Abstract
OVERVIEW: Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic disorder characterized by an acute increase in blood pressure, and by headaches, altered mental status, seizures, and visual loss. It is usually seen on computed tomographic scans as white-matter vasogenic edema predominantly affecting the posterior occipital and parietal lobes of the brain. Risk factors include malignant hypertension, eclampsia, medications such as immunosuppressants (including tacrolimus and cyclosporine), chemotherapy, biotherapy, and renal failure. Early recognition of the signs and symptoms of PRES, particularly identifying and treating high blood pressure, can prevent permanent neurologic disability.