Severe hyponatraemia in the setting of hypopituitarism associated with empty sella and herniation of the optic chiasm and gyrus rectus.

We present a patient with progressive weakness over months caused by untreated hyponatraemia. When hyponatraemia became severe, the patient could not move without help, was lethargic and had endocrinological dysfunction. Symptomatic therapy brought no improvement. MRI of the brain showed empty sella with gross herniation of the optic chiasma, gyrus rectus and third ventricle. After fluid and salt supplementation was combined with hydrocortisone, the patient regained his strength and could leave the hospital. Panhypopituitarism caused by empty sella should always be considered when hyponatraemia is not responsive to salt and fluid substitution alone. Additional hydrocortisone supplementation can be life saving.