治療方針の決定にMRIが有用であった石灰化慢性硬膜下血腫の1手術例

A Case of Calcified Chronic Subdural Hematoma Wherein MRI was Useful for Decision of the Treatment Strategy

Ⅰ．はじめに

　石灰化慢性硬膜下血腫は全慢性硬膜下血腫の0.4～2.6%と稀なものである^1,18)．脳と癒着した被膜の剝離操作に起因する脳表の損傷の危険性があることや，手術による症状改善は期待できないとする報告^2,3,6-8)もあり，治療法については手術の是非も含め一定の見解は得られていない．今回われわれは，術前のmagnetic resonance imaging（MRI）所見から，脳を損傷することなく被膜を含めた摘出が可能と判断して手術に臨み，顕微鏡下に全摘出し得た1例を経験したので，文献的考察を加え報告する．

　Calcified chronic subdural hematoma is a rare condition, representing 0.4-2.6% of all chronic subdural hematomas. It is often difficult to remove the hematoma without damaging the brain, owing to the adhesion between hematoma capsule and brain. Therefore, surgical intervention in managing calcified chronic subdural hematoma cases is still considered controversial.

　We report a case of calcified chronic subdural hematoma, which was successfully performed under microscopic guidance. A 72-year-old man complained of progressive left hemiparesis of 6-month duration. A CT scan revealed a calcified chronic subdural hematoma, 10cm long and 4.5 cm thick, in the right convexity. On MRI, T2-weighted images showed a thin layer of cerebrospinal fluid intensity between the hematoma capsule and brain. There was no brain edema adjacent to the chronic subdural hematoma. Based on these MRI observations, we believed that adhesion between the hematoma capsule and brain would be mild. We then planned and succeeded in total removal of the calcified chronic subdural hematoma mass under microscopic guidance. The left hemiparesis disappeared after surgery. The patient was discharged without any neurological deficit.

　While considering surgical management in calcified chronic subdural hematoma cases, it should be important to evaluate adhesion between the hematoma capsule and brain with MRI.