Hyponatremia in a pediatric stroke patient: syndrome of inappropriate antidiuretic hormone secretion or cerebral salt wasting?

ABSTRACT

OBJECTIVE: To determine the potential role of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in the pathogenesis of cerebral salt wasting. DESIGN: Clinical case report. SETTING: Regional pediatric intensive care unit. PATIENT A 3-yr-old boy with a cerebral infarct secondary to traumatic carotid artery dissection who developed hyponatremia associated with weight loss and excessive renal sodium excretion on the sixth day after hospitalization. MEASUREMENTS AND MAIN RESULTS: Plasma concentrations of ANP, BNP, antidiuretic hormone, and renin were determined serially and compared with concentrations measured in a group of eight healthy children undergoing elective surgical procedures. Compared with controls, ANP and BNP plasma concentrations on the eighth day after hospitalization were increased 1.9-fold and 7.7-fold, respectively. Thereafter, the course of ANP and BNP paralleled that of sodium and H2O excretion and remained elevated until the 14th (BNP) and 16th (ANP) days after hospitalization. Serum antidiuretic hormone and renin concentrations were within normal ranges during the entire observation period. CONCLUSION: Cerebral salt wasting is associated with elevated plasma concentrations of ANP and BNP. Natriuretic peptides may play a role in the pathogenesis of this syndrome.