Endocrine Flashcards
What is it called when there is a tumour that produces hormones?
Paraneoplastic syndrome
How is congenital adrenal hyperplasia inherited? and what enzyme is defected?
Autosomal recessive
21 alpha hydroxylase
What drugs can cause adrenal insufficiency?
Ketoconazole
Rifampicin
Barbiturates
Outline clinical findings of Addisons?
Hyponatraemic
Hyperkalaemia
Increased Urea
Creatinine levels increase
Increased renin
Reduced androgens
- DHEA
How is the adrenal insufficiency test done?
Short SynACTHen test
- 250mg given IV.
30mins later if <450nmol/L cortisol then positive
Management of adrenal insufficiency:
hydrocortisone
FLudrocortisone
- sick day rules
- treatment of TB if present
- insulin titration
What are the definitions for hypoglycemia:
Diabetic: <4mmol/L
Non Diabetic <3mmol/L
List some causes of hypoglycemia out with diabetes:
Inappropriate insulin release:
- insulinomas
- MEN -1
Insulin Mimicking pathologies:
- Lymphomas
- Tumours secrete IFG-2
Drug induced:
- sulfonlureas
- repaglinide
Impaired gluconeogenesis
- organ failure
- alcohol
What is the symptoms of hypoglycaemia?
Whipples Triad
- Neuroglycopenic
- autonomic
- Measured glucose level
- improvement with glucose
At what level of blood glucose is there EEG changes?
<2mmol/L
What level of blood glucose is there come and convulsions?
<1.5mmol/L
What the common causes of primary aldosteronism?
Adrenal adenoma - 40%
Adrenal hyperplasia - 60%
What are the symptoms of primary aldosteronism?
- hypertension
- hypokalemia
- alkalosis
- mildly hypernatremic
What are some important tests in primary aldosteronism?
Renin: aldosterone ratio
Suppression test
- 2L of saline
4 hours later if aldosterone >27pmol/L= positive
Plasma renin/ aldosterone ratio
- >35>300 diagnostic
What are the managements for primary aldosterone?
Surgical:
- only if unilateral
- laparoscopic
Medication:
- spironolactone
- eplerenone
What investigations should be done on pituitary tumour?
- MRI
- visual field testing
- prolactin levels
What are the symptoms of a prolactinoma?
Galactorrhoea
menstrual disturbance
reduced libido
headaches
disturbed vision
what investigations should be done for a suspected prolactinoma?
Serum prolactin
FSH and LH levels (since these are supressed)
MRI
What is the treatment options for prolactinoma?
Cabergoline
- dopamine agonist
Surgery
What are the symptoms of acromegaly?
Coarse facial appearance
enlarged tongue
increased iner-dental space
sweats
headaches
joint pains
hypertension
diabetes
bowel cancer
What is considered a macroadenoma?
> 1cm
Name some causes of hypopituitrism:
Tumours infarction infiltrations trauma congenital
What tests are done for cushing’s syndrome?
24 hour cortisol test
Late night salivary cortisol sample
Dexamethasone suppression test
CRH test
- to see if ACTH is increased
What drugs can be used to treat cushings?
Ketoconazole
symptoms of Pheochromocytoma?
Hypertension
Episodes of:
- Headaches
- palpitations
- sweating
- abdominal pain
- anxiety
What are the etiologies of pheochromocytomas?
75% sporadic mutations
25% associated with conditions making them more vulnerable to developing the tumour:
- MEN2
- Neurofibromatosis
- Von Hippel Lindau disease
Investigations into pheochromocytoma?
- Blood pressure
- Thyroid function
- Urinary catecholamines
- noradrenaline
- adrenaline
- metadrenalines
- Normetadrenalines
*CT
Treatment for Pheochromocytoma?
Alpha blocker
- doxazosin
Beta blockers
Adrenalectomy
**medication given before surgery
What investigations need to be done for a male with hypogonadism?
- history
- weight distribution
- sexual activity
- Examination
- orchidometer
- Basal levels of testosterone
- highest in morning
- LH and FSh
- semen analysis
- chromosomes
What are some etiologies of hypogonadism in men?
Hypogonadotropic hypogonadism
- pituitary tumour
- prolacitnoma
- head trauma
Primary gonadal failure
What’s the most common cause of hypogonadotropic hypogonadism?
Kallmann’s syndrome
What genes are associated with Kallmann’s syndrome:
X- linked - KAL1 gene
Autosomal Dominant KAL2 gene
What is the pathophysiology of Kallmann’s syndrome?
Failure of the GnRH cells to migrate from the olfactory placode to the hypothalamus
develop lack of sense of smell as well
What are the clincal features of Klamman’s syndrome?
Lack of FSH and LH
Cryptochidism
Micro-penis
small growth
What is the pathology in primary gonadal disease?
Direct problem with the Leydig cells.
- dysfunctional testosterone
- trauma,
- chemo
- radiotherapy
- multisystemic disorders
Why do men with Klinefelter’s syndrome have low testosterone?
Seminferous tubules regress and do not function correctly
List some symptoms of hypercalcaemia
- confusion, tiredness
- Bone pain
- shortening of QT interval
- dehydration
- renal stones
What are the PTH related causes of hypercalcemia?
adenoma of parathyroid
diffuse hyperplasia of parathyroid
Familial hypocalcuric hypercalcaemia
What is the pathogenesis of familial hypocalcuric hypercalcaem?
Lack of CaSR receptors on parathyroid and kidneys
- defect in chromosome 3
thus PTH doesn’t switch off.
Kidneys it continues to reabsorb
What is a significant clinical finding in FHH that differentiates it from other hypercalcemia?
Urine calcium: Plasma calcium ratio
What are some non- PTH related causes of hypercalcaemia?
Carcinoma
Malignancy
- PTH -related peptide
Granulomatous disorders
- produce 1 alpha hydroxylase
Drugs
- thiazides
- lithium
Paget’s disease
Hyperthyroidism
Investigations carried out for hypercalcaemia?
Corrected calcium for albumin levels
- x-ray
- for lung cancer
- FBC
- thyroid function tests
- urine/ plasma ration
- end organ damage
- DEXA scan
- alkaline phosphatase
Treatment of hypercalcaemia:
*stop causitive agent
- IV fluids
- flush calcium out
- loop diuretics
- bisphosphonates
- steroids
- thyroidectomy
What must be present to carry out a thyroidectomy?
Only on those who can survive, usually <50 years old
intractable symptoms
renal stones
hypercalciuria
What drug can be associated with hyperthyroidism?
Amiodarone
- has a high content of iodine which may trigger increased thyroxine in already hyperthyroid patients.
May lead to an acute hypersecretion of T4, T3 due to an immediate thyrotoxicosis
followed by hypothyroidism
- seen in previously healthy thyroids
What chemical marker may be seen with amiodarone hyperthyroidism and why is this?
high T4>T3 levels.
because amiodarone prevents the break down of T4 into T3
How is hyperthyroidism and thyrotoxicosis different?
Hyperthyroidism refers to the thyroid directly being over active.
Thyrotoxicosis is a syndrome that refers to the over amount of free T4 and T3 regardless of cause.
- doesn’t have to strictly come about through hyperthyroidism i.e a damaged gland releasing T4 and T3
What are some primary causes of thyrotoxicosis
Graves
toxic multinodular goitre
toxic adenoma
What are some secondary causes for thyotoxicosis?
TSHoma - of pituitary
Gestational thyrotoxicosis
thyroid hormone resistance syndrome
What are the drugs used for hyperthyroidism?
which is used for pregnancy or if pregnancy is planned?
Carbimazole
Propylthiouracil
Propylthiouracil is used for pregnancy
What are the two regimens used for the drug dosages in hyperthyroidism?
Reducing regimen
Block and replace
What risk factors increase the likely hood of opthalmopathy in Graves disease?
Smoking
male sex
age
radioactive iodine treatment
What would prompt immediate referral to an ophthalmologist in Grave’s disease?
Poor vision
blurred vision
rapid change in vision
poor colour vision
What are some causes of hypothyroidism?
Hashimotos thyroiditis
destructive thyroiditis
secondary hypothalamic
iodine deficiency
treatment of hyperthyroidism
idiopathic
What is the treatment for hypothyroidism?
50 -100mcg levothyroxine
25mcg for ischemic heart disease
What is the term giving to the build up of mucopolysaccharides in the skin?
myxedema
What’s a serious complication of hypothyroidism that can result in death?
Myexdema coma
- bradycardia - heart failure
- bradyypnea
- hypothermia
What drugs are given for hyperthyroidism, how do they work and what are some major side effects?
Carbimazole
Propylthiouracil
reduced activity of peroxidase
reduced conversion of T4 to T3
Agranulocytosis
- much watch patients for infection
Which of the thyroid diseases would cause periods to stop?
Hyperthyroidism
What Antibodies are associated with Hashimoto’s
Anti-thyroglobulin
Anti-thyroid peroxidase
What is a modifiable risk factor towards Graves disease?
Smoking - showing to make it much more likely
What are the drugs used in Graves disease?
Carbimazole
Propylthiouracil
What immune modulators may be used for Grave’s disease?
Interferon
Alemtuzemab - CD52
Why might a lady on contraception or a pregnant women, present with an increase in total T4 levels?
Contraception and pregnancy increase Thyroglobulin binding hormone. thus the thyroid has to increase output to maintain the free amount.
the free amount will be normal
What is it called when an injection of iodine is given to someone with hyperthyroidism, which results in suppression of thyroid hormone?
Wolff Chaikoff effect
What is it called when relatively small amount of iodine is given to someone with hyperthyroidism, and causes a massive increase in thyroid hormone? and name a drug that this is an example off:
Jod - Basedow Phenomenon
- given a relatively small amount of iodine which triggers thyroid hormone release from a hyperthyroid gland. normal glands will counter regulate.
it is the opposite of Wolff Chaikoff effect.
Amiodarone is an exmaple.
whats it called when a neonate has hypothyroidism and symptoms associated?
Cretinism
Mental retardation
Course facial features
short stature
What effect does testosterone have on RBCs?
Increases erythropoiesis
What is a level of diagnostic prolactin?
> 6000
Following what infection may lead to hyperthyroidism?
Yersina Infection
E.Coli infection
Name some causes of Secondary hyperthyroidism:
Pituitary adenoma TSHoma
Gestational Thyrotoxicosis
List some causes of primary gonald insufficiency:
Chemotherapy
Trauma
radiotherapy
What is it called where there is a congenital reduction in hypothyroidism - and what are some symptoms and what are some of the major causes:
Cretinism
Coarse facial features
Glossis hypoplasia
Development delay
Myexdema
Thyroid dysgenesis
TSH receptor dysgensis
Dysmorphogenesis in thyroperioxidase
May also be caused by maternal reduction in thyroid hormone
What are the main antibodies associated with Graves:
What gene is it most associated with?
TSH Antibodies
Thyroperioxidase antibodies
HLA DR3
What is the main antibody implicated in Hashimotos disease:
Thyroperioxidase
There are two thyroid disease caused by amiodarone, what are they and how are they treated?
Type 1: Autoimmune thyrotoxicosis
- Carbimazole
Type 2: Destructive Thyroiditis
- Corticosteroids
What do the test results look like for sub-clinical hypothyroidism?
High TSH
Normal T4
What kind of tumour is Thyroid C Cancer?
Medullary cancer
derives from the parafollicular C Cells
Calcitonin producing
Which gene is associated with Familial Medullary thyroid Cancer?
RET gene
Associated with MEN2
- autosomal dominant
Protoncogene that is passed on. one of the few that is.
List the other types of thyroid cancer:
Follicular Carcinoma
- metastasis to bone
papillary adenocarcinoma
How do you treat hyperkalemia? and give an example in an emergency situation that it may be raised (outwith DKA as there is different management for that) and name an important investigation to monitor the effects of the high K+ and what would you expect to see?
Calcium Resonium
Insulin - actrapid
+/- Glucose
Calcium Gluconate
**if they become acidotic then treat with bicarb
Example would be:
AKI
due infective secretion of the K+ ions
*ECG = talk peaked T waves
