• Korean Journal of Biological Psychiatry
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• v.12 no.1
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• pp.32-41
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• 2005

Objective:Impaired processing of working memory is one of the cognitive deficits seen in patients with schizophrenia. This aimed at corroborating the differences in the brain activities involved in the process of working memory between patients with schizophrenia and the control subjects. Method:Fourteen patients with schizophrenia and 12 healthy volunteers were recruited in this study. Functional magnetic resonance imaging(fMRI) was used to assess cortical activities during the performance of a 2-back visual working memory paradigm using the Korean alphabet as mnemonic content. Results:Group analysis revealed that left lateral prefrontal cortex and right parietal lobule showed decreased cortical activities in the patient group. On the other hand, an increased activation in left superior and middle frontal gyrus, left middle temporal gyrus, right cuneus, both occipital lobes, right fusiform gyrus and right cingulate gyrus. The activation in left anterior lobe and both declive of cerebellum was also increased. Conclusions:This study showed a decreased activation in left lateral prefrontal and right parietal neural networks from the patient group and confirmed the earlier findings on the impaired working memory of patients with schizophrenia using fMRI investigation. The regions implicated in our study suggest an abnormal functioning of the fronto-parietal cortical areas that are critical to the information processing stream, which might be correspondent to common pathophysiology rather than a common etiology in schizophrenia.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.216-221
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• 1996

The quantitative EEGs of obsessive-compulsive disorder patients were analyzed using spectral analysis and compared to age and sex-matched controls. The subjects were 19 patients(men=15, women=4) suffering from obsessive-compulsive disorder(DSM-III-R). Absolute power, relative power and interhemispheric asymmetry of EEG were used to compare obsessive-compulsive disorder patients with controls. In order to fit the EEG data to a normal distribution, a log transformation of power values of every bandwidth in each deviation was calculated prior statistical analysis. The Wilcoxon rank test was performed to compare obsessive-compulsive group to the control group. In obsessive-compulsive disorder, abnormalities of quantitative EEGs are prominent in fronto-central. These results ore compatible with other brain imaging studies of obsessive-compulsive disorder and suggested that fronto-central area plays an important role in the pathophysiology of obsessive-compulsive disorder.

• The Journal of Internal Korean Medicine
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• v.26 no.4
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• pp.806-819
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• 2005

Objective : The purpose of this study is to investigate clinical characteristics and remedial value oriental medical therapy for sufferers of severe headache. Methods : On the authority of DongEuiBoCam, patients were classified into three groups: migraine, qi-syncope headache and phlegm-headache. All patients wert treated with acupuncture therapy and herb medicines. After that inquiry was made into the extent of improvement of headache. Results : 1. In accordance with the statistics, 56 cases(50.5%) had phlegm-syncope headache, 28 cases(25.2%) had qi-syncope headache and 27 cases(24.3%) had migraine. 2. The ratio between males and females was about 1:4. Most patients were in their forties. 3. 12 cases(31.6%) with migraine had pain only on the right side of the head, 20 cases(26.3%) with phlegm-syncope and 17 cases(45.6%) with qi-syncope headache suffered from the frontal lobe headache. 4. 8 cases(29.6%) with migraine had been suffering for a week or less, 12 cases(21.4%) with phlegm-syncope headache had been suffering for over six months and under one year and 6 cases(21.4%) with qi-syncupe headache had suffered over one year and under five. 5. Overwork and stress was deemed the main cause of migraine. Phlegm-syncope headache was also attributed to stress and tense situations. Qi-syncope headache was believed to be variously caused by traffic accident, noise, blood pressure and other reasons. 6. 46 cases(30%) felt dull headache and 32 cases(20.9%) felt dizzy. The common associated symptoms of migraine and qi-syncope headache included back, neck and shoulder pain and other pains. Dizziness was an especially prevalent symptom of phlegm-syncope headache. 7. After the oriental medical therapy, 12 cases(10.8%) almost entirely recovered, 50 cases(45%) were in about half as much pain, 45 cases(40.5%) improved little and 4 cases(3.6%) felt no improvement. Conclusions : The results support a role for oriental medical therapy in treatment of headache.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.17-26
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• 2002

Driver's psychophysiological load is one of the key measures for evaluating the safety of the highway. The purpose of this study is to propose and to test the methodology of evaluating the length limit of tangent section using driver's psychophysiological load. Driver's psychophysiological data is represented by the data acquire by frontal and occipital lobe. In order to compare the differences between tangent segments and the orders, real road driving experiments were performed. We collected psychophysiological data during the operation of vehicles. The experimental data were analyzed using FFT (Fast Fourier Transform) and relative power spectrum tools. These routine produces the beta value which is a major factor in consideration of driver's condition. The results in this study are summarized as follows: (1) A new methodology of evaluating the length limit in tangent section of highway using driver's psychophysiological load was proposed. (2) It was observed that driver's work load at tangent section was three times lower than that at the other section types. The beta value at tangent section is 2.219, while that at general section is 0.821. (3) It was observed that the driver's work load was significantly dropped to 0.428 after the continuous driving of 4.2km tangent section. (4) Based on the experimental subjects(from 27 Years to 31). we suggest that 30 times of design speed(3.0 km) could be acceptable as the length limit of tangent section in highway rather than the Previous limit which is 20 times of design speed(2.0km).

• 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 Physiology & Pathology in Korean Medicine
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• v.28 no.3
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• pp.337-345
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• 2014

The present study examined the effects of soybean-derived phosphatidylserine (SB-PS) on the learning and memory function and the neural activity in rats with trimethyltin (TMT)-induced memory deficits. The cognitive improving efficacy of SB-PS on the amnesic rats, which was induced by TMT, was investigated by assessing the Morris water maze test and by performing cholineacetyl transferase (ChAT), acetylcholinesterase (AChE) and cAMP responsive element binding protein (CREB) immunohistochemistry. A positron emission tomography (PET) scanning the rat brain was by performed administer 18F-Fluorodeoxy-glucose (18F-FDG). The rats with TMT injection showed impaired learning and memory of the tasks and treatment with SB-PS produced a significant improvement of the escape latency to find the platform in the Morris water maze at the 2nd day compared to that of the MCT group. In the retention test, the SB-PS group showed increased time spent around the platform compared to that of the MCT group. Consistent with the behavioral data, SB-PS 50 group significantly alleviated the loss of acetyl cholinergic neurons in the hippocampus compared to that of the MCT group. Treatment with SB-PS significantly increased the CREB positive neurons in the hippocampus as compared to that of the MCT group. In addition, SB-PS groups increased the glucose uptake in the hippocampus and SB-PS 50 group increased the glucose uptake in the frontal lobe, as compared to that of the MCT group. These results suggest that SB-PS may be useful for improving the cognitive function via regulation of cholinergic marker enzyme activity and neural activity.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.3-20
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• 2019

With advancements in technology of virtual reality, it is used for various purposes in many fields such as medical care and healthcare, but as the same time there are also increasing reports of nausea, eye fatigue, dizziness, and headache from users. These symptoms of motion sickness are referred to as cybersickness, and various researches are under way to solve the cybersickness problem because it can cause inconvenience to the user and cause adverse effects such as discomfort or stress. However, there is no official standard for the causes and solutions of cybersickness at present. This is also related to the absence of tools to quantitatively measure the cybersickness. In order to overcome these limitations, this study proposed quantitative and objective cybersickness evaluation method. We measured 128-channel EEG waves from ten participants experiencing visually stimulated virtual reality. We calculated the relative power of delta and alpha in 11 regions (left, middle, right frontal, parietal, occipital and left, right temporal lobe). Multiple regression models were obtained in a stepwise manner with the motion sickness susceptibility questionnaire (MSSQ) scores indicating the susceptibility of the subject to the motion sickness. A multiple regression model with the highest under the area ROC curve (AUC) was derived. In the multiple regression model derived from this study, it was possible to distinguish cybersickness by accuracy of 95.1% with 11 explanatory variables (P_D.MF, P_D.LP, P_D.MP, P_D.RP, P_D.MO, P_A.LF, P_A.MF, P_A.RF, P_A.LP, P_A.RP, P_A.MO). In summary, in this study, objective response to cybersickness was confirmed through 128 channels of EEG. The analysis results showed that there was a clearly distinguished reaction at a specific part of the brain. Using the results and analytical methods of this study, it is expected that it will be useful for the future studies related to the cybersickness.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.21-34
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• 2019

This study was an examination of the relevance and clinical significance of electroencephalographic (EEG) indexes (e.g., mental/physical stress and attention) and indexes of heart rate variability (HRV) with regard to cognitive function and physiological health conditions in elderly people. A device was used to record two-channel EEGs of the frontal lobe and a one-channel ECG simultaneously. Subjects were 76 people average aged 73. The significant findings are as follows: First, subjects whose intrinsic alpha rhythm had high amplitude, regardless of peak, showed higher resistance to mental stress and lower physical stress than did subjects with low-amplitutde intrinsic alpha rhythm. Second, HRV, SDNN, and RMSSD indexes showed strong positive correlations between the two groups of subjects regardless of the division of groups. Third, the alpha asymmetry of the left and right sides of the brain in subjects with low-amplitude intrinsic alpha rhythm was larger, and the delta/alpha ratio (reflecting physical stress) and theta/sensorimotor rhythm (SMR) ratio (showing the decline in attention) were bigger. Fourth, the subjects in whom intrinsic alpha rhythm peak occurred during slow rhythm had a higher theta/SMR ratio than did subjects whose peak occurred during fast rhythm, which was related to a steeper decline in attention. Therefore, the presence or absence of intrinsic alpha rhythm peak and amplitude on quantitative EEG may be an index reflecting the cognitive function and physiological health of elderly people.

• Korean Journal of Cognitive Science
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• v.14 no.4
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• pp.1-7
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• 2003

The common features of the behavioral inhibition and the action monitoring that are considered as one of the executive functions were investigated using event-related brain potentials (ERPs) and source localization analysis. The electrophysiological correlates of behavioral inhibition and action monitoring ate analyzed when the subjects performed the Go/NoGo task. Two ERP components of behavioral inhibition termed as N200 and P300 in NoGo condition were differ from those of Go condition, that is the amplitudes of NoGo N200 and P300 are largest on the fronto-central region, which may reflect the inhibitory control of frontal lobe required in NoGo condition. The error-related negativity (ERN) observed on the fronto-central region when the subjects committed error was much larger in amplitude and faster in latency than those of the correct-related negativity (CRN), which may indicate that the signal of action monitoring is much more required for the error response. The correlation analysis for the ERP components of behavioral inhibition and action monitoring revealed the significant negative correlation among the latencies of NoGo N200 and P300 and the amplitude of ERN, which may reflects that the faster subjects inhibit response, the more monitor their own action. The close relationship between behavioral inhibition and action monitoring was also supported by the results of source localization analysis, which showed the common neural sources of NoGo N200 and ERN was anterior cingulate cortex.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.30-35
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• 2008

Purpose : We evaluated clinical presentations of brain abscesses, including predisposing factors, causative organisms, and mortality rate in neonates and children. Methods : We retrospectively reviewed the medical charts of neonates and children with brain abscesses treated at Severance Hospital from January 1997 through December 2006. Results : Among 27 neonates and children with brain abscesses, overall mortality was 22 % and 38% of survivors developed neurologic sequelae. The mortality rate was 38% in 8 infants with brain abscesses. The most common location of brain abscesses were frontal and parietal lobes, followed by temporal lobe. There were 7 cases with multiple brain abscesses. Streptococci (33%), Staphylococci (27%), and Gram-negative enterics (20%) were commonly isolated. The common predisposing conditions were neurosurgical procedure (30 %), cyanotic congenital heart disease (15%), and sinusitis/otitis (7%). Fever (74%), headache (37%), nausea/vomiting (33%), and altered mental status (33%) occurred commonly. Compared with children older than 1 year of age, infants were associated with multiple brain abscesses (63%, P=0.011) and high rates of death or neurologic sequelae (88%, P= 0.033). Conclusion : We should have a high index of suspicion in order to recognize the condition as early as possible, especially in infancy with brain abscesses who presents vague or nonspecific symptoms and signs.