A rare case of pontine and extrapontine myelinolysis in a pediatric patient with chronic renal failure.

Osmotic demyelination syndrome (ODS) is a very rare condition in childhood occurring usually secondary to the rapid increase of serum sodium levels. This situation occurring secondary to the rapid correction of hyponatremia can be seen more rarely in the form of extrapontine myelinolysis and even the coexistence of these two conditions besides central pontine demyelinolysis. However, osmotic demyelination syndrome due to the rapid correction of hyponatremia in chronic renal failure (CRF) patients is very rare depending on existing uremia. In this article, we present an extremely rare case of pontine and extrapontine myelinolysis, which occurred in a pediatric patient with chronic renal failure, secondary to the rapid correction of hyponatremia. In the diffusion and cranial magnetic resonance imaging (MRI), bilateral symmetrical caudate, putamen, and thalamus involvements and hyperintense linear lesions at the pons, cortical, and subcortical areas were revealed. It was evaluated as pontine and extrapontine myelinolysis. This clinical situation presents that the presence of severe hyponatremia and extremely rapid correction of it can develop pontine and extrapontine myelinolysis even though it is very rare in uremic patients.