The never-ending story of hyponatremia: a current problem to overcome

Hyponatremia is a common complication in patients undergoing neurosurgery. If undiagnosed, it has a negative prognostic impact. The two dominant causes of refractory hyponatremia include syndrome of inappropriate ADH secretion (SIADH) and cerebral salt wasting syndrome (CSWS). Discrimination between the two types of disease is not always obvious. We present a case of undiagnosed chronic hyponatremia caused by CSWS after neurosurgery, which not only resulted in a longer hospital stay but also slowed the patient’s postoperative recovery. Meticulous clinical evaluation and the performance of appropriate laboratory tests are therefore essential not only for decisive treatment, but also for the establishment of comprehensive diagnostic algorithms that allow timely diagnosis and decisive therapy.