Pituitary Disorders Flashcards
What is the effect of upwards growth of pituitary tumour?
Visual field loss due to compression of optic chiasm
What is the effect of lateral growth of a pituitary tumour?
Pain
Double vision
What happens to pituitary hormones with a pituitary hormone?
Decrease
- GH
- LH/FSH
- TSH
- ACTH
Increase
- prolactin
What happens with a growth hormone deficiency?
Children
- short stature
- delayed puberty
Adults
- reduced quality of life
- loss of secondary sexual characteristics
What happens with a TSH deficiency?
Low thyroid hormones
Weight gain
Tiredness
Bradycardia
Low T4
Non-elevated TSH
What happens with ACTH deficiency?
Low cortisol Tired Dizziness Low BP Low sodium
How do you test for adrenal axis deficiency?
SynACTHen
- direct stimulation of adrenals
Insulin stress test
- response to hypoglycaemic stress
How do you test for adrenal axis esxcess
Dexamethasone
- suppress ACTH axis with steroids
How do you test for GH axis deficiency?
Insulin stress test
- response to hypoglycaemic stress
How do you test for GH axis excess?
Glucose tolerance test
- suppress GH axis with glucose load
How do you investigate suspected pituitary disease?
Radiology
- MRI
Bloods
- thyroid function
- LH
- FSH
What is a prolactinoma?
Prolactin secreting tumour
Larger the tumour, the higher the prolactin
What are symptoms of a prolactinoma?
Women
- Menstrual disturbance
- Galactorrhoea
- fertility problems
Men
- low testosterone symptoms are non specific`
How do you manage prolactinomas?
Dopamine agonist
- shrinks tumour
- stimulates D2 receptore
Dopamine inhibits prolactin
What are the effects of hyperprolactinaemia?
Prolactin inhibits LH secretion
What is acromegaly?
Large extremities
- hands
- feet
What causes acromegaly?
High GH
Often by GH-secreting tumour
What are the long term complications of acromegaly?
Premature cardiovascular death
Increased risk of colonic tumours
Hypertension
Diabetes
What tests confirm acromegaly?
Oral glucose tolerance test with GH response
Elevated IGF-1 level
How do you treat acromegaly?
Surgical removal of tumour
Reduce GH secretion
- dopamine agonist
- somatostatin analogue
Block GH receptor
- pegvisomant
What is Cushing’s disease?
ACTH secreting tumour
What are the appearance changes in Cushings?
Round pink face Skinny limbs Thin skin Purple striae - abdomen Neck fat pad - hump
What is Cushing’s syndrome?
High cortisol due to other conditions
- adrenal tumour
- ectopic ACTH
- steroid medication
What is diabetes insipidus?
Reduced production of ADH
