Posterior Reversible Encephalopathy Syndrome, Part 1: Fundamental Imaging and Clinical Features

Abstract

SUMMARY:Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique CT or MR imaging appearance. Recognized in the setting of a number of complex conditions (preeclampsia/eclampsia, allogeneic bone marrow transplantation, organ transplantation, autoimmune disease and high dose chemotherapy) the imaging, clinical and laboratory features of this toxic state are becoming better elucidated. This review summarizes the basic and advanced imaging features of PRES, along with pertinent features of the clinical and laboratory presentation and available histopathology. Many common imaging/clinical/laboratory observations are present among these patients, despite the perception of widely different associated clinical conditions.

The effect of presymptomatic hypertension in posterior reversible encephalopathy syndrome

“…Clinical symptoms are headache, visual disturbance, mental alteration, and seizure. The characteristic radiologic finding is the vasogenic edema in the posterior part of the brain (Bartynski, 2008a,2008b). Diverse brain imaging patterns are currently reported with the advances of the imaging techniques (McKinney, Jagadeesan, & Truwit, 2013).…”

An atypical subacute presentation of posterior reversible encephalopathy syndrome

“…The characteristic neuro-radiologic feature of PRES is white matter vasogenic edema notable on brain MRI as hyper-intense lesions on T2/FLAIR sequences [3,6]. While the patterns of distribution of such signal hyper intensities are now known to vary, historically PRES was thought to produce bilateral and symmetric lesions in the posterior temporal, parietal, and occipital regions of the brain [2,6].…”

“…This syndrome was first described in 1996 in a small case series of patients presenting with headaches, vomiting, confusion, seizures, cortical blindness and other visual abnormalities, and motor signs as reversible posterior leukoencephalopathy syndrome (RPLS) [2]. Typical magnetic resonance imaging (MRI) findings include vasogenic edema in the subcortical white matter of the posterior parietal and occipital regions bilaterally, but additional cortical and anterior findings are possible as well [3–6]. Severe hypertension, abrupt increases in blood pressure, renal disease, pre-eclampsia and eclampsia, autoimmune disease, immunodeficiency states including human immunodeficiency virus infection (HIV) and use of immunosuppressants or immune modulators are the most commonly implicated causes [2,4,7–11].…”

Dialysis disequilibrium leading to posterior reversible encephalopathy syndrome in chronic renal failure

“…Both these hypothesis fit in the clinical context of PRES, where hypertension or hypertensive urgency plays a major role in the midst of other complications. Although literature suggests that acute rise in blood pressure leading to autoregulation failure is the mainstay for PRES many studies have revealed that in approximately -20 to -40 % of cases, PRES is seen in the absence of hypertension [8]. In renal failure with advanced uremia, and controlled blood pressure, etiopathogenesis of PRES is exactly unknown.…”