Cerebral Salt Wasting Syndrome

Cerebral salt wasting (CSW) is a potential cause of hyponatremia associated with central nervous system (CNS) disease. This condition is characterized by hyponatremia, elevated urine sodium levels, and hypovolemia. The literature is currently debating whether CSW is a distinct clinical entity or a variant of the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Differentiating between CSW and SIADH is crucial, as their treatments differ significantly: CSW is managed with fluid and sodium replacement, whereas SIADH requires fluid restriction. CSW typically resolves within weeks to months but may persist chronically. The proposed pathophysiology of CSW involves either the release of brain natriuretic peptide or hypothalamic damage leading to impaired sympathetic nervous system function.