D'Osvaldo D H, Otero J M, Mosconi J B, Oviedo J D
Division of Neurosurgery, Deutsches Hospital, Buenos Aires, Argentina.
Acta Neurochir (Wien). 2002 Apr;144(4):385-8. doi: 10.1007/s007010200054.
Syringomyelia associated with posterior fossa tumours is a very infrequent combination of pathological entities. The few cases which have been reported generally were asymptomatic in respect of the spinal cavitations. The authors report on a 36-year-old woman with a large extradural posterior fossa epidermoid tumour with a concomitant holocord symptomatic syringomyelia. Some of her symptoms were clearly attributed to the intraspinal cavitation. The lesions were both diagnosed by magnetic resonance imaging (MR). The patient did well after surgery of the brain lesion, with an objective improvement in her neurological status and a complete resolution of the syrinx documented by the MR 7 months after tumour removal. Syringomyelia in this case could be explained by blockage of the cerebrospinal fluid (CSF) circulation at the foramen magnum which in turn resulted in cranio-spinal pressure dissociation. This led to an accumulation of extracellular fluid (ECF) in the central canal, starting cavitation. Consequently, the syrinx was slowly expanded by the long-standing "slosh" effect of the systolic pressure waves. However, also via a distortion mechanism within the posterior fossa a pathologically plugged obex could have contributed to syrinx formation by means of preventing drainage of fluid from the ventricular CSF system.
与后颅窝肿瘤相关的脊髓空洞症是一种非常罕见的病理实体组合。已报道的少数病例通常在脊髓空洞方面无症状。作者报告了一名36岁女性，患有巨大的硬膜外后颅窝表皮样肿瘤，并伴有全脊髓症状性脊髓空洞症。她的一些症状明显归因于脊髓内空洞。病变均通过磁共振成像（MR）诊断。患者在脑部病变手术后情况良好，神经状态客观改善，肿瘤切除7个月后MR显示脊髓空洞完全消失。本例脊髓空洞症可解释为枕骨大孔处脑脊液（CSF）循环受阻，进而导致颅-脊髓压力分离。这导致细胞外液（ECF）在中央管积聚，开始形成空洞。因此，由于收缩压波的长期“晃动”效应，脊髓空洞逐渐扩大。然而，后颅窝内的一种扭曲机制也可能通过阻止脑室CSF系统的液体引流，导致病理上堵塞的闩部促成脊髓空洞的形成。
