Dipsogenic diabetes insipidus

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 2, 2016
StartDiseasesDipsogenic diabetes insipidus

Dipsogenic diabetes insipidus refers to abnormalities in the thirst mechanism, which results in a fluid imbalance. Dipsogenic diabetes insipidus involves the hypothalamus not functioning properly.

Contents

Definition & Facts

A person with dipsogenic diabetes insipidus will feel extremely thirst which will then compel them to drink an excessive amount of liquids and in turn expel an excessive amount of urine (polyuria). Diabetes insipidus generally involves the insufficient production of hormones that regulates thirst and urination.

Symptoms & Complaints

The most commonly seen symptoms for dipsogenic diabetes insipidus are extreme thirst, even after drinking a great amount of water, and expelling an excessive amount of urine that is diluted.

The amount of urine that is expelled will depend on the severity of the disorder and how much fluid is taken in. In some of the most severe cases, the amount of urine expelled can be as much as 16 quarts within one day. The normal healthy adult will usually expel around 3 quarts a day.

Other symptoms can include wetting the bed (nocturnal enuresis) and needing to urinate in the middle of the night (nocturia). Additional symptoms could include:

Causes

Dipsogenic diabetes insipidus happens when the body is unable to regulate how it should be handling the fluids in the body though the underlying cause of the dysfunction is largely unknown or (idiopathic). There have also been some links to mental disorders or behavioral disorders as the cause. It's possible surgery, cancer, tumors, infection, or inflammation may play a role in interfering with the thirst mechanism.

Ordinarily, excess body fluid that is in the bloodstream will be removed by the kidneys. This fluid will then go into the bladder to be stored until it is expelled through urination. When the body is regulating fluids properly, the kidneys will know to hold onto the fluid rather than sending it to the bladder if the water in the body is decreased. The amount of fluid the kidneys will hold onto or release into the bladder is controlled by the amount of anti-diuretic hormone (ADH) which is also called vasopressin, that the body makes and then sends into the bloodstream. 

The ADH is made within a portion of the brain called the hypothalamus and is then stored in the pituitary gland also located in the brain. If the body starts to get dehydrated, ADH will be released into the bloodstream and concentrate the urine by telling the kidneys to release more water back into the bloodstream rather than into the bladder to be expelled as urine. In dipsogenic diabetes insipidus, there are no issues with the production of ADH but rather its secretion.

Diagnosis & Tests

The signs and symptoms of dipsogenic diabetes insipidus could be caused by a number of other disorders as well, so a doctor will need to run some tests in order to properly diagnose their patient. Some of the tests that are commonly used include:

  • Water deprivation test. This test will be able to confirm the diagnosis and will often be able to help determine what the cause is. While this test is being done, the patient is under the supervision of medical personnel for their own safety. The patient will need to stop drinking fluids for a period of time. The doctor will then measure any changes in weight, concentration of urine and blood, and the amount of urine output. The doctor may also measure the amount of ADH in the blood during this test. When this test is done for children or pregnant women, they are monitored closely.
  • Urinalysis. This is a chemical and physical examination of the urine. They will check to see if the urine is less concentrated or more concentrated. When the urine is less concentrated, it contains more water than other substances. When it is more concentrated, it contains lower amounts of water than other substances. If the patient's examination shows that the urine is less concentrated, it could be because of the dipsogenic diabetes insipidus.
  • Magnetic resonance imaging (MRI). An MRI uses radio waves and a powerful magnetic field to create detailed pictures of the tissue of the brain. The doctor may want to use an MRI to determine whether or not there are any abnormalities near or in the pituitary gland.

Treatment & Therapy

There are currently no treatment options available that are used for dipsogenic diabetes insipidus. The doctor will want their patient to try and reduce the amount of fluid that is taken in, which will reduce the amount of urine that is expelled. 

But if the patient is suffering from a mental illness or behavior disorder which could be causing this disorder, then the patient should get treatment for the mental illness. Psychotherapy including cognitive behavioral therapy, counseling, and psychiatric medication may help relieve the symptoms that the patient is having.

Prevention & Prophylaxis

There is currently no way to prevent this disorder because its causes remain largely unknown.