金属製鈍的器物による経眼窩的穿通性脳損傷の1例

A Case of Transorbital Penetrating Brain Injury by a Blunt Metal Rod

Ⅰ．はじめに

　頭蓋内への穿通性損傷は経眼窩的あるいは経鼻的なものが多いが，頭部外傷の中で穿通性脳損傷は0.4％とされ¹⁰⁾，比較的稀に発生する外傷である．

　経眼窩的穿通性脳損傷の創部はときに外観上軽微であることがあり，加えて無症状であれば脳損傷は見過ごされる可能性がある．一方で経眼窩的脳損傷はその診断および治療が遅れなければ比較的予後は良好であるとされ⁷⁾，初期診療は重要である．

　This report presents a case of a transorbital penetrating brain injury caused by a metal rod. A 47-year-old male injured his left lower eyelid with no witness during working hours. The two days later, he presented with a right hand tremor and abnormal behavior, and was admitted to the hospital. A CT showed a bone fracture of the left orbital roof and a low-density lesion of the left frontal lobe. The initial diagnosis was a cerebral contusion due to a blow-out fracture. However, sagittal MR images on the tenth day in the hospital demonstrated a penetrating tract that was running linearly from the left orbital roof to the left caudate head. Therefore, the final diagnosis was a transorbital penetrating brain injury. This case had no severe complications in spite of the delayed diagnosis. Careful examinations are thus required in order to make a correct diagnosis at the first examination, because a transorbital penetrating brain injury might initially present as a slight wound with no neurological signs.