Diabetes insipidus centralis

Diabetes insipidus centralis is a disease caused by a deficiency of ADH (vasopressin).

Lack of hormone in the body manifests itself polyurii and large fluid loss leads to  polydipsii.

The cause of the disease may be the involvement of the hypothalamic nuclei producing ADH, a disorder neurohypophysis and the transport of ADH into the bloodstream.

Etiology
Insufficient ADH production can be caused by various mechanisms
 * Congenital disorders and genetic defects in hormone production.
 * Hypothalamic-pituitary tumors, most commonly craniopharyngeal, pituitary adenoma, meningioma.
 * Autoimmune affects the hypothalamus and destroys the nuclei that produce the hormone.
 * Trauma or other mechanical involvement of the hypothalamus or pituitary gland.
 * Inflammation.
 * Vascular lesions, hemorrhage.
 * Iatrogenic disability.
 * Diabetes insipidus centralis is up to 45% idiopathic.

Clinical symptoms

 * Hypotonic urinary polyuria can vary widely, from slightly elevated (3 l / day) to marked (15 l / day).
 * Also, polydipsia is individual in patients. The feeling of thirst may or may not be maintained.
 * When thirst is broken, the patient does not compensate for fluid loss by adequate intake and Dehydration occurs, which can be fatal.

Diagnostics
A patient with diuresis greater than 2.5 liters, with a finding of  hypotonic urine,  hypernatremia and  serum hyperosmolality should be examined. . However, if the patient compensates for the loss with higher intakes, serum osmolality and sodium levels may be normal. Then we proceed to the concentration test. The patient thirsts for 36 hours and diuresis, serum and urine osmolality are monitored every hour. The patient must be closely monitored and when the weight is reduced by more than 3%, the test is stopped to avoid dehydration. If the patient is unable to concentrate the urine, serum osmolality increases and polyuria persists, the test is positive. To distinguish the central form of diabetes insipidus from renal, we give at the end of the test Renal diabetes insipidus does not respond to desmopressin administration and the condition does not improve. As an additional examination, MRI of the hypothalamic-pituitary region is performed to clarify the etiology.

Treatment
We use desmopressin as a substitute for ADH. Doses should be carefully titrated due to serum osmolality and sodium.

Related articles

 * Diabetes insipidus
 * Diseases of the hypothalamic-pituitary system
 * Urine examination