Occurs when the effects of ADH are absent.
Central, aka, primary, DI is due to a lack of ADH secretion.
- Causes: Can be idiopathic, or it can be caused by brain injury caused by trauma, surgery, infiltrative infections or tumors.
Nephrogenic, aka, secondary DI, occurs when defects in the ADH receptor response prohibit a normal reaction to circulating ADH. In the absence of ADH or its effects, aquaporins are also lacking, and less water is reabsorbed.
- Causes: Inherited receptor or aquaporin defects, or, can be acquired in response to certain drugs (including lithium, foscarnet, and clozapine), infiltrating infections, sickle cell disease, hypercalcemia, hypokalemia, and pregnancy.
Signs/Symptoms of Diabetes Insipidus:
Patients produce large quantities of dilute urine (high volume, low osmolality), polyuria (production of abnormally large volumes of urine) and polydipsia (abnormally increased thirst).
- Be aware that, if water is limited, the patient will be hypernatremic.
Due to excessive body water loss, patients will be hypovolemic with dehydration, weakness, fatigue, and often complain of nocturia (frequent urination in the night).
- In children, this may present as bedwetting.
Treatment: we often prescribe desmopressin, a synthetic form of vasopressin (in addition to DI treatment, it's also given to stop bleeding in hemophiliacs), and, of course, treat the underlying causes.
Detailed List of Causes
Head trauma
Pituitary surgery
Various neoplasms (i.e. craniopharyngioma, meningioma, suprasellar pituitary adenoma, dsygerminoam, lypmphoma, leukemia, metastatic breast and lung cancer)
Granuloma infections (sarcoidosis, histiocytosis)
Other infections (meningitis, viral encephalitis, toxoplasmosis)
Inflammation (sclerdoma, SLE, lymphocytic hypophysitis, granulomatosis w/ polyangiitis)
Vascular (Sheehan syndrome, hypoxic encephalopathy, aneurysm)
Toxins
Gestational
Idiopathic
- Congenital malformations
- Genetic disorders (Wolfram syndrome, autosomal dominant mutation in vasopressin gene)
