頭部有限要素モデルを用いた衝撃に対する小児急性硬膜下血腫の検証

抄録

Head injuries are one of the most frequent outcomes of paediatric accidents. Severe head injuries such as cranial fractures and intracranial bleedings are difficult to diagnose by external appearances. Of those critical head trauma, acute subdural haematoma (ASDH) causes high death rate and serious sequela. Some former studies stated ASDH as a representative case for shaken baby syndrome (SBS), claiming that ASDH is a sequel of strong shaking events inflicted to a child head. On the other hand, some researches found peaks of global head accelerations and velocities under shaking events were very low compared to impact situations. Since past studies mainly focused on the head acceleration for the investigation of head traumas, cause of ASDH was always a controversial topic. However, a recent study suggested that relative motions between skull and intracranial subjects could be the cause of ASDH. The study used a finite element (FE) model to investigate the intracranial behavior. Findings over the relative motion between skull and brain using the FE model enlightened new perspectives of ASDH researches. Due to paucity of infant PMHS data, there are very few paediatric FE models ever built. Hence, the current study newly developed a 6mo head FE model, and its biofidelity was validated against quantitative experimental data. The validated model was then used for simulations, and conditions susceptible to ASDH were investigated. As a result, no general correlation was to be found between head acceleration peaks and a relative motion regarding brain and skull. An importance to distinguish the head impact location was indicated as well, since occipital impacts showed a significant risk of sustaining ASDH, regardless of the drop height.