Cushings syndrome

Question 1

What electrolyte imbalance does cushings syndrome cause

Answer 1

Hypokalemic metabolic alkalosis

Question 2

What is cushings syndrome caused by

Answer 2

Cortisol excess

Question 3

Why does cushings cause hypokalemia

Answer 3

Cotisol -> stimulates aldosterone, increases Na+ and water retention - increases K+ excretion

Question 4

Electrolyte imblanaces in cushings

Answer 4

High bicarb - pH alkalosis
low potassium

Question 5

When do you do dynamic testing for hormones

Answer 5

Hormone is lacking - stimulate
Hormone being produced in excess - supress

Question 6

Thyroid horomone cycle

Answer 6

Hypothalamus -> TRH ->pituitary -> TSH -> thyroid -> T4 +T3
Somatostatin + dopamine from hypothalamus inhibit TSH release from pituitary

Question 7

How assess thyroid function

Answer 7

measuring TSH, free T4 and free T3

Question 8

Primary hyperthyroidism on bloods

Answer 8

Too much free T4 - supressed TSH

Question 9

Cushing syndrome vs disease

Answer 9

Syndrome = clinical features
Disease = features + piuitary source

Question 10

Where do aldosterone vs cortisol originate

Answer 10

Mineralcorticoid -> aldosterone
Glucocorticoid - cortiosl

Question 11

Signs of cushings

Answer 11

Obesity - central, nuchal or SC fat pads, thin arms and legs
Plethora - red
Moon face
Extensive striae
Decreased libido Menstrual changes
Hirsutism
HPTN
Ecchymoses - extensive skin brusining
Poor healing, skin fragility
Lethargy, depressionn
Abnormal glucose toleranec
Decreased libido
Dorsal kyphosis

Question 12

Types of cushings syndrome

Answer 12

ACTH dependent and independent

Question 13

What causes cushings disease

Answer 13

Pituitary tumours -> ACTH
ACTH dependent

Question 14

What auses cushings syndrome

Answer 14

Adrenal adenoma -> cortisol
ACTH independent

Question 15

Why do midnigth cortisol in cushings

Answer 15

Normlaly lowest at this point - in cushings loss of diurnal variation

Question 16

Investigations for cushings

Answer 16

Elevated 24 hour urinary free cortiosl exretion
Overnight 1mg dex supression test
Plasma cortisol

Question 17

What test for in 24 hour urine cortiols excretion

Answer 17

Cortisol:creatinine ratio

Question 18

How do dex supresson test + positive results

Answer 18

give 1mg dex at 11pm
Test at 9am
Cushings if 9am cortisol not supressed eg >50

Question 19

What investigations do if undetectable ACTH

Answer 19

Suggests adrenal pathology -> adrenal imaging - CT scan

Question 20

What investigation do if dectabel ACTH

Answer 20

48 hour high dose dex supress test

Question 21

How do 48 hours high dose dex supression test

Answer 21

2mg dex every 6 hours - 8am, 2pm, 8pm, 2am
If <50% basal value after 48 hours (50-90% accepted) means supression

Question 22

What does supression on high dose 48 hr dex test but not overnigth suggest

Answer 22

Pituitary cushings disease -> pituiatry MRI

Question 23

What does elevation in both overnigth and high dose dex supressiont ests suggest

Answer 23

Extopic ACTH production or adrenal tumours

Question 24

Pr op management in cushings

Answer 24

Lower cortisol - imporve wound healing and tissue repair
Meyrape
Ketoconazole

Question 25

What can ketoonazole cause

Answer 25

Addisons disease

Question 26

What is the deficinitve treatment for cushings disease

Answer 26

Surgery - transsphenoidal for pituitary tumours -> radiotherapy if not cured Adrenal tumours - laparascopic or open adrenalectomy

Question 27

What can low dose overnight dex supression test tell you

Answer 27

if there is abnormal cortisol secretion.

Question 28

What can high dose dex supression 48 hour test tell you

Answer 28

Excess cortiols due to adrenal glands - syndrome, not supressed OR ACTH high levels from pituitary - disease, supressed

Question 29

Electrolytes in cushings

Answer 29

Low potassium - gluco+mineralcorticoid excess action -> K+ loss HYPOKALEMIC METABOLIC ALKALOSIS

Question 30

Excess cortisol ->

Answer 30

weight gain, muscle weakness, high blood pressure, diabetes, and osteoporosis.

Question 31

What is cuhsings disease

Answer 31

Exces cortisol BUT specifically from ACTH secreting pituitary adenoma

Question 32

Musculoskeletal manifestations of cushigns disease

Answer 32

Prozima myopathy hip - hide rising from seat Osteopenia +osteoporosis - increased fracture rsik esp vertebral compression Avascular necoriss of femoral head

Question 33

Derm features of cushings

Answer 33

Hirsutism, acne, seborrheic dermatitis, thin skin, poor wound healing

Question 34

Endocrine symptoms cushings

Answer 34

Glucose intolerance or T2DM Mentrual irregularities - oligo or amenorrhea, decreased libido and ED HPG acis supressed

Question 35

Neuropsych in cushings

Answer 35

Depression, anxiety, irritability, emotional lability, and cognitive deficits such as impaired memory or concentration Sleep disturbances including insomnia or hypersomnia

Question 36

CVS complications from cushgins

Answer 36

HPTN - sodium retntion Increased VTE risk - hypercoagulable

Question 37

Children concerns in scushings

Answer 37

n children, growth retardation may occur due to cortisol-mediated suppression of growth hormone secretion Precocious puberty may be observed in some cases

Question 38

What is ectopic ACTH secretion (eg small cell lung cancer) ass with?

Answer 38

Very low K+ levels

Question 39

Will both cortisol and ACTH be supressed in cushings disease in high dose dex supress test

Answer 39

Yes

Question 40

Which condition is both cortisol and ACTH not supressed in high dose dex test

Answer 40

Ectopic ACTH

Question 41

First line to third line of cushings disease

Answer 41

First-line = trans-sphenoidal removal of pituitary tumour (hypophysectomy) Second-line = repeat trans-sphenoidal surgery, pituitary radiotherapy Third-line = bilateral adrenalectomy

Question 42

Complications of bilateral adrenalectomy

Answer 42

Hypoadrenal crisis - addisons lifelong treat Nelsons syndrome

Question 43

Nelsons syndrome

Answer 43

Bilateral adrenectomy -> pituitary enlargement -> mass effects nad skin hyperpigmenetation AKAjust get cushings again