Endo - Hypopituitarism

Question 1

What is primary and secondary hypopituitarism?

Answer 1

Primary - Gland itself fails and doesn’t produce enough hormones

Secondary - No signals from hypothalamus or anterior pituitary gland

Question 2

What is the difference between primary and secondary hypoadrenalism?

Answer 2

Primary:

• Autoimmune destruction of the adrenal cortex
• Cortisol falls and ACTH increases to try and increase cortisol levels

Secondary:

• Pituitary tumour damaging corticotrophs
• Can’t make ACTH
• ACTH falls, cortisol falls

Question 3

What is the difference between primary and secondary hypothyroidism?

Answer 3

Primary:

• Autoimmune destruction of the thyroid
• T3 & T4 fall, TSH increases to try and counteract this

Secondary:

• Cant make TSH
• TSH falls
• T3 & T4 also fall due to this

Question 4

What is the difference between primary and secondary hypogonadism?

Answer 4

Primary:

• Destruction of testes or ovaries
• Testosterone or oestrogen fall, LH and FSH increase

Secondary:

• Pituitary tumour damaging gonadotrophs for example
• Cant make LH & FSH
• LH & FSH fall and then testosterone or oestrogen fall

Question 5

What are the congenital causes of hypopituitarism and why is it easily spotted at a young age?

Answer 5

• RARE
• Usually due to transcription factor genes needed for anterior pituitary development
• Easily spotted at a young age as lack of GH(growth hormone) has very obvious results, short stature

Question 6

What are the acquired causes of hypopituitarism?

Answer 6

• Tumours
• Radiation
• Infections, eg meningitis
• Traumatic brain injury
• Inflammatory(hypophysitis)
• Sheehan’s syndrome

Question 7

What are the presentations of hypopituitarism?

Answer 7

FSH/LH:

• Reduced libido
• Secondary ammenorrhoea
• Erectile dysfunction
• Reduced pubic hair

ACTH:

• Fatigue
• Weight loss

TSH:
- Fatigue

GH:

• Reduced quality of life
• NB short stature only in children

Prolcatin:
- Inability to breastfeed

Question 8

What is Sheehan’s syndrome?

Answer 8

During pregnancy, the pituitary gland grows so that there are more lactatrophs for preparation to breastfeed
If a lot of blood is lost during child birth (post partum haemorrhage), there can be a reduction in the amount of blood reaching the enlarged pituitary gland resulting in pituitary infarction
Relevant hormones are not produced as much anymore

Question 9

What is pituitary apoplexy?

Answer 9

• Intra-pituitary haemorrhage (or, less commonly, infarction)
• Often dramatic presentation in patients with pre-existing pituitary tumours (adenomas
• Can be precipitated by anti-coagulants

Question 10

What are the effects of pituitary apoplexy?

Answer 10

• Severe sudden onset headache
• Visual field defect - compressed optic chiasm, bitemporal hemianopia
• Cavernous sinus involvement may lead to diplopia (IV, VI), ptosis (III)

Question 11

How do you diagnose hypopituitarism?

Answer 11

Blood tests, but have to analyse with caution:

• Cortisol: What time of the day is it?
• T4: Circulating T4 has a half life of 6 days
• FSH/LH: Cyclical in women
• GH/ACTH: Pulsatile
• Give patient insulin to induce hypoglycaemia, which is an induced stress on the body#
• Results in release of ACTH and GH
• ACTH should cause increased cortisol levels which can be measured and then see if the person can produce the hormones or not
• Do this multiple times

Question 12

What are the treatments for hypopituitarism?

Answer 12

Can give:
GH - give replacement
TSH - give thyroxine, aim for fT4 above the middle range
LH & FSH
ACTH - 1xPrednisolone or 3xHydrocortisone
CANNOT give Prolactin