Gadolinium Enhancement in a Case of Uncomplicated Posterior Reversible Encephalopathy Syndrome

rebral CT was normal. Serum lactic dehydrogenase (LDH) levels rapidly increased. After 2 h she presented a right-sided motor seizure. Few hours later she was no longer able to follow objects in the visual field. Neurological examination was negative for other focal signs. About 10 h after the clinical onset, the patient underwent an MRI examination that showed hyperintense areas on fluidattenuated inversion recovery (FLAIR; fig. 1 B, H) and fast spin echo T 2 -weighted sequences, in the occipital cortex and in the subcortical white matter bilaterally, more evident in the deep white matter of the left frontoparietal lobe. Diffusion-weighted images showed restricted diffusion of the left frontal lesion ( fig. 1 A). In the same location and in the occipital lobe bilaterally ( fig. 1 C, I), contrast-enhanced images showed blood-brain barrier (BBB) disruption. After few hours, SBP normalized. The LDH serum level decreased gradually. The cortical blindness recovered within 24 h and no other seizures occurred. Magnetic resonance studies conducted 15 days and 6 weeks later detected only a minimal hyperintensity on FLAIR images with a dramatic volume reduction of the left frontal lesion ( fig. 1 E), corresponding to the one with previous diffusion restriction and gadolinium enhancement. Dear Sir, Posterior reversible encephalopathy syndrome (PRES) is typically related to severe high systemic blood pressure (SBP) but may occur with a mildly elevated or normal SBP. MRI characteristic findings are hyperintense areas on T 2 -weighted images, usually resolving if the underlying causes are promptly treated [1] . Early differentiation between reversible and permanent lesions is not possible with conventional MRI. Gadolinium contrast enhancement is not considered a feature of PRES and, if present, is considered a marker of adverse outcome.