• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.322-335
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• 2000

Purpose: For quantitative estimation of cerebrovascular reserve (CVR), we estimated the cerebral blood flow (CBF) using Lassen's nonlinearity correction algorithm and Tc-99m HMPAO brain SPECT images acquired with consecutive acquisition protocol. Using the values of CBF in basal and acetaBolamide (ACZ) stress states, CBF increase was calculated. Materials and Methods: In 9 normal subjects (age; $72{\pm}4$ years), brain SPECT was performed at basal and ACZ stress states consecutively after injection of 555 MBq and 1,110 MBq of Tc-99m HMPAO, respectively. Cerebellum was automatically extracted as reference region on basal SPECT image using threshold method. Assuming basal CBF of cerebellum as 55 ml/100g/min, CBF was calculated lot every pixel at basal states using Lassen's algorithm. Cerebellar blood flow at stress was estimated comparing counts of cerebellum at rest and ACZ stress and Lassen's algorithm. CBF of every pixel at ACZ stress state was calculated using Lassen's algorithm and ACZ cerebellar count. CVR was calculated by subtracting basal CBF from ACZ stress CBF for every pixel. The percent CVR was calculated by dividing CVR by basal CBF. The CBF and percentage CVR parametric images were generated. Results: The CBF and percentage CVR parametric images were obtained successfully in all the subjects. Global mean CBF were $49.6{\pm}5.5ml/100g/min\;and\;64.4{\pm}10.2ml/100g/min$ at basal and ACZ stress states, respectively. The increase of CBF at ACZ stress state was $14.7{\pm}9.6ml/100g/min$. The global mean percent CVR was 30.7% and was higher than the 13.8% calculated using count images. Conclusion: The blood flow at basal and ACZ stress states and cerebrovascular reserve were estimated using basal/ACZ Tc-99m-HMPAO SPECT images and Lassen's algorithm. Using these values, parametric images for blood flow and cerebrovascular reserve were generated.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.421-429
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• 2005

Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.18 no.1
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• pp.31-37
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• 2007

Objectives : A voxel based investigation of cerebral blood flow was conducted to identify functional differences during resting state between children with early-onset schizophrenia and normal controls. Methods : 19 children and adolescents with early-onset schizophrenia(8 boys and 11 girls, mean age $14.0{\pm}1.7$ years old) and 17 comparison children(13 boys and 4 girls, mean age $11.0{\pm}1.9$ years old) were examined by HMPAO-SPECT. The SPECT images were compared using statistical parametric mapping analyses, controlling for age and sex. Results : Increased cerebral blood flow in left medial and inferior frontal gyrus, right superior and middle frontal gyrus, both inferior temporal gyrus, and right cerebellar tonsil was found in children and adolescents with early-onset schizophrenia compared to control subjects. In addition, decreased cerebral blood flow in right thalamus, left posterior cingulate gyrus, right anterior cingulate gyrus and relatively wide areas from left medical frontal gyrus to superior parietal lobule were found in children and adolescents with early-onset schizophrenia compared to control subjects. Conclusion : The results of the current study provide additional evidences for brain areas involving the onset of schizophrenia in early age.

• Research in Community and Public Health Nursing
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• v.10 no.1
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• pp.80-92
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• 1999

The purpose of this study was to survey appropriateness of admission and days of care for the cerebral ischemia patients as a basis to provide an effectiveness of hospitalization. The authors retrospectively reviewed the medical records of cerebral ischemia patients in two hospitals from November 1997 to February 1998. Of 194 medical records reviewed, there were 2108 medical days. I t is used a 'Appropriateness Evaluation Protocol' previously developed by Gertman and Restuccia (1981) and translated by Department of Health Management, Seoul National University and Korea Institute for Health Services Management (1993), It was found that the 'Appropriateness Evaluation Protocol' had a high inter-rater reliability(k=.92), Statistical significant was tested by using the percentage, mean, and logistic regression by SAS 6.12. The results were as follows; 1. The appropriate admissions were 87.6%, days of care 63.4%, and the average length of stay $10.9{\pm}6.7$ days. 2. The reasons of inappropriate admissions were for work-up(75.0%) and conservative care (25.0%). Major reasons of inappropriate days of care were 'cases in which the medical purpose of hospitalization has been accomplish or can be addressed in a less setting(45.0%)', and 'cases in which there is a delay in performing the work-up or treatment which required patients is hospitalized (44.4%)'. 3. Appropriate days of care were higher as ageing. Appropriate days of care were higher in patients with lower accademic back ground than those of upper college graduates, and in the patients who enter a hospital via emergency room than out-patients department. Appropriate days of care were higher in the patient with MCA infarction, and lower in the patient with cerebellar infarction than the patient with lacunar infarction. Appropriate days of care were higher in attack first than attack above second, in nomortension patients than hypertensive, and lower in groups who engaged in semi-private room and public room than private room in hospital. Appropriate days of care were higher in shorter length of stay than longer length of stay. 4. Diagnosis, admission path, and appropriate days of care explained appropriate admissions. Diagnosis, appropriate admissions, hypertension explained appropriate days of care. According to the above results, author confirms the substantial amount of inappropriate hospital bed utilization. To reduce inappropriateness, it is necessary to develop some alternative services such as home care services or nursing home with which can be replaced inpatient services and to introduce policy such as case management which includes Critical Pathway for consistent management. And, it should be followed the further study for the effectiveness.

• Physical Therapy Korea
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• v.10 no.3
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• pp.17-27
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• 2003

Repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. Therefore, rTMS of high or low frequency over motor cortex may change certain aspects of motor learning performance and cortical activation. This study investigated the effect of high and low frequency subthreshold rTMS applied to the motor cortex on motor learning of sequential finger movements and brain activation using functional MRI (fMRI). Three healthy right-handed subjects (mean age 23.3) were enrolled. All subjects were trained with sequences of seven-digit rapid sequential finger movements, 30 minutes per day for 5 consecutive days using their left hand. 10 Hz (high frequency) and 1 Hz (low frequency) trains of rTMS with 80% of resting motor threshold and sham stimulation were applied for each subject during the period of motor learning. rTMS was delivered on the scalp over the right primary motor cortex using a figure-eight shaped coil and a Rapid(R) stimulator with two Booster Modules (Magstim Co. Ltd, UK). Functional MRI (fMRI) was performed on a 3T ISOL Forte scanner before and after training in all subjects (35 slices per one brain volume TR/TE = 3000/30 ms, Flip angle $60^{\circ}$, FOV 220 mm, $64{\times}64$ matrix, slice thickness 4 mm). Response time (RT) and target scores (TS) of sequential finger movements were monitored during the training period and fMRl scanning. All subjects showed decreased RT and increased TS which reflecting learning effects over the training session. The subject who received high frequency rTMS showed better performance in TS and RT than those of the subjects with low frequency or sham stimulation of rTMS. In fMRI, the subject who received high frequency rTMS showed increased activation of primary motor cortex, premotor, and medial cerebellar areas after the motor sequence learning after the training, but the subject with low frequency rTMS showed decreased activation in above areas. High frequency subthreshold rTMS on the motor cortex may facilitate the excitability of motor cortex and improve the performance of motor sequence learning in normal subject.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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• pp.33-40
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• 2001

Objective : Aneurysms of vertebral artery and its branches make up approximately 3% of all intracranial aneurysms. As the aneurysm have an intimate relationship with lower cranial nerves and medulla, surgical management of the aneurysms are one of the challenging neurosurgical problems. The authors analyzed the management outcomes for aneurysms arising from vertebral artery and its branches. Methods : At the authors' institution between May 1989 and Jan. 2000, 42 patients were treated with transcranial and endovascular surgery for aneurysms of vertebral artery and its branches. The medical records and neuroimaging studies of the patients were reviewed retrospectively. Results : Forty two patients were comprised of 28 female and 14 male patients aged from 26-80 year old(mean : 51.8). Of the 42 patients, 37 patients(88%) had subarachnoid hemorrhage. Of the 37 patients with subarachnoid hemorrahge, 35 patients(95%) were in good neurological status(Hunt Hess grade I-III), 2 patients(5%) in poor grade(H-H grade IV-V) before operation. Location of the aneurysm were 16 in vertebral artery, 12 in vertebro-PICA junction, and 14 in the peripheral PICA. Twenty nine patients were treated with transcranial surgery and 13 patients with endovascular surgery. The management outcome of the transcranial surgery was : Glasgow outcome scale(GOS) I and II ; 24, GOS III ; 2, GOS IV ; 1 and GOS V(death) ; 2. The causes of mortality related to transcranial surgery were rebleeding after failure in clipping in one and suspected brainstem infarct in one. Morbidity was attributed to vasospasm(3), lower CN palsy(7, including temporary dysfunction) and pseudomeningocele(1). The management outcome of the endovascular surgery was : Glasgow outcome scale(GOS) I-II ; 9, GOS III ; 1, GOS IV ; 1, and GOS V(death) ; 2. The causes of mortality related to endovascular surgery were sepsis from pneumonia(1) and vasospasm(1). There were one cerebellar infarct and one lateral medullary syndrome. Conclusion : Excellent and good surgical results can be expected in 80% of the patients with aneurysms of vertebral arery and its branches. The outcomes of endovascular surgery in treating vertebral artery aneurysm were satisfactory and endovascular surgery may offer a therapeutic alternative especially in vertebral dissecting aneurysm.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1001-1007
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• 2000

Objective : We analysed diverse clinical features of the cavernous angioma. Also, we report the experience in differ-ent methods of the management and their results. Method : Data from 80 patients who were confirmed pathologically or diagnosed radiologically between Jan. 1990 and Sept. 1998 at our hospital were analysed. Variable factors that were examined were : clinical features, effects of treatment, and complications. Results : There were 47 male and 33 female patients. The age at the first presentation was from 3 to 57(mean 34.1) years old. Clinical features were seizure in 28 cases(38%), bleeding in 24 cases(32%), neurologic deficits in 12 cases(16%), headache in 10 cases(14%), and six incidental cases. The locations of lesion were cerebral and cerebellar hemisphere in 45 cases(56.2%), brainstem, basal ganglia, and thalamus in 32 cases(40%), multiple in 3 cases (3.8%). Seizure was common at the third decade and occurred frequently with the cavernous angioma in temporal (43%) or frontal lobe(39%). Bleeding was frequent after the third decade with peak at the fourth decade and had high incidence in brainstem or thalamus. The gamma-knife radiosurgery was done in 47 cases. Rebleeding occurred in 3 cases, but it was within postradiosurgery 1 year. Symptomatic radiation change occurred in 2 cases of 8 radiation change on MRI. On follow-up MRI, no evidence of rebleeding was found in 30 cases. Also, The lesion size was decreased in 3 cases. Resection was performed in 23 cases ; total 20, subtotal 2, partial 1. Postoperative complication occurred in 6 cases(26.1%). After surgery, 7(63.6%) of 11 seizure patients had outcome of seizure-free. Subclinical rebleeding occurred in one of two subtotal resected cases. In 11 patients, conservative management was done. There was neither rebleeding nor symptom aggravation during follow-up period of mean 17.2 months. Conclusion : The solution for prevention of rebleeding is complete removal of the lesion located at noneloquent area or accessible region, especially for the patients who presented symptoms or intractable seizure. However, the Gamma knife radiosurgery is considered when the lesions are located at eloquent area or when severe postoperative morbidity is expected.

• Journal of Korean Neurosurgical Society
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• v.44 no.4
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• pp.228-233
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• 2008

Objective : The standard treatment strategy of intracranial aneurysms includes either endovascular coiling or microsurgical clipping. In certain situations such as in giant or dissecting aneurysms, bypass surgery followed by proximal occlusion or trapping of parent artery is required. Methods : The authors assessed the result of extracranial-intracranial (EC-IC) bypass surgery in the treatment of complex intracranial aneurysms in one institute between 2003 and 2007 retrospectively to propose its role as treatment modality. The outcomes of 15 patients with complex aneurysms treated during the last 5 years were reviewed. Six male and 9 female patients, aged 14 to 76 years, presented with symptoms related to hemorrhage in 6 cases, transient ischemic attack (TIA) in 2 un ruptured cases, and permanent infarction in one, and compressive symptoms in 3 cases. Aneurysms were mainly in the internal carotid artery (ICA) in 11 cases, middle cerebral artery (MCA) in 2, posterior cerebral artery (PCA) in one and posterior inferior cerebellar artery (PICA) in one case. Results : The types of aneurysms were 8 cases of large to giant size aneurysms, 5 cases of ICA blood blister-like aneurysms, one dissecting aneurysm, and one pseudoaneurysm related to trauma. High-flow bypass surgery was done in 6 cases with radial artery graft (RAG) in five and saphenous vein graft (SVG) in one. Low-flow bypass was done in nine cases using superficial temporal artery (STA) in eight and occipital artery (OA) in one case. Parent artery occlusion was performed with clipping in 9 patients, with coiling in 4, and with balloon plus coil in 1. Direct aneurysm clip was done in one case. The follow up period ranged from 2 to 48 months (mean 15.0 months). There was no mortality case. The long-term clinical outcome measured by Glasgow outcome scale (GOS) showed good or excellent outcome in 13/15. The overall surgery related morbidity was 20% (3/15) including 2 emergency bypass surgeries due to unexpected parent artery occlusion during direct clipping procedure. The short-term postoperative bypass graft patency rates were 100% but the long-term bypass patency rates were 86.7% (13/15). Nonetheless, there was no bypass surgery related morbidity due to occlusion of the graft. Conclusion : Revascularization technique is a pivotal armament in managing complex aneurysms and scrupulous prior planning is essential to successful outcomes.

• Biomolecules & Therapeutics
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• v.15 no.1
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• pp.16-26
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• 2007

Tissue plasminogen activator (tPA) is a serine protease catalyzing the proteolytic conversion of plasminogen into plasmin, which is involved in thrombolysis. During last two decades, the role of tPA in brain physiology and pathology has been extensively investigated. tPA is expressed in brain regions such as cortex, hippocampus, amygdala and cerebellum, and major neural cell types such as neuron, astrocyte, microglia and endothelial cells express tPA in basal status. After strong neural stimulation such as seizure, tPA behaves as an immediate early gene increasing the expression level within an hour. Neural activity and/or postsynaptic stimulation increased the release of tPA from axonal terminal and presumably from dendritic compartment. Neuronal tPA regulates plastic changes in neuronal function and structure mediating key neurologic processes such as visual cortex plasticity, seizure spreading, cerebellar motor learning, long term potentiation and addictive or withdrawal behavior after morphine discontinuance. In addition to these physiological roles, tPA mediates excitotoxicity leading to the neurodegeneration in several pathological conditions including ischemic stroke. Increasing amount of evidence also suggest the role of tPA in neurodegenerative diseases such as Alzheimer's disease and multiple sclerosis even though beneficial effects was also reported in case of Alzheimer's disease based on the observation of tPA-induced degradation of $A{\beta}$ aggregates. Target proteins of tPA action include extracellular matrix protein laminin, proteoglycans and NMDA receptor. In addition, several receptors (or binding partners) for tPA has been reported such as low-density lipoprotein receptor-related protein (LRP) and annexin II, even though intracellular signaling mechanism underlying tPA action is not clear yet. Interestingly, the action of tPA comprises both proteolytic and non-proteolytic mechanism. In case of microglial activation, tPA showed non-proteolytic cytokine-like function. The search for exact target proteins and receptor molecules for tPA along with the identification of the mechanism regulating tPA expression and release in the nervous system will enable us to better understand several key neurological processes like teaming and memory as well as to obtain therapeutic tools against neurodegenerative diseases.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.635-639
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• 2000

Objective : Surgery for the microvascular decompression is mostly concerned with injury to the cranial nerves or brain stem by cerebellar retraction. Intraopeartive brain stem auditory evoked potentials(BAEPs) has been continuously monitored on surgery to evaluate the extent of injury, recovery of the nerves and prognosis. Methods : Of the 161 cases of CP angle surgery from Feb. 1996 to Apr. 1998, 103 cases were monitored during operation. Thirty five patients who had undergone similar surgery were selected and evaluated ; 23 patients were monitored and 12 were not during surgery. If monitor showed more than 0.5 mSec delay of latency, surgeon was given a warning not to retract brain any more. If more than 1mSec delay, surgeon was informed to stop surgery and wait for the returning of evoked potentials. The level of amplitudes and delay of latencies during the initial stage of operation, opening the dura, insertion of teflon patches, and closing the dura and recovery were then compared. Resuls : Twenty patients were male and 15 were female. Their average age was 50.26 years. Mean amplitude during the initial stage of operation was $0.60{\pm}0.25mV$, at opening the dura $0.56{\pm}0.26$, after teflon patches insertion $0.49{\pm}0.20$, and after closure of dura $0.47{\pm}0.28mV$. Mean latency during the early stage of operation was $6.08{\pm}0.67mSec$, at opening of dura $6.38{\pm}0.55$, insertion of teflon $6.97{\pm}0.59$, and closing the dura $6.17{\pm}0.54$. There was statistical significance in the difference of amplitudes between each procedures, and in the difference of latencies. For the complete recovery of amplitude and latency, it usually took average 5.65 minutes(0-20 min). In monitored group, only one patient required more than 20 minutes to recover and suffered from hearing disturbance after surgery. Others were recovered within 10 minutes without complications. However, 4 out of 12 patients who were not monitored showed hearing disturbance, and 1 patient had temporary facial palsy and dizziness(p＝0.000). Conclusion : The results indicate that continuous intraoperative monitoring of BAEPs during CP angle surgery is seen mandatory procedure to prevent operative complications.