• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.49-54
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• 2008

Purpose : The purpose of this study was to determine the characteristics of hypoxic-ischemic encephalopathy (HIE) on diffusion-weighted imaging (DWI) and the role of DWI for the diagnosis of HIE. Materials and Methods : Six patients with HIE underwent MRI including DWI. MR examinations were performed within 4 - 32 days (mean, 11.8 days) after hypoxic brain insult. We assessed the distribution of the lesions and compared the DWI and T2, FLAIR images for the subjective conspicuity of the lesions. Results : In all patients, symmetrical hyperintense lesions were demonstrated in the bilateral basal ganglia on T2, FLAIR, and DWI. On ADC map image, the lesions were hypointense in four of six patients and isointense in other two patients. Lesion conspicuity on DWI was higher than on T2 and FLAIR images in four of six patients and similar in other two patients. For the involvement of the cortex and subcortical white matter, in five of six patients, bilateral symmetric hyperintense lesions were seen on T2, FLAIR, and DWI. Lesion conspicuity on DWI was higher than on T2 and FLAIR images in three of them and similar in other two patients. On ADC map image, the lesions showed hypointensity in three of five patients and isointensity in other two patients. For the involvement of the deep cerebral white matter, T2, FLAIR, and DWI showed bilateral symmetric hyperintense lesions in four of six patients. Among them, Lesion conspicuity on DWI was higher than on T2 and FLAIR images in only one patient. Conclusion : HIE is characterized by symmetrical hyperintense lesions in the bilateral basal ganglia, cerebral cortex, and white matter on DWI and the lesions are more conspicuously demonstrated on DWI than on T2 and FLAIR images.

• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.100-106
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• 2000

Purpose : To evaluate the usefulness of cerebral blood flow measurement applied to perfusion weighted image with short-scan time single shot gradient echo-planar technique in measuring cerebral blood volume(rCBV) of normal rabbits. Materials and methods : With 2.1-3.6 kg weighted rabbits, image is acquired when they are in supine position in children positioner. Perfusion weighted image is acquired to 44 seconds per 1 second successively. After 4 seconds later, Gd-DTPA 2ml are injected into int. jugular vein with 2 ml per second and normal saline is also injected after that. Same technique is applied 2 times per 30 minites in same rabbit. After Image is obtained in two part of cerebral cortex at vertex, convexity, in one of basal ganglia with choosing about $3-5{\textrm{mm}^2}$ areas. Curve of signal intensity changes in time sequence is drawn. After this images are transmitted by PC and software IDL, regional cerebral blood volume is measured with imaging processing program made by us. Results : With 22 of 24 rabbits, satisfactory 1-2 signal intensity versus time curve is made. Cerebral blood capacity and contrast media stay time (ST) is measured in two cerebral cortex and basal ganglia refering in parietal cerebral cortex. Mean focal cerebral blood flow capacity ratio in cortex was $0.97{\pm}0.35$ and in basal ganglia, $0.99{\pm}0.37$, mean contrast media stay time in cortex was $9.83{\pm}1.63$ sec and in basal gaiglia, $9.42{\pm}1.14$ sec, but there was no statistically significant difference between two areas ($\rho$=0.05). Conclusion : In cerebral cortex and basal ganglia, there is no difference in mean focal blood volume and mean contrast stay time. Therefore, PWI is useful in cerebral blood flow and early diagnosis, prognosis of cerebral ischemic disease. Hereafter, it is helpful in analysing cerebral blood flow changes with comparison difference in rCBV between normal tissue and ischemic tissue, and that with DWI finding in infarcted patient.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.467-475
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• 2001

Cardiac arrest, hypoxia, shock or seizure has been known to induce cerebral ischemia. This study was designed to investigate the effect of ischemia on hippocampal pyramidal layer induced by transient bilateral occlusion of the common carotid arteries. Mature Mongolian gerbils were sacrificed at days 2, 4, and 7 after carotid occlusion for 10 minutes. Sham-operated gerbils of control group were subjected to the same protocol except for carotid occlusion. During operation for ischemia, body temperature was maintained $37{\pm}0.5^{\circ}C$ in all gerbils. Paraffin-embedded brain tissue blocks were cut into coronal slices and stained with H-E stain or immunostain by TUNEL method. Neurons with the oval and prominent nucleus and without the eosinophilic cytoplasm in the subfield of hippocamapal pyramidal layer were calculated as to be viable neurons. Their chromatins were condensed or clumped. Their nuclei appeared multiangular or irregularly shrinked. The width of the pyramidal layer was reduced due to the loss of nuclei. At day 2 after reperfusion, some neurons in the CA1 subfield were slightly eosinophilic. But most neurons in the CA2 subfield were strongly eosinophilic. At day 4 day, most neurons in the CA1 subfield were severely damaged and at day 7 day, only a few survived neurons were observed. Survived neurons per longitudinal 1mm sector in the CA1, CA2, CA3, and CA4 subfields of pyramidal layer were investigated. At day 2, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfiedls were 104.5/mm (54.3%), 51.0/mm (33.8%), 105.5/mm (85.6%), and 124.3/mm (93.5%) compared to the nonischemic control group, respectively. At day 4, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfields were 3.2/mm (1.7%), 51.5/mm(34.2%), 95.3/mm (77.4%), and 112.5/mm (84.6%), respectively. At day 7, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfiedls were 0.8/mm (0.4%), 5.7/mm(3.8%), 9.8/mm (8.0%), and 5.0/mm (3.7%), respectively. The mean numbers of apoptotic positive neurons in the CA1 subfield at day 2, 4, and 7 after reperfusion were 67.8/mm, 153.2/mm and 123.7/mm, respectively. These results suggest that the transient cerebral ischemia cause severe damages in most neurons at day 7 and that the prosminent apoptotic positive neurons in hippocampal pyramidal layer are the delayed neuronal death induced by ischemia.

• Journal of Veterinary Clinics
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• v.26 no.1
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• pp.104-108
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• 2009

Global cerebral ischemia occurs commonly in patients who have a variety of clinical conditions including cardiac arrest and shock. Cerebral ischemia results in a rapid depletion of energy stores that triggers resulting in excitotoxic death. Imaging studies of the brain with computed tomography(CT) or magnetic resonance imaging(MRI) are necessary to confirm the clinical neurolocalization, identify any associated mass effect, and rule out other causes of focal brain disorders. Cardiopulmonary arrest was occurred by propofol anesthesia in a 1 year old, intact female Beagle dog. After successful cardiopulmonary resuscitation was performed within 5 minutes, clinical signs such as vocalization, paddling, opisthotonus and seizure were represented. At the 12th day, CT and MRI examinations of the brain were performed to evaluate the brain. After euthanasia, histopathologic examination was performed. On transverse image of CT, lesions appeared as a hypodense in the right dorsal surface of the frontal lobe and level of optic canal, and dorsomedial surface of occipital lobe of cerebrum. No contrast enhancement was represented following intravenous contrast administration. On MR images of brain, the lesions were seen as a hyperintense on T2-weighted(T2W) images and a isointense or mild hypointense on T1-weighted(T1W) images. Hyperintense lesions both T2W and T1W images were observed at the surrounding cerebral sulcus. There was no significant signal changes on contrast T1WI. Histopathologic examination after euthanasia revealed that the lesion was necrosis of the cerebral cortex caused by cerebral ischemia.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.477-483
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• 2018

Transcranial doppler is a non-invasive method that measures the blood flow velocity and the direction of cerebral blood vessels through the doppler principle. The pulsatility index is an index for measuring the transcranial doppler that reflects the distal vascular resistance and is used as an index for the presence and diffusion of cerebral small vessel diseases. The purpose of this study was to evaluate the risk factors affecting the basilar artery pulsatility index in ischemic stroke patients. From January 2014 to May 2015, 422 patients were selected by measuring the transcranial doppler pulsatility index, considering their basilar artery pulsatility index. Univariate analysis was performed using the basilar artery pulsatility index as a dependent variable. Multiple regression analysis was performed considering the factors affecting the pulsatility index as variables. Univariate analysis revealed age, presence of hypertension, presence of diabetes mellitus, presence of hyperlipidemia, and hematocrit (P<0.1) as factors. Multiple regression analysis showed statistically significant results with age (P<0.001), presence of diabetes (P=0.004), and presence of hyperlipidemia (P=0.041). The risk factors affecting the basilar artery pulsatility index of transcranial doppler were age, diabetes, and hyperlipidemia. Further research will be needed to increase the cerebral pulsatility index as a surrogate marker of the elderly, diabetes, and hyperlipidemia.

• Physical Therapy Korea
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• v.13 no.3
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• pp.57-66
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• 2006

Ischemic stroke results from a transient or permanent reduction in cerebral blood flow that is restricted to the territory of a major brain artery. Thus, this study was performed to examine (1) the effects of swimming exercise on the improvement of muscle atrophy, and (2) exercise and HSP 70 expression in an ischemic stroke model induced by middle cerebral artery occlusion. The results of this study were as follows: One week after ischemic stroke was induced, changes appeared in the muscle weight of the gastrocnemius muscle due to muscle atrophy in the affected side. Group II showed statistically significant difference from group III eight weeks after ischemic stroke was induced. (p<.05). One week and eight weeks after ischemic stroke was induced there was significant decrease in the relative muscle weight of the gastrocnemius muscle in each group except Group IV, while there was statistically significant increase in group II eight weeks after ischemic stroke was induced, compared to group III (p<.05). For neurologic exercise behavior tests, Group II generally had the highest score, compared to other groups. In immunohistochemical observations, Group II showed a decrease in HSP 70. The above results suggest that swimming exercise improved muscle atrophy, changed the HSP 70 expression of ischemic stroke in rats, and contributed to the improvement of exercise function.

• Physical Therapy Korea
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• v.17 no.1
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• pp.69-76
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• 2010

Ischemia that causes stroke induces inflammation of brain cells and apoptosis and as a result, it influences much on the functional part of a man. The needle electrode electrical stimulation (NEES) that combines acupuncture of oriental medicine with electric therapy of western medicine relieves inflammation of cells and has effect on regrowth of nerve tissues. This study was conducted to verify the influence of NEES on the occurrence of c-Fos of cerebrum after applying NEES to the meridian point, Zusanli (ST 36) of a rats with induced ischemia. Global ischemia was induced by using ligation method on common carotid artery of male Sprague Dawley (SD) rats. The ligation was maintained for 5 minutes and then suture was removed for blood reperfusion. After inducing global ischemia, NEES was done to the left and right meridian points of Joksamri of a rat for 30 minutes after 12 hours, 24 hours, and 48 hours. The findings were as follows. 1. In the result of immunohistochemical method, the number of c-Fos immune response cells significantly decreased (P<.05) in NEES group than the control group (GI) that did not get NEES. 2. In the result of western blotting, the occurrence of c-Fos after 24 hours from the inducement of ischemia significantly decreased (P<.05) in NEES group than the control group (GI) that did not get NEES. Therefore, as the effect of NEES was shown highest after 24 hours from the ischemia, it is suspected that NEES would take important role in early treatment after cerebral stroke.

• The Journal of Internal Korean Medicine
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• v.24 no.1
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• pp.11-20
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• 2003

Objective : Experimental studies have been done to elucidate the effect of kangwhalyupung-tang(KWYPT) on neuronal cell damage induced by brain ischemia. Method : The cytotoxic effect of ischemia was measured in the MTS assay cultures. MTS assay, INT assay, neurofilament(NF) enzymeimmuno assay(EIA). And the KWYPT on ischemia-induced neurotoxicity were examined by in vitro assays. Results : 1. The KWYPT protected effectively neuronal cell-death resulted from brain ischemia induced by the treatment of $95%N_2/5%CO_2$ for 10 min in those dependent fashion. 2. The KWYPT effectively increased the amount of NF resulting from brain ischemia, induced by the treatment of $95%N_2/5%CO_2$ for 15 min in those dependent fashions. Conclusions : KWYPT protects the brain ischemia-induced neurotoxicity through the increase of cell viability and of neurofilament in dose-dependent manner.

• Journal of Veterinary Clinics
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• v.33 no.1
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• pp.10-15
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• 2016

The purpose of this study was to establish reproducible ischemic infarction model using allogenic blood clot in beagle dogs and identify induced ischemic lesion after middle cerebral artery occlusion using magnetic resonance imaging (MRI) and histopathologic findings. Twenty eight male beagle dogs with no evidence of neurologic disease were experimented. Allogenic embolus was made using a healthy beagle dog. After internal carotid artery (ICA) was exposure, 16G catheter was introduced through the ICA. The dog was administered 0.3 ml blood clot for 15 seconds followed by 3 ml of saline for 15 seconds. MRI scans were performed with 1.5T to evaluate ischemic lesion at 7 days after middle cerebral artery occlusion procedure. Evaluation parameters of MRI include location, distribution, infarction type, margin, shape, mass effect and intensity of T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), fluid attenuated inversion recovery (FLAIR) sequence, diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC). On MRI, all dogs (28/28) showed focal or multifocal lesion including telencephalon and thalamus lesions, especially caudate nucleus (24/28). These lesions had well-defined margin from adjacent brain parenchyma, none or mild mass effect and various shape. Most of dogs appeared hyperintensity on T1WI, T2WI, FLAIR, and DWI/ADC, corresponding to chronic infarction. These lesions were histopathologically confirmed atrophic changes and unstained lesion. In conclusion, MRI is the useful method to provide information about ischemic infarction in dogs and the best reproducible ischemic infarction model was developed by using allogenic blood clot.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1205-1210
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• 2008

Purpose : The development of the corpus callosum occupies the entire period of cerebral formation. The myelination pattern on magnetic resonance imaging (MRI) is very useful to evaluate neurologic development and to predict neurologic outcome in high risk infants. The thickness of the corpus callosum is believed to depend on the myelination process. It is possible to calculate the length and thickness of the corpus callosum on MRI. Thus, we can quantitatively evaluate the development of the corpus callosum. We investigated the clinical significance of measuring various portions of the corpus callosum in neonate with neurologic disorders such as hypoxic brain damage and seizure disorder. Methods : Forty-two neonates were evaluated by brain MRI. We measured the size of the genu, body, transitional zone, splenium, and length of the corpus callosum. Each measurement was divided by the total length of the corpus callosum to obtain its corrected size. The ratio of corpus callosal length and the anteroposterior diameter of the brain was also measured. Results : There was no statistical significance in the sample size of each part of the corpus callosum. However, the corrected size or the ratio of body of the corpus callosum correlated with periventricular leukomalacia and hypoxic ischemic encephalopathy. Conclusion : The abnormal size of the corpus callosum showed a good correlation with periventricular leukomalacia and hypoxic ischemic encephalopathy in neonates. We can predict clinical neurological problems by estimation of the corpus callosum in the neonatal period.