Pituitary Disorders - Cryar Flashcards Preview

medicine > Pituitary Disorders - Cryar > Flashcards

Flashcards in Pituitary Disorders - Cryar Deck (60):
1

What are the main pituitary disorders

Hypopituitarism
Hyperprolactinemia
Acromegaly
Cushings disease
Diabetes insipid us

2

What is hypopituitarism?

Diminished or absent secretion of anterior pituitary hormones

3

What are two ways you can have hypopituitarism?

Primary disorder of anterior pituitary cells
Reduced stimulation by the hypothalamus

4

What is pan hypopituitarism?

Generalized loss of anterior pituitary hormones

5

What are the causes of hypopituitarism?

neoplasms
infections or granulomas
vascular
infiltrative
physical injury
releasing hormone deficiencies

6

Clinical features of panhypopituitarism

weakness, malaise, nausea, vomiting
amenorrhea, breast atrophy
testicular atrophy
absence of axillary and pubic hair
waxy skin, fine periorbital wrinkling
hypothermia
hypotension, hypoglycemia

7

What features are not usually present in panhypopituitarism?

hyperpigmentation
aldosterone is less frequently involved

8

What causes the weakness, malaise, nausea and vomitting of panhypo pit?

adrenal insufficiency - lack of ACTH secretion from the ant pit

9

What is often the key diagnostic sign of panhypo pit?

absence of axillary and pubic hair

10

What causes the hypothermia of panhyp pit?

lack of thyroid hormones from the ant pit

11

What causes the hypotension and hypoglycemia of panhypo pit?

lack of glucocorticoids

12

What do the clinical features of Panhypo pit depend on?

the specific deficiencies
age
sex

13

How does age affect the clinical features of panhypo pit?

short stature and delayed puberty in children

14

How does sex affect the clinical features of panhypo pit?

impotence in men
ammenorrhea in women

15

What is pituitary apoplexy?

rapid hemorrhage into the pituitary gland

16

What is pituitary apoplexy characterized by?

sudden onset of excruciating headache
diplopia
hypopituitarism

17

What is the etiology of diplopia in apoplexy?

pressure on the oculomotor nerves

18

Hypopituitarism

sella has no way to expand

19

What is pituitary apoplexy often mistaken for?

stroke

20

What is the most important endocrine consideration for treatment with apoplexy?

Treatment of cortisol deficiency

21

How is pituitary apoplexy treated?

surgery for ocular consequences
treat cortisol def.
spontaneous improvement of both ocular and hormonal deficiencies can occur with time so milder cases can be watched and supported

22

What is Sheehan's syndrome?

infarction after postpartum hemorrhage

23

How does severe sheehan's syndrome present?

lethargy, anorexia, weight loss, failure to lactate

24

How does a mild case of Sheehan's present?

failure to lactate and failure to resume menses

25

What eventually happens to the pituitary in Sheehan's syndrome?

eventual development of small pituitary in a normal sized sella

26

What is Sheehan's sometimes mistaken for?

empty sella syndrome

27

If Sheehan's is suspected, what most be promptly assessed and treated?

adrenal insufficiency - the remaining deficiencies can be evaluated 4-6 weeks later

28

What deficiency from Sheehan's is there no treatment for?

prolactin deficiency - which prevents lactation

29

What do you find on diagnosis of panhypo pit?

low levels of target organ hormones without a compensatory increase in pituitary hormones

30

What levels do you want to avoid measuring as the only screening for a possible hormone deficiency? and why?

anterior pituitary hormones - bc the levels may be low, normal or high - the key is how they are relative to end organ hormone levels

31

How do you treat panhypo pit?

the same way you would treat primary deficiencies

32

What do you need to be cautious of when treating hypothyroidism?

Be sure to recognize and treat any underlying adrenal insufficiencies first

33

How do pituitary neoplasms often present?

headache and visual disturbances (especially if non secretory)
excessive secretion or deficiency of ant pit hormones may be present

34

How is prolactin unique among the anterior pituitary hormones?

it is under tonic suppression
this means lesions in the hypothalamus or affecting the pituitary stalk cause increased prolactin secretion

35

What are some causes of hyperprolactinemia?

prolactin secreting pituitary adenoma
loss of dopaminergic suppression from the hypothalamus
nipple stimulation or chest wall injury
estrogen - increase is proportional to levels of estrogen
hypothyroidism
chronic renal failure
multiple drugs

36

What are one of the main classes of drugs causing hyperprolactenemia?

antipsychotics

37

How does hyperprolactermia present in women?

as a microadenoma
amenorrhea
galactorrhea

38

How does hyperprolacternemia present in men?

macroadenoma
impotence
visual disturbances

39

Differential of prolactin levels?

normal < 20
intermediate 21 - 150
tumor > 150

40

What is the treatment for hyperprolactinemia?

Dopamine Agonists
- bromocriptine
- cabergoline

41

What is the major risk of treatment of hyperprolactinemia with cabergoline?

valvular heart disease seen in patients treated for parkinsons disease

42

What is MAINLY seen with acromegaly?

acral enlargement
soft tissue overgrowth

43

What are some other things seen with acromegaly?

headache
vision loss
hypopituitarism
cardivascular disease
visceral enlargement
sleep apnea
increased risk for malignancies (colon)

44

How do you clinically diagnos acromegaly?

fully developed syndrome is unmistakable
more commonly found in earlier, less pathognomonic stages

45

How do you diagnosis acromegaly with laboratory confirmation?

somatomedin-C (IGF-I) is the best screening test (GH levels are variable)

46

How do you treat acromegaly?

primary treatment is surgical - but it is often not curable
secondary therapy is - radiation of the sella or somatostatin analogues

47

What is cushings syndrome?

clinical manifestations of glucocorticoid excess (from any source)

48

What is cushings disease?

glucocorticoid excess specifically due to ACTH secretion from a pituitary adenoma

49

How do you determine the etiology of Cushing's syndrome?

exogenous steroids or adrenal tumor = low ACTH
Cushing's Disease = normal to high ACTH
ectopic ACTH = very high ACTH

50

How do you diagnos Cushing's Disease?

Relies on the ability to suppress ACTH
dexamethasone - demonstrate suppressibility of endogenous cortisol production

51

What would a dexamethosone suppression test show on a patient with Cushing's Disease?

No cortisol production suppression

52

Why is imagine problematic in cushing's disease?

50% of patients have a "normal" pituitary on CT or MRI

53

How can you localize the source of ACTH to the pituitary when no adenoma is imaged?

Inferior petrosal sinus testing for ACTH

54

How is ADH secretion regulated?

very tightly regulated by osmolality
osmotic regulation is overridden by volume status

55

What is diabetes insipidus?

failure to appropriately concentrate the urine

56

What is central vs. nephrogenic DI?

central - inadequate ADH
nephrogenic - failure of kidney to respond to ADH

57

What is the etiology of central DI?

trauma, surgery, infiltrative or idiopathic

58

How do you diagnos DI?

polyuria and polydipsia
urine volumes > 3L per day
dilute urine with a serum osmolality > 295 (although some patients can compensate)

59

What is the water deprivation testing for DI?

water is withheld until urine osmolality stable
primary polydipsia - urine osmolality > serum
DI - urine osmolality remains low while serum osmolality increases

60

How do you tell the difference bw central or nephrogenic DI?

Administer DDAVP (AHD analogue)
central DI - urine osmolality increase by 50%
nephrogenic DI - no change