Hypopituitarism Flashcards
what are the 6 hormones released by the anterior pituitary?
- growth hormone
- prolactin
- thyroid stimulating hormone
- luteinising hormone
- follicle-stimulating hormone
- adrenocorticotrophic hormone
name 2 causes of acquired hypopituitarism
- tumours
- radiation
- infection eg. meningitis
- traumatic brain injury
- pituitary surgery
- inflammatory (hypophysitis)
- pituitary apoplexy
- post-partum infarction
what is the name given to total loss of anterior and posterior pituitary function?
panhypopituitarism
which anterior pituitary hormones are most sensitive to radiotherapy?
gonadotrophins and GH
which hormone can increase after radiotherapy?
Prolactin due to loss of hypothalamic dopamine
when the gland itself is not working we call that?
primary failure
when the pituitary is not working, we call that?
secondary failure
In primary hypothyroidism, what would happen to TSH and fT4?
- TSH high
- fT4 low
In secondary hypothyroidism, what would happen to TSH and fT4?
- TSH low
- fT4 low
In primary hypoadrenalism, what would happen to cortisol and ACTH?
- cortisol low
- ACTH high
In secondary hypoadrenalism, what would happen to cortisol and ACTH?
- low cortisol
- low ACTH
In primary hypogonadism, what would happen to testosterone/oestrogen and LH/FSH
- testosterone/oestrogen low
- LH/FSH high
In secondary hypogonadism, what would happen to oestrogen/testosterone and LH/FSH
- oestrogen/testosterone low
- LH/FSH low
Why do we have to be aware of what time of day we test cortisol?
diurnal rythm
why do we have to pay attention to the 6-day half-life of T4?
there could be a delayed decrease in T4 shown in the blood
what do we need to consider when testing hypogonadism in women?
FSH and LH are cyclically released in women
why do we need to be careful when testing GH and ACTH?
they are pulsatile
How do we dynamically test ACTH, GH, TSH and FSH/LH?
- ACTH and GH are stress hormones –> put body into insulin induced hypoglycaemia –> should stimulate production of GH and cortisol if healthy
- Give TRH to stimulate TSH release if healthy
- GnRH to stimulate FSH + LH release if healthy
Treatment for growth hormone?
- Confirm deficiency
- assess QoL
- daily injection GH
- measure response by improved QoL and plasma IGF-1
how do we treat TSH deficiency?
levothyroxine, once daily
aim for fT4 in middle of the reference range
When treating TSH deficiency (secondary hypothyroidism) why do we aim for fT4 in middle of reference range?
Can’t use TSH levels to adjust, as TSH is the problem
treatment for ACTH deficiency
Synthetic glucocorticoids:
- prednisolone once daily AM
- hydrocortisone 3x per day
What is an adrenal crisis?
severe symptoms that can result in collapse and death due to intercurrent illness or not taking medication for hypoadrenalism
why is adrenal crisis less severe in secondary hypoadrenalism patients?
they can still make aldosterone, as their adrenal cortex is not destroyed, so don’t have hypotension
what are the sick day rules?
- steroid alert pendant/bracelet
- double steroid dose if fever/intercurrent illness
- If unable to take tablets (vomiting) inject IM or come to A&E
What is the treatment for men with LH/FSH deficiency, fertility required?
- inject FSH and LH to stimulate sperm production
how long does it take for sperm production to occur after FSH and LH injection?
6-12 months
what is the treatment for LH/FSH deficiency in men if no fertility is required?
Topical/IM injection of testosterone
what would give the best response of FSH and LH treatment in men?
If hypogonadism developed after puberty
How would you check for progress when giving LH and FSH treatment to men?
measure testosterone and semen analysis
If no fertility is required, what treatment would you give to women with FSH and LH deficiency?
replace oestrogen and give progestogen if uterus intact
If fertility is required for women, how would you treat LH and FSH deficiency?
induce ovulation by IVF by giving carefully timed injections of LH and FSH
What’s the best radiological way to visualise the pituitary?
MRI
How are pregnant women at risk of sheehan’s syndrome?
during pregnancy, pituitary gland enlarges due to lactotroph hyperplasia, needing more blood
haemorrhage during birth can reduce blood pressure and blood flow to the pituitary resulting in pituitary infarction
What is the presentation of sheehan’s syndrome?
- weight loss
- anorexia
- lethargy
- failure of lactation
- failure to resume menses post-delivery
what is the presentation of pituitary apoplexy?
severe, sudden headache
pituitary apoplexy is caused by what, most commonly, and what else, least commonly?
intra pituitary haemorrhage
less commonly infarction
pituitary apoplexy could be the first presentation of what disease?
pituitary adenoma
what can trigger pituitary apoplexy?
anti-coagulants
what two complications can pituitary apoplexy cause?
- bitemporal hemianopia (compressed optic chiasm)
- If blood/swelling into cavernous sinus, can compromise cranial nerves causing diplopia and prosis
what is diplopia?
double vision
what is prosis?
droopy eyelid
what could be the different causes of
- Tired
- No periods
- Difficulty breastfeeding
- Tearful
after pregnancy?
- sheehan’s syndrome
- primary hypothyroidism (immune system becomes active again after being immunosuppressed during pregnancy)
- post-natal depression
- anaemia
What is the diagnosis, if these are blood results post-pregnancy?
Haemoglobin 130 g/L (115 – 165)
Mean cell volume 89 fl (80-100)
Oestradiol <70 pmol/l (>200)
LH 0.5 U/l (2-10 U/L)
FSH 0.8 U/l (1.5 – 10 U/L)
Prolactin <50 miU/L (<500 IU/L)
fT4 6.9 pmol/L (9-23)
TSH 0.09 mU/L (0.3 – 4.2)
9AM cortisol 75nmol/L (>350 nmol/L)
Sheehan’s syndrome (post-partum pituitary infarction)
what is the treatment for Sheehan’s syndrome?
- replace oestrogen + progestogen if no fertility required
- if fertility is required, IVF
- Replace T4 with levothyroxine to just above mid-range
- glucocorticoids
