Pituitary disorders Flashcards
(21 cards)
What is panhypopituitarism
Any condition that compresses or damages pituitary gland - tumors, trauma, radiation, infection, autoimmune, etc
What are the different presentations of panhypopituitarism
- ) Prolactin deficiency - men unaffected, women inhibits lactation after birth
- ) LH/FSH deficiency: Women become ammenorheic, men cannot make tesosterone or sperm and erectile dysfunction. Both decreased libido, decreased sex hair
- ) GH deficiency: Children have short stature, adults few symptoms
What are some specific diagnostic tests you can order for panhypopituitarism
- ) TSH levels - confirm with TRH injection
- ) ACTH/Cortisol levels - confirm with cosynthropin stimulation of adrenal (recent disease = normal rise, chronic disease atrophy = decreased rise), after CRH injection
- ) Decreased LH/FSH/testosterone - no test
- ) GH - no response to arginine or GHRH
- ) Prolactin - no response to TRH
What are other less useful tests for panhypopituitarism
- ) Metyrapone - inhibits 11-B hydroxylase, causing ACTH levels to rise because cortisol goes down
- ) Insulin stimulation - should cause GH to rise due to decreased glucose
What is the treatments for panhypopituitarism
Replace end hormones, not the stimulating hormones
Thyroxine, cortisone, testosterone/estrogen, GH
What is diabetes insipidus, the etiology of each, and the causes
Definition: Decrease in amount of ADH from pituitary (central DI) or its effect on kidney (nephrogenic DI)
- ) Central: Same causes as panhypopituitarism, idiopathic, or tumor producing
- ) Nephrogenic: Kidney diseases such as chronic pylonephritis, amyloidosis, myeloma, sickle cell disease. And hypercalcemia and hypokalemia. Caused by medications lithium and demeclocycline
What are the symptoms of diabetes insipidus
High volume urine and excessive thirst
If you don’t match it with drinking water, will develop hypernatremia and subsequent neurological symptoms
How can you differentiate central and nephrogenic diabetes insipidus
Inject vasopressin - normal response = central, no response = nephrogenic
What is the treatment for central diabetes insipidus
Vasopressin long-term
What is the treatment for nephrogenic diabetes insipidus
Correct underlying cause, or hydrochlorothiazide, amiloride, and NSAIDS
What is acromegaly
Overproduction of GH leading to soft tissue growth through entire body
What is the number one, almost always cause of acromegaly
Pituitary adenoma, either alone or apart of MEN syndrome
How would a patient with acromegaly present on the USMLE
- ) Increased hat, ring, shoe size
- ) Carpal tunnel syndrome/OSA (compression from tissues)
- ) Body odor - sweat gland hypertrophy
- ) Coarsening facial features
- ) Deep voice/macroglossia
- ) Colonic polyps
- ) Arthralgias - joints growing out of alignment
- ) Hypertension
- ) Cardiac dysfunction
What is the diagnostic test for acromegaly
Best initial test - insulin like growth factor levels
Most accurate - Glucose suppression test (injecting glucose normally suppresses GH)
MRI - only after lab values are confirmed
Test prolactin too because cosecreted with GH
The treatment for acromegaly has both a surgical and medical one. What is the surgery
Transphenoidal resection of pituitary adenoma - 70% respond
The treatment for acromegaly has both a surgical and medical one. What is the medical treatments
- ) Cabergoline - dopamine inhibiting GH release
- ) Octreotide - somatostatin inhibiting GH release
- ) Pegvisomant - GH receptor antagonist - inhibits IGF from liver
What should you do if someone with acromegaly does not respond to surgery or medical treatment
Radiation
What are the causes of hyperprolactinemia
Acromegaly (cosecreted) and hypothyroidism (high TRH)
Physiologic: Intense exercise and cutting pituitary stalk (dopamine eliminated), pregnancy, chest wall stimulation
Drugs: Think psych drugs - antipsychotics, SSRI’s, tricyclics, metoclopramide, etc
What is the presentation for both men and women who have hyperprolactinemia
Women - galactorrhea, amenorrhea, and infertility
Men - Erectile dysfunction, decreased libido
All same symptoms as not having LH/FSH
What diagnostic tests should you do after you find that prolactin levels is high
Thyroid function tests, pregnancy test, kidney test since it can raise prolactin
Do MRI after these things are confirmed
What is the treatment for hyperprolactinemia
Dopamine agonists - cabergoline
Transphenoidal surgery if medications are not working
