Pituitary and Hypothalamic Disorders Flashcards Preview

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Flashcards in Pituitary and Hypothalamic Disorders Deck (72)
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1
Q

Anterior pituitary disorders?

6

A
Adenomas
Prolactinoma
Acromegaly
Gigantism
Panhypopituitarism
Cushing’s Disease
2
Q

Posterior pituitary disorders?

2

A

SIADH

Diabetes Insipidus

3
Q

6 Regulatory Hormones of the Hypothalamus

A
  1. Thyrotropin releasing hormone (TRH)
  2. Gonadotropin releasing hormone (GnRH)
  3. Corticotropin releasing hormone (CRH)
  4. Growth hormone releasing hormone (GHRH)
  5. Growth hormone inhibitory hormone (somatostatin)
  6. Prolactin inhibiting hormone (PIH)
4
Q

Major Hormones of the Anterior Pituitary

6 major

A
  1. FSH
  2. LH
  3. ACTH
  4. TSH
  5. Prolactin
  6. GH

Mnemonic: FLAT PeG

  • Also MSH (melanocyte stimulating hormone) but not a major hormone
5
Q

Hormones of the Posterior Pituitary
2

Where are these hormones manufactured?

A
  1. ADH
  2. Oxytocin

These hormones are manufactured in the hypothalamus

6
Q

What do these hormones act on?

  1. ADH?
  2. Oxytocin? 2
  3. GH? 3
  4. ACTH?
  5. TSH?
  6. FSH and LH? 3
  7. Prolactin?
A
  1. kidney
  2. breasts and uterus
  3. bones and soft tissue but also acts on liver to produce somatostatin
  4. adrenal glands
  5. thyroid
  6. testes, ovaries, corpus luteum
  7. breasts
7
Q

Sella turcica pituitary disorder?

A

depression of the bone at the base of the skull where the pituitary gland is located

8
Q

Pituitary Tumors can present a variety of ways. What are they?
3

A
  1. Hormonal abnormalities
  2. Neurologic symptoms
  3. Incidental finding on MRI obtained for another reason (the “incidentaloma”)
9
Q

What are the pituitary disorder Neurologic symptoms?

2

A

Headache

Visual field impairment

10
Q

Adenomas are what?

What are the types? 2

Which is more common?
Which can be worse?

A

a benign tumor of glandular tissue

Microadenoma

  • tumor less than 10 mm in diameter
  • More common than macroadenomas

Macroadenoma

  • Larger than 10 mm in diameter
  • May cause mass effect
11
Q

Example of a microedema?

A

Ex: Prolactinoma

12
Q

Elevated prolactin levels have multiple etiologies.
What are they? 4

Whats the most common cause of sellar region masses?

Most common type of pituitary adenoma?

What do all these usually cause?

A
  1. Adenoma (most common cause of sellar region masses)***
  2. Prolactinoma – most common type of pituitary adenoma**
  3. Trauma
  4. Medications

Hypothyroidism

13
Q

What medications can cause elevated prolactin levels?

4

A
  1. SSRI’s (antidepressants)
  2. antipsychotics,
  3. cocaine,
  4. alpha methyldopa (treats hypertension)
14
Q

A prolactinoma is a tumor of what?

What does it secrete?

May cause compression of what which leads to what?

A

anterior pituitary

Secretes prolactin

May cause compression of the optic chiasm and lead to bitemporal hemianopsia

15
Q

Signals from the hypothalamus may be interrupted with damage to the what?

What signals specifically?

And what will remain unchecked?

A

Stalk

Prolactin inhibiting hormone (dopamine) from the hypothalamus will not be transmitted to the pituitary if the stalk is damaged

Prolactin levels then increase unchecked

16
Q

Medications that increase serotonin may lead to increased what?

A

prolactin levels

17
Q

What are the medications that increase serotonin thus increasing prolactin?
4

A
  1. Antidepressants
  2. Antipsychotics
  3. Alpha methyldopa (Aldomet…antihypertensive)
  4. Serotonin is a prolactin releasing factor
18
Q

What syndrome may also lead to increased prolaction levels?

What stimulates prolaction levels that is releaased from the hypothalamus?

Why would this affect prolactin levels in hypothyroidism?

A

Hypothyroidism

TRH

Because there is low thyroid hormones being made so the body is producing more TRH

19
Q

d

A

d

20
Q

Adenomas cause increased levels of what?

What does prolaction block? 2

A

Prolactin

Prolactin blocks gonadotropins FSH and LH

21
Q

Symptoms of prolactinoma differ in men and women.
Women? 3
Men? 6

A

Women

  1. Amenorrhea,
  2. galactorrhea
  3. infertility

Men

  1. Decreased libido,
  2. gynecomastia,
  3. erectile dysfunction
  4. infertility,
  5. bitemporal hemianopsia
  6. headache

Symptoms due to decreased testosterone and mass effect from the tumor

22
Q

What test should we do for diagnosis of prolactinoma?

What additional tests?
7

A

Best initial test
Prolactin level

Additional tests to rule out causes of secondary hyperprolactinemia

  1. TSH,
  2. Beta-HCG,
  3. CMP (electrolytes, liver, renal), 4. LH, FSH,
  4. serum estradiol (women),
  5. serum free and total testosterone (men)
  6. MRI to confirm the diagnosis
23
Q

Medical treatment for prolactin issues is what?
2

Other options for therapy?
3

A

is with dopamine agonists.

Cabergoline
Best tolerated

Bromocriptine

  1. Transsphenoidal pituitary surgery for large symptomatic tumors
  2. Radiation therapy in some
  3. Chemotherapy with Temozolomide if no response to medications or radiation and if not a surgical candidate
24
Q

Acromegaly is an Anterior pituitary disorder characterized by:

A

Enlargement, thickening, and broadening of bones

Particularly extremities

25
Q

Causes of Acromegaly

2

A
  1. Hypersecretion of GH after fusion of epiphysis with shaft of bone
  2. Adenomatous tumor of anterior pituitary involving the acidophilic cells.
26
Q

Signs and symptoms
of acromegaly:

9

A

Striking features are protrusion of?

  1. Supraorbital ridges
  2. Broadening of nose
  3. Thickening of lips
  4. Thickening and wrinkles formation on forehead
  5. Lower jaw (prognathism)

Kyphosis: enlargement of hands and feet with bowing spine

Scalp is thickened and thrown into folds

Overgrowth of body hair

Visceral organs are enlarged

headache

Visual disturbance – Bitemporal hemianopia

CHF common later in life

carpel tunnel

27
Q

Lab and vital signs that will be different in acromegaly?

3

A

Thyroid, parathyroid and adrenal glands shows hyperactivity

Hyperglycemia and glucosuria
Hypertension

28
Q

Acromegaly is almost always caused by what?

What do we have excess of?

Common age?

may be associated with what? 2

A

pituitary tumor

Excess growth hormone (GH)

Most frequently occurs in ages 20-40

May also be associated with tumors of the pancreas or parathyroid glands

29
Q

Acromegalics suffer end-organ effects from what?

2

A
  1. hypertension

2. abnormal glucose metabolism

30
Q

Acromegalic Gigantism
pathophysiology?

When does this condition occur?

A

If GH is produced in excess prior to epiphyseal plate closure…..the results if gigantisim

Gigantism occurs during childhood
Acromegaly appears during adulthood

31
Q

Gigantism Pituitary disorder characterized by:

2

A
  1. Excess growth of body

2. Average height is approximately 7 – 8 feet

32
Q

Causes of Gigantism

2

A
  1. Hypersecretion of GH in childhood or in pre – adult years

2. Tumor of acidophilic cells of Anterior pituitary

33
Q

Signs and Symptoms
of gigantism?
7

A
  1. Huge stature : 7 or 8 feet height
  2. Hyperglycemia
  3. glycosuria
  4. pituitary diabetes mellitus
  5. Headache due to tumor of pituitary
  6. Visual disturbances
  7. Gigantism ends in hypopituitarism (burning of cells of anterior pituitary )
34
Q

Best initial test is rule out/in acromegaly is what?

What are the other tests that are used to diagnose acromegaly? 2

A

IGF-1 level
IGF-1 level (insulin like growth factor)

  1. Serum GH not suppressed following oral glucose load (75-100 g glucose)
  2. MRI
    Pituitary tumor in 90%
35
Q

Treatment of choice for acromegaly/ gigantism is?

Best surgical therapy?
Best medical therapy?

Alternative surgical and medial therapy? 4

A

surgical.

Transsphenoidal resection

Best medical therapy is cabergoline (oral)

Or

  1. ocreotide
  2. lanreotide
  3. pegvisomant (subcutaneous injections)
  4. Gamma knife radiosurgery if they fail transsphenoidal surgery
36
Q

Hypopituitarism etiology

7

A
  1. Pituitary apoplexy
  2. Sheehan’s syndrome
  3. Infiltration
  4. Non-functioning adenoma
  5. Trauma
  6. Stroke
  7. Mass effect
37
Q

Sheehan’s syndrome is what?

What is pituitary apoplexy?

A

Post partum pituitary ischemic necrosis

Hemorrhage into the pituitary gland

38
Q

What could cause infiltration that leads to hypopituitarism?

5

A
  1. Sarcoid
  2. hemochromatosis
  3. TB
  4. syphilis
  5. tumors
39
Q

The first hormone deficiency to develop with lack of a functioning pituitary is what?

What is the 2nd?
3rd?
4th?

A

GH
1st hormonal deficiency to develop

LH/FSH
2nd

TSH
3rd

ACTH
4th

40
Q

Deficiencies of the following hormones cause a variety of symptoms.

  1. LH/FSH? 6
  2. GH? 9
  3. TSH? 5
  4. ACTH? 5
A
1. Amenorrhea
infertility
decreased pubic and axillary hair
genital atrophy
decreased libido
erectile dysfunction
2. ↑ abdominal fat
anxiety
depression
fatigue
↓libido
↓muscle mass
osteo(porosis/penia)
↑LDL
↑Triglycerides
3. Fatigue
weight gain
weakness
decreased appetite
cold intolerance
4. Fatigue
decreased appetite
decreased pigmentation
low blood pressure
low glucose
41
Q

Congenital panhypopituitarism
signs and symtoms?
5

A
Micropenis
Midline defects
Optic atrophy
Hypoglycemia
Poor growth
42
Q

What is a Pituitary apoplexy?

Usually secondary to what?

A

Hemorrhage into the pituitary

Usually secondary to existing adenoma

43
Q

Acute symptoms of Pituitary apoplexy?
5

How would we treat it/diagnosis?
5

A
  1. headache
  2. nausea and vomiting
  3. altered mental status
  4. low blood pressure
  5. low blood glucose
    ….a rare endocrine emergency
  6. Stabilize,
  7. assessement of fluid and electrolyte balances
  8. IV steroids
  9. “Acutely unwell” patients should have prompt neurological assessement
  10. Surgery if severe ophthalmic signs or deteriorating mental status
44
Q

What is post partum ischemic necrosis of the pituitary?

What is it usually secondary to?

Symtpoms?

A

Sheehan’s Syndrome

Secondary to

  1. hypotension
  2. emboli
  3. HELLP syndrome

Symptoms

  1. Difficulty breastfeeding
  2. extended amenorrhea
45
Q

Best initial test for hypopituitary function is to check what?

Which ones are these? 4

After initial test what should we of?

A

anterior pituitary hormones

  1. LH/FSH
  2. IGF-1 or GH insulin response test
  3. TSH
  4. ACTH

MRI

46
Q

What do we do for the IGF-1 or GH insulin response test?

A

Administer insulin to lower blood glucose level

GH should increase due to insulin release

47
Q

How is ACTH measured?

A

Measured indirectly through cortisol levels

48
Q

Sheehan’s Syndrome/hypopituitary function treatment?

3

A
  1. Address underlying cause
  2. Replace needed hormones
  3. Pituitary apoplexy may require surgical decompression
49
Q

Causes of Cushing’s disease?

2

A
  1. Hypersecretion of glucocorticoids
    mainly cortisol
  2. Either pituitary origin or adrenal origin
    (disease vs syndrome)
50
Q

In cushings disease if it is pituitry of origin how would it present clinically?
3

A
  1. Increased secretion of ACTH leads to
  2. hyperplasia of adrenal cortex therefore,
  3. hypersecretion of glucocorticoids takes place
51
Q

ACTH is increased by what?

3

A
  1. Tumor in pituitary cells (basophilic cells)
  2. Malignant tumor of nonendocrine origin like cancer of lungs or abdominal viscera
  3. Hypothalamic disorder causing hypersecretion of corticotropin releasing hormone
52
Q

Signs and Symtpoms of Cushings disease:

Disproportionate distribution of body fat results in?
4

A
  1. Moon face : Fat accumulation and retention of water and salt
  2. Torso : Fat accumulation in chest and abdomen but slim legs and arms
  3. Buffalo hump : Fat deposit on the back of neck and shoulder
  4. Pot belly : Fat accumulation in upper abdomen
53
Q

Signs and Symtpoms of Cushings disease:

Purple striae : Reddish purple stripes on abdomen due to mainly three reasons?

A
  1. Stretching of abdominal wall by excess subcutaneous fat
  2. Rupture of subdermal tissues due to stretching
  3. Deficiency of collagen fibers due to protein depletion
54
Q

Other signs and symtpoms of cushings disease?

12

A
  1. Thinning of extremities
  2. Thinning of skin and subcutaneous tissues
  3. Darkening of skin on neck (aconthosis)
  4. Pigmentation of skin
  5. Facial redness (facial plethora)
  6. Weakening of muscle
  7. Facial hair growth ( Hirsutism )
  8. Bone resorption leads to osteoporosis
  9. Hyperglycemia due to gluconeogeneis leads to adrenal diabetes and glycosuria
  10. Hypertension
  11. Immunosuppression resulting in susceptibility for infection
  12. Poor healing
55
Q

What does SIADH stand for?

SIADH is characterized by what?

What is this due to?
3

A

Syndrome of Inappropriate Antidiuretic Hormone

euvolemic hyponatremia due to elevated ADH levels.

  1. Reabsorption of excess fluid
  2. Low sodium
  3. Low serum osmolality
56
Q

IF SIADH is chronic how will the patient usually present?

Symptoms of hyponatremia include? 4

A

asymptomatic.

Asymptomatic

  1. Headache
  2. Nausea and vomiting
  3. Altered mental status
  4. Seizures
57
Q

Causes of SIADH?

4

A

Traumatic brain injury
Malignancy
Meningitis
Medications

58
Q

Work up and diagnosis
of SIADH?
3

A
  1. CMP
  2. Urine sodium and osmolality
  3. Urine sodium is inappropriately high (>20 mEg/L) with low serum sodium (less than 130)
59
Q

What do we have to rule out in the work up for SIADH and how do we do that (2)?

A

Rule out SIADH producing cancers

  1. CXR (small cell cancer of the lung)
  2. CT abdomen (pancreatic cancer)
60
Q

Treatment for SIADH aims at increasing the what?

How do we do this?

FOr symtpomatic patients how would we treat it?

A

serum sodium levels.

Fluid restriction 1200-1800 mL per day

  1. Hypertonic saline (3%) 1-2 ml/kg IV over 3-4 hours

Do not correct sodium too quickly as may cause central pontine myelinolysis
AKA osmotic demyelination syndrome

61
Q

What does osmotic demyelination syndrome result in?

A

results in destruction of the myelin sheath covering nerve cells in the pons (middle brainstem)….pretty much irreversible

62
Q

Diabetes Insipidus a posterior pituitary disorder characterized by what?

A

excess excretion of water through urine

63
Q

Diabetes Insipidus occurs due to what?

What are the two kinds?
Which is more common?

A

lack of appropriate levels of ADH

Central***
Nephrogenic

64
Q

What is central diabetes insipidus due to? 2

What is nephrogenic diabetes insipidus due to?

A
  1. Deficiency of ADH (vasopressin)
  2. Resistance to ADH

Defect in the kidney tubules that interferes with water reabsorption

65
Q

What is out of sync in diabetes insipidus?

How so?

A

Plasma and urine osmolality are out of sync.

Elevated plasma sodium with an inability to concentrate the urine

66
Q

Symtpoms of diabetes insipidus?

5

A
  1. Intense thirst (2-20L per day)
  2. Polydipsia (intake of excess water)
  3. Craving for ice water
  4. Polyuria, nocturia, enuresis
  5. Hypernatremia
67
Q

WHy does polyuria occur in diabetes insipidus?

Daily output?

A

Due to absence of ADH ,the epithelial cells of distal convoluted tubule in the nephron and the collecting duct of the kidney becomes impermeable to water

Daily output is 4 to 12 liters.

68
Q

Why does polydipsia occur in diabetes insipidus?

A

Because of polyuria ,thirst center in hypothalamus results in intake of large quantity of water

69
Q

Causes of diabetes insipidus?

4

A

Develops due to the deficiency of ADH which occurs in the following conditions:
1. Lesion (injury) or degradation of supraoptic and paraventricular nuclei of hypothalamus

  1. Lesion in hypothalamo-hypophyseal tract
  2. Atrophy of posterior pituitary
  3. Inability of renal tubules to give response to ADH hormone. Called as Nephrogenic diabetic insipidus.
70
Q

Etiology of central diabetes insipidous? 6

Etiology of nephrogenic diabetes insipidous?
5

A

1 and 2. Most common…..due to trauma or tumor

  1. Idiopathic,
  2. cerebral anoxia,
  3. meningitis,
  4. radiation
  5. Meds: lithium, demeclocycline (tetracycline abx)
  6. Hypercalcemia,
  7. hypokalemia
  8. Infiltrative disease
  9. Sjogren’s syndrome
71
Q

Work up for diabetes insipidus includes comparison of what?

What tests would we do? 6

A

urine and serum sodium levels.

  1. CMP (includes a serum sodium)
  2. Plasma osmolality
  3. Plasma ADH
  4. Urine sodium and osmolality
  5. Water deprivation test

Serum sodium will continue to increase and urine sodium will still be low

  1. DDAVP (desmopressin…..synthetic replacement for vasopressin, the hormone that reduces urine production) test
    Urine sodium should increase if central DI
72
Q

Treatment for diabetes insipidus for central (1) and nephrogenic treatment? 2

A

Central
1. Best treatment is DDAVP

Nephrogenic
1. Hydrochlorothiazide or
2. amiloride
Block reabsorption of sodium in the kidneys to keep the plasma sodium down some