• Journal of the Korean Mathematical Society
• /
• v.46 no.5
• /
• pp.1071-1085
• /
• 2009

This paper considers the problem of existence and exponential stability of almost periodic solution for shunting inhibitory cellular neural networks with distributed delays and large impulses. Based on the contraction principle and Gronwall-Bellman's inequality, some sufficient conditions are obtained. The results of this paper are new and they complement previously known results.

• Journal of Korean Neurosurgical Society
• /
• v.44 no.4
• /
• pp.211-216
• /
• 2008

Objective : The cranioplasty and ventriculoperitoneal (VP) shunt operation have been used to treat a large cranial defect with posttraumatic hydrocephalus (PTH). The aim of this study was to evlauate the difference of outcomes between in the shunting after the cranioplasty (group 1) and the cranioplasty after the shunting (group 2) in a large flaccid cranial defect with PTH. Methods : In this study, a retrospective review was done on 23 patients undergoing the cranioplasty and VP shunt operation after the decompressive craniectomy for a refractory intracranial hypertension from 2002 to 2005. All of 23 cases had a large flaccid concave cranial defect and PTH. Ten cases belong to group 1 and 13 cases to group 2. The outcomes after operations were compared in two groups 6 months later. Results : The improvement of Glasgow outcome scale (GOS) was seen in 8 cases (80.0%) of total 10 cases in group 1, and 6 cases (46.2%) of 13 cases in group 2. Three (75.0%) of 4 cases with hemiparesis in group 1 and 3 of 6 cases (50.0%) in group 2 were improved. All cases (2 cases) with decrease of visual acuity were improved in each group. Dysphasia was improved in 3 of 5 cases (60%) in group 1 and 4 of 6 cases (66.6%) in group 2. Conclusion : These results suggest that outcomes in group 1 may be better than in group 2 for a large flaccid concave cranial defect with PTH.

• Journal of Yeungnam Medical Science
• /
• v.25 no.2
• /
• pp.160-164
• /
• 2008

A two-month-old girl with a history of an incidental arachnoid cyst in the prenatal period (38 weeks) presented with persistent irritability. A follow-up computed tomographic (CT) scan revealed an enlarged arachnoid cyst with hydrocephalus. We performed craniotomy and fenestration, but the cyst size did not decrease, and hydrocephalus had worsened on a follow-up CT scan performed 13 months after fenestration. The patient was treated with cystoperitoneal shunting. Follow-up magnetic resonance imaging (MRI) performed 5 years later revealed that the arachnoid cyst had decreased in size and that the hydrocephalus had resolved. Enlarging arachnoid cysts are not common, and optimal surgical treatment is uncertain. Based on the features of this case, we believe cystoperitoneal shunting is an advisable surgical intervention for patients with enlarging arachnoid cysts presenting with hydrocephalus.

• Journal of Chest Surgery
• /
• v.49 no.1
• /
• pp.22-28
• /
• 2016

Background: Carotid endarterectomy (CEA) with selective shunting is the surgical method currently used to treat patients with carotid artery disease. We evaluated the incidence of major postoperative complications in patients who underwent CEA with selective shunting under transcranial Doppler (TCD) at our institution. Methods: The records of 45 patients who underwent CEA with TCD-based selective shunting under general anesthesia from November 2009 to June 2015 were reviewed. The risk factors for postoperative complications were analyzed using univariate and multivariate analysis. Results: Preoperative atrial fibrillation was observed in three patients. Plaque ulceration was detected in 10 patients (22.2%) by preoperative computed tomography imaging. High-level stenosis was observed in 16 patients (35.5%), and 18 patients had contralateral stenosis. Twenty patients (44.4%) required shunt placement due to reduced TCD flow or a poor temporal window. The 30-day mortality rate was 2.2%. No cases of major stroke were observed in the 30 days after surgery, but four cases of minor stroke were noted. Univariate analysis showed that preoperative atrial fibrillation (odds ratio [OR], 40; p=0.018) and ex-smoker status (OR, 17.5; p=0.021) were statistically significant risk factors for a minor stroke in the 30-day postoperative period. Analogously, multivariate analysis also found that atrial fibrillation (p<0.001) and ex-smoker status (p=0.002) were significant risk factors for a minor stroke in the 30-day postoperative period. No variables were identified as risk factors for 30-day major stroke or death. No wound complications were found, although one (2.2%) of the patients suffered from a hypoglossal nerve injury. Conclusion: TCD-based CEA is a safe and reliable method to treat patients with carotid artery disease. Preoperative atrial fibrillation and ex-smoker status were found to increase the postoperative risk of a small embolism leading to a minor neurologic deficit.

• Journal of Korean Neurosurgical Society
• /
• v.52 no.3
• /
• pp.270-272
• /
• 2012

A 31-year-old man was admitted to our hospital due to hydrocephalus with neurosarcoidosis. Ventriculo-peritoneal shunting was performed in the right lateral ventricle with intravenous methylprednisolone. Subsequently, after 4 months, additional ventriculo-peritoneal shunting in the left lateral ventricle was performed due to the enlarged left lateral ventricle and slit-like right lateral ventricle. After 6 months, he was re-admitted due to upward gaze palsy, and magnetic resonance image showed an isolated fourth ventricle with both the inlet and outlet of fourth ventricle obstructed by recurrent neurosarcoidosis. Owing to the difficulty of using an endoscope, we performed neuronavigator-guided ventriculo-peritoneal shunting via the left lateral transcerebellar approach for the treatment of the isolated fourth ventricle with intravenous methyl prednisolone. The patient was discharged with improved neurological status.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.155-158
• /
• 2010

Purpose: $^{99m}Tc$-macroaggregated albumin (MAA) hepatic arterial perfusion scintigraphy was known for useful method to evaluate patients receiving intraarterial chemotherapy for liver cancer. This study evaluate about usefulness of normal liver on hepatocellular carcinoma (HCC) from HCC patients. This study is to see the usefullness of Hepatic Arterial Perfusion Scintigraphy (HAPS) by measuring mass size, shape, lung shunting and tumor to normal ratio (T/N ratio) in relative blood stream of HCC patients compared with HCC on normal liver. Materials and Methods: From June 2009 to September 2009, HAPS studies were performed on 7 patients (men 6, women 1, mean 64) who were diagnosed HCC. HAPS was performed after proper hepatic artery $^{99m}Tc$-MAA of 5 mCi (185 MBq) injection by catheter. We performed anterior, posterior, both lateral view, SPECT of chest and abdomen. Then we set up ROI and calculated lung shunting, T/N ratio for each count, count/pixel (mean value). Results: Tumor and liver size analyzed by ROI of anterior, posterior view are 2.0-10.8 cm (mean 3.75 cm), 8.8-18.5 cm (mean 14.6 cm). T/N ratio analyzed by total tumor and total normal mean value are 2.41-5.76 (mean 3.8). lung shunting analyzed by total liver count is 3.14-13.92% (mean 6.77%). Conclusion: HAPS with $^{99m}Tc$-MAA can evaluate mass size, location, quantitative analysis through T/N ratio. also HAPS can evaluate detection of arteriovenous shunt through lung uptake before radioisotope therapy. Therefore HAPS with $^{99m}Tc$-MAA can be useful method in aspect of evaluation and treatment of HCC.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.sup1
• /
• pp.99-107
• /
• 2001

Objective : Hydrocephalus and vasospasm are the common complications following subarachnoid hemorrhage (SAH). In spite of development of perioperative management and operative technique, hydrocephalus cause neurological deficit and poor prognosis. Usually CSF drainage procedure(external ventricular drainage(EVD) or shunt) is needed in hydrocephalus following SAH. The aim of this study was to investigate whether the need for shunting and the outcome after shunting in hydrocephaus following SAH can be related to the duration, daily and total amount of cerebrospinal fluid(CSF) drainage at EVD. Material and Method : IVH is one of several factors which cause hydrocephalus. In this retrospective study, firstly we investigated the incidence of IVH in total cases and frequency of IVH according to aneurysmal site and then prognosis of IVH following SAH. Among 629 patients with SAH, hydrocephalus was diagnosed by CT scan and symptoms. And then those 102 hydrocephalus following SAH were divided into two groups which were hydrocephalus with IVH group and without IVH group. In these two groups, we investigated and compared the incidence of hydrocephalus in all case, frequency of hydrocephalus according to aneurysmal site, the outcome according to H-H grade on admission and the need rate of shunt, etc. Of those hydrocephalus, 100 EVD procedures were done. The duration, daily and total amount of CSF drainage at EVD were investigated. Fifty cases expired during EVD was excluded. We analyzed whether the need rate of shunt and the final outcome after shunting can be related to IVH, the duration and daily and total amount of CSF drainage. Result : The incidence of hydrocephalus following SAH was 20%(with IVH group ; 64%, without IVH group ; 11%). As H-H grade on admission was better, the outcome of hydrocephalus was also better. The mortality rate of hydrocephalus with IVH was 64% which was higher than 40% that of hydrocephalus without IVH. The need rate of shunt in all cases of hydrocephalus following SAH was 20%, but those with IVH group excluding expired patients before shunt was 40%. This was very similar to 41% of the need rate of shunt in hydrocephalus without IVH. The total amount of CSF drainage was statistically related to the need rate of shunt(total amount : need rate of shunt/<1000cc : 15%, 1000-2000cc : 40%, >2000cc : 50%). The duration and daily amount of CSF drainage were not statistically related to the need rate of shunt, but as daily amount of CSF drainage was more and duration was longer, the need rate of shunt was increased(daily amount : need rate of shunt /<100cc : 16%, 100-200cc : 25%, >200cc : 40%//duration : need rate of shunt/<1week : 8%, 1-2weeks : 30%, >2weeks : 47%), and also the final outcome after shunting was poor. Especially the total amount of CSF drainage was significant related to the final outcome after shunting(total amount : GOS/<1000cc : I&II(3/4), 1000-2000cc : II(2/4), III(2/4), >2000cc : III&IV(6/7)). Conclusion : This study revealed that the incidence and mortality rate of hydrocephalus following SAH were influenced by IVH. So SAH associated IVH has the higher incidence of hydrocephalus and poor outcome. As the CSF drainage amount was more and duration of drainage was longer, the need rate of shunt was increased and the final outcome after shunting was poor. Especially the total amount of CSF drainage were strongly related to the need rate of shunt and the outcome after shunting.

• Journal of Korean Neurosurgical Society
• /
• v.54 no.6
• /
• pp.525-527
• /
• 2013

Upward migration of the peritoneal catheter of a subgaleo-peritoneal (SP) shunt and coiling into the subgaleal space is an extremely rare complication of a SP shunt. A 32-year-old male patient visited our hospital presenting with a large skull defect due to a prior craniectomy performed elsewhere. The patient underwent a cranioplasty with methylmetacrylate, but subsequently developed progressive pseudomeningocele and subgaleal cerebrospinal fluid (CSF) collection. The patient underwent CSF diversion via a SP shunt. After SP shunting, the pseudomeningocele disappeared completely. Six months later, the patient presented with progressive scalp swelling. Skull X-ray showed migration and coiling of the distal catheter of the SP shunt. The patient was treated by removing the entire shunt catheter and the dura was covered with a subgaleal flap. We would like to report our experience with a very rare complication of subgaleo-peritoneal shunting.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.328.2-328
• /
• 2002

General modeling of a resonant shunting damper has been made Iron piezoelectric sensor/actuator equation. It is found that an additional damping, which is augmented to a system, is generated by the shunt damping effect The transfer function of the tuned electrical absorber is derived for both series and parallel shunt circuit. The governing equations and associated boundary conditions are derived using Hamilton's Principle. The shunt voltage equation is also derived from the charge generated in PZT due to beam vibration. The frequency response function of the obtained mathematical model is compared with that of the tuned eledtrical absorber and experimental work. The vibration amplitude is reduced about 15 dB at targeted second mode frequency.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.277-280
• /
• 2004

TCE and PCE, suspected carcinogens, are the most common groundwater pollutant from extensive use as a solvent and degreaser. Escherichia coli TGI pBSKAN TOM Green and E. coli TGI pBSKAN ToMO, which were used DNA shuffling technique, produce Toluene-o-monooxygenase(TOM) and toluene-o-xylene- monooxygenase(ToMO). These cells and enzymes are degrading TCE and PCE, TOM and ToMO are needed to cofactor, such as NADH, NADPH and other cofactors. Used TCE and PCE degrading microorganisms experiment the contaminated material removal efficiency. A shunting test used NAD and Hydrogen peroxide.