Posterior reversible encephalopathy syndrome

Abstract

Background: Posterior reversible encephalopathy syndrome (PRES) is a state of reversible vasogenic edema predominantly in the posterior circulation territories reflected by its unique pattern in magnetic resonance imaging. It is a neurotoxic state associated with clinical conditions such as malignant hypertension, eclampsia/pre-eclampsia, autoimmune diseases, immunosuppressive medications, infections, organ transplant, or chemotherapy, and is accompanied by complex of symptoms such as vision loss, other visual disturbances, seizures, headaches, or altered mental status. First described in 1996 by Hinchey et al, reports of PRES-Associated conditions, different clinical presentations, and radiologic variations continue to appear in the literature. The pathophysiology and mechanism leading to posterior reversible encephalopathy is not fully understood. Case Report: A 76-yearold man with a longstanding right homonymous hemianopsia secondary to a history of cerebral infarct presented with acute bilateral vision loss in the absence of ocular pathology. Neuroimaging confirmed the presence of vasogenic edema in the posterior circulation region which was attributed to the patient's hypertensive state. His hypertension was brought under control, and a return to visual baseline was evident several months subsequently. Conclusion: Posterior reversible encephalopathy syndrome should be considered in the differential diagnosis for patients who exhibit acute vision loss in the context of systemic entities which are known to cause this condition. Neuroimaging studies are recommended to establish an early diagnosis. Prompt consultation with a primary care physician and appropriate specialists for proper management of the underlying etiology may fully reverse the clinical presentation and prevent cerebral infarction.