Hyperthyroidism

Question 1

hypothalamus hormone regulating TSH secretion:

Answer 1

trh

Question 2

autoimmune hyperthyroidism cause

Answer 2

graves’ disease. antibodies vs TSH receptor in thyroid. primary hyperthyroidism

Question 3

Graves’ disease symptoms

Answer 3

smooth goitre, tachycardia/palpitations, intolerance to heat, muscle spasms, weight loss and increased appetite, diarrhoea, exophthalmos, pretibial myxoedema (last 2 are specific to graves’)

Question 4

Radioiodine uptake in graves

Answer 4

Uniformly high

Question 5

why does exophthalmos occur

Answer 5

same antibodies bind to receptors in the eye muscles

Question 6

what are toxic nodules

Answer 6

benign adenomas that cause localised hyperthyroidism

Question 7

radioiodine uptake for toxic nodules

Answer 7

localised hot spots of activity since nodules are overactive in producing thyroxine

Question 8

how does thyroxine affect the sympathetic nervous system

Answer 8

sensitises beta-receptors to background levels of (nor)adrenaline, so there are sympathetic symptoms in hyperthyroidism such as muscle tremors and tachycardia

Question 9

what is thyroid storm

Answer 9

medical emergency of high thyroid activity

Question 10

signs and symptoms:if thyroid storm

Answer 10

hyperpyrexia above 41°C, tachycardia, delirium/psychosis, cardiac failure, hepatocellular dysfunction → jaundice

Question 11

what drugs are used to treat hyperthyroidism

Answer 11

thionamides e.g. propylthiouracil & carbimazole, potassium iodide KI, radioiodine, beta blockers(given to treat sympathetic symptoms)

Question 12

thionamides mechanism of action?

Answer 12

lower thyroxine production by inhibiting thyroid peroxidase
Given as and 18 month course with treatment expected to stop after (half are cured half relapse) if not cured consider surgery radioiodine or lifetime treatments with carbimazole

Question 13

thionamides side effects?

Answer 13

agranulocytosis - usually reversible reduction in neutrophils, rashes

Question 14

what does KI do and when is it used

Answer 14

inhibits thyroglobulin iodination, inhibits H2O2 generation and thyroid peroxidase. used for thyroid storm, hyperthyroid patient surgery prep. not regular graves’ treatment
Reduces symptoms in 1/2 days and given for 10 days usually, if any longer there may be escape and thyroid hormones might be made

Question 15

risks of thyroid surgery

Answer 15

anaesthetic risks, risk of voice change, scarring, risk of parathyroid gland loss

Question 16

radioiodine contraindications:

Answer 16

pregnancy. have to stay away from pregnant women and young children for a few days after taking.

Question 17

what is de quervain’s thyroiditis?

Answer 17

Viral thyroiditis

Question 18

de quervain’s symptoms?

Answer 18

painful dysphagia, pyrexia, thyroid inflammation,malaise and pain radiating to ear

Question 19

thyroid activity pattern during de quervain’s

Answer 19

thyroid stops making thyroxine and makes virus instead, thyroxine stores used. hyperthyroid for a month then stores depleted so hypothyroid until resolution about a month later.

Question 20

radioiodine uptake in de quervain’s

Answer 20

zero since no thyroxine is being made so no iodine is taken up

Question 21

postpartum thyroiditis cause and symptoms

Answer 21

immune system modified in pregnancy leading to similar symptoms but no pain.