RESUMEN
Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiographic syndrome with seizures, headache, altered mental status and visual disturbances. It is typically associated with posterior cerebral white matter oedema on neuroimaging. There is an increasing number of cases of PRES reported with different chemotherapeutic protocols. However, PRES is rarely reported in association with irinotecan, fluorouracil and folinic acid (FOLFIRI). We report a 28-year-old female patient with a history of Stage IV gastric cancer who presented with abdominal pain and recurrent vomiting that was thought to be related to a partial intestinal obstruction secondary to peritoneal metastasis. Eventually, she was treated with FOLFIRI. A few hours after initiation of the fluorouracil infusion in the second cycle, she developed a tonic-clonic seizure. MRI of the brain showed multiple bilateral T 2 and flair hyperintense cortical and subcortical lesions suggestive of PRES. Other causes of PRES were excluded, as well as brain metastasis. Unfortunately, the patient developed septic shock and died a few days after her presentation.