• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.241-252
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• 2005

In this study we suggest that the spatial correlation structure of the brain fMRI data be used to characterize the functional connectivity of the brain. For some concussion and recovery data, we examine how the correlation structure changes from one step to another in the data analyses, which will allow us to see the effect of each analysis to the spatial correlation or the functional connectivity of the brain. This will lead us to spot the processes which cause significant changes in the spatial correlation structure of the brain. We discuss whether or not we can decompose correlation matrices in terms of its causes of variations in the data.

• Research in Vestibular Science
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• v.17 no.4
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• pp.125-129
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• 2018

Posttraumatic vertigo can be defined as the vertiginous disorder occurred after head and neck trauma without other pre-existing vestibular disorder. Central, peripheral, and combined deficits might cause this condition. Especially, various peripheral vestibulopathies are possible causes of posttraumatic vertigo; benign paroxysmal positional vertigo, temporal bone fracture, perilymphatic fistula, labyrinthine concussion, posttraumatic hydrops, and cervical vertigo. Since the differential diagnosis of the posttraumatic vertigo is often difficult, it is essential to acquire knowledge of their pathophysiology and clinical features. In this review, peripheral vestibulopathy as the possible causes of posttraumatic vertigo were described according to the current literature.

• Korean Journal of Radiology
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• v.23 no.2
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• pp.226-236
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• 2022

Objective: This study aimed to explore the myelin volume change in patients with mild traumatic brain injury (mTBI) with post-concussion syndrome (PCS) using a multidynamic multiecho (MDME) sequence and automatic whole-brain segmentation. Materials and Methods: Forty-one consecutive mTBI patients with PCS and 29 controls, who had undergone MRI including the MDME sequence between October 2016 and April 2018, were included. Myelin volume fraction (MVF) maps were derived from the MDME sequence. After three dimensional T1-based brain segmentation, the average MVF was analyzed at the bilateral cerebral white matter (WM), bilateral cerebral gray matter (GM), corpus callosum, and brainstem. The Mann-Whitney U-test was performed to compare MVF and myelin volume between patients with mTBI and controls. Myelin volume was correlated with neuropsychological test scores using the Spearman rank correlation test. Results: The average MVF at the bilateral cerebral WM was lower in mTBI patients with PCS (median [interquartile range], 25.2% [22.6%-26.4%]) than that in controls (26.8% [25.6%-27.8%]) (p = 0.004). The region-of-interest myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (1.87 cm³ [1.70-2.05 cm³] vs. 2.21 cm³ [1.86-3.46 cm³]; p = 0.003) and brainstem (9.98 cm³ [9.45-11.00 cm³] vs. 11.05 cm³ [10.10-11.53 cm³]; p = 0.015). The total myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (0.45 cm³ [0.39-0.48 cm³] vs. 0.48 cm³ [0.45-0.54 cm³]; p = 0.004) and brainstem (1.45 cm³ [1.28-1.59 cm³] vs. 1.54 cm³ [1.42-1.67 cm³]; p = 0.042). No significant correlation was observed between myelin volume parameters and neuropsychological test scores, except for the total myelin volume at the bilateral cerebral WM and verbal learning test (delayed recall) (r = 0.425; p = 0.048). Conclusion: MVF quantified from the MDME sequence was decreased at the bilateral cerebral WM in mTBI patients with PCS. The total myelin volumes at the corpus callosum and brainstem were decreased in mTBI patients with PCS due to atrophic changes.

• Journal of Trauma and Injury
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• v.21 no.1
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• pp.53-58
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• 2008

Purpose: Skiing and snowboarding are becoming increasingly popular. Accordingly, the incidences of injuries among skiers and snowboarders are also increasing. The purpose of this study was to investigate the injury patterns of and the contributing factors to head injuries of skiers and snowboarders and to evaluate the differences in characteristics between skiing and snowboarding head injuries. Methods: One-hundred patients who visited the emergency department of Wonju Christian Hospital between January 2005 and March 2007 due to head injuries from skiing and snowboarding were enrolled. The mechanisms and the histories of the injuries were investigated by surveying the patients, and the degrees of head injuries were estimated by using brain CT and the Glasgow Coma Scale. The degrees and the characteristics of brain injuries were also analyzed and compared between skiers and snowboarders. Results: Out of 100 patients, 39 were injured by skiing, and 61 were injured by snowboarding. The mean age of the skiers was $26.7{\pm}10.0$, and that of the snowboarders was $26.7{\pm}6.2$. The percentage of male skiers was 43.6%, and that of snowboarders was 63.9%. The most frequent initial chief complaints of head-injured skiers and snowboarders were headache and mental change. The most common mechanism of injuries was a slip down. The mean Abbreviated Injury Scale Score (AIS score) of the skier group was $4.5{\pm}2.1$ and that of the snowboarder group was $5.9{\pm}5.0$ (p=0.222). The percentage of helmet users was 7.1% among skiers and 20.8% among snowboarders (p=0.346). Head injuries were composed of cerebral concussion (92.0%) and intracranial hemorrhage (8.0%). Intracranial hemorrhage was most frequently caused by falling down (62.5%). Conclusion: The most common type of head injury to skiers and snowboarders was cerebral concussion, and severe damage was usually caused by jumping and falling down. No differences in the characteristics of the head injuries existed between skiing and snowboarding injuries.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.60 no.8
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• pp.390-395
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• 2017

Background and Objectives With increasing frequency of car accidents, patients of dizziness caused by car accidents are also increasing. Various types of dizziness or vertigo can occur from car accidents depending on different injury mechanisms. Since accurate diagnosis is important for providing proper treatments, we evaluated clinical characteristics related to vestibular function of patients with dizziness caused car accidents. Subjects and Method In this retrospective case review study that runs from January 2011 to March 2013, a total of 82 patients with dizziness following car accident were enrolled consecutively. We analyzed the final diagnosis of dizziness according to different mechanisms of injury during car accident through clinical record review. Patients who developed dizziness within one month of car accident were included, excluding those who had temporal bone fracture and previous history of dizziness. Results Of the different types observed, 36.6% was head injury, 24.4% whiplash injury, 3.7% complex injury, 2.4% others and the rest was unknown. In the final diagnosis, the different types included 36.6% benign paroxysmal positional vertigo (BPPV), 23.2% unclassifiable dizziness, 18.3% cervical vertigo, 7.3% labyrinthine concussion, 3.7% BPPV with labyrinthine concussion and the rest was others. Of the different types of dizziness symptoms, 58.5% was headache, 45.1% was audiologic symptoms, and others included earfullness, tinnitus and hearing disturbance. Tinitogram and pure tone audiogram results show that 2.9% (27 people) of patients have tinnitus and 7.3% (6 people) have hearing disturbance. Conclusion An accurate diagnosis and timely management would be very important in forming a proper approach for post traumatic vertigo patients.

• Journal of Society of Preventive Korean Medicine
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• v.18 no.2
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• pp.125-132
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• 2014

Objective : The aim of this study is to review the historical development and current situation of Mongolian traditional medicine. Method : Systematic literature review for books, journals, governments statistics, reports on mongolian traditional medicine was carried out. Results : The theory of Mongolian traditional medicine is influenced by the philosophy and medical theories of the ancient orient such as India, Tibet and China-theories of hot and cold, principle of yin and yang and five elements. There are very unique treatments like brain tram concussion, fermented horse milk treatment as well as moxibustion, acupuncture, and blood letting. It appears that they are very closed to nomadic life. Training program of each institutes need to be standardized. Mongolian traditional medicine had been almost destroyed by the influence of communist idea from 1930s until the end of the 1980s. Since 1990, Mongolian government put much emphasis on the development of traditional medicine. And now about 3.7% of total beds is traditional medicine one and that there are six TM schools and the total number of traditional medicine in 2012 is 1696. However, there are still the lack of manpower, facilities, standardized training program and scientific research for traditional medicine. Conclusion : Mongolian traditional medicine has been developed over centuries in response to Mongolia's unique geographical and climate conditions and the lifestyles of its people and that made contribution to the health of mongolian people. However, it needs to be strengthened because there are poor infrastructure and training program.

• Structural Engineering and Mechanics
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• v.48 no.5
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• pp.661-679
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• 2013

In this work, the safety performance of a commercial motorcycle helmet already placed on the market is assessed. The assessed motorcycle helmet is currently homologated by several relevant motorcycle standards. Impacts including translational and rotational motions are accurately simulated through a finite element numerical framework. The developed model was validated against experimental results: firstly, a validation concerning the constitutive model for the expanded polystyrene, the material responsible for energy absorption during impact; secondly, a validation regarding the acceleration measured at the headform's centre of gravity during the linear impacts defined in the ECE R22.05 standard. Both were successfully validated. After model validation, an oblique impact was simulated and the results were compared against head injury thresholds in order to predict the resultant head injuries. From this comparison, it was concluded that brain injuries such as concussion and diffuse axonal injury may occur even with a helmet certified by the majority of the motorcycle helmet standards. Unfortunately, these standards currently do not contemplate rotational components of acceleration. Conclusion points out to a strong recommendation on the necessity of including rotational motion in forthcoming motorcycle helmet standards and improving the current test procedures and head injury criteria used by the standards, to improve the safety between the motorcyclists.

• Korean Journal of Applied Biomechanics
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• v.30 no.3
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• pp.265-273
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• 2020

Objective: The aim of this study was to investigate the effect of participation in contact sports on neurocognitive scores, dual-task walking velocity, and cognitive costs in retired athletes. Method: Forty-four retired athletes (mean age = 26.4±5.5 yrs) and thirty-eight controls (mean age = 26.1±4.9 yrs) participated in this study. Neurocognitive score was collected using computerized neurocognitive testing using RehaCom. Gait velocity was collected one single task, four dual-tasks, and two multi-tasks using Optogait. Mann-Whitney U test was performed to compared differences in cognitive scores among groups. A mixed-design two-way ANOVA and Bonferroni posthoc test were used to assess the effect of group and walking tasks for each condition. Results: The auditory divided attention of neurocognitive score of retired athletes was higher than the control group (p < 0.05). No statistical differences were observed in the other neurocognitive scores between groups. The changes in walking velocity and cognitive costs according to the dual-task walking tests differed between the two groups (p < 0.05). Conclusion: Although participation in contact sports did not affect the neurocognitive results of retired athletes, it could be confirmed that the reduction in walking velocity and an increase in cognitive costs during dual-task walking. Rather than observing only neurocognitive scores as a single evaluation item for cognitive evaluation of retired athletes in relation to daily life, the application of the dual-task gait test may provide useful information.

• The Journal of the Korean dental association
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• v.51 no.8
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• pp.442-450
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• 2013

It is well known that the majority of dental injuries occur in children and adolescent. An injury to the teeth can have serious and long-term consequences, leading to their discoloration, malformation, or possible loss. The emotional impact of such an injury can be far reaching. The majority of dental injuries in the primary and permanent dentitions involve the anterior teeth, especially the maxillary central incisors. Concussion, subluxation, and luxation are the commonest injuries in the primary dentition, while uncomplicated crown fractures are commonest in the permanent dentition. If it is decided to preserve a traumatized primary tooth, it should be carefully observed for clinical and radiographic signs of pulpal or periodontal complications. Radiographs are also examined closely to disclose any damage to the permanent successor. The intervals between reexaminations should be individualized depending on the severity of trauma, the expected type of complications and the age of the patient. Most complications are observed within the first year of the trauma. However, the follow-up evaluation of permanent teeth should continue until treatment of all complications is completed, or until a lost or extracted permanent tooth has been adequately replaced. It is important that the dentist and the other members of the dental team are well prepared to meet the many complex and challenging problems in the care of dental emergencies.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1209-1214
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• 2000

Objectives : The measurement of resistance to cerebrospinal fluid outflow($R_o$) can clearly delineate cerebrospinal fluid dynamics in patients with ventricular dilatation and can help in selecting patients to undergo shunt placement. With regards to type of infusion method, bolus injection is known to be more practical and safer than continuous infusion. The purpose of this study was to obtain $R_o$ of normal adults using lumbar bolus injection method. Material and Methods : Twenty adults aged 25 to 52 years were studied using lumbar bolus injection method. Fifteen patients with hemifacial spasm and five with cerebral concussion underwent $R_o$ measurement under propofol general anesthesia and local anesthesia, respectively. Results : The mean values of $R_o$ determined 1 minute and 2 minutes after bolus injection were $4.8{\pm}1.7$ and $4.4{\pm}1.6mmHg/ml/min$, respectively. There was no significant difference of $R_o$ between propofol general anesthesia group and local anesthesia group. Two patients showed $R_o$ greater than 6mmHg/ml/min. One patient revealed unexpectedly high level of $R_o$ due to severe spinal stenosis. Conclusion : Mean Ro in this study was higher than that of Shapiro's study. Borderline Ro near 6mmHg/ml/min should be regarded with caution and compared with clinical symptoms and results of other studies. Patients with severe spinal stenosis should be evaluated with caution.