Endo - Hypopituitarism Flashcards

1
Q

The anterior pit is …. in origin
The posterior pit is …. in origin

A

glandular
neural

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2
Q

The five anterior pituitary hormones ?

A
  • Somatotrophin
  • Prolactin
  • TSH
  • LH and FSH
  • ACTH
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3
Q

hypothalamo releasing /inhib factors travel in …. to ant pit

A

portal circulation

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4
Q

Primary hypothyroidism vs secondary ?

A
  1. eg autoimmune destruction of thyroid gland - TSH inc TRH inc, T3 + T4 fall
  2. eg pit tumour damaging thyrotrophs (ant pit that releases TSH) TSH falls, T3 + T4 fall
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5
Q

Primary vs secondary hypoadrenalism

A
  1. eg destruction of adrenal cortex , CRH inc, ACTH inc, cortisol falls
  2. eg pit tumour damaging corticotrophs, can’t make ACTH which falls, cortisol falls
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6
Q

Primary vs secondary hypogonadism?

A
  1. eg destruction of testes, GnRH inc, LH and FSH inc, testos, oes and prog fall
  2. eg pit tumour damaging gonadotrophs , can’t make LH and FSh which fall, testos etc falls
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7
Q

Congenital causes of hypopituitarism ?

A

Congenital

  • rare
  • result of mutations of transcrip factors for ant pit developm
  • deficient in GH so short and one other aph
  • hypoplastic - ant pit underdeverloped on MRI
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8
Q

Acquired

A
  • tumours
  • radiation
  • infection
  • traumatic brain injury
  • pit surgery
  • inflam (hypophytis)
  • pit apoplexy
  • peri partum infarction (Sheehan’s syndrome)
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9
Q

What is pituitary apoplexy ? dramatic in those with ? preceipitated by ? symp?

A

Haemorrhage or less commonly infarction

dramatic in patients with pit adenomas (can be first sign)

can be precipitated by anticoagulants

severe sudden onset headache

bitemp hemianopia

cavernous sinus involve- diplopia, ptosis

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10
Q

what is Hypopituitarism

A
  • ant (most often) or post pit dysfunction
  • post pit dysf usually as result of inflam or surgery
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11
Q

What is panhypopituitarism

A

total loss of ant and post pit function

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12
Q

radiotherapy induced hypopituitarism occurs due to …..

radiotherap can be … or … to pit

extend depends on

which part of ant pit most sensitive ?

What increases after radiotherapy

What is recommended with radiotherapy ?

A

pit and hypothalamus both sensitive to radiation

direct or indirect

dose

GH and gonadatrophin

Prolactin due to loss of hypothal dop

risk stays for 10 years after radiot so annual assessment

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13
Q

presentations of hypopituitarism with FSH /LH

A

FSH /LH

  • reduced libido
  • 2* amenorhhea
  • erectile dysfunction
  • redcued pubic hari
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14
Q

Hypopit presentation ACTH

A

fatigue

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15
Q

hypopit presentation with TSh

A

fatigue

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16
Q

hypopit presentation with Gh

A

reduced qol

(short stature only in kids)

17
Q

hypopit presentation with prolactin

A

Inability to breastfeed

18
Q

what is sheehan’s syndrome ?

A
  • hypotension during or after birth (post partum haemorrage which can lead to pituitary infarction) - low bp / severe blood loss
  • ant pit enlarges in pregnancy (lactotroph hyperplasia)
  • so blood loss will destroy hormone producing tissue
  • causing post partum hypopituitarism
19
Q

DOEs sheehans affect both ant and post pit ?Why?

A

Blood supply affected so post pit not usually affected

20
Q

BEst way to visualise pit gland ?

A

MRI

21
Q

Symptoms of sheehans syndrome

A
  • lethargy , anorexia, weight loss due to TSH/ ACTH/ GH deficiency
  • failure to lactate - prl defic
  • no periods after delivery
22
Q

WHy is biochem diagnosis of hypopit difficult ?

A

cortisol - dependent on time of day

FSH /LH - cyclical

CH/ACTH - pulsatile

23
Q

how do we diagnose hypopit?

A
  • biodynamic pit funciton test (series of hormone measurements over series of time pts)
  • radilogically via pit MRI
24
Q

Dynamic tests for hypopit ?

A

Trigger pit hormones to be produced - if hypopit levels stay low

ACTH & GH

  • insulin induce hypoglycaemia (<2.2)
  • induces stress
  • stress hormones released- ACTH (cortisol measured) & GH
  • low in hypopit

TSH

  • TRH stimulates TSH release

FSH/LH

  • GnRH stimulates FSH/LH release
25
Q

WHy pit MRI not CT ?

A

CT not good at seeing whole pit

26
Q

WHat can pit MRI reveal ?

A

pathology

eg haemorrhage (apoplexy) , adenoma

can have empty sella - little pit tissue

27
Q

which hormones cant be topped up in hypopit ?

A

prolactin

28
Q

TReatment of GH deficiency?

A

assess QOL using questionnaire

poor QOL –> daily injection

Measure response by improved;

  • QOL
  • plasma IGF-1
29
Q

Treatment of TSH deficiency ?

What should you not do when adjusting dose?

aim for …

A

levothyroxine (T4) 1x day

Don’t use TSH to adjust dose of levo in 2* hypothyroidism as you do in 1* because TSh is always low

Aim for T4 above middle of ref range

30
Q

Treatment of ACTH deficiency?

why might it be difficult to treat?

A

replace cotisol instead of ACTH

hard to mimic diurnal rhythm of cortisol

Two options:

  • prednisolone 1x day
  • hydrocortisone 3 x day
31
Q

Sick day rules ?

A

those with Addisons at risk of adrenal crisis triggered by intercurrent illness

adrenal crisis :

  • dizziness
  • vomiting
  • hypotension
  • weakness

sick day rules :

  • steroid alert pendant
  • double steroid dose (gluco not mineralo) if intercurr illness/fever
  • unable to take tablets - inject IM or A&E
32
Q

Treatment of FSH/LH in men where no fertility required ?

A
  • replace testosterone topically / intramuscularly
  • Measure plasma testos
  • testos won’t restore sperm production (depends on FSH)
33
Q

Treatment of FSH/LH in men where fertility required ?

best response if ?

A

trigger spermatogenesis via gonadotrophin injections

measure testos and analyse semen

sperm production : 6-12 months

best response if 2* hypogonadism develops after puberty

34
Q

Treatment of FSH /LH defic where no ferility required ?

when would you need additional progesterone?

A

replace oestorgen

oral /topical

need progesterone if intact uterus - prevent endometrial hyperplasia

35
Q

Treatment for FSH/LH deficiency when fertility is required

A

specially timed gonadotrophin injections