1.Reduced Flicker Lighting Enhances Theta-Band Phase Synchrony during Working Memory Tasks
Jun-Sang SUNWOO ; Sanghun LEE ; Ki-Young JUNG
Journal of Sleep Medicine 2021;18(1):46-54
Objectives:
We analyzed theta-band phase synchrony (TBPS) under reduced and ordinary flicker lighting to determine the effect of light flickers on neurocognitive processes.
Methods:
Nineteen healthy participants (mean age, 30.4±4.5 years; male, 63.2%) performed the Sternberg working memory tasks with event-related potential recording under reduced and control flicker conditions, respectively. We measured the P300 amplitude during memory retrieval, and for TBPS analysis, we calculated the weighted phase lag index within the P300 time window. Furthermore, we used standardized low-resolution brain electromagnetic tomography (sLORETA) to determine differences in functional cortical source connectivity between the two flicker conditions.
Results:
The hit rate (F1,18=0.862, p=0.365), reaction time (F1,18=0.021, p=0.887), and P300 amplitude (F1,18=3.992, p=0.061) did not differ between the two flicker conditions. However, connectivity analysis at the scalp level showed that TBPS under reduced flicker lighting was significantly higher than that under control flicker lighting at higher memory loads (p=0.002). Cortical source imaging with sLORETA confirmed that reduced flicker lighting significantly increased TBPS between the left prefrontal cortex and right hippocampus compared with control flicker lighting (false discovery rate<0.1).
Conclusions
Reduced flicker lighting enhanced TBPS during the working memory task compared with control flicker lighting. Reduced flicker light may improve cognitive functioning by facilitating information transfer within the brain network. Flicker conditions should be considered when optimizing lighting, especially in environments demanding high-level cognitive performance.
2.Reduced Flicker Lighting Enhances Theta-Band Phase Synchrony during Working Memory Tasks
Jun-Sang SUNWOO ; Sanghun LEE ; Ki-Young JUNG
Journal of Sleep Medicine 2021;18(1):46-54
Objectives:
We analyzed theta-band phase synchrony (TBPS) under reduced and ordinary flicker lighting to determine the effect of light flickers on neurocognitive processes.
Methods:
Nineteen healthy participants (mean age, 30.4±4.5 years; male, 63.2%) performed the Sternberg working memory tasks with event-related potential recording under reduced and control flicker conditions, respectively. We measured the P300 amplitude during memory retrieval, and for TBPS analysis, we calculated the weighted phase lag index within the P300 time window. Furthermore, we used standardized low-resolution brain electromagnetic tomography (sLORETA) to determine differences in functional cortical source connectivity between the two flicker conditions.
Results:
The hit rate (F1,18=0.862, p=0.365), reaction time (F1,18=0.021, p=0.887), and P300 amplitude (F1,18=3.992, p=0.061) did not differ between the two flicker conditions. However, connectivity analysis at the scalp level showed that TBPS under reduced flicker lighting was significantly higher than that under control flicker lighting at higher memory loads (p=0.002). Cortical source imaging with sLORETA confirmed that reduced flicker lighting significantly increased TBPS between the left prefrontal cortex and right hippocampus compared with control flicker lighting (false discovery rate<0.1).
Conclusions
Reduced flicker lighting enhanced TBPS during the working memory task compared with control flicker lighting. Reduced flicker light may improve cognitive functioning by facilitating information transfer within the brain network. Flicker conditions should be considered when optimizing lighting, especially in environments demanding high-level cognitive performance.
3.Differential Effect of Light Emitting Diode Light on Electroencephalographic Oscillations in Young and Old Healthy Subjects
Jun Sang SUNWOO ; Sanghun LEE ; Kwang Su CHA ; Tae Joon KIM ; Jung Ick BYUN ; Ki Young JUNG
Journal of Sleep Medicine 2017;14(2):61-69
OBJECTIVES: To investigate brain oscillatory characteristics according to brightness and color temperature of light emitting diode (LED) light in young and elderly subjects. METHODS: We analyzed 22 young (age, 29.0±5.2 years) and 23 elderly (age, 64.8±4.5 years) healthy subjects. A LED light source was used with a combination of two color temperature (6,500 K vs. 3,000 K) and two brightness (700 lx vs. 300 lx) conditions. Participants were exposed to each light condition in relaxed wakefulness. Then, we analyzed power spectral density and functional connectivity from eye-open electroencephalography. RESULTS: A main effect of brightness on delta (p=0.044) and theta (p=0.038) power was significant in the elderly subjects. Bright light enhanced delta and theta power in the frontal region. By contrast, power spectral density of young subjects was affected by color temperature; high color temperature significantly increased beta-band power of the central region (p=0.034). Regarding functional connectivity, a significant effect of color temperature was observed in delta (p=0.006) and beta (p=0.046) frequencies. High color temperature light enhanced beta connectivity of young subjects (p=0.007), while not affecting that of elderly subjects (p=0.979). CONCLUSIONS: The present study demonstrated that spectral power and functional connectivity as well as subjective feelings are affected by the brightness and color temperature of LED light. These results might help us to understand the neurophysiological effects of light and identify the optimal indoor lighting conditions for an individual's environment.
Aged
;
Brain
;
Electroencephalography
;
Healthy Volunteers
;
Humans
;
Wakefulness
4.Effectiveness of limited airway ultrasound education for medical students: a pilot study
Seunghun PARK ; Sanghun LEE ; Han Ho DO ; Jae Seong KIM ; Jun Seok SEO
Clinical and Experimental Emergency Medicine 2019;6(3):257-263
OBJECTIVE: The point-of-care ultrasound of the airway (POCUS-A) is a useful examination method but there are currently no educational programs for medical students regarding it. We designed a POCUS-A training curriculum for medical students to improve three cognitive and psychomotor learning domains: knowledge of POCUS-A, image acquisition, and image interpretation.METHODS: Two hours of training were provided to 52 medical students in their emergency medicine (EM) rotation. Students were evaluated for cognitive and psychomotor skills before and immediately after the training. The validity measures were established with the help of six specialists and eight EM residents. A survey was administered following the curriculum.RESULTS: Cognitive skill significantly improved after the training (38.7±12.4 vs. 91.2±7.7) and there was no significant difference between medical students and EM residents in posttest scores (91.2±7.7 vs. 90.8±4.6). The success rate of overall POCUS-A performance was 95.8%. The students were confident to perform POCUS-A on an actual patient and strongly agreed to incorporate POCUS-A training in their medical school curriculum.CONCLUSION: Cognitive and psychomotor skills of POCUS-A among medical students can be improved via a limited curriculum on EM rotation.
Airway Management
;
Curriculum
;
Education
;
Education, Medical
;
Emergency Medicine
;
Humans
;
Learning
;
Methods
;
Pilot Projects
;
Point-of-Care Systems
;
Schools, Medical
;
Specialization
;
Students, Medical
;
Ultrasonography
5.Rectal Perforation with Pneumoperitoneum Caused by Compressed Air.
Wonjin CHO ; Sanghun LEE ; Jae Seong KIM ; Han Ho DO ; Jun Seok SEO ; Jeong Hun LEE ; Seung Chul LEE
Journal of the Korean Society of Emergency Medicine 2017;28(5):535-538
Compressed air can cause serious damage to internal organs. The stomach is an organ that is rarely perforated due to its elasticity. However, intestines are weaker and thinner compared to the stomach. A 40-year-old male came to the emergency room with severe abdominal pain due to dyspnea. The patient experienced abdominal pain right after his coworker shot compressed air into the patient's pants. The patient suffered from a rigid abdomen, and bed-side ultrasonography was carried out as soon as possible. Pneumoperitoneum was diagnosed by portable X-ray. After computed tomography, emergency paracentesis was carried out for decompression. After emergency paracentesis, the patient's symptoms and vital signs were stabilized. After the procedure, the patient had an emergency laparotomy.
Abdomen
;
Abdominal Pain
;
Adult
;
Compressed Air*
;
Decompression
;
Dyspnea
;
Elasticity
;
Emergencies
;
Emergency Service, Hospital
;
Humans
;
Intestinal Perforation
;
Intestines
;
Laparotomy
;
Male
;
Paracentesis
;
Pneumoperitoneum*
;
Stomach
;
Ultrasonography
;
Vital Signs
6.Prospective Evaluation of the Recognition of Stroke In the Emergency Room (ROSIER) Scale in Emergency Department.
Sanghun LEE ; Jun Seok SEO ; Seung Chul LEE ; Jeong Hun LEE ; Hanho DOH
Journal of the Korean Society of Emergency Medicine 2015;26(5):466-473
PURPOSE: Early assessment and rapid intervention in patients with acute stroke can reduce mortality and complication. We conducted a prospective evaluation of the Recognition Of Stroke In the Emergency Room (ROSIER) scale for use in patients with suspected stroke. METHODS: We studied 312 patients with suspected acute stroke who were admitted to the emergency department within 7 months from August 2013 to February 2014. Emergency physicians used the ROSIER scale as a stroke recognition tool, compared with the Face Arm Speech Test (FAST). Patients meeting the inclusion criteria were evaluated for both the FAST and the ROSIER scale and compared with the final discharge diagnoses. Then, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under curve of the FAST, and the ROSIER scale were calculated. RESULTS: The patient group consisted of 141 males and 171 females with an average age of 60 years; 112 (35.9%) patients had ROSIER scale > or =1 indicating a stroke, 98 (31.4%) of these patients had stroke as a final diagnosis. The FAST showed sensitivity of 85.8%, specificity of 92.5%, PPV of 86.6%, and NPV of 92.0%. The ROSIER scale showed relative sensitivity of 86.7%, specificity of 93.0%, PPV of 87.5%, and NPV of 92.5%. CONCLUSION: In this study, the ROSIER scale was a useful stroke recognition tool for potential stroke patients, but showed no significant superiority over the FAST.
Area Under Curve
;
Arm
;
Diagnosis
;
Emergencies*
;
Emergency Service, Hospital*
;
Female
;
Humans
;
Male
;
Mortality
;
Prospective Studies*
;
Registries
;
Sensitivity and Specificity
;
Stroke*
7.Reference values of hematology, biochemistry, and blood type in cynomolgus monkeys from cambodia origin.
Kangmoo CHOI ; Jaejin CHANG ; Min Jae LEE ; Seungsu WANG ; Kimhong IN ; Wilhelm C GALANO-TAN ; Sanghun JUN ; Kahee CHO ; Yong Hwa HWANG ; Sung Ju KIM ; Wanje PARK
Laboratory Animal Research 2016;32(1):46-55
Cynomolgus monkeys as nonhuman primates are valuable animal models because they have a high level of human gene homology. There are many reference values for hematology and biochemistry of Cynomolgus monkeys that are needed for proper clinical diagnosis and biomedical research conduct. The body weight information and blood type are also key success factors in allogeneic or xenogeneic models. Moreover, the biological parameters could be different according to the origin of the Cynomolgus monkey. However, there are limited references provided, especially of Cambodia origin. In this study, we measured average body weight of 2,518 Cynomolgus monkeys and analyzed hematology and serum biochemistry using 119 males, and determined blood types in 642 monkeys with Cambodia origin. The average body weight of male Cynomolgus monkeys were 2.56±0.345 kg and female group was 2.43±0.330 kg at the age from 2 to 3 years. The male group showed relatively sharp increased average body weight from the 3 to 4 age period compared to the female group. In hematology and biochemistry, it was found that most of the data was similar when compared to other references even though some results showed differences. The ABO blood type result showed that type A, B, AB, and O was approximately 15.6, 33.3, 44.2, and 6.9%, respectively. The main blood type in this facility was B and AB. These biological background references of Cambodia origin could be used to provide important information to researchers who are using them in their biomedical research.
Biochemistry*
;
Body Weight
;
Cambodia*
;
Diagnosis
;
Female
;
Haplorhini
;
Hematology*
;
Humans
;
Macaca fascicularis*
;
Male
;
Models, Animal
;
Primates
;
Reference Values*
8.The clinical usefulness of radiologic report monitoring system of CT and MRI in emergency department: analysis of missed and incidental findings
Ji Hoon LEE ; Jun Seok SEO ; Seung Chul LEE ; Jeong Hun LEE ; Han Ho DO ; Sanghun LEE ; Yong Won KIM ; Jae Seong KIM
Journal of the Korean Society of Emergency Medicine 2020;31(4):391-400
Objective:
This study was undertaken to establish a radiologic report monitoring system (RRMS) for missed and incidental findings (MIFs) in computed tomography (CT) and magnetic resonance imaging (MRI) reports, to help determine the clinical significance of MIFs in the emergency department (ED).
Methods:
Patients presenting to our ED in 2017 were subjected to RRMS. Preliminary reports and final reports were subsequently compared based on the clinical significance of the MIFs. If required, the patient was contacted and instructed to revisit the ED.
Results:
Totally, 12,132 CT and MRI exams were performed during the study period, and 321 cases (2.6%) encompassed MIFs. We attempted to contact 228 cases (1.9%) who had clinically significant MIF findings; 9 patients were instructed to return to the ED, whereas 105 cases were instructed to report to the outpatient department. Hospitalization was required for 12 patients: 2 cases required surgical intervention, 2 cases had an additional procedure, and 8 cases required medical hospitalization.
Conclusion
This study applied RRMS for a timely assessment of MIFs, determine rearrangements required, and present an active response to the MIFs determined in the ED. To improve patient care and safety, we hereby propose monitoring MIFs using the RRMS or similar methods.
9.Does the large amount of ascites lateralize the inferior epigastric artery in liver cirrhosis?
Doosol KIM ; Jae Seong KIM ; Jeong Hun LEE ; Seung Chul LEE ; Jun Seok SEO ; Han Ho DOH ; Sanghun LEE
Journal of the Korean Society of Emergency Medicine 2019;30(2):166-175
OBJECTIVE: The most common cause of hemorrhage after paracentesis is direct needle puncture of the inferior epigastric artery (IEA). This study examined the relationship between the amount of the ascites and the location of the IEA in liver cirrhosis. METHODS: Abdominal computed tomography (CT) examinations of patients with liver cirrhosis were reviewed retrospectively and divided into two groups according to the amount of ascites. The distances between the midline and the IEAs of both sides were measured at the umbilicus, McBurney's point, anterior superior iliac spine, and mid-inguinal level. Branching of the IEAs, abdominal wall and mesenteric varices in the abdomen below the umbilicus level were recorded. RESULTS: A total of 120 abdominal CTs were reviewed. The distances from the midline to the IEA in the large ascites group were longer than those in the small ascites group at the level of the right McBurney's point (44.5±14.6 mm vs. 39.6±11.8 mm, P=0.043) and left McBurney's point (48.6±15.3 mm vs. 43.3±11.5 mm, P=0.035). The incidence of abdominal wall varices was higher in the large ascites group (21.7% vs. 5.0%, P=0.014). CONCLUSION: In patients with liver cirrhosis, the large amount of ascites might be associated with lateralizing the location of the IEA. Moreover, it may be necessary to confirm the blood vessels in the abdominal wall and mesentery near the puncture site by bedside ultrasound before the paracentesis.
Abdomen
;
Abdominal Wall
;
Ascites
;
Blood Vessels
;
Epigastric Arteries
;
Hemoperitoneum
;
Hemorrhage
;
Humans
;
Incidence
;
Liver Cirrhosis
;
Liver
;
Mesentery
;
Needles
;
Paracentesis
;
Punctures
;
Retrospective Studies
;
Spine
;
Tomography, X-Ray Computed
;
Ultrasonography
;
Umbilicus
;
Varicose Veins
10.Clinical course of compressed air injury with pneumocephlaus and orbital emphysema: a case report
Howon NA ; Yong Won KIM ; Sanghun LEE ; Han Ho DO ; Jun Seok SEO ; Jeong Hun LEE ; Seung Chul LEE
Journal of the Korean Society of Emergency Medicine 2021;32(3):273-276
Orbital emphysema with pneumocephalus is an unusual condition encountered in non-fracture craniofacial trauma. We report a case of orbital emphysema with disseminated pneumocephalus without any fracture, due to an orbital trauma caused by compressed air.