Neurosurgical Diseases and Disorders (A-L) / Acromegaly (Growth Hormone-Secreting Adenoma)

General Information

• Acromegaly is a serious condition nearly always caused by a tumor (an adenoma) of the pituitary gland that secretes excessive growth hormone (GH).
• Symptoms result from both overproduction of GH and from the tumor compressing and injuring the normal pituitary gland, optic nerves and related portions of the brain.
• Untreated acromegaly causes noticeable changes in bony and soft tissue, including an altered facial appearance, enlargement of the hands and feet, sleep apnea, and carpal tunnel syndrome.
• More serious problems may include accelerated heart disease, high blood pressure, diabetes and an increased risk of colon cancer.
• If the tumor develops before bone growth is completed in adolescence, overdevelopment of the entire body (gigantism) is the result.
• Because excessive GH causes serious changes throughout the body, treatment is essential, typically with transsphenoidal surgery.

Symptoms

• Symptoms typically affect multiple systems of the body. They include soft tissue thickening on the palms of the hand; enlargement of hands, feet and head; enlargement of forehead and jaw with pronounced under bite, spreading teeth and enlarging tongue; carpal tunnel syndrome; arthritis; oily skin and excessive sweating; tiredness and fatigue; depression; impotence and loss of sex drive; interrupted menstrual cycle; overproduction of breast milk; heart disease and enlargement; high blood pressure; diabetes mellitus; sleep apnea; vision loss; headaches; and colon polyps and colon cancer.

Diagnosis

• Diagnosis involves testing for elevated levels of both GH and insulin-like growth factor (IGF-1, also known as somatomedin-C).
• After a blood test confirmation of acromegaly, a magnetic resonance imaging (MRI) or computed tomography (CT) brain scan of the pituitary should be performed to confirm the presence of a pituitary adenoma.
• Comparison of old and recent photographs often show the marked change in facial appearance.

Treatment

• Surgery
  • The only way to cure pituitary acromegaly is with transsphenoidal surgery to remove the tumor.
  • In patients with particularly large and invasive tumors that cannot be removed with surgery, treatment options include medication or radiation therapy.
• Medication
  • Octreotide injections suppress GH production in about 70 percent of patients, cause tumor shrinkage in 30 percent to 50 percent of patients, and often improve symptoms of soft tissue swelling, headache, joint pains and sleep apnea.
  • Bromocriptine lowers GH secretion and shrinks tumors in 10 percent to 15 percent of acromegalic patients. The major side effect is gastrointestinal upset.
  • Another medical option is Cabergoline (Dostinex). The orally administered drug is better tolerated than bromocriptine and only needs to be taken once or twice a week. However, the cost is higher and little is known about the potential side effects for pregnant women.
• Radiotherapy
  • For patients whose acromegaly is not controlled with surgery, both conventional (external radiation beam) and stereotactic radiosurgery are relatively effective.
  • The lowering of GH and IGF-1 levels takes significantly longer with external beam radiotherapy (average seven years) compared with stereotactic radiotherapy (average 18 months). Also, external beam radiation causes loss of normal pituitary function over five to 10 years. Complications such as vision loss, weakness and memory impairment occur on rare occasions with either.

Outcome

• In general, the higher the pre-operative GH level, the lower the chance for cure.
• Long-term cure of acromegaly after transsphenoidal surgery is seen in approximately 80 percent to 85 percent or patients with smaller tumors (microadenomas) and in approximately 50 percent to 60 percent of patients with larger tumors (macroadenomas).

The Neuro-ICU cares for patients with all types of neurosurgical and neurological injuries, including stroke, brain hemorrhage, trauma and tumors. We work in close cooperation with your surgeon or medical doctor with whom you have had initial contact. Together with the surgeon or medical doctor, the Neuro-ICU attending physician and team members direct your family member's care while in the ICU. The Neuro-ICU team consists of the bedside nurses, nurse practitioners, physicians in specialty training (Fellows) and attending physicians. UCLA Neuro ICU Family Guide