Hypopituitarism Flashcards
Which hormone is released from somatotrophs?
Growth hormone
What hormones are released by the anterior pituitary gland?
- Growth hormone
- Prolactin
- Thyroid stimulating hormone (TSH)
- Luteinising hormone (LH) and Follicle stimulating hormone (FSH)
- Adrencorticotrophic hormone (ACTH)
Which glands can fail resulting in endocrine hormone deficiencies?
Thyroid gland
adrenal cortex
gonads
Pituitary gland
What are the hormone levels in primary hypothyroidisim?
T3 and T4 deficiency
TSH increases
What are the hormone levels in secondary hypothyroidism?
Insufficient TSH secretin causing downstream reduction in T3 and T4.
Which hormone is regulated by ACTH?
Cortisol
A cortisol deficiency will lead to an increase in which hormone?
ACTH
What is an example of secondary hypoadrenalism?
Pituitary tumour damaging corticotrophs
What are the common causes of primary hypogonadism?
Trauma Mumps (destruction of testes) Chemotherapy (ovaries).
Which mutation is concerned with congenital hypopituitarism?
PROP1 mutation (transcription factor required for anterior pituitary development)
A pituitary MRI will reveal what type of gland abnormality in congenital hypopituitarism?
Hypoplastic (underdeveloped)
What are the associated causes of acquired hypopituitarism?
- Adenomas, metastases, cysts
- Radiation (Hypothalamic/pituitary damage)
- Infection (meningitis)
- Traumatic brain injury
- Pituitary surgery
- Inflammation (hypophysitis)
- Pituitary apoplexy (haemorrhage)
- Peri-partum infarction (Sheehan’s syndrome)
What is panhypopituitarism?
Total deficit in anterior and posterior pituitary gland function
Which types of hormones are most sensitive to radiotherapy?
Growth hormones and goadotrophins
Prolactin (loss of hypothalamic dopamine)_
Why can prolactin increase in during radiotherapy?
Loss of hypothalamic dopamine
What are the common presentation of hypogonadism?
- Reduced libido
- Secondary amenorrhoea
- Erectile dysfunction
- Reduced pubic hair
What are the common presentations of an ACTH deficit?
- Addison’s disease (Not salt losing)
- fatigue
What causes post-partum hypopituitarism?
Hypotension associated with a post-partum haemorrhage, this can lead to a pituitary infarction (obstruction to blood supply to pituitary tissue)
What type of hyperplasia occurs during pregnancy within the anterior pituitary gland?
Lactotroph hyperplasia.
What are the symptoms of Sheehan’s syndrome?
Lethargy, anorexia, weight loss- TSH/ACH/GH deficiency
- Failure of lactation - Prolactin deficiency
- Failure to resume menses post delivery
What is a pituitary apoplexy?
Intra-pituitary haemorrhage or infarction
-Can be precipitated by anti-coagulants.
What are the associated symptoms with a pituitary apoplexy?
- Severe sudden onset headache
- Visual field defect compressed optic chiasm - bitemporal hemianopia
- Cavernous sinus involvement may lead to diplopia (IV, VI), ptosis (III)
Which hormones are released by the anterior pituitary gland in response to hypoglycaemia (<2.2mM)?
GH
ACThH
-Insulin-induced hypoglycaemia stimulates this release
What are the radiological diagnoses of hypopituitarism?
Empty sella, thin rim of pituitary tissue.
What is the available treatment for a growth hormone deficiency?
growth hormone replacement
How are the effects of growth hormone replacement therapy measured?
Improvement in the quality of life
Measure plasma IGF-1
What is the treatment for a TSH deficiency?
Levothyroxine (Aim for fT4 above the middle of the reference range)
How is an ACTH deficiency managed?
Cortisol replacement
Prednisolone (once daily AM)
Hydrocortisone (thrice daily)
What are the clinical features of an adrenal crisis?
Hypotension, dizziness, vomiting, weakness and potential collapse/death.
What are the sick day rules for patients who take prednisolone/hydrocortisone?
steroid alert pendant
Double steroid dose if fever/intercurrent illness
-Inject Intramuscularly or attend A&E if unable to orally take medication (vomiting)
How can an FSH/LH deficiency be treated in males without the desirability for fertility?
Replace testosterone through intramuscular injections (measure plasma testosterone)
-This does not restore sperm production (endogenous testosterone is required within the seminiferous tubules)- dependent on FSH.
How can male fertility be restored in patients with a FSH/LH deficiency?
Gonadotropin injections (Sperm production may take 6-12 months)
Ideal response after puberty (secondary hypogonadism)
How can an FSH/LH deficiency be treated in patients not requiring fertility?
Replace oestrogen (Orally or topically) \+Progesterone to prevent endometrial hyperplasia of uterus.
