Dementia due to acute hyponatremic encephalopathy in an elderly patient with Arnold-Chiaria syndrome

Symptoms and signs of hyponatriemic encephalopathy are reported in 0.15 % of hospitalized patients. It is very important to recognize whether hyponatremia is of acute or chronic character, because these two forms require different therapeutic approaches. A 65-year-old male patient operated because of necrotic hemorrhagic pancreatitis, came to our observation with gait and balance disorders, as well as neurological disturbances. He showed a persistent hyponatremia and hypopotassemia. Magnetic resonance imaging revealed the presence of Arnold-Chiari-I anomaly (AC-I). He was treated with infusion of hypertonic sodium chloride at various doses for 3 days, until the normalization of natremia and potassemia was achieved. After one week, the patient was discharged in good general conditions. This case report highlights that that the correction of symptomatic hyponatremia is a fundamentally simple intervention, but it may save the life of patients who carry earlier malformations such as AC-I, which increase the risk of cerebellar herniation in these electrolytic imbalances.