Flashcards in Pituitary and Hypothalmic Disorders Deck (31):
What hormones are manufactured in the hypothalamus?
What is hyperprolactinemia?
elevated prolactin levels. caused by prolactinoma, trauma, meds (SSRIs, antipsychotics, cocaine, alpha methyldopa), hypothyroidism
What is a prolactinoma?
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.
What happens to prolactin levels if the stalk of the hypothalamus is damaged?
prolactin inhibiting hormone (dopamine) will not be transmitted to the pituitary. Prolactin levels then increase unchecked
What medications increase serotonin and may lead to increased prolactin levels?
Antidepressants, Antipsychotics, Alpha methyldopa (antihypertensive). Serotonin is a prolactin releasing factor
What does prolactin block?
gonadotropins FSH and LH
What are the symptoms of prolactinoma in women?
microadenoma more common in women. Amenorrhea, galactorrhea, infertility
What are the symptoms of prolactinoma in men?
macroadenoma more common in men. Decreased libido, gynecomastia, erectile dysfunction, infertility, bitemporal hemianopsia, headache. decreased testoterone levels
How is prolactinoma diagnosed?
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
How is prolactinoma treated?
dopamine agonists: cabergoline (best tolerated) or bromocriptine. transsphenoidal pituitary surgery, radiation, or chemo w/temozolomide. depends on symptoms and size of tumor.
What is acromegaly?
excess growth hormone. almost always caused by a pituitary tumor. occurs btw 20-40. may be associated w/tumors of the pancreas or parathyroids.
What are signs and symptoms of acromegaly?
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)
How is acromegaly diagnosed?
best initial test is IGF-1 level. Serum GH not suppressed following oral glucose. MRI
How is acromegaly treated?
transsphenoidal resection is best choice. Gamma knife radiosurgery is transsphenoidal fails. meds: cabergoline. or ocreotide, lanreotide, pegvisomant (sub Q injections)
What is gigantism?
excessive growth hormone in youth prior to closure of epiphyses. work up and treatment is the same as acromegaly
What are the different possible etiologies of hypopituitarism?
pituitary apoplexy, Sheehan's syndrome, infiltration, non-functioning adenoma, trauma, stroke, mass effect
What is the order of hormone deficiency of hypopituitarism?
What is pituitary apoplexy and its symptoms?
Hemorrhage into the pituitary. Usually secondary to existing adenoma. headache, nausea, vomiting, altered mental status, low blood pressure, low blood glucose
What is Sheehan's syndrome and its symptoms?
Post partum ischemic necrosis of the pituitary. Secondary to hypotension, emboli, HELLP syndrome. Difficulty breastfeeding, extended amenorrhea
How is hypopituitarism diagnosed?
check anterior pituitary hormones: LH/FSH, IGF-1 or GH insulin response test, TSH, ACTH (measured thru cortisol levels). MRI
What is a GH insulin response test?
administer insulin to lower blood glucose level. GH should increase due to insulin release
What is SIADH (Sudden Inappropriate Diuretic Hormone)?
characterized by euvolemic hyponatremia due to elevated ADH levels. Reabsorption of excess fluid, low sodium, low serum osmolality.
What are symptoms of SIADH?
if chronic it's asymptomatic. HA, N/V, altered mental status, seizures
What are possible etiologies of SIADH?
trauma, malignancy, meningitis, meds
How is SIADH diagnosed?
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
How is SIADH treated?
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)
What is diabetes insipidus?
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.
What are symptoms of diabetes insipidus?
intense thirst, polydipsia, craving for ice water, polyuria, nocturia, enuresis, hypernaturemia
What is the etiology of diabetes insipidus?
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
How is diabetes insipidus diagnosed?
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