• Journal of Korean Neurosurgical Society
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• v.45 no.1
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• pp.11-15
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• 2009

Objective : The aim of study was to review our patient population to determine whether there is a critical aneurysm size at which the incidence of rupture increases and whether there is a correlation between aneurysm size and location. Methods : We reviewed charts and radiological findings (computed tomography (CT) scans, angiograms, CT angiography, magnetic resonance angiography) for all patients operated on for intracranial aneurysms in our hospital between September 2002 and May 2004. Of the 336 aneurysms that were reviewed, measurements were obtained from angiograms for 239 ruptured aneurysms by a neuroradiologist at the time of diagnosis in our hospital. Results : There were 115 male and 221 female patients assessed in this study. The locations of aneurysms were the middle cerebral artery (MCA, 61), anterior communicating artery (ACoA, 66), posterior communicating artery (PCoA, 52), the top of the basilar artery (15), internal carotid artery (ICA) including the cavernous portion (13), anterior choroidal artery (AChA, 7), A1 segment of the anterior cerebral artery (3), A2 segment of the anterior cerebral artery (11), posterior inferior cerebellar artery (PICA, 8), superior cerebellar artery (SCA, 2), P2 segment of the posterior cerebral artery (1), and the vertebral artery (2). The mean diameter of aneurysms was $5.47{\pm}2.536\;mm$ in anterior cerebral artery (ACA), $6.84{\pm}3.941\;mm$ in ICA, $7.09{\pm}3.652\;mm$ in MCA and $6.21{\pm}3.697\;mm$ in vertebrobasilar artery. The ACA aneurysms were smaller than the MCA aneurysms. Aneurysms less than 6 mm in diameter included 37 (60.65%) in patients with aneurysms in the MCA, 43 (65.15%) in patients with aneurysms in the ACoA and 29 (55.76%) in patients with aneurysms in the PCoA. Conclusion : Ruptured aneurysms in the ACA were smaller than those in the MCA. The most prevalent aneurysm size was 3-6 mm in the MCA (55.73%), 3-6 mm in the ACoA (57.57%) and 4-6 mm in the PCoA (42.30%). The more prevalent size of the aneurysm to treat may differ in accordance with the location of the aneurysm.

• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.207-212
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• 2005

Objective: Classically, single photon emission tomography is known to be the reference standard for evaluating the hemodynamic status of patients with moyamoya disease. Recently, T2-weighted perfusion magnetic resonance(MR) imaging has been found to be effective in estimating cerebral hemodynamics in moyamoya disease. We aim to assess the utility of perfusion-weighted MR imaging for evaluating hemodynamic status of moyamoya disease. Methods: The subjects were fourteen moyamoya patients(mean age: 7.21 yrs) who were admitted at our hospital between Sep. 2001 to Sep 2003. Four normal children were used for control group. Perfusion MR imaging was performed before any treatment by using a T2-weighted contrast material-enhanced technique. Relative cerebral blood volume(rCBV) and time to peak enhancement(TTP) maps were calculated. Relative ratios of rCBV and TTP in the anterior cerebral artery(ACA), middle cerebral artery(MCA) and basal ganglia were measured and compared with those of the posterior cerebral artery(PCA) in each cerebral hemispheres. Using this data, we analysed the hemodynamic aspect of pediatric moyamoya disease patients in regarding to the age, Suzuki stage, signal change in FLAIR MR imaging, and hemispheres inducing symptoms. Results: The mean rCBV ratio of ACA, MCA did not differ between normal children and moyamoya patients. However the significant TTP delay was observed at ACA, MCA territories (mean = 2.3071 sec, 1.2089 see, respectively, p < 0.0001). As the Suzuki stage of patients is advanced, rCBV ratio is decreased and TTP differences increased. Conclusion: Perfusion MR can be applied for evaluating preoperative cerebral hemodynamic status of moyamoya patients. Furthermore, perfusion MR imaging can be used for determine which hemisphere should be treated, first.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.222-231
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• 1999

Uwhangchungsimwon(UC) has been used in the treatment of a wide variety of conditions including stroke, hypertension, arteriosclerosis, autonomic imbalance, mental instablity, etc in Korean traditional hospitals, In particular it is often initialy chosen for emergency care of acute stroke. The aim of this study was to evaluate the effect of UC on cerebral hemodynamics. Using transcranial Doppler ultrasound, we studied changes of mean flow velocity and pulsatility index(PI) of middle cerebral arteries (MCAs) from 11 health young volunteers who were administrated with 1 pill UC and 11 health controls who were not. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with breath-holding index(BHI). Systolic blood pressure, diastolic blood pressure, and heart rate were measured using ambulatory blood pressure monitoring(ABPM). In UC administration group, the evaluation was performed during basal condition. and repeated at 20, 40, and 60 min after administration. In controls, the evaluation was performed at corresponding time intervals. Mean flow velocity in middle cerebral artery, systolic blood pressure, diastolic blood pressure, and heart rate did not change during the observation period and were not different between these two groups. However, administration of UC was associated with decreases in PI by $3.6{\sim}12.4%$ in BHI by $17.9{\sim}24.8%$ compared with pre-administration period. Decreases in PI and BHI with UC were significantly different compared with control group (p<0.05). These results indicate that UC decreases PI and BHI in cerebral artery, which is due to a dilation of cerebral resistance vessels.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.195-202
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• 2018

Hyperglycemia is one of the major risk factors for stroke. Hyperglycemia can lead to a more extensive infarct volume, aggravate neuronal damage after cerebral ischemia. ${\alpha}$-Synuclein is especially abundant in neuronal tissue, where it underlies the etiopathology of several neurodegenerative diseases. This study investigated whether hyperglycemic conditions regulate the expression of ${\alpha}$-synuclein in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury. Male Sprague-Dawley rats were treated with streptozotocin (40 mg/kg) via intraperitoneal injection to induce hyperglycemic conditions. MCAO were performed four weeks after streptozotocin injection to induce focal cerebral ischemia, and cerebral cortex tissues were obtained 24 hours after MCAO. We confirmed that MCAO induced neurological functional deficits and cerebral infarction, and these changes were more extensive in diabetic animals compared to non-diabetic animals. Moreover, we identified a decrease in ${\alpha}$-synuclein after MCAO injury. Diabetic animals showed a more serious decrease in ${\alpha}$-synuclein than non-diabetic animals. Western blot and reverse-transcription PCR analyses confirmed more extensive decreases in ${\alpha}$-synuclein expression in MCAO-injured animals with diabetic condition than these of non-diabetic animals. It is accepted that ${\alpha}$-synuclein modulates neuronal cell death and exerts a neuroprotective effect. Thus, the results of this study suggest that hyperglycemic conditions cause more serious brain damage in ischemic brain injuries by decreasing ${\alpha}$-synuclein expression.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.239-252
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• 2024

Dexmedetomidine displays multiple mechanisms of neuroprotection in ameliorating ischemic brain injury. In this study, we explored the beneficial effects of dexmedetomidine on blood-brain barrier (BBB) integrity and neuroinflammation in cerebral ischemia/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h and reperfusion for 24 h to establish a rat model of cerebral ischemia/reperfusion injury. Dexmedetomidine (9 ㎍/kg) was administered to rats 30 min after MCAO through intravenous injection, and SB203580 (a p38 MAPK inhibitor, 200 ㎍/kg) was injected intraperitoneally 30 min before MCAO. Brain damages were evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, Nissl staining, and brain water content assessment. BBB permeability was examined by Evans blue staining. Expression levels of claudin-5, zonula occludens-1, occludin, and matrix metalloproteinase-9 (MMP-9) as well as M1/M2 phenotypes-associated markers were assessed using immunofluorescence, RT-qPCR, Western blotting, and gelatin zymography. Enzyme-linked immunosorbent assay was used to examine inflammatory cytokine levels. We found that dexmedetomidine or SB203580 attenuated infarct volume, brain edema, BBB permeability, and neuroinflammation, and promoted M2 microglial polarization after cerebral ischemia/reperfusion injury. Increased MMP-9 activity by ischemia/reperfusion injury was inhibited by dexmedetomidine or SB203580. Dexmedetomidine inhibited the activation of the ERK, JNK, and p38 MAPK pathways. Moreover, activation of JNK or p38 MAPK reversed the protective effects of dexmedetomidine against ischemic brain injury. Overall, dexmedetomidine ameliorated brain injury by alleviating BBB permeability and promoting M2 polarization in experimental cerebral ischemia/reperfusion injury model by inhibiting the activation of JNK and p38 MAPK pathways.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.234-241
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• 1999

The present study assessed the cerebroprotective effect of platelet-activating factor(PAF) antagonists in transient cerebral ischemia of rats. Right middle cerebral artery (MCA) of Sprague-Dawley rats was occluded for 2 hours using an intraluminal filament technique, and was reperfused for 6 hours following cerebral ischemia. The infarct area of seven coronal brain slices was measured morphometrically following stain ing in the 2% 2,3,5-triphenyltetrazolium chloride solution. The changes in regional cerebral blood flow (rCBF) and pial arteriolar diameter were measured by laser-Doppler flowmetry and by a videomicroscopy, respectively. The infarct size was significantly reduced by PAF antagonists, BN 52021 and CV-6209, which were administered i.p. 10 min before MCA occlusion. Pretreatment with PAF antagonists significantly restored the changes in pial arterial diameter as well as those in rCBF during the period of cerebral ischemia-reperfusion. PAF antagonists significantly inhibited the inducible nitric oxide synthase activity in the pial arteries ipsilateral to ischemia. These results suggest that PAF antagonists exert a cerebroprotective effect against ischemic brain damage through an improvement of postocclusive cerebral blood flow.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.268-271
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• 2012

Objective : To propose grading of intracerebral hemorrhage (ICH) in ruptured middle cerebral artery (MCA) aneurysms, which helps to predict the prognosis more accurately. Methods : From August 2005 to December 2010, 27 cases of emergent hematoma evacuation and aneurysm clipping for MCA aneurysms were done in the author's clinic. Three variables were considered in grading the ICH, which were 1) hematoma volume, 2) diffuse subarachnoid hemorrhage (SAH) that extends to the contralateral sylvian cistern, and 3) the presence of midline shifting from computed tomography findings. For hematoma volume of greater than 25 mL, we assigned 2 points whereas 1 point for less than 25 cc. We also assigned 1 point for the presence of diffuse SAH whereas 0 point for the absence of it. Then, 1 point was assigned for midline shifting of greater than 5 mm whereas 0 point for less than 5 mm. Results : According to the grading system, the numbers of patients from grade 1 to 4 were 4, 6, 8 and 9 respectively and 5, 7, 8, 4 and 3 patients belonged to Glasgow Outcome Scale (GOS) 5 to 1 respectively. It was found that the patients with higher GOS had lower ICH grade which were confirmed to be statistically significant (p<0.01). Preoperative Hunt and Hess grade and absence of midline shifting were the factors to predict favorable outcome. Conclusion : The ICH grading system composed of above three variables was helpful in predicting the patient's outcome more accurately.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.699-704
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• 2001

Objectives : The rupture of middle cerebral artery(MCA) aneurysm usually cause or is associated with higher incidence of intracerebral hemorrhages(ICH) than any other aneurysmal ruptures. Also, the outcome of patients who had ICH is known to be worse than patients who had subarachnoid hemorrhage(SAH) only. The authors report the bleeding pattern and outcome of ruptured MCA aneurysm patients. Patients and Methods : A total 106 ruptured MCA aneurysm patients who were surgically treated were included and they were divided into 2 groups by the initial brain CT findings according to the presence or absence of ICH over 10cc in amount. The clinical data were analysed retrospectively. Results : The overall mortality was 18.9%. Among 81 patients(76.4%) who had subarachnoid hemorrhage(SAH) only, 68 patients(84%) showed favorable outcome. Twenty five patients(23.6%) had ICH over 10cc in amount with or without SAH, and among them, 11 patients(44%) showed favorable outcome. The ICH was located in temporal lobe(15 patients, 60%), frontal lobe(3, 12%), sylvian fissure(6, 24%) and frontal-temporal lobe(1, 4%). Among 15 patients who had ICH in temporal lobe, only 4 patients(26.6%) showed favorable outcome and all 3 patients who had ICH in frontal lobe showed favorable outcome. Conclusion : ICH was presented in 23.6% of ruptured MCA aneurysm patients and the prognosis of patients with ICH was worse than patients with SAH only. The ICH was located mainly in the temporal lobe and sylvian fissure.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.3
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• pp.141-146
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• 2004

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins, composed of two presynaptic membrane proteins [synaptosomal-associated protein of 25 kDa (SNAP-25) and syntaxin] and a presynaptic vesicular protein [vesicle-associated membrane protein (VAMP)], serve as a core of exocytotic fusion machinery, which can be affected by ischemia. Synaptic protein in core region, striatum and cortex has been shown to alter after focal ischemia, however, little is known in hippocampus. Hippocampus is remote from ischemic core, but it is one of the most vulnerable regions. Using immunohistochemistry, the present study was undertaken to investigate the alteration of expression of SNAP-25, syntaxin, and VAMP in the hippocampus of rats which were subjected to middle cerebral artery occlusion (MCAO) for 2h and allowed to reperfuse. At 2 weeks of reperfusion, the SNAP-25 and syntaxin immunoreactivity was increased in the stratum oriens of the CA1 and the stratum lucidum of the CA3 in the ipsilateral hippocampus. However, VAMP immunoreactivity didn't show significant change. These results demonstrate that the level of the presynatpic plasma membrane proteins (SNAP-25 and syntaxin) in the rat hippocampus is more sensitively affected by focal ischemia than that of the synaptic vesicle protein (VAMP).

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.269-275
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• 2016

Objective : Although middle cerebral artery (MCA) aneurysms are less amenable to coil embolization, an increasing number of studies support favorable endovascular treatment for them. The purpose of this study is to compare the outcomes of two different treatments (surgery versus coiling) and evaluate the benefits of surgical clipping for MCA aneurysms. Methods : Here we retrospectively analyzed the outcomes of 178 ruptured and unruptured MCA aneurysms treated in patients between September 2008 and April 2012. Parameters assessing treatment outcomes include degree of aneurysm occlusion, presence of regrowth, clinical status, and complications. Results : Among 178 MCA aneurysms, 153 were treated surgically. After a mean follow-up of 12 months, the surgery group showed a clinically significant complete occlusion rate (98%) compared with the coiling group (56%) (p<0.001). Follow-up radiologic evaluation showed a higher regrowth rate (four of 16 cases) in the coiling group than in the surgery group (one of 49 cases) (p=0.003). There was no statistically significant difference in favorable clinical outcome rate between the two groups. The procedure-related permanent morbidity and mortality rates were 2% (three of 153 cases) in the surgery group and 0% (0 of 25 cases) in the coiling group. Conclusion : Compared to endovascular treatment, surgical neck clipping for both ruptured and unruptured MCA aneurysms results in a significantly higher complete obliteration rate and less regrowth. Therefore, even in this endovascular era, we still recommend surgical clipping as the primary treatment option for MCA aneurysms rather than coil embolization.