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ABSTRACT: To clarify the clinical role of traumatic subarachnoid hemorrhage (tSAH), stratified analysis with grouping of tSAH was performed. Their blood flow changes and correlations with outcome were assayed.
One hundred seventeen tSAH patients were classified into several groups according to their initial computerized tomography scans. Group I included patients with tSAH only in the posterior interhemispheric fissure, whereas Group II contained patients with tSAH located elsewhere. Group II was further subdivided into IIa, little SAH; IIb, extensive SAH; IIc, little SAH with intraventricular hemorrhage (IVH); and IId, extensive SAH with IVH. The cerebral blood flow velocity was monitored using transcranial Doppler sonography (TCD).
Both age and initial coma scale were independent predictors of poor outcome. The poor outcome rates in various subgroups of tSAH increased stepwise from group I to group IId (I, 7.4%; IIa, 18.4%; IIb, 33.3%; IIc, 62.5%; and IId, 90.9%) (p = 0.0010). Stratified analyses revealed that patients with extensive tSAH (group IIb + IId) were more likely to have unfavorable outcomes (47.7%) than patients with little tSAH (group IIa + IIc) (26.1%) (p = 0.0185); patients with IVH (group IIc + IId) also displayed a higher incidence (78.9%) of poor outcomes than patients without IVH (group IIa + IIb) (25.4%) (p = 0.0030). TCD study demonstrated that patients with extensive tSAH (group IIb + IId) were more likely to have the vasospasm based on TCD criteria than did patients in group I and group IIa + IIc (37.5% vs. 5.9% and 7.7%, p = 0.0105). Notably, there was a tendency of worse outcome in patients with vasospasm on the basis of TCD-derived criteria than those without, with the unfavorable outcome rates being 47.4% and 24.7% (p = 0.0799).
Age, initial coma scale, extensive tSAH, and IVH are independent predictors of poor outcome in the cohort of tSAH patients. Statistically, patients with extensive tSAH are significantly more likely to have vasospasm.
The journal of trauma and acute care surgery. 07/2012; 73(1):131-6.
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ABSTRACT: Liver cirrhosis was identified as an independent predictor of poor outcomes in patients suffering trauma and in those undergoing major surgeries. The aim of this study was to report the authors' experiences treating patients with cirrhosis who undergo brain surgeries.
Between 2004 and 2009, 121 consecutive patients with cirrhosis underwent 144 brain procedures. Patients were categorized as Child-Turcotte-Pugh (referred to as "Child") Class A, B, or C. The patient profiles, including the severity of cirrhosis, reason for surgery, complications, and prognosis factors, were analyzed.
In this retrospective study, the overall surgical complication rate for patients with cirrhosis was 52.1% and the mortality rate was 24.3%. For patients with acute traumatic brain injury (TBI), the complication, rebleeding, and mortality rates reached 84.4%, 68.8%, and 37.5%, respectively. Surgery for TBI was a significant risk factor for postoperative complications (p = 0.0002) and postoperative hemorrhage (p < 0.0001). Otherwise, according to the Child classification, the complication rate increased in a stepwise fashion from 38.7% to 60% to 84.2%, the rebleeding rate from 29.3% to 48.0% to 63.2%, and the mortality rate from 5.3% to 38% to 63.2% for Child A, B, and C, respectively. The Child classification was associated with higher risk of complications-Child B vs A OR 2.84 (95% CI 1.28-6.29), Child C vs A OR 5.39 (95% CI 1.32-22.02). It was also associated with risk of death-Child C vs A OR 30.43 (95% CI 7.71-120.02), Child B vs A OR 10.88 (95% CI 3.42-34.63).
Liver cirrhosis is a poor comorbidity factor for brain surgery. The authors' results suggest that the Child classification used independently is a poor prognostic factor; in addition, grave outcomes were observed in patients with TBI.
Journal of Neurosurgery 05/2012; 117(2):348-53. · 2.96 Impact Factor
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ABSTRACT: This study proposes a micro vibration mitigation system using viscous dampers to solve the problem of vibration in a high-tech
building. Due to the operating frequency of the air conditioners and fundamental mode of the floors, a resonant phenomenon
is occasionally experienced at the upper levels of the structure. Several strategies were considered, and viscous dampers
combined with a suspension system were chosen to mitigate this annoying situation. A theoretical analysis was first executed
to determine the optimal design value of the damper and the suspension spring. An efficient reduction in floor velocity of
approximately 50 % was achieved by the proposed system. Practical verifications including a performance test of the micro-vibration-oriented
dampers, the pragmatic application result, and a comparison in one-third octave spectrum was then carried out. The performance
of the system was demonstrated by the data measured. It alleviated more trembling than was numerically expected. The energy
absorbed by the viscous dampers is illustrated by the hysteresis loops and the one-third octave spectrum. It is found that
with the proposed system, the vibration can be effectively captured by the viscous damper and converted to lower frequency-content
tremors. The success of this project greatly supports the proposed standard two-stage analysis procedure for mitigating micro-vibration
problems in practice. This research extends the use of viscous dampers to a new field.
Earthquake Engineering and Engineering Vibration 04/2012; 8(4):569-582. · 0.57 Impact Factor
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ABSTRACT: We report the case of a 68-year-old man with a 6-year history of renal cell carcinoma (RCC), who presented with severe low backache and paraparesis for a month before admission. In addition, he experienced urinary retention for 2 weeks. A spinal magnetic resonance imaging scan revealed the presence of an intradural extramedullary solitary mass at the conus medullaris. We performed a laminectomy and completely excised the tumor. The histopathological findings were suggestive of spinal metastasis of RCC. After the operation, the patient did not complain of backache and urinary retention, and paraparesis improved significantly. Spinal metastases of RCC are usually extradurally located. Intradural metastases of RCC are rare. Thus far, only six cases of RCC metastasizing to the cauda equina have been reported; however, RCC metastasis to the conus medullaris has not yet been reported. Conus medullaris lesions may cause symmetrical motor and sensory deficits accompanied by early autonomic system impairment. Surgery is the treatment of choice in cases of resectable RCC metastases, especially in cases of solitary metastasis.
The Kaohsiung journal of medical sciences 01/2011; 27(1):45-8. · 0.61 Impact Factor
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ABSTRACT: In this report, we present comprehensive recommendations for the diagnosis and treatment of large hemispheric infarction (LHI). A systematic literature search was conducted until June 30, 2010. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation (Table 1). The guideline was revised after several official meetings with local experts, and was reviewed by 3 expert reviewers. Early diagnosis of malignant large hemispheric infarction (MLHI) is critical. Studies have shown that using computed tomography (CT) or transcranial sonography to track midline shifting of the cerebrum and applying diffusion-weighted magnetic resonance imaging might contribute to the early recognition of MLHI. Glycerol and mannitol should be administered only when a patient shows evidence of brain edema or mass effect. The effect of barbiturate coma on improving prognosis is inconclusive and requires close monitoring of the patient. Meanwhile, using steroids on patients with stroke is not recommended. The effect of hyperventilation on reducing intracranial pressure is rapid but short-lived, and is used only in emergency situations. The target levels of PaCO2 are 30-35 mmHg. Moderate hypothermia (32-34°C) may be effective in controlling intracranial hypertension, but should be used cautiously along with rigorous monitoring. Timely decompressive craniectomy can probably offer patients a better chance of survival and quality of life. Usually, surgery for MLHI is indicated in patients with clinical deterioration associated with a significant mass effect, as observed on neuroimaging. However, with a reliable indicator of MLHI, early decompressive craniectomy before clinical deterioration may further reduce mortality and lead to a better functional outcome.
Acta neurologica Taiwanica 12/2010; 19(4):296-302.
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ABSTRACT: The purpose of this study was to evaluate hemispheric asymmetry of cerebral blood flow changes during various mental tests by applying transcranial Doppler sonography (TCD) to simultaneously monitor bilateral cerebral blood flow velocity changes.
Twenty-one participants without cerebrovascular disease performed 3 left hemispheric tasks (reading, calculation, and color scaling) and 3 right hemispheric tasks (face recognition, space imagination, and line orientation).
Mean velocities of the rest and performing periods did not differ significantly between the left and right hemispheric tasks. Although greater acceleration of blood flow velocity was observed on the left than on the right in most of the 6 tasks except line orientation (mean left - right ratio difference [D(l-r)] ranged from -0.018 to 0.071), this difference was larger for left hemispheric tasks (mean D(l-r) ranged from 0.050 to 0.071) than right hemispheric tasks (mean D(l-r) ranged from -0.018 to 0.034; P < .001). Further comparisons of each pair of (ie, left and right) hemispheric tasks revealed that the most suitable left and right hemispheric tasks to show hemispheric asymmetry were reading and line orientation, respectively (P < .001).
Hemispheric asymmetry of cerebral blood flow changes during mental tests is demonstrable with TCD only when comparing the D(l-r) in response to suitable paired left and right hemispheric tasks.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 11/2009; 28(11):1487-92. · 1.25 Impact Factor
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ABSTRACT: Spontaneous spinal epidural hematoma (SSEH) is a rare disease. The goal of this study was to clarify the treatment results and management options in SSEH.
Patients with SSEH who were surgically treated in the authors' center between June 2003 and June 2008 were included in this study. Patients were treated as early as possible if their neurological deficits were incomplete or had been complete for 12 hours or less. The patients were assigned to 1 of 2 groups based on completeness of preoperative cord dysfunction (complete vs incomplete deficit). Surgical outcomes of the 2 groups were compared by functional performance, coded as Nurick grades at 1, 3, and 6 months after the operation. Also compared were duration of hospital stay and the number of days needed to regain the ability to function independently (defined as Nurick Grades 1 and 2) after the operation.
There were 17 patients (7 female and 10 male) with pathologically confirmed SSEH. Coagulopathy, greater size (length) of SSEH, and preoperative complete spinal dysfunction were found to contribute to poor postoperative functional recovery (p < 0.05). Patients with incomplete preoperative deficits (ASIA Impairment Scale Grades B, C, and D) were able to achieve functional independent recovery within a month after surgery and had significantly better outcomes (lower Nurick grades) at 1, 3, and 6 months postoperatively than those with complete deficits (p < 0.001, p = 0.027, and p = 0.027, respectively). Median time to independent functional recovery and median length of hospital stay were significantly shorter in patients with incomplete preoperative deficits than in those with complete deficits (6 vs 110 and 9 vs 58 days, respectively; both p < 0.001).
Impaired preoperative hemostasis contributes to larger size of SSEH, high probability of postoperative recurrence of spinal epidural hematoma, and poor functional recovery following surgical evacuation. Incomplete spinal cord dysfunction before surgery predicts good outcome and warrants emergent evacuation of SSEH especially in the cervical and thoracic regions, where the clots are located in proximity to the spinal cord.
Journal of neurosurgery. Spine 10/2009; 11(4):480-6. · 1.61 Impact Factor
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Ching-Chang Chen,
Peng-Wei Hsu,
Tai-Wei Erich Wu,
Shih-Tseng Lee,
Chen-Nen Chang,
Kuo-chen Wei,
Chih-Cheng Chuang,
Chieh-Tsai Wu,
Tai-Ngar Lui,
Yung-Hsin Hsu, Tzu-Kang Lin,
Sai-Cheung Lee,
Yin-Cheng Huang
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ABSTRACT: Stereotactic biopsy is a widely used surgical technique for the histological diagnosis of intracranial lesions. Potential risks of this procedure, such as hemorrhage, seizure, and infection have been established, and different risk factors have been characterized. However, these risks have been addressed by only few studies conducted in Asian countries.
The study group is comprised of 299 consecutive stereotactic biopsy procedures by 11 neurosurgeons between 2004 and 2007. The pre-operative medical conditions, methods of biopsy and postoperative complications were analyzed.
The overall diagnostic yield was 90.64%. Complications were observed in 7.36% of the cases, with symptomatic hemorrhages occurring in 4.35% of the cases, and the overall mortality rate in this study population was 1.34%. Patients with liver cirrhosis were at a higher risk of hemorrhage. Other clinical, radiological, or histological variables were not associated with an increased risk of complications.
Stereotactic brain biopsy is a safe and reliable way to obtain a histological diagnosis. Based on our recent clinical experiences, the data suggests that more attention should be paid to liver cirrhotic patients, since the chance on hemorrhage is significantly larger.
Clinical neurology and neurosurgery 09/2009; 111(10):835-9. · 1.30 Impact Factor
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ABSTRACT: A novel smart control system based on genetic algorithms (GAs) is proposed in this paper. The system is comprised of three parts: the fiber Bragg grating (FBG) sensor-based sensing network for structural health monitoring, the GA-based location optimizer for sensor arrangement, and the GA-based controller for vibration mitigation under external excitation. To evaluate the performance of the proposed system, an eight-story steel structure was designed specifically to represent a structure with large degrees of freedom. In total 16 FBG sensors were deployed on the structure to implement the concept of a reliable sensing network, and to allow the structure to be monitored precisely under any loading. The advantage of applying a large amount of information from the sensing system is proven theoretically by the GA-based location optimizer. This result greatly supports the recent tendency of distributing sensors around the structure. Two intuitive GA-based controllers are then proposed and demonstrated numerically. It is shown that the structure can be controlled more effectively by the proposed GA-strain controller than by the GA-acceleration controller, which represents the traditional control method. A shaking table test was carried out to examine the entire system. Experimental verification has demonstrated the feasibility of using this system in practice. Copyright © 2008 John Wiley & Sons, Ltd.
Earthquake Engineering & Structural Dynamics 11/2008; 38(4):457 - 475. · 1.78 Impact Factor
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ABSTRACT: This study improves a NEURO-FBG active control system to mature the concept of a smart structure. Originally, a system similar to the human brain is created from FBG sensors and neural networks. The system comprises three parts, namely, a structural condition surveillance system, a NEURO-FBG converter, and a NEURO-FBG controller. To solve the inherent time-consuming and reliability problem of the NEURO-FBG converter, a new technology is first proposed, and the relationship between inter-story drift and strain data is established. Global indices such as displacement and velocity of the structure are then reconstructed for searching the optimal control force of the actuator. Meanwhile, the soundness of a building with hydraulic actuators is also an important issue to be solved. To make the building sound, the characteristics of earthquakes are considered for enhancing the performance of the NEURO-FBG controller. Theoretical analysis shows satisfactory improvement to the control efficiency of both displacement and acceleration. To verify the enhanced system, a series of shaking table tests was conducted. Experimental results demonstrated that the new NEURO-FBG system can effectively manage the structure; and the controller, taking into consideration the ground acceleration effect, is more reliable and robust for practical application than a conventional controller. Copyright © 2007 John Wiley & Sons, Ltd.
Earthquake Engineering & Structural Dynamics 02/2008; 37(3):427 - 445. · 1.78 Impact Factor
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Journal of Neurosurgery 12/2006; 105(6):932. · 2.96 Impact Factor
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ABSTRACT: This paper demonstrates the reliability and accessibility functions of fiber Bragg grating (FBG) sensors in a radiation structural health monitoring and safety evaluation application. FBG sensors, dial gages and conventional resistance strain gages (RSGs) were attached to the temporary H-beam frame, and distributed below the path of the rail tracks for online safety measurements during the process of moving the structure of the research reactor. The results showed the high level of performance of the FBG sensors for an online structural health monitoring system. The measurement data from the FBG monitoring system were comparable to the theoretical calculation results and the FEM simulations as the movement progressed. The result of this investigation also clearly demonstrates that FBG sensors can overcome the harsh environments of electric and magnetic interference, while conventional RSG sensors are subject to serious fluctuations providing useless feedback.
Smart Materials and Structures 09/2006; 15(5):1421. · 2.09 Impact Factor
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ABSTRACT: Subarachnoid hemorrhage (SAH) resulting from aneurysmal rupture is the major cause of nontraumatic SAH. We hypothesized that oxidative stress could be increased following aneurysmal SAH due to hemoglobin release and ischemia-reperfusion injury and that may further contribute to poor outcome. We collected plasma and cerebrospinal fluid (CSF) samples from 11 non-SAH controls and 15 aneurysmal SAH patients for up to 10 days after surgery and investigated status of oxidative stress in patients. Results showed that mean or peak levels of F(2)-isoprostanes (F(2)-IsoPs), a specific marker of lipid peroxidation, and total nitrate/nitrite, metabolites of nitric oxide and peroxynitrite, in CSF and plasma were significantly higher in SAH patients than in controls. First-day levels were also higher in CSF, but not in plasma, in SAH patients. Moreover, mean and peak levels of CSF F(2)-IsoPs were positively correlated with poor outcome or severity of clinical conditions in patients. Furthermore, levels of retinol, delta-tocopherol, beta+gamma-tocopherol, lutein, beta-carotene, and coenzyme Q(10) in plasma were significantly lower in SAH patients than in controls. Our results indicate that oxidative damage may play important roles in the severity and complications of aneurysmal SAH and suggest that means to suppress lipid peroxidation may be beneficial in improving the outcome of aneurysmal SAH.
Free Radical Biology and Medicine 05/2006; 40(8):1466-73. · 5.42 Impact Factor
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ABSTRACT: Central neurocytomas (CNs) are typically located in the lateral ventricle. Primary origins in the fourth ventricle are very rare. We discuss the clinical symptoms, imaging findings, and microscopic features of these rare tumors.
We report a case of a fourth ventricle CN in a 35-year-old male patient with the initial symptoms of progressive headaches and blurred vision for more than 2 months. Computed tomography and magnetic resonance imaging of the brain revealed a slightly enhanced tumor in the fourth ventricle, with obstructive hydrocephalus.
Total surgical removal of the tumor was performed. The tumor was initially diagnosed as an oligodendroglioma. The final definitive diagnosis as a CN was made after special immunohistochemical studies.
CNs located in the fourth ventricle are extremely rare. Immunohistochemical stains and transmission electron microscopy can provide useful diagnostic information. Total tumor excision is associated with favorable prognoses. Postoperative radiotherapy may be considered for cases of subtotal excision, anaplastic histological variants, or recurrent tumors.
Neurosurgery 07/2002; 50(6):1365-7. · 2.79 Impact Factor
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ABSTRACT: This paper presents the results of applying the FBG sensors to monitor the strain and temperature of a full scale pre-stressed concrete bridge made with high performance concrete during the construction process. The advantages and disadvantages of FBG as compared with other types of sensors are also discussed.
Optical Fiber Sensors Conference Technical Digest, 2002. Ofs 2002, 15th; 02/2002
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ABSTRACT: Recently, a new concept of smart structures has been proposed and widely discussed. To implement the smart concept, much state-of-the-art technology developed these days is applied. Fiber Bragg grating (FBG) sensors, originated from the field of fiber optics, have been seeing stunning ability in dynamic instrumentation in the last decade. In addition, neural networks, commenced from artificial intelligence, have also shown their outstanding performance in complex problems. To implement the concept of a smart structure, a smart active control system is presented in this paper. Both FBG sensors and neural networks are used to comprise a system similar to the human-brain. The smart system is composed of three parts: structural condition surveillance system, NEURO-FBG CONVERTER and NEURO-FBG CONTROLLER. By distributing as many sensors as possible in the important parts of buildings, FBG sensors can be applied for structure scrutiny, as well as representing the dendrites of a neural network system. For transferring and predicting the structural response from local data into global information, a new NEURO-FBG CONVERTER technique is built and tested. The optimal control force is then determined from the capability of the chosen actuator with the co-operation of NEURO-FBG CONVERTERs and the NEURO-FBG CONTROLLER is established by the collected patterns. Comparison of structural responses under uncontrolled and NEURO-FBG control system is made to illustrate the advantages of using this new technique. The results have demonstrated that the NEURO-FBG system can effectively control the structure and offer a more reliable choice than ordinary active control.
