Posterior reversible encephalopathy syndrome: a neurologic phenomenon in cancer patients.

Posterior reversible encephalopathy syndrome is a well-recognized entity associated with a variety of benign and malignant conditions. This syndrome typically manifests itself with headache, visual loss, and seizures. Radiographic abnormalities consist of white matter edema involving the posterior parietal and occipital lobes, manifested as increased T2 and fluid-attenuated inversion recovery signal intensity on magnetic resonance imaging. In the last decade, there has been a reported increase in the incidence of posterior reversible encephalopathy syndrome in cancer patients. The diagnosis can be challenging in this patient population. Early recognition and initiation of appropriate therapy with removal of the causative agent is essential in order to prevent permanent neurologic sequelae.