Herniation of cerebellar tonsils following supratentorial shunt placement

摘要: Acquired Chiari 1 following ventriculoperitoneal shunting is an extremely unusual event. We report the case of 8-year-old boy who presented with clinical and radiological signs cerebellar tonsil herniation shortly after placement a cystoperitoneal shunt. Quantitative analysis posterior fossa volumes (PFV) revealed that patient had smaller than age-matched normal controls. This abnormality, expressed as decreased ratio between supratentorial cavities (PFR), already been present when preoperative MRI was done. Our results suggest pre-existing structural abnormalities in may constitute important factor development tonsillar shunts.