Posterior Reversible Encephalopathy Syndrome (PRES) Complicated by Subarachnoid Hemorrhage Induced by Chemotherapy: A Rare Case and Literature Review

Posterior Reversible Encephalopathy Syndrome (PRES) is a rare neurological entity characterized by vasogenic cerebral edema, often triggered by hypertension, renal failure, preeclampsia, certain immunosuppressive drugs, or chemotherapeutic agents. We report the case of a 68-year-old woman with multifocal metastatic intrahepatic cholangiocarcinoma who developed PRES complicated by subarachnoid hemorrhage following the administration of the third cycle of FOLFOX chemotherapy. The clinical picture included headaches, visual disturbances, and recurrent generalized tonic-clonic seizures. Brain magnetic resonance imaging (MRI) confirmed the diagnosis by showing bilateral and symmetrical T2/FLAIR hyperintensities predominantly in the parieto-occipital regions, consistent with vasogenic edema, associated with minimal leptomeningeal bleeding signs. Management consisted of immediate discontinuation of chemotherapy, strict blood pressure control, and anticonvulsant therapy, leading to a rapidly favorable outcome. This case highlights the rarity of oxaliplatin as a causative agent and the importance of heightened clinical vigilance for any acute neurological symptom in a patient undergoing chemotherapy, to enable early management and improve prognosis.