Lazareff J A, Kelly J, Saito M
Division of Neurosurgery, UCLA School of Medicine, Los Angeles, CA 90095-7039, USA.
Childs Nerv Syst. 1998 Aug;14(8):394-7. doi: 10.1007/s003810050252.
Acquired Chiari 1 following ventriculoperitoneal shunting is an extremely unusual event. We report the case of an 8-year-old boy who presented with clinical and radiological signs of cerebellar tonsil herniation shortly after the placement of a cystoperitoneal shunt. Quantitative analysis of posterior fossa volumes (PFV) revealed that the patient had a smaller posterior fossa than age-matched normal controls. This abnormality, expressed as a decreased ratio between the posterior fossa and the supratentorial cavities (PFR), had already been present when the preoperative MRI was done. Our results suggest that preexisting structural abnormalities in the posterior fossa may constitute an important factor in the development tonsillar herniation following supratentorial shunts.
脑室腹腔分流术后获得性Chiari 1畸形是一种极其罕见的情况。我们报告一例8岁男孩，在进行囊肿腹腔分流术后不久出现小脑扁桃体疝的临床和影像学表现。后颅窝容积（PFV）的定量分析显示，该患者的后颅窝比年龄匹配的正常对照者小。这种异常表现为后颅窝与幕上腔隙的比值（PFR）降低，在术前MRI检查时就已存在。我们的结果表明，后颅窝预先存在的结构异常可能是幕上分流术后扁桃体疝形成的一个重要因素。
