遅発性骨弁陥没による脳ヘルニアの1例

A Case of Brain Herniation due to Delayed Bone Flap Sinking

Ⅰ．はじめに

　外減圧開頭術後に皮膚弁が著しく陥凹し脳機能に影響を与える病態はsinking skin flap syndromeとして知られている^2,5)が，骨弁を戻したにも関わらず，遅発性に骨弁全体が落ち込み神経症状を来したものはわれわれが文献を検索する限りない．今回，初回の手術から15年後に骨弁全体が落ち込み，神経症状を来した1例を経験したので文献的考察をふまえ報告する．

　Marked depression of the skin flap after external decompressive craniotomy, affecting the brain function, is known as sinking flap syndrome. However, to our knowledge, there have been no reports of delayed sinking of the entire bone flap after the procedure, inducing neurological symptoms. We encountered a patient with neurological symptoms due to sinking of the entire bone flap 15 years after the first operation. A 59-year-old male underwent clipping by craniotomy due to subarachnoid hemorrhage resulting from the rupture of a left internal carotid aneurysm 15 years earlier. He was discharged, but developed paresis in the right upper and lower limbs 6 months before symptom onset. CT showed sinking of the free bone flap, while MRI revealed left uncal herniation. After uncal resection and free flap fixation, the symptoms improved. This case confirmed the necessity of firm bone flap fixation at the time of cranial closure.