Cushing's

Question 1

What is Cushing’s syndrome?

Answer 1

An endocrine disorder which occurs when your body makes too much cortisol

Question 2

Symptoms of Cushing’s syndrome?

Answer 2

Weight gain
Easy bruising
Depression, insomnia 

Muscle weakness
GI changes

Question 3

Signs of Cushing’s syndrome?

Answer 3

Moon face
Buffalo hump
Abdominal striae

Acne, hirsuitism, menstrual changes – virilisation
Osteoporosis 

HTN
Glucose intolerance  
Myopathy

Question 4

Investigations for Cushing’s?

Answer 4

U+E: hypokalaemia, hypernatraemia, metabolic alkalosis, hyperglycaemia

Low dose dexamethasone suppression test
High dose dexamethasone suppression test
ACTH levels

Question 5

What is the low dose dexamethasone suppression test?

Answer 5

1mg dexamethasone at 11pm

Measure cortisol levels at 9am next day

Question 6

How to understand low dose dexamethasone suppression test results?

Answer 6

If cortisol low = normal

If cortisol raised = Cushing’s syndrome

Question 7

What is the low dose dexamethasone suppression test used for?

Answer 7

To diagnose Cushing’s syndrome

Question 8

What is the high dose dexamethasone suppression test?

Answer 8

8mg dexamethasone at 11pm

Measure cortisol levels at 9am next day

Question 9

How to understand low dose dexamethasone suppression test results?

Answer 9

If cortisol low = Cushing’s disease (pituitary adenoma)

If cortisol raised = ACTH levels

Question 10

What is the high dose dexamethasone suppression test used for?

Answer 10

To differentiate Cushing’s disease (pituitary adenoma) from Cushing’s syndrome

Question 11

What are ACTH levels used for?

Answer 11

ACTH levels determine whether the tumour is ectopic (ACTH dependent) or adrenal (ACTH independent)

Question 12

How to understand ACTH results?

Answer 12

ACTH low = adrenal tumour

ACTH high = ectopic tumour

Question 13

Management of Cushing’s?

Answer 13

Treat cause

Pituitary adenoma or adrenal tumour = surgery