Neurosurgical Diseases and Disorders (M-Z) / Pituitary Failure

General Information

• Hypopituitarism is any under function of the pituitary gland. Causes include damage to either the pituitary or the hypothalamus, the area of the brain just above the gland that contains hormones necessary for normal pituitary function.
• Injury to the pituitary itself can occur from an enlarging pituitary tumor, radiation treatment to the pituitary, pituitary apoplexy, trauma and abnormal iron storage, called hemochromatosis. As pituitary damage increases hormonal function decreases.
• Hormone function loss due to increasing damage is predictable. The most vulnerable functions to least vulnerable are growth hormone (GH), gonadotrophins (LH and FSH), TSH and ACTH. 
  
  
  • Growth hormone dificiency
    
    
    • General Information
      • Growth hormone is necessary for children to grow and for adults to maintain body composition.
      • GH may also help maintain adequate energy level, optimal cardiovascular status and some mental functions.
        
        
    • Symptoms: GH deficiency in adults can cause fatigue, poor exercise performance and psychological problems related to social isolation.
      
      
    • Treatment: GH is available only in injectable form and must be given daily.
      
      
  • Deficiency of LH and FSH (hypogonadotropic hypogonadism)
    
    
    • Symptoms
      • Women develop ovarian suppression with irregular periods or absence of periods (amenorrhea), infertility, decreased sex drive, decreased vaginal secretions, breast atrophy, and osteoporosis. Blood levels of estradiol are low.
      • Men develop testicular suppression with decreased sex drive, impotence, decreased ejaculate volume, loss of body and facial hair, weakness, fatigue and often anemia. Blood levels of testosterone are low.
        
        
    • Treatment
      • In women, estrogen should be replaced and can be given orally as Premarin or estrace, or can be given as a patch applied twice weekly. Women taking estrogen also need to take progesterone replacement.
      • In men, testosterone should be replaced, usually in injectable or patch form. Injectable testosterone lasts two weeks in most patients.
        
        
  • Deficiency of TSH and thyroid hormone
    
    
    • Symptoms
      • Deficiency of thyroid hormone causes a syndrome encompassing decreased energy, increased need to sleep, inability to stay warm, dry skin, constipation, muscle aching and decreased mental functions.
      • This constellation of symptoms is very uncomfortable and is often the set of symptoms that drives patients with pituitary disease to seek medical attention.
        
        
    • Treatment
      • Replacement therapy consists of thyroxin (Syntroid), which is monitored by blood levels of thyroid hormone.
        
        
  • Deficiency of ACTH and cortisol
    
    
    • General Information: Deficiency of ACTH resulting in cortisol deficiency is the most dangerous and life threatening of the hormonal deficiency syndromes.
      
      
    • Symptoms
      • With gradual onset over days or weeks, symptoms are often vague and may include weight loss, fatigue, weakness, depression, apathy, nausea, vomiting, anorexia and hyperpigmentation, or darkening of the skin.
      • If the deficiency comes on rapidly or become severe, Addisonian crisis may occur. Symptoms may include confusion, stupor, psychosis, abnormal electrolytes (low serum sodium, elevated serum potassium), and vascular collapse (low blood pressure and shock), which can be fatal.
        
        
    • Treatment
      • Treatment consists of administering cortisol or another similar steroid under strict supervision. For patients with Addisonian crisis, rapid intravenous administration of high dose steroids is essential to reverse the crisis.
        
        
  • Antidiuretic Hormone deficiency causing diabetes insipidus
    
    
    • General Information
      • This problem arises from damage to the pituitary stalk or the posterior pituitary gland.
      • It also may occur after transsphenoidal surgery but is rarely permanent.
        
        
    • Symptoms: Patients with diabetes insipidus have increased thirst and urination.
      
      
    • Treatment: Replacement of antidiuretic hormone resolves these symptoms. DDAVP, a synthetic type of ADH, can be taken once or twice a day.