두개부 손상 시 치료 모델 개발 번역(한국어 원본)Head 는 road traffic accidents, sport activity, assaults, falls 등의 원인으로 가장 빈번하게 injury가 발생하는 부위이며, fatal injury의 경우 약 40%에서 Head injury가 발견되고 있다(1-1). Traumatic brain injury(TBI)에는 cerebral contusion, cerebral concussion, diffuse axonal injury(DAI), Subdural hemorrhage(SDH) 등이 대표적이며, SDH와 DAI는 other lesions에 비해 치명적이다. Brain의 deformation에 의해 발생되는 DAI에 대해서는 많은 연구가 진행되어 injury threshold가 define 되어있으나, injury발생 mechanism이 복잡한 SDH는 상대적으로 진행된 연구가 적다.
Subdural hemorrhage는 Skull에 붙어있는 경막(dura mater)과 뇌 표면을 둘러싸고 있는 지주막(arachnoid membrane) 사이를 이어주는 혈관(bridging vein)이 파열되어 뇌와 경막 사이의 경막하 공간(subdural space)에 혈액이 고이는 상태를 의미한다. SDH는 severely head injured patients의 약 30%에서 발견되며(2), marked increase in intracranial pressure와 serious deformation of the brain을 야기하여 약 60-80%의 높은 사망률을 보인다(3). The most common type of SDH results from tearing of the cerebral bridging veins alone. 이와 같은 현상은 Head impact나 assaults등 과 같이 머리의 급격한 motion이 발생 할 경우 skull 과 brain사이에 excessive relative motion이 발생하여 이 사이에 연결되어 있는 vein이 stretched and torn 되어 발생한다.
SDH에 대한 분석을 위해 cadaver와 동물을 이용한 다양한 방식의 experimental test가 진행되었다. 그러나 실험으로는 SDH에 대한 정확한 injury mechanism을 구현하기가 어려울 뿐만 아니라, head/brain은 다른 신체 부위에 비해 동물 대 인간의 scaling이 어려워 SDH에 대한 real threshold가 아직 정의되지 않은 상태이다. 반면에 Finite element(FE) analysis proved to be a useful method of investigating the mechanical response of the head. Many FE human head models have been developed in order to achieve a better understanding of SDH.
기존에 발표된 연구에서는 skull-brain interface 사이에 위치한 parasagittal bridging vein(PSBV)을 string 이나 cable 요소로 모델링하여 이 요소에서의 strain 량을 계산하여 SDH 가능성을 예측하곤 하였다. 그러나 모델링 시 PSBV를 정확히 모사하기가 어려울 뿐만 아니라 충격 상태에서 skull-brain interface사이에서의 sliding량을 비교할만한 실험 data가 없다. 게다가 FE modeling 시 dura matter 와 arachnoid membrane을 tied interface or node-sharing method를 사용하여 skull-brain interface를 고정 하는 modeling 방법이 실험결과에 더 유사한 결과를 도출한다고 알려져 있다.
따라서 본 연구에서는 skull-brain interface 에서 SDH risk prediction이 가능한 새로운 모델을 개발하여 various loading condition에 따른 SDH을 예측하고자 하였다. |
두개부 손상 시 치료 모델 개발 번역(영어 번역본)The head is the area where injury occurs most frequently due to traffic accidents, sports activities, assault, or falls. In the case of fatal injuries, a head injury is found in about 40% of the cases(1-1). The representative types of traumatic brain injury(TBI) include cerebral contusion, cerebral concussion, diffuse axonal injury(DAI), and subdural hemorrhage(SDH). Compared to injuries from other lesions, SDH and DAI are more fatal. A lot of research has been done on DAI caused by brain deformation and the injury threshold has been defined. However, relatively little research has been done on SDH as it has a more complex injury mechanism.
SDH is blood gathering in the subdural space between the brain and the dura mater due to the tearing of bridging veins that connect the dura mater, which is attached to the skull, and arachnoid membrane, which envelops the brain surface. SDH is found in about 30% of patients with severe head injury(2), and it results in high mortality rate of about 60-80% by causing a marked increase in intracranial pressure and a serious deformation of the brain(3). The most common type of SDH results from tearing of the cerebral bridging veins alone. It occurs when the veins that connect the skull and brain are stretched and torn due to excessive relative motion between the skull and the brain by rapid motion, such as head impact and assault.
For the analysis of SDH, a variety of experimental tests using cadavers and animals have been done. However, real threshold for SDH has not been defined yet as it is difficult to embody the accurate injury mechanism of SDH with experiments and compared to other body parts, scaling of head/brain between humans and animals is difficult. On the other hand, the finite element(FE) analysis proved to be a useful method of investigating the mechanical response of the head. Many FE human head models have been developed in order to achieve a better understanding of SDH.
Previous studies modeled parasagittal bridging vein(PSBV), which is located in the skull-brain interface, using string or cable elements and predicted the possibility of SDH by calculating the amount of strain in these elements. However, it is very difficult to accurately simulate PSBV for modeling and there is not enough experimental data to compare the amount of sliding in the skull-brain interface upon impact. Moreover, it is known that for the FE modeling, fixing the skull-brain interface using tied interface or node-sharing method of dura mater and arachnoid membrane produces results that are more similar to the experiment results.
Therefore, this study tries to predict SDH according to various loading conditions by developing a new model that can predict the risk of SDH in the skull-brain interface. |
