Hypothalamic dysfunction

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Central nervous system

Definition

Hypothalamic dysfunction is a problem with the region of the brain called the hypothalamus, which helps control the pituitary gland and regulate many body functions.

Causes, incidence, and risk factors

The hypothalamus helps control the pituitary gland, particularly in response to stress. The pituitary, in turn, controls the:

• Adrenal glands
• Ovaries
• Testes
• Thyroid gland

The hypothalamus also helps regulate:

• Body temperature
• Childbirth
• Emotions
• Growth
• Milk production
• Salt and water balance
• Sleep
• Weight and appetite

Causes of hypothalamic dysfunction include:

• Anorexia
• Bleeding
• Bulimia
• Genetic disorders
• Growths (tumors)
• Head trauma
• Infections and swelling (inflammation)
• Malnutrition
• Radiation
• Surgery
• Too much iron

The most common tumors in the area are craniopharyngiomas in children.

Symptoms

Symptoms are usually due to the hormones that are missing. In children, there may be growth problems -- either too much or too little growth -- or puberty that occurs too early or too late.

Tumor symptoms:

• Headaches
• Loss of vision

Hypothyroidism symptoms:

• Cold intolerance
• Constipation
• Depressed mood
• Fatigue
• Hair or skin changes
• Hoarseness
• Impotence
• Loss of body hair and muscle (in men)
• Mental slowing
• Menstrual cycle changes
• Weight gain

Low adrenal function symptoms:

• Dizziness
• Weakness

Other, less common symptoms may include:

• Body temperature problems
• Emotional problems
• Excess thirst
• Obesity
• Uncontrolled urination

Kallmann's syndrome (a type of hypothalamic dysfunction that occurs in men) symptoms:

• Lowered function of sexual hormones (hypogonadism)
• Inability to smell

Signs and tests

Blood or urine tests to determine levels of hormones such as:

• Cortisol
• Estrogen
• Growth hormone
• Pituitary hormones
• Prolactin
• Testosterone
• Thyroid

Other possible tests:

• Hormone injections followed by timed blood samples
• MRI or CT scans of the brain
• Visual field eye exam (if there is a tumor)

Treatment

Treatment depends on the cause of the hypothalamic dysfunction.

• Tumors -- surgery or radiation
• Hormonal deficiencies -- replace missing hormones

Specific treatments may be available for bleeding, infection, and other causes.

Expectations (prognosis)

Many causes of hypothalamic dysfunction are treatable. Most of the time missing hormones can be replaced.

Complications

Complications of hypothalamic dysfunction depend on the cause.

Brain tumors:

• Permanent blindness
• Specific problems related to the brain area where the tumor occurs
• Vision disorders

Hypothyroidism:

• Heart problems
• High cholesterol

Adrenal insufficiency:

• Inability to deal with stress (such as surgery or infection)

Gonadal deficiency:

• Heart disease
• Impotence (in men)
• Infertility
• Thin bones (osteoporosis)

Growth hormone deficiency:

• High cholesterol
• Osteoporosis
• Short stature (in children)
• Weakness

Calling your health care provider

Call your doctor if you have:

• Headaches
• Symptoms of hormone excess or deficiency
• Vision problems

Prevention

Maintain a healthy diet and don't exercise too strenuously or lose weight too quickly. If you believe you have an eating disorder such as anorexia or bulimia, get medical attention: these conditions can be life-threatening.

If you have symptoms of a hormonal deficiency, discuss replacement therapy with your health care provider.

References

Low MJ. Neuroendocrinology. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Williams Textbook of Endocrinology. 11th ed. Philadelphia, PA: Saunders Elsevier; 2008:chap 7.

Review Date: 11/23/2009

Reviewed by: Ari S. Eckman, MD, Division of Endocrinology and Metabolism, Johns Hopkins School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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