Hypopituitarism Flashcards
(24 cards)
What are the hormones of the anterior pituitary?
Growth Hormone Prolactin Thyroid stimulating hormone Luteinising hormone Adrenocorticotrophic hormone
What is primary gland failure?
The gland itself fails/ is damaged due to an autoimmune condition
What is secondary gland failure?
There are no signals from the hypothalamus or anterior pituitary to the gland
What are the expected hormone levels of TSH and T3/T4 during primary hypothyroidism?
eg. Autoimmune destruction of the thyroid gland - low T3/T4 and high TSH (lack of inhibition via neg. feedback)
What are the expected hormone levels of TSH and T3/T4 during secondary hypothyroidism?
eg. Pituitary adenoma - low TSH as thyrotrophs are damaged and thus low T3/T4 (no TSH to stimulate its production)
What are the expected hormone levels of ACTH and cortisol during primary hypoadrenalism?
eg. Destruction of the adrenal cortex - low cortisol and high ACTH (lack of inhibition)
What are the expected hormone levels of ACTH and cortisol during secondary hypoadrenalism?
eg. Pituitary tumour damaging corticotrophs - low ACTH and thus low cortisol
What are the expected hormone levels of FSH/ LH and testosterone/ oestrogen during primary hypogonadism?
eg. destruction of the testes (mumps) or destruction of ovaries (chemo) - testosterone/ oestrogen low and high LH/ FSH
What are the expected hormone levels of FSH/ LH and testosterone/ oestrogen during secondary hypogonadism?
eg. Pituitary tumour damaging gonadotrophs- low LH/ FSH and thus low LH/ FSH
What are two categories of causes of hypopituitarism?
Congenital and Acquired
What is an example of the mechanism of congenital hypopituitarism?
PROP1 mutation - mutation of the transcription factor genes for the normal development of anterior pituitary - leads to deficiency in GH and at least one more hormone
What are examples of acquired hypopituitarism?
Tumours Radiation Infection - meningitis Peri-partum infaction (Sheehan's syndrome) Pituitary apoplexy
Which hormones are most sensitive to radiotherapy
gonadotrophins and GH
How does low FSH/ LH present?
Reduced libido
Secondary amenorrhea
Erectile dysfunction
Reduced pubic hair
How does low ACTH present?
Fatigue
How does low TSH present?
Fatigue
How does low Gh present?
reduced quality of life
Short stature in children
How does low prolactin present?
Inability to breastfeed
How is Sheehan’s syndrome caused?
Post-partum haemorrhage leads to hypotension. The anterior pituitary is enlarged during pregnancy due to lactotroph hyperplasia and in its enlarged state, the drop in BP leads to pituitary infarction and subsequent loss of pituitary function
What are symptoms of Sheehan’s syndrome?
Lethargy
Anorexia
Weight loss
TSH/ ACTH deficiency
Failure of lactation (prolactin deficiency)
Failure to resume menses post delivery (longer than usual)
Note: posterior pituitary not usually affected
How can Sheehan’s syndrome be treated?
HORMONE REPLACEMENT:
Levothyroxine for TSH deficiency (use fT4 to adjust dose)
Prednisolone/ hydrocortisone for ACTH deficiency (MUST BE TOLD SICK DAY RULES)
Oestrogen + progesterone (oral/ topical) - if fertility is required, must take FSH/ LH injections
GH injections after deficiency identified + QoL questionnaire indicated its need
How is pituitary apoplexy caused?
Intra-pituitary haemorrage or infarction
Usually caused by a bleed into an existing pituitary tumour
Can be precipitated by anti-coagulants such as warfarin
What are symptoms of pituitary apoplexy?
Severe sudden onset headache
Vision issues – bitemporal hemaniopia (compressed optic chiasm)
Diplopia (see two images of the same thing )/ ptosis (drooping or falling of the upper eyelid) if cavernous sinus is involved
How can pituitary apoplexy be treated?
Severe: requires surgery to relieve pressure on pituitary gland/ improve vision impairment
Less severe: conservative management – hormone replacement and regular check ups
Cortisol replacement (prednisolone/ hydrocortisone) to reduce swelling and treat ACTH deficiency
