Cerebral salt wasting syndrome

Hyponatremia is frequently seen in patients with neurologic disease and can be a feature of the syndrome of cerebral salt wasting, in which a renal loss of sodium leads to hyponatremia and a decrease in extracellular fluid volume. Cerebral salt wasting must be distinguished from the syndrome of inappropriate secretion of antidiuretic hormone. The appropriate treatment of cerebral salt wasting and fluid and salt replacement, is opposite from the usual treatment of hyponatremia caused by inappropriate secretion of antidiuretic hormone. This article summarizes the evidence in favor of cerebral salt wasting in patients with intracranial disease, examines the possible mechanisms responsible for this phenomenon, and discusses methods for diagnosis and treatment.