Hyperthyroidism

Question 1

What hormones does the thyroid gland make?

Answer 1

Triiodothyronine (T3) and Thyroxine (T4)

Question 2

T_____ refers to the effects of an abnormal and excessive quantity of thyroid hormones in the body

Answer 2

Thyrotoxicosis

Question 3

Primary hyperthyroidism is due pathology where?

Answer 3

In the thyroid itself, producing excessive thyroid hormone

Question 4

Secondary hyperthyroidism is due to pathology in the…

Answer 4

hypothalamus or pituitary gland
The pituitary gland produced too much TSH (thyroid stimulating hormone)

Question 5

What is the most common cause of hyperthyroidism?

Answer 5

Grave’s disease

Question 6

Grave’s disease is an _____ condition

Answer 6

autoimmune

Question 7

In Grave’s disease, what antibodies cause primary hyperthyroidism?

Answer 7

TSH receptor antibodies (produced by immune system)

Question 8

What is toxic multinodular goitre?

Answer 8

Also called Plummer’s disease
Nodules develop on thyroid gland, not regulated by TSH axis so continuously make excessive thyroid hormones.

Question 9

What age group is toxic multinodular goitre most common in?

Answer 9

Patients over 50

Question 10

What are common symptom of Graves’ disease?

Answer 10

Proptosis (also called exophthalmos)
Pretibial myxoedema
Goitre
Thyroid acropachy (hand swelling and finger clubbing)

Question 11

Why is proptosis seen?

Answer 11

Inflammation, swelling and hypertrophy of the tissue behind the eyeballs force them forward, causing them to bulge out of the sockets.

Question 12

Why is pretibial myxoedema seen?

Answer 12

Deposits of glycosaminoglycans under the skin on the anterior aspect of the leg gives the skin a discoloured, waxy, oedematous appearance. Reaction to TSH receptor antibodies.

Question 13

What are the causes of hyperthyroidism?

Answer 13

Think GIST

Grave’s disease
Inflammation (eg thyroiditis)
Solitary toxic thyroid nodule
Toxic multinodular goitre

Question 14

What are some universal feature of hyperthyroidism?

Answer 14

Fatigue
Insomnia
Anxiety
Irritability
Sweating
Heat intolerance
Weight loss
Frequent loose stools
Sexual dysfunction
Brisk reflexes on examination

Question 15

The nodules seen in solitary toxic thyroid nodule and toxic multinodular goitre are usually benign ______ and treatment involves surgical removal

Answer 15

adenomas

Question 16

What is struma ovarii?

Answer 16

Rare ovarian tumour where over 50% of its mass is made from thyroid tissue

Question 17

What is de Quervain’s thyroiditis and what are the 3 phases?

Answer 17

Also called subacute thyroiditis.
Temporary inflammation of thyroid gland

Thyrotoxicosis
Hypothyroidism
Return to normal

Question 18

What does the initial thyrotoxic phase of de Quervain’s thyroiditis involve?

Answer 18

Excessive thyroid hormones
Thyroid swelling and tenderness
Flu-like illness
Raised inflammatory markers

Question 19

What triggers de Quervain’s thyroiditis?

Answer 19

Believed to be triggered by a viral infection such as enteroviruses like coxsackie virus

Question 20

How do you treat de Quervain’s thyroiditis?

Answer 20

Self-limiting condition
May give NSAIDS for pain and inflammation
Beta blocker for symptoms of hyperthyroidism
Levothyroxine for symptoms of hypothyroidism

Question 21

What is a thyroid storm?

Answer 21

Also called thyrotoxic crisis, rare and most severe presentation of hyperthyroidism.
Often abrupt onset and triggered by infection, surgery, trauma or discontinuation of anti-thyroid medication.
Presents with fever, tachycardia and delirium.

Question 22

What additional supportive care may be given for a thyroid storm?

Answer 22

Anti-thyroid medication = propylthiouracil

Potassium iodide

Fluid resuscitation, anti-arrhythmic medication and beta blockers

Question 23

What is the first line anti-thyroid drug for hyperthyroidism?

Answer 23

Carbimazole.

Once patient has normal thyroid hormone levels after 1-2 months, continue on maintenance carbimazole

Question 24

What is “titration-block” method for hyperthyroidism?

Answer 24

Once thyroid hormone levels are normal with carbimazole, the dose is titrated to maintain the normal levels.

Question 25

What is “block and replace” method for hyperthyoidism?

Answer 25

A higher dose of carbimazole is given to block all production of thyroid hormone. Levothyroxine is added and titrated to effect.

Question 26

What is a side effect of carbimazole?

Answer 26

Agranulocytosis (decreased numbers of basophils, neutrophils and eosinophils)

Makes patients vulnerable to severe infections so if patient has sore throat on carbimazole, need urgent full blood count and aggressive treatment of any infections.

Question 27

What is the second line anti-thyroid drug for hyperthyroidism?

Answer 27

Propylthiouracil (small risk of severe liver reactions)

Question 28

What is radioactive iodine treatment for hyperthyroidism?

Answer 28

Drinking single dose of radioactive iodine. Thyroid takes this up and the radiation emitted destroys a population of thyroid cells causing decrease in production of thyroid hormone.
Remission can take 6 months

Question 29

What happens if the thyroid becomes too underactive after radioactive iodine treatment?

Answer 29

Long-term levothyroxine is needed

Question 30

What are used to block the adrenaline-related symptoms of hyperthyroidism?

Answer 30

Beta blockers
eg propranolol which non-selectively blocks adrenergic activity.

Question 31

What is a definitive treatment option for hyperhtyroidism?

Answer 31

Surgery to remove the whole thyroid gland (thyroidectomy) or the toxic nodules.
If thyroidectomy, requires life-long levothyroxine

Question 32

Other than TSH-receptor antibodies, what antibodies can be found in Graves’ patients?

Answer 32

Anti-TPO antibodies

TPO is thyroid peroxidase and is needed to make T3 and T4 in the thyroid.

Antibodies to TPO can indicate an autoimmune process.