Central (Neurogenic) Diabetes Insipidus: Symptoms, Causes, and Treatments

Central diabetes insipidus or central DI has several other names it's known by -- "pituitary DI," "hypothalamic DI," "neurohypophyseal DI," or "neurogenic DI." The disease is completely unrelated to diabetes mellitus even though both display the common symptoms of increased urination and thirst. Central DI is less common than diabetes mellitus, and treatments for the two diseases are completely different.

The major characteristic of central diabetes insipidus is extreme thirst and excessive urination. The disease occurs when the body fails to produce enough of the antidiuretic hormone vasopressin, which regulates the output of urine from the kidneys. The deficit of vasopressin typically is caused by damage or injury to the hypothalamus or pituitary gland. The damage is usually caused by infections, inflammation, head injuries, tumors, surgery, or genetic defects.

What is central (neurogenic) diabetes insipidus?

Central diabetes insipidus is caused by a lack of the hormone vasopressin. Vasopressin is an antidiuretic hormone that is produced by the hypothalamus gland in the brain and stored by the pituitary gland. In the body, vasopressin limits urine output by increasing the concentration of the urine.

Without vasopressin, the kidneys cannot function properly and the body experiences rapid water loss in the form of diluted urine. Then in a vicious cycle, this rapid water loss causes people with central DI to become extremely thirsty. As a result, they drink large amounts of water. For example, someone with central diabetes insipidus may produce more than 3 liters of urine a day, and drink even more water than that.

Central DI affects both men and women equally. It is a relatively uncommon disease, occurring in about 1 out of every 25,000 people. Central diabetes insipidus is typically a manageable disease and not fatal. However, if the fluids that are lost due to central DI aren't replaced, severe dehydration, heart failure, and even death can occur. This is especially the case with children and the elderly.

What causes central diabetes insipidus?

In about half the cases, the cause of central DI is unknown. Other times, the reduced levels of vasopressin may be the result of damage to the hypothalamus or the posterior part of the pituitary gland where the hormone is normally produced. This damage can be due to surgery, head trauma, tumor, inflammation, or infection. In very rare cases, central DI is caused by a genetic defect. Doctors determine that the disease is inheritable when the onset occurs in early childhood and there is a family history of central DI.

Usually, central DI cannot be prevented. The risk of developing central DI can be reduced, though, by prompt treatment of injuries, infections, and tumors.