Pituitary infarction is the death of an area of tissue in the pituitary gland, a small gland joined to the hypothalamus (part of the brain). The pituitary produces many of the hormones that control essential body processes.

Pituitary infarction is most commonly caused by bleeding into a benign tumor of the pituitary, which kills an area of tissue in the pituitary gland. When this bleeding occurs in a woman during or immediately after childbirth, it is called Sheehan's syndrome.

Risk factors for pituitary infarction include diabetes, bleeding disorders, head trauma, pituitary radiation, and use of a breathing machine. However, in most cases, the cause is not clear.

Pituitary infarction is usually acute (short period of symptoms) and can be life-threatening.

Symptoms are usually acute and include severe headache, ophthalmoplegia (paralysis of the eye muscles causing double vision), and symptoms of acute adrenal insufficiency (low blood pressure, nausea, and vomiting).

Less commonly, pituitary dysfunction may appear more slowly. In Sheehan's syndrome, for example, the initial symptom may be a failure to produce milk caused by a lack of the hormone prolactin.

Over time, insufficiency in other pituitary hormones may develop, causing symptoms of the following conditions:

• Hypogonadism
  • Amenorrhea in women
  • Sexual dysfunction and loss of muscle mass in men
• Hypothyroidism
  • Dry skin
  • Mental slowing
  • Weight gain
  • Cold intolerance
  • Hoarseness
• Hypoadrenalism (if not already present or treated)
  • Low blood pressure
  • Nausea
  • Inability to deal with physical stress
• Growth hormone deficiency
  • Fatigue
  • Lack of energy
  • Loss of bone and muscle
  • Increased abdominal fat
  • Dyslipidemia (problems with fat metabolism)

When the posterior pituitary is involved (rare), there may be uncontrolled urination.

Signs of acute infarction may include ophthalmoplegia, visual field defects, and hypotension (low blood pressure).

Signs of chronic pituitary insufficiency include:

• Hypogonadism
  • Sparse axillary and pubic hair
  • Loss of sexual function
  • Cessation of mentrual cycle in women
  • Erectile dyfunction in men
• Hypothyroidism
  • Dry hair and skin
  • Puffy face
  • Delayed reflexes
• Hypoadrenalism
  • Hypotension
  • Poor response to stress and infection
• Hypoprolactinemia -- lack of lactation
• Growth hormone deficiency -- loss of muscle mass
• General -- fine, pale, wrinkled skin

Tests may include:

• Test for abnormal visual fields
• MRI or CT scan showing hemorrhage
• Low estradiol/testosterone with low FSH and LH
• Low free T4 and TSH
• Low cortisol and ACTH -- rise of cortisol may be absent with Cortrosyn stimulation
• Low GH and somatomedin C (IGF-1)
• Low prolactin
• Elevated LDL cholesterol
• Low bone density

Treatment for acute infarction may require surgery to decompress the area of the pituitary and improve visual symptoms. Severe cases constitute a surgical emergency. Immediate treatment with adrenal replacement hormones (glucocorticoids) is essential.

Replacement of other missing hormones is also required, including sex hormones (estrogen/testosterone) and thyroid hormone. Evidence is growing for the need for growth hormone replacement.

Call your health care provider if you have any signs or symptoms of chronic pituitary insufficiency.

Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of acute pituitary infarction, including headache, eye weakness, low blood pressure (which can cause fainting), nausea, and vomiting.

Patients with a diagnosed pituitary tumor should have a heightened level of suspicion if these symptoms arise.