Differential diagnosis between the syndrome of inappropriate ADH secretion and cerebral salt-wasting syndrome 1

Abstract

Hyponatraemia is one of the most common complications in patients with disorders of the central nervous system or those who have undergone cerebral neurosurgery. The differentiation between the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and the cerebral salt-wasting syndrome (CSWS) is important because the two diseases have different prognoses and require different specific treatment. Although most physicians are familiar with SIADH, they are much less familiar with CSW. This paper emphasizes the need for CSW to be included in the differential diagnosis of hyponatraemia; it reviews the aetiology, pathophysiology, treatment and differential diagnoses of CSW; particular attention is given to diagnostic laboratory markers, both those that are already established and those that are still under investigation.