cushings/hypopituitarism/diabetes insipidus Flashcards
what is cushings syndrome
the term is used to refer to the signs and symptoms that develop after prolonged elevation of cortisol
excess cortisol >
protein loss ie myopathy, osteoporosis, thin skin, altered carbohydrate/lipid metabolism and altered psyche
excess mineralocorticoid > HPT, oedema
excess androgen > virilism, hirsutism, acne, oligo/amenorrhea
what is cushings characterised by
thin skin - striae, bruising
proximal myopathy
frontal balding in women
conjuncitval oedema
osteoporosis
moon face
buffalo hump
not just obese
“lemon on matchsticks”
screening tests for cushings
dexamethasone suppression test
if cortisol >130mmolL that is abnormal
(dexamethasone should negatively feedback on the hypothalamus and pituitary (lowers ACTH and CRH) and so if cortisol is not suppressed we see cushings syndrome
urine free cortisol
if cortisol/creatinine ratio is <25 that is normal
diurnal cortisol variation
MRI brain
chest CT
abdominal CT
diagnostic tests for cushings
high dose dexamethasone
what is cushings disease
pituitary tumour pathology
what causes cushings syndrome (overall)
exogenous steroids (ie long term high dose patients)
cushings disease (pituitary adenoma releasing excessive ACTH)
adrenal adenoma
paraneoplastic cushings ie when excess ACTH is released from a cancer ie SCLC
tx for cushings
pituitary - hypophysectomy and external radiotherapy if recurs
bilateral adrenalectomy
adrenal - adrenalectomy
ectopic - remove or bilateral adrenalectomy
drug tx for cushings
metyrapone
ketaconazole (heptatoxic)
pasireotide LAR (somatostatin analogue)
causes of hypopituitarism
> pituitary tumours
> other local brain tumours
> iatrogenic surgery
granulomatous disease
vascular disease
trauma
secondary metastatic lesions
autoimmune
clinical signs of hypopit.
menstrual irregularities
infertility/impotence
gynaecomastia
abdominal obesity
loss of facial hair
loss of axillary and pubic hair
dry skin and hair
growth retardation
hypothyroid face
tests for hypopit. anterior pit hormones
tx for hypopit.
goal = hormone replacement
thyroxine 100-150mcg
hydrocortisone 10-25 mg and split 2-3 times per day
ADH desmospray
GH nightly
sex steroids
how to inject testosterone
IM injection every 3/4 weeks
skin gel (testogel)
prolonged IM injection 10-14 weeks (nebido)
what are the risks of testosterone replacement
polycythaemia
prostate enlargement - does not cause cancer but if its already there can make it grow
hepatitis
benefit of growth hormone replacement
improves well-being and quality of life
improves bone strength etc
causes of cranial DI
familial -
DIDMOAD
acquired -
idiopathic
trauma
tumour
diagnostic test for DI
water deprivation test
check serum and urine osmolalities for 8hour and then 4 hour after giving IM DDA VP
> 1.8-2 then normal otherwise DI
treatment for DI
desmospray
nasally - 10-60mcg/day
desmopressin oral tablets
100-1000mcg/oer day
desmopresson injection
1-2mcg IM per day
a baseline urine to serum osmolality >2 usually avoids the need for a water deprivation test
T/F
true
what are clinical signs of hypercortisolism
HPT
cardiac hypertrophy
hyperglycaemia (T2DM)
depression
insomnia
what is hypopituitarism
when the pituitary does not produce a number of pituitary hormones
A 60 year old man with Acromegaly has been under the care of the neurosurgeons for a pituitary operation to remove his pituitary tumour. 3 months after the operation he starts to become symptomatic with sweats, raised glucose levels and headaches. He is found to still be biochemically producing excess growth hormone. Which of the following medication types would be the best first line to treat his condition?
somatostatin analogues
eg octreotide are used 1st line generally to control excess GH - they work by blocking GH production
how does cortisol increase plasma glucose
inhibits insulin-mediated glucose disposal
can often get DM with Cushings
A 48 year old woman presents to her GP with newly diagnosed type 2 diabetes. She also describes central weight and sweats. Her mood has been irritable for several months and she feels generally weak, tired and run down even after she has been started on oral hypoglycaemic medication and her glucose levels normalise.
Which of the following is the best initial investigation?
suspect cushings >
overnight dexamethasone test
*screening = key word
