Guía clínica del diagnóstico y tratamiento de los trastornos de la neurohipófisis

Diagnostic tests in polyuric states include baseline evaluation with simultaneous determination of plasma and urinary osmolality and, if these tests are inconclusive, the water deprivation test allows symptoms of potomania and diabetes insipidus, whether central of nephrogenic, to be distinguished. Diagnosis of neurogenic diabetes insipidus requires hypothalamic-pituitary magnetic resonance imaging and hormonal study of the anterior pituitary gland. The treatment of choice for central diabetes insipidus is the vasopressin analog, desmopressin. The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) results from non-physiological AVP secretion and is characterized by the presence of hyponatremia due to impaired free water excretion. This syndrome can be caused by tumors, neurological processes, pulmonary disease, and drugs. Diagnosis is based on findings of hyponatremia with plasma hypoosmolality, elevated urine osmolality, absence of volume depletion states and hypervolemia, and normal renal, adrenal, and thyroid function. Treatment consists of water restriction in mild and moderate hyponatremia. Hypertonic saline is required in severe hyponatremia.