Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DEMS Unit IV - Endocrine > Pituitary Gland Dysfunction > Flashcards

Pituitary Gland Dysfunction Flashcards

1
Q

What pattern of regulation exists for growth hormone?

A

Pulsatile, Diurnal pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Biochemical evaluation requires assessment of _____ and their _____

A

Pituitary hormones and their target gland hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is the problem for a primary gland failure?

A

High trophic hormone level and low target gland level (Target endocrine gland deficiency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

TSH-oma - what kind of failure is this?

A

Uncommon, easily missed
High target gland hormone and high trophic hormone
Can be:
- autonomous secretion of trophic hormone
- resistance to target gland hormone action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of problem is there for secondary/tertiary gland failure?

A

Low trophic hormone and low target gland hormone

Trophic Hormone Deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What kind of defect may exist with low trophic hormone level and high target gland hormone level?

A

Autonomous secretion of target endocrine gland hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Dynamic pituitary testing

A
  1. Hormone excess assessed by: suppression test (ie oral glucose tolerance)
  2. Hormone deficiency assessed by: stimulation test (ie insulin tolerance test)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Problems of GH excess

A
  1. Gigantism - GH excess before puberty

2. Acromegaly - GH excess after puberty (acral bony overgrowth and soft tissue swelling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the best screening test for GH excess?

A

Look for an elevated IGF-1 level (make sure that this is age and gender matched).
Integrated 24 hr secretion. Long half-life.

Tx:

  • Surgery
  • Somatostatin analogs
  • GH receptor antagonist
  • Radiation therapies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Somatopause

A

Changes with aging that may make us flabby. Decline of 14% per decade of GH/IGF-1 levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Manifestations of adult GHD

A 
Body composition
- inc fat deposition
- dec muscle mass, strength, & exercis
Bone strength
- inc bone loss and fracture risk
Metabolic and cardiovascular effects
- inc cholesterol levels
- inc inflammatory and prothrombotic markers (CRP)
Psychological well-being
- loss of spunk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is GH not approved for by the FDA?

A
  • Anti-aging
  • Obesity
  • Chronic fatigue syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do you diagnose AoGHD?

A

Provocative test for GH Reserve = Inducing hypoglycemia

  • this is dangerous
  • do not do in elderly, h/o seizure disorder, CAD, or cerebrovascular disease

Second best test:
GHRH-Arginine test (not available in US), instead we just have Arginine and glucagon stimulation test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Hyperprolactinemia causes

A

PRL level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Prolactinoma presentation

A
  • Most common functional pituitary tumor
  • F:M is 10:1, median age of diagnosis = 34 y/o

Different presentations in men and women

Women:
- microadenoma 1 cm
- no galactorrhoea
- visual field abnormalities
- impotence
- E.O.M. paralysis
(anterior pituitary malfunction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Diagnosis of prolactinoma

A

Random PRL level (correlate with tumor size)
> 100-150 ng/dl = microadenomas
> 200-250 ng/dl = macroadenomas

Pituitary MRI

17
Q

Prolactin deficiency

A

Etiology: severe pituitary destruction
Presentation: failed lactation in women, no known effect in males
Dx: low basal PRL level

18
Q

Primary functions of cortisol

A
  • Gluconeogenesis
  • Breakdown of fat and protein for glucose production
  • control inflammatory reactions
19
Q

Complications of chronic cortisol excess

A

Cushings Syndrome

  • Changes in carb, protein and fat metabolism
  • Changes in sex hormones
  • Salt and water retention
  • Impaired immunity
  • Neurocognitive changes
20
Q

Endogenous hypercortisolism types and etiologies

A

ACTH - dependent (70-75%)

  • Corticotrope adenoma (Cushing’s)
  • Ectopic Cushing’s (ACTH/CRH tumors)

ACTH - independent (25-30%)

  • adrenal adenomas
  • adrenal carcinoma
  • nodular hyperplasia (micro or macro)
21
Q

What are the high discriminatory features of Cushing’s syndrome?

A
  • Plethoric/moon facies
  • Wide (>1cm) violaceous striae (abdominal and axillary)
  • Spontaneous ecchymoses
  • Proximal muscle weakness
  • Early/atypical osteoporosis (atraumatic rib fx)
22
Q

What are the cortisol rhythms?

A
  • Episodic ACTH/cortisol secretions daily
  • Major ACTH/cortisol burst in early morning
  • Cortisol Nadir 11-12 pm

Note: most cortisol is bound to transcortin, only 5% is free

23
Q

Screening tests for Cushing’s

A
  • Disrupted circadian rhythm (midnight salivary or serum cortisol)
  • Increased filtered cortisol load (24 hr urine free cortisol)
  • Attenuated negative feedback (low dose dexamethasone suppression test)
24
Q

What is pseudo-cushing’s disease?

A
  • Overactivation of the HPA axis, without tumorous cortisol hyper-secretion (ramps up the whole system)
25
Q

How do you work-up Cushings?

A
  1. ACTH level - plasma ACTH levels are high-normal to mildly elevated
  2. Imaging - Pituitary MRI, only 50% identified on MRI (surgery if can see, else move on to #3)
  3. Inferior petrosal sinus sampling - for a negative/equivocal MRI
26
Q

What are the etiologies of central adrenal insufficiency?

A
  • Most common cause: supraphysiologic exogenous glucocorticoid use
  • Drugs: opioids and megace
  • Hypothalamus/Pituitary diseases and their treatments
  • Other isolated ACTH deficiency (rare)
27
Q

Clinical presentation of AI

A
  • Fatigue
  • Anorexia, nausea/vomiting and weight loss
  • Generalized malaise/aches
  • Scant axillary/pubic hair
  • Hyponatremia and hypoglycemia
28
Q

Testing for AI

A

Basal testing: random a.m. cortisol level 18 excludes AI

Stimulation testing:

  • insulin induced hypoglycemia - assess the entire HPA axis
  • Cosyntropin stimulation test valid for assessing HPA axis only if prolonged loss of pituitary signaling and resulting adrenal atrophy (not good for if someone just comes into hospital acutely)
29
Q

Hypogonadism Differential Dx

A

High FSH/LH:

  • Congenital anorchia
  • Klinefelter’s Syndrome
  • Testicular injury
  • Autoimmune testicular dz
  • Glycoprotein tumor (rarely)

Low FSH/LH

  • Macroadenomas, prolactinomas, XRT
  • Isolated GnRH Deficiency (Kallman’s anosmia vs. idiopathinc)
  • Hemochromatosis
  • Functional deficiency
  • Critical illness, OSA, starvation, meds-opiates, glucocorticoids
30
Q

Gonadotropin excess presentation

A
  • Clinically silent
  • Rare presentation: ovarian hyper-stimulation syndrome or macro-orchidism
  • Usually middle-aged patient with macroadenomas and related mass effects
31
Q

Gonadotropinoma diagnosis

A
  • Blood tests: low FSH/LH, T/E2
  • Pituitary MRI
  • Immunohistochemical analyses (+ FSH, LH or ASU staining) of resected tumor
32
Q

Etiologies of TSH elevation

A

Secondary

  • Thyrotropin secreting pituitary tumor - very rare
  • Thyroid hormone resistance
33
Q

Clinical presentation of hyperthyroidism

A

Thyrotropinoma
- heat intolerane, hair loss, goiter, tremor, weight loss, diarrhea, irregular menses or mass effects

Dx:
- Elevated free T4 and a non-suppressed TSH

DEMS Unit IV - Endocrine (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions