MRI Features of Posterior Reversible Encephalopathy Syndrome

Abstract

Background and Purpose: Posterior Reversible Encephalopathy Syndrome (PRES) represents a clinico-radiological constellation of neurological symptoms and radiological features. The syndrome tends radiologically to be present with certain features and patterns. Our aim in this study is to investigate the PRES radiological features by which it does present in our community and to correlate the findings clinically. Methods: The MR images obtained for the 17 patients included in the study were analyzed for the PRES features and patterns. Fluid Attenuation Inversion Recovery (FLAIR) sequence was the mainly used sequence for assessment. Diffusion images with their apparent diffusion coefficient maps, T2* images, and Angiography were also utilized for further assessment and characterization. Results: Most of the cases demonstrated a bilateral involvement (94%). The regional distribution supra-tentorially included parietal and occipital affection in 94%, frontal lobe affection in 76%, and a temporal lobe affection in 71%. Infra-tentorial involvement was noted in 41% of the cases. Pattern percentages were slightly different from those available in the literature with the Holo-hemispheric Watershed pattern being the most common (35%). Conclusion: The originally described PRES features are present in the majority of the studied cases. The identified PRES patterns may reflect underlying clinical or pathological correlations, and hence can vary across communities.