Pituitary and Hypothalamic Disorders

Question 1

Pituitary disorders Anterior

Answer 1

Adenomas
Prolactinoma
Acromegaly
Gigantism
Panhypopituitarism

Question 2

Pituitary disorders Posterior

Answer 2

SIADH

Diabetes Insipidus

Question 3

ormones of the anterior pituitary

Answer 3

FSH
LH
ACTH
TSH
Prolactin
GH (Growth hormone)

Mnemonic: FLAT PeG

Question 4

Hormones of the posterior pituitary

Answer 4

ADH
Oxytocin

These hormones are manufactured in the hypothalamus

Question 5

Pituitary Adenomas

Answer 5

Microadenoma:
tumor less than 10 mm in diameter
More common (Prolactinoma)

Macroadenoma:
Larger than 10 mm in diameter
May cause mass effect

Question 6

Adenomas cause increased levels of prolactin, what is the function of prolactin?

Answer 6

Prolactin blocks gonadotropins FSH and LH

So adenoma can lead to amenorrhea, infertility, decreased libido, etc.

Question 7

Medical treatment of Hyperprolactinemia

Answer 7

is with dopamine agonists
Cabergoline (Best tolerated)
Bromocriptine

Question 8

Acromegaly

Answer 8

Acromegaly is almost always caused by a pituitary tumor.
Excess growth hormone
Most frequently occurs in ages 20-40
May also be associated with tumors of the pancreas or parathyroid glands

Question 9

Best initial test to rule out/in acromegaly

Answer 9

IGF-1 level
Serum GH not suppressed following oral glucose load (75-100 g glucose)

MRI:Pituitary tumor in 90%

Question 10

Acromegaly Treatment

Answer 10

Treatment of choice is surgical.
Transsphenoidal resection
Best medical therapy is cabergoline (oral)
Or ocreotide, lanreotide, pegvisomant (sub Q injections)
Gamma knife radiosurgery if fail transsphenoidal surgery

Question 11

Hypopituitarism Etiology

Answer 11

Pituitary apoplexy
	Hemorrhage into the pituitary gland
Sheehan’s syndrome
	Post partum pituitary ischemic necrosis
Infiltration
	Sarcoid, hemochromatosis, TB, syphilis
Non-functioning adenoma
Trauma
Stroke
Mass effect

Question 12

The hormone deficiency to develop with lack of a functioning pituitary

Answer 12

GH : 1st hormonal deficiency to develop
LH/FSH: 2nd
TSH: 3rd
ACTH: 4th

Question 13

Pituitary apoplexy

Answer 13

Hemorrhage into the pituitary

Usually secondary to existing adenoma

Acute symptoms: headache, nausea, vomiting, altered mental status, low blood pressure, low blood glucose

may treat with surgery

Question 14

Sheehan’s syndrome

Answer 14

Post partum ischemic necrosis of the pituitary

Secondary to hypotension, emboli, HELLP syndrome

Symptoms: Difficulty breastfeeding, extended amenorrhea

Question 15

Best initial test for hypopituitary function is to check anterior pituitary hormones.

Answer 15

LH/FSH
IGF-1 or GH insulin response test
TSH
ACTH: Measured indirectly through cortisol levels

MRI

Question 16

SIADH Syndrome of Inappropriate Antidiuretic Hormone

Answer 16

SIADH is characterized by euvolemic hyponatremia due to elevated ADH levels.
Reabsorption of excess fluid
Low sodium
Low serum osmolality

Question 17

SIADH Work up and diagnosis

Answer 17

CMP
Urine sodium and osmolality
Urine sodium is inappropriately high (>20 mEg/L) with low serum sodium (<130)
Evaluate medications
CT of the head
**Rule out SIADH producing cancers:
CXR (small cell cancer of the lung)
CT abdomen (pancreatic cancer)

Question 18

Diabetes Insipidus

Answer 18

Diabetes Insipidus occurs due to lack of appropriate levels of ADH
Central:
Deficiency of ADH (vasopressin)
Resistance to ADH

Nephrogenic:
Defect in the kidney tubules that interferes with water reabsorption

Question 19

Diabetes Insipidus Work up

Answer 19

comparison of urine and serum sodium levels.
CMP (includes a serum sodium)
Plasma osmolality
Plasma ADH
Urine sodium and osmolality
Water deprivation test
DDAVP test