Hypopituitarism Flashcards
(8 cards)
Define
Deficiency of one or more of the hormones secreted by the anterior pituitary
Panhypopituitarism is deficiency of all pituitary hormones
They are affected in this order:
- Growth hormone
- Gonadotropins: FSH and LH
- Prolactin
- Thyroid-stimulating hormone (TSH)
- Adreno-corticotropic hormone (ACTH)
Causes
Hypothalamus: anorexia, starvation, over-exercise
- Pituitary masses: most commonly adenomas
- Pituitary trauma: radiation, surgery, skull base fracture
- Infiltration: TB, sarcoidosis, haemochomatosis
- Vascular: pituitary apoplexy, Sheehan’s syndrome
- Infection: meningitis, encephalitis
- Genetic mutations
Pituitary apoplexy: haemorrhage/ infarction of a pituitary tumour Life threatening – headache, visual loss, CN palsies
Sheehan’s syndrome: pituitary infarction, haemorrhage and necrosis following post-partum haemorrhage
Epidemiology
pituitary adenomas 9/100 000
Causes
Depends on CAUSE
Symptoms and signs are dependent on the hormone that is deficient:
GH
- CHILDREN: short stature
- ADULTS: low mood, fatigue, reduced exercise capacity and muscle strength, increased abdominal fat mass
LH or FSH
- Delayed puberty
- FEMALES: loss of secondary sexual hair, breast atrophy, menstrual irregularities, dyspareunia, decreased libido, infertility
- MALES: loss of secondary sexual hair, gynaecomastia, small and soft testes, decreased libido, impotence
ACTH - signs/symptoms of adrenal insufficiency
TSH - signs/symptoms of hypothyroidism
Prolactin - absence of lactation (not usually noticed clinically)
Pituitary Apoplexy has some other symptoms:
- Headache
- Visual loss
- Cranial nerve palsies
Investigation
Pituitary Function Tests
Basal Tests
- 9 am cortisol
- LH and FSH levels
- Testosterone levels
- Oestrogen levels
- IGF-1 levels
- Prolactin levels
- Free T4 and TSH levels
Dynamic Tests (rarely performed)
- Insulin-induced hypoglycaemic (should cause a rise in GH and cortisol)
Short synacthen test (for adrenal insufficiency)
MRI/CT of brain
Visual field testing
Management
Hormone Replacement
Hydrocortisone
Levothyroxine
Sex hormones
- Testosterone in males
- Oestrogen with/without progesterone in females
- Growth hormone
- Desmopressin (if central diabetes insipidus as a result of panhypopituitarism)
Complications
Addisonian crisis
Hypoglycaemia
Myxoedema coma
Infertility
Osteroporosis
Dwarfism (children)
Complications of pituitary mass:
- Optic chiasm compression (leading to bitemporal hemianopia)
- Hydrocephalus
- Temporal lobe epilepsy
Prognosis
GOOD prognosis with lifelong treatment
