BACKGROUND The coexistence of falcine and occipital sinuses is rare and its natural course has not been reported. CASE REPORTS Two patients with persistent falcine and occipital sinuses are described. Both patients had straight sinuses. In one, both the transverse and sigmoid sinuses were hypoplastic and the patient had an acquired Chiari I malformation. The other patient had no other venous anomalies and had a normal posterior cranial fossa. CONCLUSION The coexistence of falcine and occipital sinuses can lead to an acquired Chiari I malformation. These cases suggest the importance of checking other venous and brain anomalies in this situation.

中文翻译：

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持续性镰状窦和枕窦两例

背景镰状窦和枕窦并存的情况很少见，其自然病程尚未见报道。病例报告 描述了两名患有持续性镰状窦和枕窦的患者。两名患者都有直鼻窦。其中一个，横窦和乙状窦发育不良，患者有获得性 Chiari I 畸形。另一名患者没有其他静脉异常，后颅窝正常。结论 镰状窦和枕窦的共存可导致获得性 Chiari I 畸形。这些病例表明在这种情况下检查其他静脉和大脑异常的重要性。