後頭骨陥没骨折による同名4分盲性暗点の1例

A case of homonymous quadrantanoptic scotoma consequent to focal occipital skull injury

　後頭骨の陥没骨折により，きわめてまれな視野欠損である，左右一致性の黄斑回避を伴う右下同名4分盲性暗点をきたした症例を経験した．障害部位はその特異な視野の形状から，左鳥距溝上唇部後端と推定した．またCTスキャンや脳血管造影など脳外科的検査では，障害部位の検出が不能であったことから，とくに視野検査が頭部外傷の際に重要であることを述べた．

A 52-year-old male was hit by a falling machine block in his skull, slightly inferior and left to the inion. A depressed fracture resulted, 20mm in dia-meter and 6mm in depth. While the visual acuity was not impaired, homonymous right inferior quadrantanoptic scotoma developed with macular sparing. We could prove the scotoma to be due to upper lip damage of the left calcarine fissure caused by the injury. Carotid angiography and CT-scan failed to show pathological lesions in the involved brain area. The present case illustrates the impor-tance of visual field examination in the evaluation of patients with skull fracture.