Blood-transfusion-related posterior reversible encephalopathy syndrome - A description of a new case and review of the literature.

Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome associated with headache, altered mental status, seizures, and visual disturbances and characterized by white matter vasogenic edema affecting predominantly the posterior occipital and parietal lobes of the brain. Neurological complications of blood transfusion are uncommon, and blood-transfusion-related PRES is seldom reported. We report here one such case of PRES. A 61-year-old Asian woman with chronic anemia presented with a history of fall, causing fracture of the left femur neck. As her hemoglobin was 5 g per deciliter, she was transfused with four units of packed cells in three consecutive days. At the time of admission, she was alert, normotensive, and afebrile. Later, she developed mild headache and had a generalized tonic-clonic seizure. Her brain magnetic resonance (MR) imaging showed edema in bilateral frontal lobes and parieto-occipital lobes with normal MR venogram, consistent with PRES. We described her disorder as blood-transfusion-related PRES. Immunologic, as well as non-immunologic complications of blood transfusion, are known but, PRES is rare. Cumulative effects of blood transfusion on blood flow, blood viscosity, endothelial dysfunction leads to blood-brain barrier dysfunction, which culminates into vasogenic edema and vasoconstriction despite normal systemic blood pressure, leading to blood-transfusion-related PRES.