Hypopituitarism Flashcards

Lesson 1 endo

1
Q

What are the 5 hormones released by the anterior pituitary

A
Growth Hormone ( somatotropin) 
Prolactin 
TSH (thyrotrophin) 
LH + FHS
ACTH ( corticotrophin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens in the hypothalamo- pituitary portal system

A

Hypothalamic releasing/ inhibitory factors travel in portal system to anterior pituitary to regulate hormone production

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

Function of GH

A

Growth

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

Function of prolactin

A

Milk production

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

Function of LH and FSH

A

Stimulate oestrogen, progesterone and testosterone production

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

Function of TSH

A

Produce T3 ( triiodothyronine ) and T4 ( thyroxine)

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

Function of ACTH

A

Cortisol production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is primary failure vs secondary failure

A

Primary: Gland itself fails ( usually thyroid. adrenal cortex for cortisol or gonads)
Secondary: No signal from hypothalamus or Anterior pituitary

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

Causes of primary hypothyroidism, hypoadrenalism , hypogonadism

A

Autoimmune destruction of thyroid gland, adrenal cortex, destruction of testes ( mumps) or ovaries( chemotherapy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Diagnosis of primary hypothyroidism

A

High TSH , low T3, T4 ( TRH also high but unmeasurable)

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

Causes of secondary hypothyroidism, hypoadrenalism , hypogonadism

A

Pituitary tumour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Diagnosis of secondary hypothyroidism,

A

Low TSH, Low t3 and t4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Diagnosis of 1st hypoadrenalism

A

Low cortisol, high ACTH ( high CRH unmeasurable)

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

Diagnosis of 2nd hypoadrenalism

A

low ACTH, low cortisol

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

Diagnosis of 1st hypogonadism

A

Testosterone / Oestrogen low
LH , FSH high
(GnRH high but unmeasurable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Diagnosis of secondary hypothroidism

A

Low LH/FSH

Low testosterone / oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Causes of hypotiuitarism

A

Congenital ( rare)

Aquired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What causes congenital hypopituitarism

A

Mutation of transcription factor genes for normal anterior pituitary development ie PROP1 mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Outcome of congenital hypopiuitarism

A

Deficient in GH and >1 more anterior pituitary hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Effects of congenital hypopituitarism

A

short stature

hypoplastic ( underdeveloped) anterior pituitary on mri

21
Q

What cases acquired hypopituitarism

A

Tumours ( adenomas, metastases, cysts)
Inflammation ( hypophysitis)
Radiation ( hypothalamic / pituitary damage)
Traumatic brain injury
Pituitary apoplexy –> haemorrhage or infarction ( infarction uncommon)
Peri-Partum infection (Sheehan’s syndrome)

22
Q

what can cause posterior pituitary dynsfunction

A

inflammation ( hypophysitis ) or surgery

23
Q

What is panhypopituitarism

A

loss of a and posterior pituitary

24
Q

why does radiotherapy induce hypopituitarism

A

Pituitary and hypothalamus both sensitive to radiation. direct radiation to pituitary ( due to acromegaly) or indirect ( nasopharyngeal carcinoma) can cause hypopituitarism.
extent depends on dose of radiotherapy

25
what happens to hormones released during radiotherapy
GH and gonadotropin most sensitive Prolactase can increase Risk persists up to 10y after therapy so annual assessment
26
Symptoms of hypopituitarism
FSH,LH --> low libido, secondary amenorrhea , erectile dysfunction reduced pubic hair ACTH --> fatigue ( no salt crises as that is part of renin - angiotensin ) TSH --> fatigue GH--> reduced quality of life , short stature ( children only) PRL --> inability to breastfeed
27
What is sheehan's syndrome
secondary post partum hypopituitarism due to hypotension from post partum haemorrhage (pph) --> anterior pit enlarges in pregnancy ( lactotroph hyperplasia) pph leads to pituitary infacrtion
28
Symptoms of sheehan's syndrome
``` Lethargy , anorexia and weight loss TSH/ACTH/GH deficient PRL deficiency if fail to lactate Failure to resume meses post delivery post pit not usually effected ```
29
What is pituitary apoplexy
intra pituitary haemorrhage or infarction ( infarction uncommon) --> often dramatic presentation in patients with pre existing adenomas ( pit tumours)
30
Symptoms of pituitary apoplexy
Severe sudden headache Bitemporal hemianopia --> compressed optic chiasm canervous sinuous involvement may lead to diplopia ( IV,VI) ( two images of same thing aka blurry vision) , ptosis (III) ( droopy eyelid)
31
what can cause pituitary apoplexy
``` use of anticoagulants pituitary adenomas ( pit apoplexy is usually an indicator of adenomas) ```
32
Why is cortisol not used in diagnosis of hypopituitarism
fluctuates during time of day
33
why is T4 not used in diagnosis f hypopituitarism
Long half life -- circulating t1/2 is 6 days
34
Why is FSH/LH not used as a diagnosis of hypopituitarism
Cyclical in women
35
Why is GH /ACTH not a perfect diagnosis of hypopituitarism
They are Pulsatile
36
What is used to diagnose hypopituitarism
Dynamic pituitary function ( series of hormone measurements into a series of time) 1) Measure ACTH and GH --> these are stress hormones. When hypoglycaemia occurs the body responds to it like stress. Therefore can create an insulin induced hypoglycaemia to stimulate GH and ACTH release to measure cortisol levels. In normal : when induced levels of Gh and ACTH should increase 2) Give TRH stimulating TSH release and measure 3) Give GnRH stimulating FSH and LH release and measure
37
what machine and what does the image show to diagnose hypopituitarism using radiology
Use pit MRI ( CT not good) | --> empty sella due to thin rim of pituitary tissue
38
what hormones can be treated in hypopituitarism
all ( Growth hormone,TSH, LH+FSH, ACTH) except prolactin
39
How to treat GH deficiency and how can we improve the treatment ?
1) confirm GH on dynamic pit function test 2) Assess quality of life using questionnaire 3) daily injection of GH improvements: Better QoL questionnaire, plasma IGF-1
40
How to we treat TSH deficiency
Replace with levothyroxine daily ( Remember TSH is low so can't use this to adjust the dose as you would do in primary hypothyroidism) --> aim for free T4 above the middle of the reference range
41
How to treat ACTH deficiency
Replace cortisol not ACTH ( though will be hard to mimic diurnal variation of cortisol) 2 ways:use synthetic glucocorticoids 1) Prednisolone one daily AM 2) Hydrocortisone 3 times per day
42
Why is it important to have sick day rules for patients with ACTH deficincy
Patients with ACTH deficiency or 1ary adrenal failure ( addisons) are at risk of adrenal crisis trigged by illness
43
Features of adrenal crisis
dizziness, hypotension,vomiting, weakness --> results in collapsing and death
44
Who must be told sick day rules with ACTH deficiency and what must they do?
Ppl who take steroid replacements ( ie prednisolone, hydrocortisone) rules: 1) Must have steroid alert pendant / bracelet 2) take double steroid dose ( glucocorticoid not mineralocorticoid) if fever / intercurrent illness 3) if unable to take tablets ie vomiting must inject intramuscularly or go to Aand E
45
what is the treatment for FH/LH deficiency in men if no fertility is required?
1) Measure plasma testosterone 2) Testosterone replacement --> topical or intramuscular Note : testosterone replacement doesn't restore sperm production ( this is dependent on FSH)
46
what is the treatment for FH/LH deficiency in men if fertility is required?
1) induce spermatogenesis by gonadotropin injections ( works best if 2ary hypogonadism has developed post puberty ) 2) Measure test + semen analysis ( sperm prod may take 6-12 months)
47
what is the treatment for FH/LH deficiency in women if no fertility is required?
1) Oestrogen replacement ( oral / topical) | 2) Need additional progestogen if uterus is intact to prevent endometrial hyperplasia
48
what is the treatment for FH/LH deficiency in women if fertility is required?
induce ovulation using gonadotropin injections ( IVF)