[An old woman with sudden pareses and blindness]

We present a patient with Posterior Reversible Encephalopathy Syndrome (PRES). A 74-year-old woman was admitted with sepsis, which originated from erysipelas on her neck the following day. She developed respiratory obstruction due to oedema, septic shock, disseminated intravascular coagulation (DIC), acute renal failure and atrial fibrillation. She responded well to treatment and improved rapidly, despite of her serious condition. When she had almost fully recovered after 15 days, her general condition worsened, and she developed confusion, blindness and pareses. MRI showed vasogenic oedema in the parietooccipital regions of the brain and in the cerebellum, consistent with PRES. PRES is a clinical and radiological diagnosis consisting of headache, confusion, cortical blindness, convulsions and sometimes pareses. MRI of the cerebrum with diffusion-weighted imaging (DWI) and Apparent Diffusion Coefficient (ADC) map are decisive to the diagnosis, and usually shows a characteristic bilateral vasogenic oedema in the parietooccipital region. This can distinguish PRES from brain infarction, which shows a cytotoxic oedema on MRI. We discuss our patient in the light of different conditions leading to PRES, possible pathophysiological factors and treatment options.