Pituitary and Hypothalmic Disorders

Question 1

What hormones are manufactured in the hypothalamus?

Answer 1

ADH, oxytocin

Question 2

What is hyperprolactinemia?

Answer 2

elevated prolactin levels. caused by prolactinoma, trauma, meds (SSRIs, antipsychotics, cocaine, alpha methyldopa), hypothyroidism

Question 3

What is a prolactinoma?

Answer 3

a tumor of the anterior pituitary that secretes prolaction. may cause compression of the optic chiasm and bitemporal hemianopsia. most common type of pituitary adenoma.

Question 4

What happens to prolactin levels if the stalk of the hypothalamus is damaged?

Answer 4

prolactin inhibiting hormone (dopamine) will not be transmitted to the pituitary. Prolactin levels then increase unchecked

Question 5

What medications increase serotonin and may lead to increased prolactin levels?

Answer 5

Antidepressants, Antipsychotics, Alpha methyldopa (antihypertensive). Serotonin is a prolactin releasing factor

Question 6

What does prolactin block?

Answer 6

gonadotropins FSH and LH

Question 7

What are the symptoms of prolactinoma in women?

Answer 7

microadenoma more common in women. Amenorrhea, galactorrhea, infertility

Question 8

What are the symptoms of prolactinoma in men?

Answer 8

macroadenoma more common in men. Decreased libido, gynecomastia, erectile dysfunction, infertility, bitemporal hemianopsia, headache. decreased testoterone levels

Question 9

How is prolactinoma diagnosed?

Answer 9

best initial test is the prolactin level. additional tests to rule out secondary hyperprolactinemia: TSH, beta-HCG (pregnancy test), CMP, LH, FSH, serum estradiol (wm) or serum/total testosterone (mn). MRI to confirm the diagnosis

Question 10

How is prolactinoma treated?

Answer 10

dopamine agonists: cabergoline (best tolerated) or bromocriptine. transsphenoidal pituitary surgery, radiation, or chemo w/temozolomide. depends on symptoms and size of tumor.

Question 11

What is acromegaly?

Answer 11

excess growth hormone. almost always caused by a pituitary tumor. occurs btw 20-40. may be associated w/tumors of the pancreas or parathyroids.

Question 12

What are signs and symptoms of acromegaly?

Answer 12

skeletal changes, coarsening of facial features (jaw protrusion, prominent brow), enlargement of the hands and feet, deepening of the voice, carpal tunnel, CHF (organ enlargement)

Question 13

How is acromegaly diagnosed?

Answer 13

best initial test is IGF-1 level. Serum GH not suppressed following oral glucose. MRI

Question 14

How is acromegaly treated?

Answer 14

transsphenoidal resection is best choice. Gamma knife radiosurgery is transsphenoidal fails. meds: cabergoline. or ocreotide, lanreotide, pegvisomant (sub Q injections)

Question 15

What is gigantism?

Answer 15

excessive growth hormone in youth prior to closure of epiphyses. work up and treatment is the same as acromegaly

Question 16

What are the different possible etiologies of hypopituitarism?

Answer 16

pituitary apoplexy, Sheehan’s syndrome, infiltration, non-functioning adenoma, trauma, stroke, mass effect

Question 17

What is the order of hormone deficiency of hypopituitarism?

Answer 17

GH–>LH/FSH–>TSH–>ACTH

Question 18

What is pituitary apoplexy and its symptoms?

Answer 18

Hemorrhage into the pituitary. Usually secondary to existing adenoma. headache, nausea, vomiting, altered mental status, low blood pressure, low blood glucose

Question 19

What is Sheehan’s syndrome and its symptoms?

Answer 19

Post partum ischemic necrosis of the pituitary. Secondary to hypotension, emboli, HELLP syndrome. Difficulty breastfeeding, extended amenorrhea

Question 20

How is hypopituitarism diagnosed?

Answer 20

check anterior pituitary hormones: LH/FSH, IGF-1 or GH insulin response test, TSH, ACTH (measured thru cortisol levels). MRI

Question 21

What is a GH insulin response test?

Answer 21

administer insulin to lower blood glucose level. GH should increase due to insulin release

Question 22

What is SIADH (Sudden Inappropriate Diuretic Hormone)?

Answer 22

characterized by euvolemic hyponatremia due to elevated ADH levels. Reabsorption of excess fluid, low sodium, low serum osmolality.

Question 23

What are symptoms of SIADH?

Answer 23

if chronic it’s asymptomatic. HA, N/V, altered mental status, seizures

Question 24

What are possible etiologies of SIADH?

Answer 24

trauma, malignancy, meningitis, meds

Question 25

How is SIADH diagnosed?

Answer 25

CMP, urine sodium is inappropriately high >20mEg/L with low serum sodium <130. CT. Rule out SIADH producing cancers: CXR small cell cancer of lung, CT abdomen pancreatic cancer

Question 26

How is SIADH treated?

Answer 26

increase sodium levels by fluid restriction (1200-1800ml/day). For patients w/neuro sx-hypertonic saline IV over 3-4hrs (may cause central pontine myelinolysis if administered too quickly)

Question 27

What is diabetes insipidus?

Answer 27

lack of appropriate levels of ADH leads to elevated plasma sodium w/inability to concentrate urine . Central- deficiency of ADH or resistance to ADH. Nephrogenic- defect in kidney tubules that interferes w/water reabsorption.

Question 28

What are symptoms of diabetes insipidus?

Answer 28

intense thirst, polydipsia, craving for ice water, polyuria, nocturia, enuresis, hypernaturemia

Question 29

What is the etiology of diabetes insipidus?

Answer 29

Central- deficiency of ADH or resistance to ADH due to trauma or tumor. Nephrogenic- defect in kidney tubules that interferes w/water reabsorption due to lithium, demeclyocyline, infiltrative disease, Sjogren’s syndrome

Question 30

How is diabetes insipidus diagnosed?

Answer 30

CMP, plasma osmolality, plasma ADH, urine sodium. Water deprivation test- serum sodium will increase but urine sodium will be low. DDAVP test- urine sodium increases if central DI

Question 31

What is the treatment of diabetes insipidus?

Answer 31

Central- DDAVP. Nephrogenic- hydrochlorothiazide or amiloride: block reabsorption of sodium in the kidneys to keep the plasma sodium levels down