Hypopituitarism
partial or complete loss of anterior function
that may result from any lesion that destroys the pituitary or hypothalamus or that interferes with the delivery of releasing and inhibiting factors to the anterior hypothalamus.
GH and gonadotropins (FSH, LH) are typically lost early.
Pituitary adenomas are the most common cause of panhypopituitarism.
Aldosterone secretion form the adrenal gland is ACTH-independent and primarily regulated by the RAA axis; therefore, serum potassium is normal. Hyponatremia may be present due to an inappropriate increase in ADH or from cortisol deficiency. Hypoglycemia is commonly seen due to deficiencies of cortisol and GH. Patients also typically have pale skin due to low ACTH and MSH levels.
Pituitary apoplexy is a syndrome associated with acute hemorrhagic infarction of a preexisting pituitary adenoma, and manifests as severe headache, N or V, and depression of consciousness. It is medical and neurosurgical emergency.
Sheehan postpartum necrosis
initial sign being the inability to lactate
Dynamic pituitary function tests
A dynamic pituitary function test is used to assess patients with suspected primary pituitary dysfunction
Insulin, TRH and LHRH are given to the patient following which the serum glucose, cortisol, growth hormone, TSH, LH and FSH levels are recorded at regular intervals. Prolactin levels are also sometimes measured*
A normal dynamic pituitary function test has the following characteristics: