P509 Posterior reversible encephalopathy syndrome (PRES) in a child with steroid-dependent nephrotic syndrome: a case report

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition characterized by headache, nausea, vomiting, seizures, and visual disturbances with typical radiological features of symmetrical edema mostly involving the white matter in the occipital regions (1–2). PRES can develop in association with a wide array of clinical conditions, including systemic infections, hypertension, organ transplantation, and immunosuppression (especially with calcineurin inhibitors). Children who are on prolonged steroid therapy or on calcineurin inhibitor therapy in nephrotic syndrome (NS) are at risk of developing PRES (3–4). A 6-year-old Moroccan-boy, followed in his country for nephrotic syndrome, was hospitalized in our unit of pediatrics for severe generalized body edema, proteinuria (18600 mg/day), low serum albumin (0.9 g/L), high serum cholesterol (468 mg/dl). His arterial blood pressure value was 122/77 mmHg. We treated him with steroid intravenous, albumin supplementations and we continued cyclosporine. While his general conditions were improving, on the seventh day of hospitalization he developed headache, vomiting, dizziness, temporal blindness. A non-contrast computerized tomography was performed and it showed symmetrical hypodensities in parieto-occipital regions. His blood pressure was 132/71 mmHg. Then he developed two episodes of generalized tonic clonic convulsion, followed by unconsciousness. Magnetic resonance imaging (MRI) showed hyperintense signal in the parieto-occipital regions, and revealed bilateral cortical and subcortical white matter edema in parieto-occipital lobes The child was treated with antihypertensive medications, diuretic, steroids and immunosuppressant (cyclosporine A), thereafter he got no seizure and regained full consciousness and vision. His blood pressure was kept at normal range and urinary protein excretion gradually decreased. MRI performed two weeks later revealed no abnormality of the brain, which is a usual phenomenon in case of PRES The pathophysiology of PRES remains controversial, and two main hypotheses have been suggested; impaired cerebral autoregulation resulting in increased cerebral blood flow, and endothelial dysfunction with cerebral hypoperfusion (5–6). PRES must be managed carefully and its pathogenic factors should be suspected and recognized as soon as possible in order to properly treat the patient. In hypertension-related and drug-induced PRES, in fact, effective management includes prompt withdraw of offending agent, aggressive control of blood pressure, timely anti-convulsant therapy. In our case, hypertension was undoubtedly an important cause, but we were uncertain whether cyclosporine also played a pathogenic role. PRES should be always considered in the differential diagnosis of a child with idiopathic nephrotic syndrome, headache and visual disturbance.