Posterior reversible encephalopathy syndrome: characteristics, diagnostic accuracy, prognostic factors and long-term outcome in a paediatric population.

Posterior reversible leukoencephalopathy syndrome (PRES) is a rare entity among children, characterised by acute neurological symptoms and radiological findings. The role of clinical symptoms and neuroimaging in predicting the prognosis of PRES have not been well-characterised. A retrospective descriptive study of children with PRES, admitted to a Paediatric Intensive Care Unit during a 10-year period, was performed to describe its characteristics, compare the accuracy of computed tomography (CT) scan and MRI on diagnosis and identify prognostic factors on paediatric population. Sixteen cases were identified. Most patients (13; 81%) presented underlying disorders, including malignancies (5; 31%), chronic kidney disease (3; 19%) and post-transplant status (3; 19%). Hypertension (15; 94%) was the most common trigger. All patients had seizures, 9 patients (56%) altered state of consciousness, 8 (50%) headache. CT scan was performed in 15 patients (94%) and MRI in 13 (81%); 1 patient underwent only MRI. MRI allows the identification of new areas of vasogenic oedema and a correct diagnosis of PRES when CT scan was inconclusive. Two patients (13%) remained with neurological sequelae and one died. In two patients (13%) cognitive disorders (specific learning disorder, intellectual disability, motor tic disorder) were diagnosed during follow-up period. Clinical presentation was not statistically associated with outcome. Also, atypical neuroimaging (haemorrhagic and unilateral lesions) were not statistically related with poor neurological or cognitive outcome. However, prospective studies with a larger cohort are needed to establish prognostic factors of PRES in the paediatric population.