cushings syndrome Flashcards
define Cushing syndrome
Increased levels of cortisol in the body which leads to adverse symptoms
what are the two ways that the cortisol levels in your blood can increase?
- ACTH-dependent
2.ACTH-independent
what do ACTH- dependant causes revolve around?
increased ACTH release which stimulates the adrenal glands to release cortisol
what can ACTH dependant Cushings be due to?
a pituitary adenoma which releases excess ACTH (Cushing’s Disease), ACTH therapyor due to ectopic ACTH release.
what are two examples of ACTH independent cushings syndrome?
-taking too many exogenous steroids
-an adrenal adenoma that releases too much cortisol.
describe pesudo cushings
- has similar features to cushings
- has increased cortisol
what are the complications of Cushing syndrome?
-Osteoporosis
-T2DM
-Hypertension
-ischaemic Heart Disease (Angina
what can pseudo cushings be due to?
can be due to alcohol excess, depression, obesity and pregnancy
what can pseudo cushings result in during diagnosis? how do you differentiate this?
It can result in a false positive in diagnosis, but it can be differentiated with an insulin stress test.
what are the signs of cushings syndrome?
-Central Obesity
-Moon Face
-Abdominal Striae
-Buffalo Hump
-Ecchymoses and Fragile skin
-Hypertension
what are the symptoms of Cushing syndrome?
-Weight gain
-Mood change
-Menstrual irregularity
-Reduced libido
-Hyperglycaemia
-Increased susceptibility to infection
how is Cushing syndrome diagnosed?
- the DEXAMETHASONE SUPRESSION TEST**
- a PLasma ACTH test
what does the dexamethasone suppression test tell you when diagnosing cushings syndrome?
Normally it should be suppressed but in Cushing’s it is not.
what are the three types of dexamethasone suppression tests when diagnosing cushings syndrome?
- low dose overnight
- low dose 48 hrs
- high dose 48 hrs
what is the low dose overnight test done for when diagnosing cushings syndrome?
screening test to exclude cushings
when is the low dose 48hrs test done when diagnosing cushings syndrome?
used when cushings is suspected
when is the high dose 48 hrs test done when diagnosing cushings syndrome?
Used to confirm the cause of Cushing’s
what does a plasma ACTH test tell you when diagnosing cushings syndrome?
tell you the levels of ACTH:
-If it is high, the cause is ACTH-dependent
- if it is low, it is independent.
what is the treatment for Cushings syndrome when cushings disease is the cause?
Transsphenoidal Tumour or Bilateral Adrenalectomy
what is the treatment for Cushings syndrome when adrenal adenomas are the cause?
Tumour Resection or Unilateral Adrenalectomy
what is the treatment for Cushings syndrome when a tumour releasing ACTH ( SCLC) is the cause?
Surgical removal of the tumour
what is a complication of the treatment for Cushings syndrome?
Nelson’s syndrome
what is nelsons syndrome?
where an ACTH pituitary tumour develops due to negative feedback and lack of cortisol
what does nelsons syndrome results is?
in skin pigmentation and bitemporal hemianopia.
when can nelsons syndrome occur?
due to bilateral adrenalectomy
what should the dexmaethasone suppression test look like in a normal person?
low dose 48hrs - low
high dose 48hrs- low
ACTH- normal
what should the dexmaethasone suppression test look like with a pituitary adenoma?
low dose 48hrs - not suppressed
high dose 48hrs- low
ACTH- high
what should the dexmaethasone suppression test look like with a adrenal adenoma?
low dose 48hrs - not suppressed
high dose 48hrs- not surpassed
ACTH- low
what should the dexmaethasone suppression test look like with ectopic ACTH?
low dose 48hrs - not suppressed
high dose 48hrs- not surpassed
ACTH- high
what drug is used to treat Cushings?
metyrapone- reduces cortisol
when is a low dose dexamethasone and a high dose dexamethasone test done?
LOW DOSE- to confirm your diagnosis of cushings
HIGH dose- to see whether its pituitary or ectopic ACTH release
