Hyposecretion of anterior pituitary hormones Flashcards
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Name 6 hormones secreted by the anterior pituitary.
FSH
LH
Prolactin
GH
TSH
ACTH
What is the difference between primary and secondary endocrine gland disease?
secondary is caused by anterior pituitary disorder
primary caused by endocrine gland disorder.
Outline the endocrine chain of command.
hypothalamus –> anterior pituitary –> endocrine gland.
Define hypopituitarism.
Decreased production of all anterior pituitary hormones or some specific hormones.
congential/acquired
What causes congenital panhypopituitarism?
•Usually due to mutations of transcription factor genes needed for normal anterior pituitary development
e.g. PROP 1 mutation.
What is the result of congenital panhypopituitarism?
Deficiency of GH and at least one more APT hormone –> short stature
How is congenital panhypopituitarism diagnosed?
hypoplastic anterior pituitary gland on MRI
Name potential causes of acquired panhypopituitarism.
Tumours
- hypothalamic (craniopharyngiomas)
- pituitary )adenomas, metastases, cysts)
Radiation
-hypothalamic/pituitary damage (GH most vulnerable, TSH resistant)
Infection.
Traumatic brain injury
Infiltrative disease
Inflammatory (hypophysitis)
Pituitary apoplexy
- haemorrhage or infarction.
- pre-oartum infarction (Sheehan’s syndrome)
Give another name for Panhypopituitarism.
Simmond’s disease.
What causes the symptoms of panhypopituitarism. Give some examples.
Symptoms due to deficient hormones.
e.g. FSH/LH - secondary hypogonadism, reduced libido, secondary amenorrhea, erectile dysfunction.
ACTH - secondary hypoadrenalism (cortisol deficiency), fatigue.
TSH - secondary hypothyroidism, fatigue.
Explain Sheehan’s syndrome.
Describes post-partum hypopituitarism secondary to hypotension post partum haemorrhage.
Anterior pituitary enlarges in pregnenacy (lactotroph hyperplasia).
PPH –> pituitary infarction.
Give 4 ways Sheehan’s syndrome presents.
Lethargy, anorexia, weight loss - due to TSH/ATCH/GH deficiency.
Failure of lactation - PRL deficiency.
Failure to resume menses post delivery.
Posterior pituitary usually not affected.
What is pituitary apoplexy.
•Intra-pituitary haemorrhage or (less commonly) infarction
Give 2 things that may cause pituitary apoplexy.
Anti-coagulants.
Pituitary adenoma (can be the first presentation)
Label pituitary diagram.
Give 3 potential symtpoms of pituitary apoplexy.
Severe, sudden headache.
Visual field defect (compressed optic chiasm)
Diplopia (IV, VI) and ptosis (III) with cavernous isnus involvement.
Outline the limitations of using basal plasma concentrations to diagnose hypopituitarism.
Limited interpretation:
cortisol present.at low levels + fluctuates throughout day.
T4 has a hald life of 6 days in the blood: may last after function.
FSH/LH are cyclical.
GH/ACTH are pulsatile.
Outline how stimulated pituitary function tests work.
Induce stress then measure stress hormone levels (ACTH and GH).
Induce hypoglycaemia (>2.2mM) = ‘stress’ –> GH and ACTH release (measure cortisol).
TRH stimulates TSH
GnRH stimulates FSH and LH.
How can hypopituitarism be diagnosed radailogically.
Pituitary MRI.
Can reveal specific pituitary pathology.
Fill table showing deficient hormones, their replacements, and how to check.
What is an indicator of somatotrophin deficiency.
Short stature in children (2 SDs below mean height)
Less clear in adults.
GIve 7 causes of short stature in childre.
°Genetic
Down’s syndrome, Turner’s syndrome, Prader Willi syndrome
°Emotional Deprivation
°Systemic disease
Cystic Fibrosis, Rheumatoid arthritis
°Malnutrition
°Malabsorption
Coeliac disease
°Endocrine Disorders
Cushing’s syndrome, Hypothyroidism, GH deficiency, poorly controlled T1DM
°Skeletal dysplasias
Achondroplasia, osteogenesis imperfecta
Label growth axis diagram
What causes Prader Willi Syndrome.
GH deficiency secondary to impaired hypothalamic function.
