Differential Diagnosis - Syndrome of inappropriate ADH-Secretion (SIADH) versus Cerebral Salt-Wasting Syndrome (CSW)

Hyponatraemia is a common complication in patients with disorders of the central nervous system or undergoing neurosurgery. The differentiation between the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and the cerebral salt-wasting syndrome (CSW) is important, because both diseases have different prognosis and require different specific treatment. Although most physicians are familiar with SIADH, they are much less familiar with CSW. This review emphasizes the need for CSW to be included in the differential diagnosis of hyponatraemia. We review the aetiology, mechanisms, treatment and differential diagnosis, wit a special focus on laboratory markers of CSW.