• Clinical and Experimental Pediatrics
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• v.56 no.12
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• pp.534-539
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• 2013

Purpose: Electroencephalography (EEG) is frequently ordered for patients with febrile seizures despite its unclear diagnostic value. We evaluated the prevalence of abnormal EEGs, the association between clinical findings and abnormal EEGs, and the predictive value of EEG for the recurrence of febrile seizures Methods: Data were collected on 230 children who were treated for febrile seizures at Kyung Hee University Medical Center from 2005 to 2009. EEGs were recorded after 1-2 days of hospitalization when children became afebrile. EEG patterns were categorized as normal, epileptiform, or nonspecific relative to abnormalities. The patients' medical records were reviewed, and telephone interviews with the families of the children were conducted to inquire about seizure recurrence. The relationships between clinical variables, including seizure recurrence, and EEG abnormalities were evaluated. Results: Of the 131 children included, 103 had simple and 28 had complex febrile seizures. EEG abnormalities were found in 41 children (31%). EEG abnormalities were more common in children with complex than simple febrile seizures (43% vs. 28%), but the difference was not statistically significant. Logistical regression analysis showed that having multiple seizures in a 24-hour period was significantly predictive of abnormal EEG (odds ratio, 2.98; 95% confidence interval, 1.0 to 88; P =0.048). The frequency of recurrence did not differ significantly in the normal (31%) and abnormal (23%) EEG groups. Conclusion: Multiple seizures within 24 hours were predictive of abnormal EEG in children with febrile seizures. Abnormal EEG was not predictive of febrile seizure recurrence.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.4
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• pp.296-308
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• 2021

Electroencephalography (EEG) provides the most accurate and quickest diagnosis of epilepsy. It is also an important examination for the real-time evaluation of brain function and seizures, no matter where. In the field of epilepsy, it is appropriate for a clinical pathologist with considerable knowledge of EEG and clinical experience to perform the role of a Physician Assistant (PA). The electrode attachment method is based on the international 10-20 system. The EEG reading is mainly taken by longitudinal bipolar montage. However, a reading using only one montage may result in an error. Hence, two or more montages should be used for readings according to the clinical situation. In the EEG, electric potentials are seen as contour lines. The most important principle in EEG reading is under-reading, not over-reading. The higher the repetitions of the EEG recording, the greater the sensitivity of the reading. For a good reading, the EEG recording must be of good quality. So, the relationship between the neurologist and the EEG technician is very important. In the future, it is expected that the field of activities of the EEG technician with abundant EEG reading experience and clinical practical knowledge will be further expanded.

• Annals of Clinical Neurophysiology
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• v.19 no.2
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• pp.118-124
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• 2017

Electroencephalography (EEG) is frequently used to assist the diagnosis of brain death. However, to date there have been no guidelines in terms of EEG criteria for determining brain death in Korea, despite EEG being mandatory. The purpose of this review is to provide an update on the evidence and controversies with regarding to the utilization of EEG for determining brain death and to serve as a cornerstone for the development of future guidelines. To determine brain death, electrocerebral inactivity (ECI) should be demonstrated on EEG at a sensitivity of $2{\mu}V/mm$ using double-distance electrodes spaced 10 centimeters or more apart from each other for at least 30 minutes, with intense somatosensory or audiovisual stimuli. ECI should be also verified by checking the integrity of the system. Additional monitoring is needed if extracerebral potentials cannot be eliminated. Interpreting EEG at high sensitivities, which is required for the diagnosis of brain death, can pose a diagnostic challenge. Furthermore, EEG is affected by physiologic variables and drugs. However, no consensus exists as to the minimal requirements for blood pressure, oxygen saturation, and body temperature during the EEG recording itself, the minimal time for observation after the brain injury or rewarming from hypothermia, and how to determine brain death when the findings of ECI is equivocal. Therefore, there is a strong need to establish detailed guidelines for performing EEG to determine brain death.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1333-1342
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• 2018

Until now, Electroencephalography(: EEG) has been the most important and convenient method for the diagnosis and treatment of epilepsy. However, it is difficult to identify the wave characteristics of an epileptic EEG signals because it is very weak, non-stationary and has strong background noise. In this paper, we analyse the effect of dimensionality reduction methods on Epileptic EEG feature selection and classification. Three dimensionality reduction methods: Pincipal Component Analysis(: PCA), Kernel Principal Component Analysis(: KPCA) and Linear Discriminant Analysis(: LDA） were investigated. The performance of each method was evaluated by using Support Vector Machine SVM, Logistic Regression(: LR), K-Nearestneighbor(: K-NN), Decision Tree(: DR) and Random Forest(: RF). From the experimental result, PCA recorded 75% of highest accuracy in SVM, LR and K-NN. KPCA recorded 85% of best performance in SVM and K-KNN while LDA achieved 100% accuracy in K-NN. Thus, LDA dimensionality reduction is found to provide the best classification result for epileptic EEG signal.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.154-157
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• 2016

A continuous electroencephalography (cEEG) can be helpful in detecting vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage (SAH). We describe a patient with an aneurysmal SAH whose symptomatic vasospasm was detected promptly by using a real-time cEEG. Patient was immediately treated by intraarterial vasodilator therapy. A 50-year-old woman without any significant medical history presented with a severe bifrontal headache due to acute SAH with a ruptured aneurysm on the anterior communicating artery (Fisher grade 3). On bleed day 6, she developed a sudden onset of global aphasia and left hemiparesis preceded by cEEG changes consistent with vasospasm. A stat chemical dilator therapy was performed and she recovered without significant neurological deficits. A real-time and protocol-based cEEG can be utilized in order to avoid any delay in detection of vasospasm in aneurysmal SAH and thereby improve clinical outcomes.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1211-1212
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• 2003

본 연구에서는 감성 변화가 빈번하게 일어나는 오라인 포커 게임을 대상으로 EEG를 이용하여 게임 중 발생 할 수 있는 감성 변화를 알아내고자 하는 연구를 수행하였다. 포커 게임에서 나타날 수 있는 사용자의 감성과 행동을 Task Analysis를 이용하여 구분하였고 전두엽 표면 뇌파를 측정하여 Neural Network 및 통계적 처리를 이용하여 분석하였다. 이후 분석될 뇌파에서 인간의 감성상태를 구분할 수 있는 Index를 찾아내었다. 향후 ECG를 추가적으로 연구하여 감성상태를 더 정확하게 파악하는 연구가 진행될 것이다.

• Clinical and Experimental Pediatrics
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• v.52 no.9
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• pp.964-970
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• 2009

Neonatal seizures are generally not only brief and subtle but also not easily recognized and are usually untreated. In sick neonates, seizures are frequently not manifested clinically but are detected only by electroencephalography (subclinical EEG seizures). This phenomenon of electroclinical dissociation is fairly common in neonates. On the other hand, neonates frequently show clinical behaviors such as stiffening, apnea, or autonomic manifestations that mimic seizures, which is usually associated with underlying encephalopathy and non-epileptic seizures. Therefore, it might be difficult to confirm the diagnosis of neonatal seizures. Early recognition of neonatal seizures is important to minimize poor neurodevelopmental outcomes, including cognitive, behavioral, and learning disabilities, as well as the development of postnatal epilepsy. EEG is a reliable tool in the determination of neonatal seizures. Continuous EEG monitoring is essential for the identification of seizures, evaluation of treatment efficacy, and prediction of the neurodevelopmental outcome. However, there is not yet a wide consensus on the optimal "standard" lead montage for the continuous EEG monitoring.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.10-17
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• 2009

Accurate electroencephalography (EEG) forward calculation is of importance for the accurate estimation of neuronal electrical sources. Conventional studies concerning the EEG forward problems have investigated various factors influencing the forward solution accuracy, e.g. tissue conductivity values in head compartments, anisotropic conductivity distribution of a head model, tessellation patterns of boundary element models, the number of elements used for boundary/finite element method (BEM/FEM), and so on. In the present paper, we investigated the influence of modeling errors in the boundary element volume conductor models upon the accuracy of the EEG forward solutions. From our simulation results, we could confirm that accurate construction of boundary element models is one of the key factors in obtaining accurate EEG forward solutions from BEM. Among three boundaries (scalp, outer skull, and inner skull boundary), the solution errors originated from the modeling error in the scalp boundary were most significant. We found that the nonuniform error distribution on the scalp surface is closely related to the electrode configuration and the error distributions on the outer and inner skull boundaries have statistically meaningful similarity to the curvature distributions of the boundary surfaces. Our simulation results also demonstrated that the accumulation of small modeling errors could lead to considerable errors in the EEG source localization. It is expected that our finding can be a useful reference in generating boundary element head models.

• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.1-17
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• 1996

To demonstrate the clinical usefulness of electroencephalography (EEG) and factors increasing the usefulness of EEG, the authors evaluated each relationship between EEG related factors and clinical variables, and neuroimaging studies (CT and MRI)-related factors, and factors which are related with routine neurological examination for 207 patients who had been evaluated with both of EEG and neuroimaging study(CT or/and MRI). The results were as follows: 1) Abnormality of EEG findings had significant relationships with chief complaints, diagnosis, medication use, seizure attack, pathological reflex, and level of consciousness. However there were no significant correlations between abnormality of EEG findings and neuroimaging studies (CT and MRI)- related factors. 2) Laterality of EEG findings had significant relationships with abnormality, laterality, and focality of CT findings, and also with abnormality of MRI findings. But there were no significant correlations between laterality of EEG findings and clinical variables, and neurological examination-related factors. 3) Anterior-posterior distribution of EEG findings was significantly related with medication use. 4) Focality of EEG findings had significant relationships with sex, sensory dysfunction sign, and cerebellar dysfunction sign. But there were no significant correlations between focality of EEG findings and neuroimaging studies(CT and MRI) related factors. 5) Abnormal EEG pattern had significant correlations with various factors, such as age, chief complaints, duration from onset of symptom to taking MRI, seizure attack, abnormality and nature of lesion in CT findings, cortical atrophy in MRI findings, motor dysfunction sign, sensory dysfunction sign, and pathological reflex. 6) With abnormality on sleep activation, age, age of onset, seizure attack, ventricular enlargement in CT findings, and abnormality of MRI findings were significantly correlated. 7) With abnormality on hyperventilation activation, duration of illness and laterality of MRI findings were significantly correlated. Above results may suggest that abnormality of EEG findings is more closely related with functional change of the brain than structural changes of the brain and laterality of EEG findings is vice versa. And also that medication use has an influence on anterior versus posterior distribution of EEG findings and focality of EEG findings is not related with structural changes of the brain. Activation with sleep may be effective to show age differences and provocation of seizure activity and hyperventilation may be effective to detect the abnormal EEG findings by cerebrovascular insufficiency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.159-160
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• 2014