Cushings, hypopituitarism and diabetes insipidus Flashcards
What is cushings syndrome?
Excess cortisol
What are the clinical manifestations of protein loss in cushings?
Proximal myopathy
Osteoporosis
Thin skin: striae, bruising
What are the clinical manifestations of altered carb/lipid metabolism in cushings?
Diabetes mellitus
Obesty
What are the clinical manifestations of altered psyche in cushings?
Psychosis
Depression
What are the clinical manifestation of excess mineralocorticoid activity in cushings?
Hypertension
Oedema
What are the clinical manifestations of excess androgen production in cushings syndrome?
Virilism
Hirsutsm
Acne
Oligo/amenorrhoea
How can you differentiate cushings from obesity?
Cushings: Thin skin Proximal myopathy Frontal balding Conjunctival oedema Osteoporosis
What is the test for cushings?
Exogenous dexamethasone which in normal people would result in a low serum cortisol
What are the screening tests for cushings?
Overnight 1mg dexamethasone suppression test: cortisol >100nmol/l cushings
Urine free cortisol (24hr urine collection): >250 abnormal, cortisol/creatinine ration >25 normal
Diurinal cortisol variation (midnight/8am)
What is the definitive test for cushings?
2 day 2mg/day dexa test
Cortisol >130, defos cushings
What is the aetiology of cushings syndrome?
Pituitary adenoma - cushings disease
Adenoma of adrenal gland
Ectopic ACHT production (thymus, lung and pancreatic cancer)
Pseudo - alcohol and depression, steroid medication
What will cushings syndrome of pituitary origin (cushings disease) show upon tests
Abnormal low dose dexa test
ACTH <300
Suppression by 50% of high dose dexa test
What will cushings syndrome of adrenal origin show upon tests?
Abnormal Low dose dexa test
ACTH levels <1
No suppression upon high dose dexa test
What will cushings syndrome of ectopic ACTH origin show upon tests?
Abnormal low dose dexa test
ACTH >300
No suppression on high dose dexa test
What will the CRH test show in cushings disease?
50% increase in ACTH
20% increase in cortisol
What is the treatment of cushings disease?
Hypophysectomy and external radiation if recurs
Bilateral adrenalectomy
What is the treatment of cushings syndrome of adrenal origin?
Adrenalectomy
What is the treatment of cushings syndrome of ectopic ACTH origin?
Removal or source e.g. SCC of lung
Bilateral adrenalectomy
What is the drug treatment for cushings?
Metyrapone (acts on steroid axis) if surgery fails or whilst waiting for radiotherapy to work
What are common S/E of metyrapone?
N+V Dizziness Headache Hypotension Sedation
What other drug treatments are avaliable if metyrapone fails?
Ketoconzaole
Pasireotide LAR which is a somatostatin analogue
What can result from panhypopituitarism?
Ant pit: GH (growth failure) TSH (thyroidism) LH/FSH (hypogonadism) ACTH (hypoadrenal) Prolactin Post Pit: Diabetes insipidus
What can cause hypopituitarism?
Pituitary tumours
Secondary met lesions (lung, breast)
Local brain tumours (astrocytome, meningioma, glioma)
Granulomatous disease (TB, histocytosis, sarcoidosis)
Trauma (RTA, skull fracture)
Hypothalamic disease (syphilis, meningitis)
Iatrogenic; surgery
Autoimmune; sheenan
Infection; meningitis
What are symptoms and signs of anterior hypopituitarism?
Menstrual irregulatities Infertility, impotence Gynaecomastic Abdominal obesity Loss of facial hair Loss of axillary and pubic hair Dry skin and hair Hypothyroid face (moon face) Growth retardation
What tests are best for the steroid axis?
Synacthen test
Insulin tolerance test
What should the levels of LH and FSH be like in post-menopausal women?
High and therefore if the levels are normal or low this suggest pituitary pathology
What are the replacement therapies in place for hypopituitarism?
Thyroxine 100-150 mcg/day Hydrocortisone 10-25 mg/day ADH - desmospray or tablets Gh - GH nightly SC Sex steroids - HRT/Oest/Prog pill Testosterone for males
What will GH do in adults?
Decreases abdo fat Increases muscle mass, strength and exercise capacity and stamina Improves cardiac function Decreases cholesterol and increases HDL Increases bone density
What are risks of testosterone replacement?
Prostate enlargement
Polycythaemia
Hepatitis
What should be performed prior to testosterone replacement therapy?
PR exam and PSA - makes prostate grow
FBC for polycythaemia
LFTs for hepatitis
What can cause cranial diabetes insipidus?
Familal: isolated in most cases, DIDMOAD
Acquired: idiopathic, RTA, surgery, skull fracture
RARE: tumour, sarcoid, ext irradiation, meningitis
What is DIDMOAD?
DI; diabetes insipidus
DM; diabetes mellitus
OA; optic atrophy
D; deaf
What is the treatment for DI?
Desmospray
Desmopression oral tablets (100-1000mcg per day)
Desmopressin injection (emergency or post pituitary surgery)
