[Central pontine myelinolysis as potential complication of cerebellar astrocytoma: report of a case].

Central pontine myelinolysis (CPM), a rare condition first observed by Adams et al. in 1959 in a group of malnourished chronic alcoholic subjects, has subsequently been seen in patients treated with thiazide diuretics, patients hyperhydrated postoperatively, and in other clinical situations. it is characterized by quadriplegia and pseudobulbar palsy which sometimes evolves into a locked-in syndrome. The rapid correction of severe hyponatremia (> 12 mmol/L/24 h) seems to be the causal factor, with consequent osmotic edema in the richly vascularized white matter of the pons as the proposed pathogenetic mechanism. We describe the case of a chronic psychotic man with nutritional disorders and inappropriate water intake who came to our attention for a clinical picture of CPM. Neuroradiological findings and postmortem studies revealed a slow-growing cerebellar astrocytoma in addition to the typical features of CPM. We discuss the hypothesis that damage to the nervous pathways and centers involved in water and electrolyte regulation could be the causal factor of CPM pathogenesis in this case.