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Biomedical subjects

Ki-Young Jung

Publications and source records attributed to Ki-Young Jung.

9 recordsLinked to original sources

Prediction of personalized antiseizure medications response based on clinical signatures in epilepsy.

Despite the increasing number of available antiseizure medications (ASMs), optimal medical therapy is still a process of trial and error. We aimed to predict the responsiveness of various ASMs based on initial tests using artificial intelligence. The study consisted of 2586 patients fulfilling the following criteria: (1) first visit to the epileptologists from 2008 to 2017, (2) a diagnosis of epilepsy, and 3) ≥ three years of follow-up duration. The clinical characteristics, ASM history, seizure frequency, laboratory, EEG, and MRI results, were collected. Machine algorithms were utilized to predict the responsiveness of specific regimens. Valproate showed the highest area under curve (AUC), 0.636. The AUCs of levetiracetam, oxcarbazepine, and lamotrigine were 0.614, 0.633, and 0.674. The AUCs of common dual regimens were 0.543 for levetiracetam + oxcarbazepine, 0.454 for levetiracetam + valproate, and 0.583 for levetiracetam + lamotrigine. Levetiracetam + carbamazepine showed the highest AUC, 0.686. In Shapley Additive exPlanations analysis, seizure type significantly impacted prediction performance for valproate responsiveness, and onset age and disease duration for lamotrigine. The prediction performances for the response based on initial data differ according to ASMs. An enormous dataset from a multicenter would improve the prediction power of ASM responsiveness in the future.

Humans↗

Classification of epilepsy types through global network analysis of scalp electroencephalograms.

Epilepsy is a dynamic disease in which self-organization and emergent structures occur dynamically at multiple levels of neuronal integration. Therefore, the transient relationship within multichannel electroencephalograms (EEGs) is crucial for understanding epileptic processes. In this paper, we show that the global relationship within multichannel EEGs provides us with more useful information in classifying two different epilepsy types than pairwise relationships such as cross correlation. To demonstrate this, we determine the global network structure within channels of the scalp EEG based on the minimum spanning tree method. The topological dissimilarity of the network structures from different types of temporal lobe epilepsy is described in the form of the divergence rate and is computed for 11 patients with left (LTLE) and right temporal lobe epilepsy (RTLE). We find that patients with LTLE and RTLE exhibit different large scale network structures, which emerge at the epoch immediately before the seizure onset, not in the preceding epochs. Our results suggest that patients with the two different epilepsy types display distinct large scale dynamical networks with characteristic epileptic network structures.

Artificial Intelligence↗

Reflex movements in patients with brain death: a prospective study in a tertiary medical center.

Reflex movements have been reported to occur in up to 75% of brain-dead patients, but this issue has not been addressed in Korea. The patients admitted to our hospital who met the criteria for brain death were enrolled between March 2003 and February 2005. The frequency and type of reflex movements in these patients were evaluated prospectively using a standardized protocol. Brain death was determined according to the guideline of Korean Medical Association. Of 26 patients who were included, five (19.2%) exhibited reflex movements such as the pronation-extension reflex, abdominal reflex, flexion reflex, the Lazarus sign, and periodic leg movements. This finding suggests that the frequency of spinal reflex movements is not rare and the awareness of these movements may prevent delays in brain-dead diagnosis and misinterpretations.

Adult↗

Independent component analysis of generalized spike-and-wave discharges: primary versus secondary bilateral synchrony.

OBJECTIVE: To differentiate between primary and secondary bilateral synchrony (PBS and SBS, respectively) in generalized spike-and-wave discharges (GSWD), we applied independent component analysis (ICA) to GSWD, and analyzed the characteristic patterns of independent components. METHODS: EEGs from 19 patients with GSWD (9 PBS patients, 10 SBS patients) were studied. Thirty GSWD epochs were selected and concatenated to construct an EEG data matrix that was subjected to ICA. Selected independent components were localized by mapping them on a spherical model of the head by means of brain electrical source analysis (BESA) to define dipole sources. RESULTS: Epileptic components of GSWD were clearly separated by the ICA algorithm in all patients. Between one and three components per patient were responsible for GSWD. In PBS patients, 70.6% of the independent components had dipole sources within the dorsolateral frontal region, and 56.5% of the independent components in SBS patients were within the medial frontal region (P=0.012). The orientation of all of the independent components in PBS patients was radial, whereas 47.8% of the independent components in SBS patients were tangential; this difference was statistically significant (P=0.001). CONCLUSIONS: Spatiotemporal decomposition of GSWD by using ICA might be helpful for differentiating SBS from PBS. SIGNIFICANCE: The localization of the dipole sources of the independent components may provide insight into the pathophysiological origins of GSWD.

Action Potentials↗

Delivery modes and neonatal EEG: spatial pattern analysis.

BACKGROUND: Animal studies indicate that postnatal adaptation and development of neonates could be different due to the birth method and that these effects may last throughout adulthood. STUDY DESIGN: We applied a spatio-temporal analysis to EEG recordings of a group of neonates to investigate the influence of a cesarean section on maturation and extrauterine adaptation of the brain. EEG were recorded at 2 h and at 24 h after delivery. SUBJECTS: A spectral analysis technique, the so-called Karhunen-Loeve (KL) method, was applied to EEG of 10 neonates from vaginal delivery and 17 from C-section to obtain the spatio-temporal eigenpatterns. RESULTS: Spatio-temporal analysis showed noticeable pattern differences between the two groups. Compared to the C-section, the vaginal delivered neonate's EEG recordings showed a significant increase of amplitude at Fp1 in the pattern 24 h after the delivery, but not 2 h after delivery. Dynamics in this spectral analyses were not significantly different between both groups 2 h after delivery, but the regional differences increased during the next day between both groups. CONCLUSIONS: This could come from the early insufficient complexity in C-section neonates. Global EEG complexity in C-section neonates fell short of that of vaginal delivered neonates 2 h after delivery. Many aspects of pattern change in C-section neonates followed the nature of vaginal delivered neonates. These could be considered as parts of a retarded transition of C-section neonates in the early adaptation, but some of the differences in global EEG pattern could not be explained in this way. Pattern analysis suggests that the neuronal activities of the neonatal brain are changing regionally concurrent with bi-hemispheric global dynamics. Moreover, the delivery modes could have an influence on the early postneonatal adaptation of the physiological activity in brain.

Adult↗

Nonlinear dynamic characteristics of electroencephalography in a high-dose pilocarpine-induced status epilepticus model.

We applied nonlinear analysis to the results of electroencephalography (EEG) in a pilocarpine-induced status epilepticus (SE) model to characterize nonlinear dynamics according to SE phase. Nine male Sprague-Dawley rats weighing 150-250 g were used. EEG was classified into four phases in addition to baseline EEG (phase 0) as follows: phase 1, discrete seizures; phase 2, continuous ictal discharges; phase 3, early periodic epileptiform discharges (PEDs); and phase 4, late PEDs. High-dose diazepam was administered at phase 4 to terminate SE. Diazepam controlled SE in five rats (group 1), while it failed to stop SE in the rest (group 2). The presence of nonlinearity was determined by time reversal asymmetry statistics using a surrogate data set. The correlation dimension (D(2)) was calculated to characterize the dimensional complexity of each phase of SE. EEG of later phases of SE showed strong nonlinearity, whereas no or only weak nonlinearity was noted at phases 0 and 1. D(2) showed the highest value at phase 0 and decreased progressively. Considering therapeutic responsiveness, D(2) showed significant differences between the two groups at phases 2 and 4. These results suggest that nonlinear dynamic changes in the later SE phases reflect underlying pathophysiological changes that contribute to determining therapeutic responsiveness in the pilocarpine-induced SE model.

Animals↗

Patterns of interictal spike propagation across the central sulcus in benign rolandic epilepsy.

It has been reported that the rolandic area generating spikes is hyperexcitable, and that rolandic spikes propagate across the central area. However, the pattern of rolandic spike propagation and how the dipolar distribution of the spikes is related to the propagation pattern have not yet been studied. Thirty-nine EEGs from 27 patients with benign rolandic epilepsy (BRE) were examined. Sequential topographic mapping in 4-ms steps was used to analyze the pattern of spike propagation. The locations of maximum negative foci, the presence and distribution of the dipolar field, and the propagation pattern were examined. Dipoles were present in 23 (85.2%) out of 27 patients and in 43 (72.9%) out of 59 foci. Thirty-two foci (54.2%) in 20 patients demonstrated a propagation pattern. The typical pattern consisted of propagation from central to mid-temporal locations across the central sulcus. Most spike foci exhibiting a propagation pattern had a dipolar distribution (87.5%; p=0.008). These results suggest that rolandic spikes originate from sulcal or gyral cortices on either side of the central sulcus, and that spike propagation can ensue by intracortical spreading across the central sulcus.

Brain↗

Changes in brain complexity during valproate treatment in patients with partial epilepsy.

OBJECTIVE: The effect of valproate (VPA) on human electroencephalography (EEG) was studied using nonlinear dynamics analysis to investigate changes in brain complexity. METHODS: We propose a spatial linear mode complexity (SLMC) measure to quantify the complexity of spatial linear modes in multichannel EEGs. Nine patients with complex partial seizures who had not previously been exposed to antiepileptic drugs (AEDs) were included in this study. Eighteen-channel EEG data were collected before and after VPA therapy. Changes in brain complexity were examined using the proposed SLMC measure, which reflects brain complexity. Fifteen normal, healthy subjects were included as a control group. To compare SLMC with spectral analysis, we performed spectral analysis within the conventional frequency bands. RESULTS: Spectral analysis showed that the patient group had decreased relative power of the alpha2 band in the T7, P3, O1 and C4 leads before VPA treatment and an increased relative theta power in the O1 lead relative to the control group. However, no significant changes occurred in any lead at any frequency band after VPA treatment. The mean SLMC value was significantly lower in the patient group before treatment than in the control group (p = 0.026). The average SLMC value for all patients increased after treatment and neared that of the control group, although statistical significance was not attained (p = 0.074). CONCLUSIONS: These results suggest that epilepsy patients have interictal abnormalities that are demonstrated by reduced brain complexity, and that VPA partially reverses this trend. Nonlinear analysis of EEG data may be useful in evaluating the effect of AEDs.

Adolescent↗