Lavin Chapter 12

132   Section 2 • Hypothalamic-Pituitary Dysfunction

5. Traumatic brain injury has been reported to cause GHD in as many as 25% of all patients where the injury occurred years earlier (Table 12-2) (see Chapter 6). Studies of traumatic brain injury from all causes have found evidence of chronic hypopituitarism, defined by deficient production of one or more pituitary hor- mones at least 1 year after injury. Hypopituitarism, and in particular adult GHD, is associated with symptoms that resemble those of post-traumatic stress disorder, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction, cognitive deficiencies, and decreased quality of life. C. Empty sella syndrome in adults 1. The empty sella syndrome may be associated with endocrine dysfunction, including isolated GHD, as well as multiple pituitary hormone deficiencies. 2. Empty sella is characterized by the herniation of the subarachnoid space within the sella, which is often associated with some degree of flattening of the pituitary gland. In a study of 34 patients diagnosed radiographically to have empty sella, 12 had endocrine dysfunction. The most common endocrine disorder noted was hyperprolactinemia, which was seen in five patients, and the most common hormonal deficiency was isolated GHD, seen in four patients. The high incidence of endocrine abnormalities in patients with primary empty sella mandates that these patients should routinely undergo an endocrine evaluation to detect these deficiencies early and appropriate replacement instituted where necessary, thus ensuring them of a better quality of life.

VIII. CLINICAL AGHDS may include the following signs and symptoms (Table 12-3): A. Weakened heart muscle contraction and heart rate B. Arterial plaques C. Elevated blood pressure

D. Decreased cardiac ejection fraction and diminished arterial distensibility E. Increased inflammatory markers, such as C-reactive protein (CRP) F. Elevated lipids or fats in the blood, such as total cholesterol, low-density lipoproteins (LDLs), and triglycerides G. Decreased exercise capacity, probably secondary to decreased cardiac output H. Decreased energy

I. Abnormal body composition 1. Increased abdominal obesity 2. Decreased bone density 3. Increased incidence of fractures and osteoporosis 4. Decreased muscle strength and muscle size 5. Decreased lean body mass 6. Increased fat mass

Etiology of GHD

TABLE 12-2

1. Pituitary disease: pituitary adenoma, metastatic neoplasm, parasellar surgery, craniofacial irradiation, pituitary apoplexy, head trauma, lymphocytic hypophysitis 2. Hypothalamic etiologies: irradiation, infiltrative processes, primary or metastatic neoplasms, ependymoma, third ventricular cyst, trauma 3. Hypophyseal stalk injury: head trauma, metastatic lesions, infiltrative disease 4. Craniopharyngioma, hypothalamopituitary damage, parasellar lesions: meningioma, central nervous system lymphoma, chordomas, arterial-venous malformation, internal carotid aneurysms 5. Idiopathic isolated GHD of childhood: adult patients with prior childhood diagnosis of GHD 6. Systemic factors: hypothyroidism, Addison disease, high-dose glucocorticoids or Cushing syndrome, obesity, advanced age, hypothermia, acute overfeeding, protracted critical illness

GHD, growth hormone deficiency.