Severe Symptomatic Hyponatremia Due to Syndrome of Inappropriate Antidiuretic Hormone From Mild Closed Head Trauma and Concussion

Abstract

We report the first published case of severe, symptomatic hyponatremia resulting from syndrome of inappropriate antidiuretic hormone (SIADH) incurred as the result of a blow to the head inducing a concussion without any additional signs of head injury. A 38-year-old male in excellent health suffered a fall from a tree causing a right leg fracture and blunt trauma to the head with concussion but no other signs of head injury. The patient was discharged several days after surgery for repair of his leg fracture and subsequently became severely ill with nausea, vomiting, headache, and seizures. He was readmitted with a serum sodium of 114 mEq/L (mmol/L) with a presumed diagnosis of dehydration. After several days of saline administration he was discharged, but within 24 hours he again experienced severe, symptomatic hyponatremia and was admitted for the third time with a serum sodium of 110 mEq/L (mmol/L). A diagnosis of SIADH was made, and the patient was successfully treated with fluid restriction, intravenous saline, and demeclocycline resulting in a full recovery without further incident. This case emphasizes the need to consider SIADH as a possible cause of severe hyponatremia in patients sustaining relatively minor closed head trauma. J Med Cases. 2015;6(1):27-29 doi: http://dx.doi.org/10.14740/jmc2001w