenosis. Many neurosurgeons use a shunt to reduce perioperative ischemic complications. However, the use of shunting is still controversial, and the shunt procedure can cause several complications. In our institution, we used two types of modified arteriotomy suture techniques instead of using a shunt. Methods In technique 1, to prevent ischemic complications, we sutured a third of the arteriotomy site from both ends after removing the plaque. Afterward, the unsutured middle third was isolated from the arterial lumen by placing a curved Satinsky clamp. And then, we opened all the clamped carotid arteries before finishing the suture. In technique 2, we sutured the arteriotomy site at the common carotid artery (CCA). We then placed a curved Satinsky clamp crossing from the sutured site to the carotid bifurcation, isolating the unsutured site at the internal carotid artery (ICA). After placing the Satinsky clamp, the CCA and external carotid artery (ECA) were opened to allow blood flow from CCA to ECA. By opening the ECA, ECA collateral flow via ECA-ICA anastomoses could help to reduce cerebral ischemia. Results The modified suture methods can reduce the cerebral ischemia directly (technique 1) or via using collaterals (technique 2). The modified arteriotomy suture techniques are simple, safe, and applicable to almost all cases of CEA. Conclusion Two modified arteriotomy suture techniques could reduce perioperative ischemic complications by reducing the cerebral ischemic time.

Measurement of cortisol in hair is a reliable method for determining long-term cortisol exposure reflecting chronic stress. Research using hair cortisol concentration has been limited to mainly cardiometabolic diseases. The association between hair cortisol concentration and aneurysmal rupture has not yet been studied. We aimed to investigate the relationship between the degree of chronic stress as measured by hair cortisol concentration and aneurysmal rupture. Sixty-eight patients diagnosed with intracranial aneurysms were included in this study (ruptured group, 30; unruptured group, 38). Hair cortisol was measured in 3-cm hair segments, reflecting roughly 3 months of hair growth. For a risk factor analysis, patient-specific factors and aneurysm-specific factors as well as hair cortisol concentration were investigated. Hair cortisol concentrations were significantly higher in the ruptured group than in the unruptured group (55.8 ± 22.0 ng/dL vs. 19.1 ± 6.4 ng/dL; P

CoCrNi medium entropy alloy (MEA) and stainless steel 316L (SS316L) were manufactured by direct energy deposition of additive manufacturing (DED-AM). Exceptional mechanical properties of DED CoCrNi at 210K were achieved by the activities of a multiple deformation scheme that changed from dislocation slip to twinning-induced plasticity followed by transformation-induced plasticity. While SS316L at room temperature has micro-twins, CoCrNi at 210K exhibited nano-twins, resulting from lower stacking fault energy. Moreover, transformed hexagonal close-packed (HCP) phases were found near the face-centered cubic (FCC) {111} grain boundaries, where remarkable stacking faults and severe lattice distortion were measured. The formation of HCP substructure was understood from stacking fault probability, mean square strain, and lower temperature, which increased the strain hardening rate of several orientations in the FCC matrix, finally improving the strength of CoCrNi at 210K. A combination of CoCrNi MEA and DED-AM achieves a synergistic effect of strength, ductility and toughness for low temperature applications.

We examined the repetitive stress relaxation behavior of extruded AA7075 subjected to different heat-treatments (solid-solutionized (SS), under-aged (UA), peak-aged (PA)). Compared to SS and UA, the PA showed the highest stress drop (Δσs), plastic strain change (Δep) and re-yielding (Δσr), in conjunction with the largest reduction in mobile dislocation density right after stress relaxation. As stress relaxation cycles repeated, the stress drop decreased due to lower activities of mobile dislocations. During stress relaxation, the harder the grain orientation was, the more was the reduction in lattice strain. However, this tendency was not consistent with the order in the magnitude of the shear stresses imposed on the respective grains based on Schmid's law. The current results confirm the grain-orientation dependency on the relative activities of dislocation slip and diffusion-controlled creep during the stress relaxation at room temperature.

Distal peripheral artery aneurysms in moyamoya disease (MMD) remain difficult to treat given their deep location, small size, and fragility. Here, we report two cases of choroidal artery aneurysms associated with MMD who were treated through direct clipping and coil embolization. Timing of aneurysm formation remains unclear, however, annual follow-up DSA for surveillance of hemodynamic status is necessary and prompt treatment of aneurysm should be performed when diagnosed. Moreover, choroidal artery aneurysms may benefit from endovascular coil embolization due to their characteristics.

In patients with intracerebral hematoma (ICH), it is well known that brain atrophy occurs in the hemisphere ipsilateral to the hematoma. The present study aimed to investigate contralateral hemispheric volume changes in patients with ICH as well as related factors.Of 112 patients with ICH who were surgically treated at our hospital between January 2011 and December 2015, 44 were included in the present study. We measured contralateral hemispheric brain areas in 3 planes of axial brain computed tomography images. We obtained the proportion of contralateral hemispheric parenchyma to the hemispheric intracranial area to adjust for individual differences in head size. We analyzed the relationship between various factors and volume changes in the contralateral hemisphere.The average volume percentages of preoperative and follow-up contralateral hemispheric parenchyma were 92.3% versus 88.8%, 90.3% versus 85.3%, and 86.9% versus 82.5% in the level of foramen of Monro, septum pellucidum, and lateral ventricle, respectively. These decreases were all statistically significant (paired t-test; P 0.001). As far as the causes of these decreases, the presence of intraventricular hematoma was the most significant factor for a decrease (P = 0.006). Glasgow coma scale score on arrival, as well as, smoking were independent factors in a multivariate analysis (P = 0.016, 0.039).Contralateral parenchymal volumes were significantly decreased at the 3-month follow-up brain computed tomography scan. These findings may offer important clinical information on the remote brain injury of ICH.

Nonsaccular vertebral artery aneurysms involving the posterior inferior cerebellar artery (PICA) are rare. Treatment is considered a significant challenge because of their angiographic and anatomical features, especially in high-riding PICA. Therefore, meticulous preoperative angiographic and anatomical evaluation is necessary. Moreover, consideration of the distance between the cerebellar skull base and caudal loop of the PICA is important. We present two cases of occipital artery-high-riding PICA bypass and discuss important preoperative technical considerations.

Background Ruptured vertebral artery dissecting aneurysms (VADAs) involving the posterior inferior cerebellar artery (PICA) are the most difficult to treat among variations of VADAs but require prompt treatment. The major challenge is to preserve the PICA while occluding the aneurysm. Despite advances in the management of ruptured VADAs involving the PICA, each treatment, whether it is combined or not, is associated with a significant degree of risk. Case Description This study presents 4 cases of ruptured VADAs involving the PICA that were successfully treated using a staged, combined method. Embolization of the rupture point in the acute stage was followed 3–4 weeks later by occlusion of the proximal vertebral artery (VA) and PICA origin after occipital artery–PICA bypass in the chronic stage. Conclusions Although it is sometimes very difficult to determine the exact rupture point of VADAs, ruptures tend to occur at distal segments of a dissecting aneurysm presenting as bleb. Also, when planning a trapping of the VA, careful examination of angiography is needed to assess the contralateral VA and rupture point. Our staged and combined strategy may provide another valuable treatment option for treating VADAs involving the PICA with special emphasis on the safety and efficacy in our method.

Background The unilateral interhemispheric approach for distal anterior cerebral artery aneurysms presents several risks, such as postoperative venous infarction due to occasional sacrifice of parasagittal bridging vein and postoperative frontal lobe damage due to retraction force. To overcome these risks, we used a bifrontal craniotomy with straight dural incision and cutting of the superior sagittal sinus. Methods We retrospectively reviewed 61 patients (42 unruptured and 19 ruptured A2 and A3 aneurysms) who under aneurysm clipping through bifrontal interhemispheric approach between March 2007 and December 2017. There were 35 A2 aneurysms and 27 A3 aneurysms, and mean size of aneurysms was 5.45 mm. The modified bifrontal interhemispheric approach involved 3 steps: bifrontal craniotomy of centrobasal portion of the frontal bone, ligation and division of anterior one third of the superior sagittal sinus, and approaching the aneurysm via the interhemispheric space. All patients underwent computed tomography on postoperative days 3 and 7 for evaluation of brain retraction damage or venous infarction. Results Among patients with ruptured aneurysms, 79% had a favorable outcome (Glasgow Outcome Scale score 4 or 5) 6 months after primary subarachnoid hemorrhage; all patients with unruptured aneurysms had favorable outcomes. Surgical outcome was strongly related to preoperative neurologic Hunt and Hess grade. Three patients had poor outcomes due to poor Hunt and Hess grade on admission (grade 3 in 2 patients, grade 4 in 1 patient). Follow-up CT showed that venous infarction did not occur in any of the patients. Conclusions Modified bifrontal interhemispheric approach may be a safe and effective method for treating A2 and A3 aneurysms with relatively good clinical outcome and no surgery-related complications.

Acute epidural hematoma (AEDH) is one of the most common pathological types of head trauma, and may develop without an accidental event, although this is uncommon. The present study reports the case of a 41-year-old male patient that developed spontaneous AEDH due to skull metastasis of hepatocellular carcinoma (HCC). The man was admitted to Chonnam National University Hwasun Hospital and Medical School due to drowsiness and right-sided hemiparesis. A computed tomography scan of the head revealed the presence of a large AEDH and a lytic bone lesion in the left posterior fossa and parieto-occipital region, which exhibited heterogeneous enhancement. The perioperative findings revealed a large amount of mixed-stage epidural hematoma and a soft hemorrhagic mass that exhibited lytic change on the occipital bone. No evidence of head trauma, such as skull fracture or scalp contusion, was detected. The pathological diagnosis was hematoma with metastatic HCC. The current study reports the rare case of a patient with a metastatic tumor located in the skull that resulted in the development of spontaneous AEDH. Once a sudden and unpredicted neurological deficit occurs in a patient with HCC that is also diagnosed with skull metastasis, the possibility of spontaneous AEDH developing from the metastasis should be considered.

This study developed multi-functional acrylic urethane coating materials with anti-graffiti, anti-contamination, and anti-adhesion properties. The newly-developed coating was synthesized by high glass transition temperature ( T g ) acrylic polyol and low-viscosity single-end-type silicone oil. The coating materials were chemically bonded and reacted with isocyanate to form acrylic urethane. The hardness, surface energy, color difference value, and anti-adhesion properties were examined using nanoindentation, a contact angle analyzer, a color difference meter, and a universal tensile test machine, respectively. In addition, the degradation of the coating was evaluated using an accelerated weathering test, taking into account various degradation factors (UV, humidity, high temperature, and water). In general, the properties of the coating degraded due to the loss of silicone oil after the accelerated weathering test. However, the degradation was retarded when high T g acrylic polyol and low-viscosity single-end-type silicone oil were chemically bonded. The newly-developed multi-functional acrylic urethane coating exhibited long-term stability against an accelerated weathering test of 120 h. The developed coating will be useful in broad applications, including harsh environments such as underground walls, heritage, facilities, and subways.

A system of electromagnetic semi-active suspension reclaiming energy (ESASRE), with an novel control varying charge voltage in steps (CVCVIS) based optimal integrated controller, is newly proposed to improve ride comfort and energy reclaiming. The proposed CVCVIS is built by changing the number of battery packs. The dynamic model of the semiactive suspension reclaiming energy is established first, which fully accounts for the non-linear characteristics of the damping actuator reclaiming energy (DARE). The parameters of DARE are decided by a compromise between ride comfort and manufacturing cost, with consideration of installation convenience. A integrated control system for ESASRE includes a controller for calculating the real-time ideal control force based on optimal linear quadratic Gaussian (LQG) control and the other for calculating the number of charging batteries to obtain the real-time actual control force using the proposed quasilinear relation function. Performance comparisons are implemented using three suspension types: ESASRE, the passive suspension, and the ideal active suspension. The performance index of ESASRE is 19.8% lower than that of the passive suspension, and 3.82% higher than that of the active suspension. With ESASRE, the power flowing into the battery pack accounts for 77.72% of the total vibration energy absorbed by DARE.

Introduction This study was designed to evaluate the clinical and radiologic results of stand-alone synthetic polyetheretherketone (PEEK) cages for two- or three-level anterior cervical discectomy and fusion (ACDF), with a focus on subsidence. Materials and methods We retrospectively reviewed a total of 68 patients who underwent two- or three-level ACDF with a stand-alone PEEK cage between April 2005 and August 2016. Radiologic parameters were assessed on lateral radiographs, and fusion was assessed on computed tomography scans. For the evaluation of clinical outcomes, visual analogue scale, neck disability index, and modified Japanese Orthopedic Association scores were measured. Results Among the total of 68 patients with a total of 144 segments, ACDF at two and three levels was performed in 60 and 8 patients, respectively, with a mean follow-up duration of 27.6 months. The overall fusion rate was 81.3% (117 of 144 segments), and subsidence occurred in 63 segments (43.8%) at the last follow-up. There was no statistically significant difference between the subsidence group and the nonsubsidence group in terms of fusion rate, radiologic outcomes, and clinical outcomes (p > .05). Conclusion Subsidence might be an inevitable course and only a radiologic phenomenon with no effect on the clinical and radiologic outcomes of the use of stand-alone cages.

Background Olfactory neuroblastoma (ONB) is an uncommon neoplasm that arises from olfactory epithelium in the nasal cavity near the cribriform plate. Although local recurrence or direct extension along olfactory epithelium and metastasis to the central nervous system has been reported, remote leptomeningeal metastasis is quite rare. In our report of a leptomeningeal metastasis of ONB without recurrence of primary site, we discuss the possible pathogenesis of this rare phenomenon with a review of the literature. Case Description A 56-year-old woman was admitted with epistaxis. Magnetic resonance imaging revealed a mass in the right cribriform plate and ethmoid sinus with intracranial extension. She was primarily treated with craniofacial resection followed by radiotherapy. Gross total resection was achieved, but annual follow-up magnetic resonance imaging showed a new enhancing mass in the left parietal meninges mimicking meningioma without local recurrence at 5 years after the first operation. A second operation was performed, and pathologic examination confirmed the lesion as metastatic olfactory neuroblastoma. Conclusions ONB is a locally aggressive tumor, but it also potentially spreads to remote leptomeninges via blood or cerebrospinal fluid. Therefore, careful evaluation is needed not to misdiagnose a meningioma and delay the treatment. Moreover, understanding the route of remote leptomeningeal metastasis and en-bloc resection of tumor at first operation might reduce leptomeningeal metastasis, irrespective of surgical corridors.

This paper presents the design of a quantitative feedback control system for a three-axis hydraulic road simulator. The road simulator is a multiple input-output (MIMO) system with parameter uncertainties which should be compensated with a robust control method. The objective of the present paper is to reproduce the random input signal or real road vibration signal by three hydraulic cylinders. The re- placed m 2 MISO equivalent control system is suggested, which satisfies the design specification of the original mxm MIMO control sys- tem by decoupling each of the three axes. Quantitative Feedback Theory (QFT) is used to control the simulator. The QFT illustrates a tracking performance of the closed-loop controller with low order transfer function G (s) and pre-filter F (s) having the minimum band- width for the uncertain plant with parameter uncertainty. The efficacy of the designed controller is verified through dynamic simulation, which is co-simulated with hydraulic models of Matlab and Adams multi-body. The simulation and the experimental results show that the proposed control technique works well for uncertain hydraulic plant systems.

An overall simulation model for fuel cell hybrid vehicle (FCHV) power train in parallel configuration using MATLAB/Simulink programming is constructed in this study. The model runs on power control strategy by using logic-threshold approach, achieved by the hybrid control unit (HCU) and fuel cell stack number. Using accelerator and decelerator pedal positions deduced from the driving schedule as the primary input, the simulation implements power flow and distribution under different vehicle operating modes. The HCU control strategy also incorporates regenerative braking and recharge for battery capacity recovery. Using the D-optimality method for experiment points selection and sequential quadratic programming (SQP) algorithm for obtaining the optimal operational parameters, three control threshold variables of HCU and optimal stack cell number are selected for hydrogen fuel economy under certain driving cycles. The proposed method provides optimized configurations of the FCHV model and the fuel cell stack, which has the capability in satisfying drive power request while satisfying vehicle driving schedule and battery state of charge (SOC) recovery with lower fuel consumption.

RATIONALE A subdural empyema (SDE) following burr hole drainage of a chronic subdural hematoma (CSDH) can be difficult to distinguish from a recurrence of the CSDH, especially when imaging data is limited to a computed tomography (CT) scan. PATIENTS CONCERNS All patients underwent burr hole drainage of the CSDH at first, and the appearance of the SDE occurred within one month. DIAGNOSES A contrast-enhanced magnetic resonance imaging (MRI) scan, with diffusion-weighted imaging (DWI), revealed both the SDE and diffuse meningitis in all patients. INTERVENTIONS In Case 1, because the patient was very young, burr hole drainage of the SDE, rather than craniotomy, was performed. However, subsequent craniotomy was required due to recurrence of the SDE. In Cases 2 and 3, an initial craniotomy was performed without burr hole drainage. OUTCOMES Symptoms improved for all patients, and each was discharged without any neurologic deficits or subsequent recurrence. LESSONS Neurosurgeons should consider the possibility of infection if recurrence of CSDH occurs within 1 month following drainage of a subdural hematoma. A contrast-enhanced MRI with DWI should be performed to differentiate SDE from CSDH. In addition, surgical evacuation of the empyema via wide craniotomy is preferred to burr hole drainage.

Using MATLAB/Simulink, we constructed a comprehensive simulation model for the fuel cell hybrid vehicle (FCHV) power train in parallel with a power control strategy that uses a logic threshold approach implemented with a hybrid control unit (HCU). The simulation implements power flow and power distribution under different vehicle operating modes using the accelerator and decelerator pedal positions deduced from the driving schedule as primary inputs. The HCU control strategy also incorporates regenerative braking and recharging for recovery of battery capacity. Using the D-optimality method for selection of the optimal experiment values, three control threshold variables for the HCU are selected to maximize the hydrogen fuel economy under certain driving cycles. The proposed method provides the optimal configuration of the FCHV model, which has the capability of achieving the requested drive power while also meeting the vehicle driving schedule and recovery needs of the state of charge (SOC) battery, with lower fuel consumption levels.

In this paper a magnetic bearing system is designed for the suppression of rotor vibration. Magnetic bearing is able to support the shaft without mechanical contacts, and it is also able to control the rotational vibration. Magnetic bearing is composed of position sensors, a digital controller, actuating amplifiers, and electromagnets. In order to control the vibration of a magnetic bearing system effectively, Time Delay Control (TDC) is utilized. It proposes the design skill of an optimal controller when the system has the uncertainty, i.e. it has a difficulty in extracting the exact mathematical expressions, as well as it has external disturbances. The observer with the position information is utilized as a feedback signal for regulating the rotor whirling motion. Simulation is performed first to check the validation of the proposed controller in suppressing the rotor whirling. Experiments are followed to guarantee its usefulness in the rotor rig with a magnetic actuator. The vibrating suppression is confirmed with TDC and its effect is compared with proportional and derivative controller’s one.

This paper investigates an active front steering control strategy based on quantitative feedback theory (QFT). By incorporating feedback from a yaw rate sensor into the active steering system, the control system improves the dynamic response of the vehicle. The steering response of a vehicle generally depends upon uncertain quantities like mass, velocity, and road conditions. Thus, QFT is used to design a controller with robust performance. A multi-degree-of-freedom nonlinear model is co-simulated here by MATLAB Simulink and ADAMS/CAR. The performance of the control system is evaluated under various emergency maneuvers and road conditions. The result shows that the designed robust control system has good control performance and can efficiently improve handing qualities and stability characteristics.

This paper presents the road simulator control technology for reproducing a road input signal to implement real road data. The simulator consists of a hydraulic pump, a servo valve, a hydraulic actuator and its control equipment. QFT (Quantitative Control Theory) is utilized to control the simulator effectively. The control system illustrates a tracking performance of the closed-loop controller with a low order transfer function G(s) and a pre-filter F(s) for a parametric uncertainty model. A force controller is designed to communicate the control signal between the simulator and digital controller. Tracking specification is satisfied with upper and lower bound tolerances on the steep response of the system to the reference signal. The efficacy of the QFT force controller is verified through the numerical simulation in which combined dynamics and actuation of the hydraulic servo system are tested. The simulation results show that the proposed control technique works well under an uncertain hydraulic plant system. The conventional software (Labview) is used to make up for the real controller on a real-time basis, and the experimental works show that the proposed algorithm works well for a single road simulator.

Objective The importance of traumatic dural venous sinus injury lies in the probability of massive blood loss at the time of trauma or emergency operation resulting in a high mortality rate during the perioperative period. We considered the appropriate methods of treatment that are most essential in the overall management of traumatic dural venous sinus injuries. Methods We conducted a retrospective review of all cases involving patients with dural venous sinus injury who presented to our hospital between January 1999 and December 2014. Results Between January 1999 and December 2014, 20 patients with a dural venous sinus injury out of the 1,200 patients with severe head injuries who had been operated upon in our clinic were reviewed retrospectively. There were 17 male and 3 female patients. In 11 out of the 13 patients with a linear skull fracture crossing the dural venous sinus, massive blood loss from the injured sinus wall could be controlled by simple digital pressure using Gelfoam. All 5 patients with a linear skull fracture parallel to the sinus over the venous sinus developed massive sinus bleeding that could not be controlled by simple digital pressure. Conclusion When there is a linear skull fracture parallel to the sinus over the dural venous sinus or a depressed skull fracture penetrating the sinus, the surgeon should be prepared for the possibility of potentially fatal venous sinus injury, even in the absence of a hematoma.

Non-Hodgkin's lymphoma (NHL), a disease which may involve the spine, is frequently associated with advanced disease. Radiculopathy caused by spinal root compression as the initial presentation in patients with NHL is very rare and thought to occur in less than 5% of cases. A 69-year-old woman complained of a history of low back pain with right sciatica for 1 month prior to admission. Computed tomography and magnetic resonance imaging of the lumbar spine showed a dumbbell-shape epidural mass lesion extending from L2 to L3, which was suggestive of a neurogenic tumor. After paraspinal approach and L2 lower half partial hemilaminectomy, total excision of the tumor was achieved, followed by rapid improvement of back pain and radiating pain. The lesion was confirmed to be Burkitt's lymphoma by histopathological examination. We then checked whole-body PET-CT, which showed multifocal malignant lesions in the intestine, liver, bone and left supraclavicular lymph node. Although a rare situation, Burkitt's lymphoma should be considered in the differential diagnosis for patients presenting with back and lumbar radicular pain without a prior history of malignancy. Burkitt's lymphoma could be the cause of dumbbell-shape spinal tumor.

Background Craniofacial resection (CFR) has been regarded as a standard treatment for various tumors involving the anterior skull base. The purpose of this study was to evaluate the results of CFR for the patients with anterior skull base malignancies in our hospital. Methods We retrospectively analyzed 17 patients with anterior skull base malignancies treated with CFR between 2001 and 2012. Mean follow-up duration was 41 months (range, 2-103 months). Results Intracranial involvement was found in 11 patients (65%) and orbital extension in 6 patients (35%). Classical bifrontal craniotomy was combined with endoscopic endonasal approach in 14 patients and external approach in 3 patients. Vascularized flap was used for reconstruction of the anterior fossa floor in 16 patients (94%). The most common pathological type was squamous cell carcinoma (6 patients). Gross total resection was achieved in all cases. Postoperative complications developed in 4 patients (24%) and included local wound problem and brain abscess. One patient with liver cirrhosis died from unexpected varix bleeding after the operation. Although postoperative treatment, such as radiotherapy or chemotherapy, was performed in 14 patients, local recurrence was seen in 6 patients. The mean overall survival time after the operation was 69.0 months (95% confidence interval: 47.5-90.5 months) with a 1-, 2-, and 5-year survival rate of 82.3%, 76.5%, and 64.7%, respectively. Postoperative radiotherapy was found to be the powerful prognostic factor for favorable survival. Conclusion Considering the higher local control rate and acceptable complication or mortality rate, CFR with adjuvant radiotherapy is a gold standard treatment option for malignant tumors involving anterior skull base, especially with extensive intracranial involvement.

Background A lumbar drainage catheter is frequently placed intra-operatively to decrease fluid pressure on the brain in aneurysmal subarachnoid cases. In rare cases, this catheter placement can lead to intracranial hypotension, resulting in brain stem herniation termed “brain sag” and it can lead to neurological injury and may prove to be fatal. We present our patient with brain sag secondary to intraoperative lumbar drainage. Case description A 56-year-old woman was admitted with a sudden onset of severe headache. A computed tomography (CT) scan revealed diffuse subarachnoid hemorrhage with ruptured anterior communicating artery aneurysm. After general anesthesia, a lumbar drainage catheter was placed intra-operatively to reduce pressure on the brain and 50 cc of CSF was removed during a 5-h period. Three to five days after operation, her neurologic symptoms became worse with an altered mental state and pupillary asymmetry. CT and magnetic resonance imaging (MRI) showed slit lateral ventricles, effacement of the cisterns and an elongated brain stem. After placing the patient in the Trendelenburg position, the patient rapidly recovered to her baseline neurologic state. Discussion Typical complications of subarachnoid hemorrhage such as vasospasm or hydrocephalus also manifest as neurological deterioration, but their treatments differ greatly from those for brain sag. Thusly, it is important to distinguish between causes. Treatments such as lumbar or extra-ventricular drainage, induced hypertension or administration of mannitol must be stopped once brain sag is suspected. Also, care should be taken for typical imaging features of brain sag on CT or MRI scan. For brain sag, placing the patient in the Trendelenburg position can improve neurological status in a rapid fashion. Conclusions Brain sag is a rare but serious condition and can be fatal if not rapidly diagnosed and treated. We therefore recommend including brain sag in the differential diagnosis, along with vasospasm, hydrocephalus or cerebral edema as part of possible complications following subarachnoid hemorrhage treatment. We hope our clinical and imaging data from this case study contribute to the correct diagnosis of brain sag, as its early detection is important.