Posterior Reversible Encephalopathy Syndrome and Subarachnoid Hemorrhage After Lumboperitoneal Shunt for Fulminant Idiopathic Intracranial Hypertension.

A 33-year-old woman presented with severe visual loss from fulminant idiopathic intracranial hypertension. Her lumbar puncture opening pressure was 97 cm H2O. Soon after lumboperitoneal shunt surgery, she had a generalized tonic-clonic seizure. Magnetic resonance imaging demonstrated frontal subarachnoid hemorrhage (SAH) and neuroimaging findings consistent with posterior reversible encephalopathy syndrome (PRES). We hypothesize that an abrupt drop in intracranial pressure after lumboperitoneal shunting led to maladjustment of cerebral vascular autoregulation, which caused SAH and PRES.