Posterior reversible encephalopathy syndrome in the pediatric renal population

Posterior reversible leukoencephalopathy syndrome (PRES) clinically presents with seizures, severe headaches, and mental and visual changes. Our goal was to describe the clinical features, triggering factors, neuro-imaging findings, and electroencephalogram (EEG) findings in a pediatric cohort with renal disease. We retrospectively analyzed the records of 18 children with the diagnosis of PRES between January 2001 and June 2006 at the University of Miami/Holtz Children's Hospital, USA. There were 22 PRES episodes. The most common clinical presentation was generalized tonic-clonic seizures in 59% (13/22). The most common identified trigger of PRES was hypertensive crisis in 59% (13/22). Almost half of the children had no evidence of on-going uncontrolled hypertension; 44% (8/18) had normal funduscopic examination findings, and 50% (9/18) had no or mild left ventricular hypertrophy. Two of the 18 patients had recurrent PRES episodes, three episodes each. Diffuse slowing was the most common finding on the EEGs. Atypical magnetic resonance imaging (MRI) findings were more prevalent in the imaged cases (62% vs 25%, P < 0.05). All the computerized tomography (CT) scans were normal, despite the positive MRI findings in four cases when both types of imaging was used. All the episodes had total clinical resolution. In conclusion, despite the diverse initial trigger, acute hypertension seems to be the common pathogenic pathway for pediatric PRES. MRI seems superior to CT, with better sensitivity due to its high resolution and diffusion-weighted imaging. The lesions do not necessarily have to be in the posterior white matter and may not be totally reversible.