Do Un Jeong

Frontal Glucose Hypometabolism in Abstinent Methamphetamine Users

Changes in relative regional cerebral glucose metabolism (rCMRglc) and their potential gender differences in abstinent methamphetamine (MA) users were explored. Relative rCMRglc, as measured by 18F-fluorodeoxyglucose positron emission tomography, and frontal executive functions, as assessed by Wisconsin card sorting test (WCST), were compared between 35 abstinent MA users and 21 healthy comparison subjects. In addition, male and female MA users and their gender-matched comparison subjects were compared to investigate potential gender differences. MA users had lower rCMRglc levels in the right superior frontal white matter and more perseveration and nonperseveration errors in the WCST, relative to healthy comparison subjects. Relative rCMRglc in the frontal white matter correlated with number of errors in the WCST in MA users. In the subanalysis for gender differences, lower rCMRglc in the frontal white matter and more errors in the WCST were found only in male MA users, not in female MA users, relative to their gender-matched comparison subjects. The current findings suggest that MA use causes persistent hypometabolism in the frontal white matter and impairment in frontal executive function. Our findings also suggest that the neurotoxic effect of MA on frontal lobes of the brain might be more prominent in men than in women.

Asymmetrically altered integrity of cingulum bundle in posttraumatic stress disorder

Previously, our group reported the altered white matter tract integrity of the left anterior cingulate in posttraumatic stress disorder (PTSD) in whole-brain exploration. Current study intended to explore whether the alteration was more prominent in any specific regions of the cingulum bundle. Diffusion tensor images of 21 PTSD subjects and 21 healthy comparison subjects were acquired. Eight isocubic regions of interest (ROIs), i.e. bilateral rostral, subgenual, dorsal, and upper cingulum bundle, were selected. Fractional anisotropy values in each ROI, which indicate the white matter tract integrity, were measured and compared between groups. Relative to comparison subjects, PTSD subjects had significantly smaller fractional anisotropy values in the left side of rostral, subgenual and dorsal cingulum bundle (26.7, 25.0, 22.2% decrease, respectively), but not in the right side ROIs. We report an asymmetrical alteration of the cingulum bundle in PTSD.

Disrupted white matter tract integrity of anterior cingulate in trauma survivors

The objective of this study was to examine the integrity of whole-brain white matter in posttraumatic stress disorder patients. Twenty posttraumatic stress disorder patients who survived the Taegu subway fire incident and 20 healthy volunteers participated in this study. Statistical parametric mapping was used to evaluate the global differences in fractional anisotropy values between the two groups. The results show that posttraumatic stress disorder patients had significantly lower fractional anisotropy values in the left anterior cingulate regions. Posttraumatic stress disorder symptom severity negatively correlated to the level of decrease in anterior cingulate fractional anisotropy values. The outcome of the current study suggests that the disruption of the left anterior cingulate white matter tract integrity may play an important role in the pathophysiology of posttraumatic stress disorder.

Decreased N-acetyl-aspartate levels in anterior cingulate and hippocampus in subjects with post-traumatic stress disorder: a proton magnetic resonance spectroscopy study

The purpose of this study was to investigate the concentration of N‐acetyl‐aspartate (NAA) in the brain and its relationship with clinical characteristics in patients with post‐traumatic stress disorder (PTSD). Proton magnetic resonance spectroscopy was performed in order to measure NAA concentrations in the anterior cingulate cortex (ACC) and bilateral hippocampus in 26 subjects with fire‐related PTSD, who were survivors of a subway fire in South Korea, and 25 age‐ and sex‐matched healthy comparison subjects. There were decreased NAA levels in the ACC (t = −3.88, d.f. = 49, P < 0.001) and bilateral hippocampus (right, t = −3.88, d.f. = 49, P < 0.001; left, t = −3.62, d.f. = 49, P < 0.001) in the PTSD group relative to the healthy comparison group. Also, NAA levels of the ACC (r = –0.43, n = 26, P = 0.027) and bilateral hippocampus (right, r = –0.48, n = 26, P = 0.013; left, r = −0.40, n = 26, P = 0.04) were negatively correlated with re‐experience symptom scores in subjects with PTSD. In conclusion, our findings suggest that subjects with PTSD had decreased neuronal viabilities in the ACC and bilateral hippocampus, and that these deficits may play an important role in the pathophysiology of PTSD, especially regarding the re‐experiencing of traumatic events.

Automatic ballistocardiogram (BCG) beat detection using a template matching approach

This paper suggests a beat detection method for ballistocardiogram (BCG) from an unconstrained cardiac signal monitoring devices. A fiducial peak point of BCG is an I-J-K complex which corresponds with ventricle contraction and Electrocardiogram (ECG) QRS complex. The goal of the method is extraction of J peak without ECG synchronization. The detection method is based on a “template matching” rule evaluated using a correlation function in a local moving-window procedure. The total beat detection algorithm operates in two stages, template definition stage and beat detection stage with defined template in previous stage. In the first stage, the BCG template is constructed by the expert with an empirical analysis of BCG signal and measurement device. In the second stage, the correlation function calculates an accuracy of template with BCG signal using a local moving-window. The data analysis has been performed on the subjects tested at Seoul National University Hospital Sleep Medicine Center and presents 95.16% of sensitivity and 94.76% of positive predictivity value for the J peak detection.

Basis research of nail style photoplethysmogram measurement system for motion artifact reduction

Pulse wave is basic and, important living body signal for vital sign of measurement target or patient’s disease diagnosis. Reflection style of existent pulse wave measurement system is system that receipt light element, emitting light element hangs on palm part of finger or receipt light element, emitting light element hangs on finger lower and upper parts of permeation style. Such existent pulse wave measurement system is sensitive to motion artifact. In this study, it is going to reduce motion artifact irritableness that existent pulse wave measurement sensor has comparative rigidity degree sensor that receipt light element, emitting light element is situated on nail latitude reveal and do basic research that do example addition. This is considered to become reduction of motion artifact of other pulse wave sensor.

Respiration rate variability between REM- and NREM-sleep

Summary form only given. We describe the respiration rate variability (RRV) in sleep. The nasal respiration signal was analyzed for the difference of respiration rate between rapid eye movement (REM) and non rapid eye movement (NREM) sleep. Using a digital polysomnographic system which records patients biomedical signals with remote acceptability through the Internet, the nasal RRV could be analyzed in real time. The analyzed data show that there are some differences between them. These differences can be used for the analysis of the autonomic nervous system function during sleep.