• Annals of Clinical Neurophysiology
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• 제19권1호
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• pp.58-63
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• 2017

Studies of interictal epileptiform discharges are essential for improving the diagnosis, classification, and management of epilepsy. In this case series we sought to identify the clinical and neurophysiological significance of bifid spikes, whose pattern bears a strong resemblance to the cardiac M pattern. We hypothesize that, analogous to the cardiac M pattern, the cerebral M pattern is generated by a conduction defect associated with asynchronous spatiotemporal averaging of electrical signals in the cortex, resulting in the signals reaching the scalp with different latencies. Unlike the cardiac M pattern, the pathology underlying the cerebral M pattern is unknown, although congenital CNS anomalies may be a culprit.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.205-206
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• 1998

In this paper, we present the detection algorithm of interictal epileptic waveform using LVQ network and wavelet transform. First wavelet coefficients is used to represent the characteristics of a single channel EEG wave, and make a number of neural network input node smaller. Then, three-layer neural network employing LVQ network is trained and tested using parameters obtained from the first stage. This study showed that preprocessed EEG data can be successfully used to train ANNs to detect epileptogenic discharges with a high success.

• 대한핵의학회지
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• 제35권1호
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• pp.23-32
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• 2001

목적: CD의 발작간기 SPECT소견과 병리적 등급에 따른 MRI와 SPECT의 비교분석을 통하여 SPECT의 CD에 대한 진단적 유용성을 알아보고자 하였다. 대상 및 방법: 수술 후 병리소견에서 CD로 진단된 16명의 환자를 대상으로 하였다. 모든 환자에서 수술 전에 발작간기 및 발작기 Tc-99m ECD SPECT를 시행하였으며 T1과 T2-강조의 MRI를 얻었고 2명의 환자에서 3차원 MRI를 얻었다. 병리적 등급은 조직학적 소견에 따라 1등급에서 3등급으로 나누었다. SPECT와 MRI에서 혈류양상과 뇌피질의 모양, 병변의 위치, 병리적 등급에 따른 서로간의 일치성을 분석하였고 각각의 검사에서 일치하지 않는 병변은 보이는 검사를 토대로 다시 재분석을 하였다. 결과: SPECT와 MRI에서 각각 38개와 27개의 병변이 관찰되었다. 발작간기 SPECT의 35개 병변은 다양한 소견을 보였는데 26개(74.3%)에서 혈류감소를 보였고 그 외 7개(20.0%)에서 혈류증가와 2개(5.7%)에서 이소성 회백질을 보였다. 정상혈류를 좌여 SPECT에서 위음성을 보인 1개의 병변은 MRI를 통해 분열뇌증임을 확인하였다. 반대로 SPECT에서는 뇌혈류 이상소견을 보였으나 MRI에서는 정상고견을 보였던 병변은 12개로 이중 4개는 SPECT결과를 토대로 MRI를 재검토한 결과 CD를 발견할 수 있었고 나머지 8개는 구조적 이상소견을 발견할 수 없었다. 26개의 병변은 SPECT와 MRI 모두에서 일치하였다. 병리적 등급에 따른 비교에서 두 가지 신경영상검사에서 일치한 병변은 등급이 낮을수록 증가하였고(G1, 75%; G2, 65% ; G3, 50%), SPECT에서만 이상소견을 보인 병변은 등급이 높을수록 증가하였다(G1, 20%; G2, 40%; G3, 50%). MRI에서만 이상소견을 보인 병변은 1등급에서만(5%) 관찰되었다. 결론: CD는 발작간기 SPECT에서 혈류감소, 혈류증가, 이소성 회백질, 위음성 등의 다양한 혈류소견을 보이지만 대부분 혈류감소로 나타나며 MRI와 병행시 간과되었던 병변을 찾는데 도움을 줄 수 있고 병리적 등급이 높을수록 SPECT에서 MRI보다 진단적 유용성을 가졌다.

• Annals of Clinical Neurophysiology
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• 제11권1호
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• pp.16-23
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• 2009

Background: The intermittent delta activity in electroencephalographies (EEGs) of patients with focal brain lesions has been reported to be a marker of an epileptogenic focus. This study investigated the concordance between the current source distribution (CSD) of the interictal epileptiform discharges (IEDs) and that of the background delta frequency bands (DFBs) of the scalp EEG. Methods: We collected scalp EEGs of 13 patients with focal epilepsy that contained uniregional IEDs and unilateral delta to theta slow waves. We applied a distributed source model using LORETA$^{(R)}$ to determine the CSD of the peak points of the IEDs and the DFBs of the background activity. Results: The CSDs of the DFBs were ipsilateral to the CSDs of the peak point of the averaged IEDs in ten patients, and bilateral with ipsilateral predominance in three patients. In the cases with an ipsilateral CSD of the DFB, 8 of 10 patients had concordance of the CSD localization between the averaged IED and the DFB. In the cases with bilateral CSD of the DFB, 2 of 3 patients had concordance of the CSD localization between the averaged IED and the DFB. Conclusions: The CSD localization and lateralization appear to be concordant between the IEDs and the DFB of background activity in epileptic patients. Therefore, the CSD of the DFB in EEGs with visually observable slow activities may predict those of IEDs.

• Annals of Clinical Neurophysiology
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• 제25권2호
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• pp.103-105
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• 2023

Transient epileptic amnesia and transient global amnesia both exhibit temporary memory loss. The lack of clues of epileptic events and the absence of epileptiform abnormalities in electroencephalography, a clear brain lesion, and interictal cognitive decline can make diagnoses challenging. Here we present a middle-aged female who experienced long-term recurrent transient epileptic amnesia with subtle epileptic features over a period of 3 years.

• Annals of Clinical Neurophysiology
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• 제1권1호
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• pp.31-35
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• 1999

Dignosis of migraine is only based on the medical history, and objective methods to aid the clinical diagnosisare absent. Although transcranial Doppler ultrasonography (TCD) abnormalities in headache-free migraineurs have been reported previously, diagnostic criteria for migraine is still lacking and this may limit the practical application of TCD for migraine. We prospectively studied several abnormal TCD indices in interictal migraineurs and their sensitivity and specificity to define the optimal diagnostic criteria. Young (20 yrs$age=29.0{\pm}6.1yrs$) were compared to 69 controls (M:F=25:44, Mean $age=31.2{\pm}5.5yrs$). Elevated MFV (> 2SD)was observed in 63% of migraineurs while n 12% of control (p<0.01). High AI (>25%) or high HI (>3.0) was present in 17% of migraineurs, while 3% and none in controls (p<0.01). Sensitivity of elevated MFV, high AI, and high HI was 63%, 17%, 17% and specificity was 88%, 97%, 100%, respectively. If all these indices were combined, sensitivity and specificity reached 69% and 86%. These preliminary results suggest pathophysiological implication of vasospasm in interictal migraineurs, and TCD may be practically applicable for migraine. Optimal diagnostic criteria and therapeutic options for patients with abnormal TCD findings remain to bo determined.

• 대한핵의학회지
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• 제26권2호
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• pp.244-250
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• 1992

Both interictal and ictal $^{99m}Tc-HMPAO$ brain SPECT were performed in 22 patients with medically intractable epilepsy. Localization of epileptic foci in our patients was made by combined results of EEG and other tests, including Wada test, magnetic resonance imaging, and neuropsychometric test. Among them, ictal $^{99m}Tc-HMPAO$ SPECT, localized epilptic foci in 20 of 22 patients and provided evidence of epileptic focus in 12 patients by demonstrating maximally increased regional cerebral perfusion (rCP) in epileptic foci during the ictal study with decreased rCP in interictal study. Ictal $^{99m}Tc-HMPAO$ SPECT was particularly useful for investigating epileptic foci, and when correlated with simultaneously recorded ictal EEG, provided further insight for localizing epileptic foci. Conclusively, $^{99m}Tc-HMPAO$ SPECT is. a useful, noninvasive method of localizing epileptic activity which may be particularly important for presurgical investigations, especially in those patients without large morphological lesions.

• Annals of Clinical Neurophysiology
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• 제13권1호
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• pp.21-25
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• 2011

Periodic lateralized epileptiform discharges (PLEDs) had been debated whether it is ictal or non-ictal phenomenon. As most of PLEDs occur in patients with acute structural lesions, some epileptologists prefer PLEDS as a non-ictal phenomenon, rather an obscure epiphenomenon of etiological diseases. But, almost half of the patients with PLEDs do not have acute structural lesions in the brain and metabolic disorders or old CNS lesions may cause PLEDs and even more, no brain lesion was identified in some patients. There are many data supporting PLEDs as ictal phenomena. Occurrence of PLEDs usually accompanied by decreased mentality and is improved as PLEDs disappeared. Current SPECT study showed marked hyperperfusion in the lesion side of PLEDs, that is striking evidence of PLEDs as ictal phenomena. Also careful review of EEG with PLEDs revealed it is a dynamic process rather than a static state. Despite of these evidences, as PLEDs are an end-stage of animal status epilepticus models, it may be a transition of ictal to interictal state.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.427-428
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• 2009

Optical imaging offers excellent spatio-temporal sensitivity that is unparalleled by any other perfusion based imaging techniques. We used in vivo optical recording of intrinsic signals (ORIS) to map neurovascular hemodynamics of perfusion, oximetry and membrane potential during epileptic events in rat and mouse neocortex. Studies of hemodynamic changes with ORIS alone were also performed in human. Laboratory studies in rodent epilepsy models have demonstrated a persistent increase in deoxygenated hemoglobin (Hbr) and a decrease in tissue oxygenation during interictal spikes and ictal events. This "epileptic dip", like the "initial dip" recorded during normal sensory processing, implies that the enormous rise in cerebral blood flow (CBF) is inadequate to meet the increased metabolic demands associated with synchronized epileptic activity. These findings are critically important to the interpretation of the perfusion-based imaging studies, such as fMRI. In addition, we visualized the effect of direct cortical electrical stimulation, an alterative epilepsy treatment. The optical data following direct cortical electrical stimulation showed that hemodynamic signals are sensitive to different electrical stimulation parameters. Furthermore, our recent data demonstrated that the application of unilateral electrical stimulation is able to elicit bilateral hemodynamic responses in rat neocortex.

• Clinical and Experimental Pediatrics
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• 제53권8호
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• pp.779-785
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• 2010

In pre-surgical evaluation of pediatric epilepsy, the combined use of multiple imaging modalities for precise localization of the epileptogenic focus is a worthwhile endeavor. Advanced neuroimaging by high field Magnetic resonance imaging (MRI), diffusion tensor images, and MR spectroscopy have the potential to identify subtle lesions. $^{18}F$-FDG positron emission tomography and single photon emission tomography provide visualization of metabolic alterations of the brain in the ictal and interictal states. These techniques may have localizing value for patients which exhibit normal MRI scans. Functional MRI is helpful for non-invasively identifying areas of eloquent cortex. These advances are improving our ability to noninvasively detect epileptogenic foci which have gone undetected in the past and whose accurate localization is crucial for a favorable outcome following surgical resection.