A 74-year-old woman with probable cerebral amyloid angiopathy was found unresponsive. Initial head CT showed a frontoparietal hematoma with intraventricular extension, edema, and mass effect on the right lateral ventricle. She was intubated, and hyperosmolar therapy was initiated. CT 2 days later showed a new hypodensity in the right frontal lobe extending from the lateral ventricle to the cortical gray-white matter junction (Figure 1). On MRI, this lesion was T2-hyperintense and fluid-attenuated inversion recovery–attenuated, representing a CSF "volcano" dehiscing the frontal lobe due to ventricular entrapment and rupture (Figure 2). The course of hyperosmolar therapy was extended based on this finding. Porencephaly, a CSF cyst due to ventricular rupture, has been described in fetuses because of antenatal intraventricular hemorrhage or developmental anomalies.¹ There are also rare reports of ventricular rupture in adults with chronic hydrocephalus.² However, compression from intraparenchymal hemorrhage leading to lateral ventricle entrapment and rupture has not been previously described.

一名 74 岁女性疑似患有脑淀粉样血管病，被发现已失去反应。最初的头部 CT 显示额顶血肿伴脑室内扩展、水肿和右侧侧脑室占位效应。她被插管，并开始高渗治疗。2 天后 CT 显示右额叶出现新的低密度，从侧脑室延伸至皮质灰白质交界处（图 1）。在 MRI 上，该病变呈 T2 高信号且液体衰减反转恢复衰减，代表脑脊液“火山”由于脑室卡压和破裂而使额叶裂开（图 2）。基于这一发现延长了高渗治疗的疗程。孔脑畸形是一种由于脑室破裂而导致的脑脊液囊肿，由于产前脑室内出血或发育异常而在胎儿中出现过。¹也有罕见的慢性脑积水成人脑室破裂的报道。²然而，先前尚未描述过脑实质内出血压迫导致侧脑室卡压和破裂的情况。