Cushing's, Hypopituitarism and Diabetes Insipidus Flashcards Preview

The Endocrine System > Cushing's, Hypopituitarism and Diabetes Insipidus > Flashcards

Flashcards in Cushing's, Hypopituitarism and Diabetes Insipidus Deck (38)
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1
Q

Cushing’s syndrome is cause by what?

A

Excess cortisol

2
Q

Ass well as cortisol excess, what else is found in excess in Cushing’s syndrome?

A
  1. Androgens
  2. Mineralocorticoids
3
Q

What is the result of excess androgens in Cushing’s syndrome?

A
  1. Virilism
  2. Hirsutism
  3. Acne
  4. Oligo/amenorrhoea
4
Q

What is the result of excess mineralocorticoid in Cushing’s syndrome?

A
  1. Hypertension
  2. Oedema
5
Q

Due to altered carbohydrate and lipid metabolism in Cushing’s syndrome, there is an associated with which two conditions?

A
  1. Diabetes
  2. Obesity
6
Q

What are the conditions associated with protein loss experienced in Cushing’s syndrome?

A
  1. Myopathy
  2. Osteoporosis
  3. Thin skin
7
Q

Why does hypertension occur in Cushing’s syndrome?

A

Excess mineralocorticoid causes Na+ and K+ retention

8
Q

Does Cushing’s syndrome have an impact on mental health?

A

Yes

Altered psyche, psychosis and depression

9
Q

Which type of myopathy is associated with Cushing’s syndrome?

A

Proximal myopathy

10
Q

Why may obesity have a postitive outcome in Cushing’s syndrome?

A

Obesity increases bone desnity counteracting an increased osteoporosis risk

11
Q

How may thin skin present in Cushing’s syndrome?

A
  1. Bruising
  2. Striae
12
Q

By which eye sign can Cushing’s disease be characterised?

A

Conjunctival oedema (chemosis)

13
Q

Frontal balding in women is a sign of which condition?

A

Cushing’s syndrome

14
Q

Which complication must not be forgotten when assessing any fractures to the femoral head/hip in patients with Cushing’s syndrome?

A

Avascular necrosis

15
Q

When Cushing’s syndrome is suspected, which test would be done first?

A

Steroid suppression test

e.g. Dexamethasone

(a urine free cortisol test can also be done)

16
Q

What is the expected outcome in a steroid suppression test assuming the patient achieves a normal result?

A

Reduced cortisol levels

17
Q

Which screening tests exist to test for Cushing’s disease?

A
  1. Steroid suppression with dexamethasone (1mg at night then test cortisol in the morning, <50nmol/l normal, >100nml/l abnormal)
  2. Urine free cortisol (total <250 normal, cortisol/creatinine ratio <25 normal)
  3. Diurnal cortisol variation (midnight vs 8am)
18
Q

What is the definitive test for Cushing’s syndrome?

A

2 day 2mg/day low dose dexamethasone suppression test

Cortisol <50nmol/L 6 hours after the last dose confirms no Cushing’s

19
Q

Most Cushing’s has what cause?

A

Pituitary tumour

(in these instances the condition is referred to as Cushing’s disease)

20
Q

What are the main causes of Cushing’s syndrome?

A
  1. Pituitary tumour
  2. Adenoma of adrenal glands
  3. Ectopic cortisol release from the thymus, lung or pancreas
21
Q

Pseudo-Cushing’s has what causes?

A
  1. Alcohol
  2. Depression
  3. Steroid medication
22
Q

Can the cause of Cushing’s (pituitary tumour, ectopic cortisol release, adrenal adenoma) be determined from a low dose dexamethasone cortisol suppression test?

A

No

All of these will show an abnormal result

23
Q

Can the cause of Cushing’s (pituitary tumour, ectopic cortisol release, adrenal adenoma) be determined by measuring ACTH levels?

A

Yes/Potentially

  • Pituitary tumour - ACTH is raised (<300)
  • Adrenal adenoma - ACTH is decreased (<1)
  • Ectopic cortisol release - is raised (>300)
24
Q

Can the cause of Cushing’s (pituitary tumour, ectopic cortisol release, adrenal adenoma) be determined from a high dose dexamethasone cortisol suppression test?

A

Potentially

  • Pituitary - Cortisol suppressed by around 50%
  • Adrenal adenoma - No change
  • Ectopic cortisol release - No change
25
Q

Which arteries pass by either side of the pituitary gland?

A

Internal carotid arteries

26
Q

What are the treatment options for pituitary tumour causing Cushing’s disease?

A

Hypophysectomy

(external radiotherapy if recurrence)

27
Q

What is the treatment for Cushing’s disease if the cause is a adrenal tumour?

A

Uni or bilateral adrenalectomy

28
Q

Pan hypopituitarism is a condition involving what?

A

Inadequate or absent production of anterior pituitary hormones

29
Q

What are the main causes of hypopituitarism?

A
  1. Pituitary tumours
  2. Secondary metastatic tumours
  3. Local brain tumours
  4. Granulomatous disease
  5. Vascular diseases
  6. Hypothalamic diseases
  7. Iatrogenic
  8. Autoimmune
  9. Infection
30
Q

Which type of granulomatous disease may be associated with hypopituitarism?

A
  1. TB
  2. Histiocytosis X
  3. Sarcoidosis
31
Q

What are the signs and symptoms of hypopituitarism?

A
  1. Menstrual irregularities
  2. Infertility/impotence
  3. Gynaecomastia
  4. Central obesity
  5. Loss of facial hair
  6. Loss of axillary and pubic hair
  7. Dry skin and hair
  8. Hypothyroid faces
  9. Growth retardation in children
32
Q

What are the replacement therapy options of hypopituitarism?

A

Thyroxine 100-150mcg

Hydrocortisone 10-25mg

Desmospray (nasal) or tablets - ADH

GH nightly SC - GH

HRT/Oestrogen/Progesterone - Females

Testosterone - Males

33
Q

Growth hormone in adults has which positive effects?

A
  1. Decreases abdominal fat
  2. Increases muscle mass and strength
  3. Improves cardiac function
  4. Decreases cholesterol and LDL
  5. Increases bone density
34
Q

What are the risks of testosterone replacement?

A
  1. Prostate enlargement
  2. Polycythaemia
  3. Hepatitis (only oral tablets)
35
Q

What is polycythaemia?

A

When the bone marrow produces exessive quantities of red cells

36
Q

What are the common causes of diabetes insipidus?

A
  1. DIDMOAD
  2. Idiopathic
  3. Trauma
  4. Rare causes - tumour, sarcoid, external irradiation, meningitis
37
Q

How can diabetes insipidus be diagnosed?

A

Water deprivation test

38
Q

What is the treatment for diabetes insipidus?

A

Desmopressin (an antidiuretic)

Desmospray, desmopressin oral tablets, desmopressin IM injection