Thyrotoxicosis / Hyperthyroidism

Question 1

Hyperthyroidism refers to when there is over production of riiodothyronine (T3) and thyroxine (T4), by the thyroid gland, also referred to as thyrotoxicosis. This can be primary or secondary, which of the following is primary hyperthyroidism?

1 - pituitary pathology
2 - thyroid pathology
3 - hypothalamus pathology
4 - adrenal pathology

Answer 1

2 - thyroid pathology

Secondary hyperthyroidism is pathology due to anything other than the thyroid gland

Question 2

Which of the following is the most common cause of primary hyperthyroidism?

1 - Addisons disease
2 - Toxic multinodular goitre
3 - Graves disease
4 - Hyperfunctioning thyroid adenoma

Answer 2

3 - Graves disease

Toxic multinodular goitre is due to a mutation in a TSH receptor that keeps follicular cells active, creating excess T3 and T4.
- common in >50 y/o

Question 3

Graves disease is the most common cause of primary hyperthyroidism. What is the most common trigger for this to develop?

1 - inflammation
2 - infection (i.e. TB)
3 - drugs
4 - autoimmune condition

Answer 3

4 - autoimmune condition

Specifically B cells create:
- thyroid stimulating hormones (TSH) receptor antibodies
- TSH receptor antibodies bind to receptors on the thyroid gland
- thyroid gland secretes excess T3 and T4

Question 4

The mnemonic GIST can be used to identify the cause of primary hyperthyroidism. What does the G stand for?

1 - Giant thyroid adenoma
2 - Graves disease
3 - Gingivitis
4 - all of the above

Answer 4

2 - Graves disease

G = Graves disease
I = Inflammation
S = Solitary toxic nodular nodule
T = Toxic multinodular nodule

Question 5

Most of T4 is converted to T3, which is able to bind and be absorbed by almost all cells of the body. Which of the following is NOT a function of T3?

1 - increase metabolic rate (produces more proteins and burns more energy)
2 - reduces cardiac output
3 - stimulates bone reabsorption
4 - stimulates sympathetic nervous system

Answer 5

2 - reduces cardiac output

T3 is important for fight or flight response

Question 6

Primary hyperthyroidism induces a hypermetabolic rate. Which of the following is NOT a typical presentation of a patient with primary hyperthyroidism?

1 - Anxiety and irritability
2 - Sweating and heat intolerance
3 - Tachycardia
4 - Weight gain
5 - Fatigue
6 - Insomnia
7 - Frequent loose stools
8 - Sexual dysfunction
9 - Brisk reflexes on examination

Answer 6

4 - Weight gain

Causes weight loss as hypermetabolic rate

Question 7

Graves disease can present with all of the common presentations of a patient with Primary hyperthyroidism. However, all of the following EXCEPT which one is specific to Graves disease?

1 - Diffuse goitre (without nodules)
2 - Graves’ eye disease, including exophthalmos
3 - De Quervain tenosynovitis
4 - Pretibial myxoedema
5 - Thyroid acropachy (hand swelling and finger clubbing)

Answer 7

3 - De Quervain tenosynovitis

Common in patients with temporary inflammation of the thyroid gland.

Question 8

De Quervain’s Thyroiditis is a temporary inflammation of the thyroid gland. There are 3 phases, which of the following is NOT one of these?

1 - Thyrotoxicosis
2 - Hypothyroidism
3 - Return to normal
4 - Excess cortisol and aldosterone

Answer 8

4 - Excess cortisol and aldosterone

Thyrotoxicosis

Question 9

Which of the following can present in a patient in the Thyrotoxicosis phase of De Quervain’s Thyroiditis?

1 - Excessive thyroid hormones
2 - Thyroid swelling and tenderness
3 - Flu-like illness (fever, aches and fatigue)
4 - Raised inflammatory markers (CRP and ESR)
5 - All of the above

Answer 9

5 - All of the above

Question 10

Thyroid storm is a rare presentation of hyperthyroidism, also known as thyrotoxic crisis. It is a rare and more severe presentation of hyperthyroidism causing all of the following EXCEPT which one?

1 - fever
2 - tachycardia
3 - delirium
4 - seizures

Answer 10

4 - seizures
- not common

Can be life-threatening and requires admission for monitoring and may need additional supportive care with fluid resuscitation, anti-arrhythmic medication and beta blockers

Question 11

When treating a patient with of De Quervain’s Thyroiditis, which of the following would NOT be used?

1 - NSAIDs
2 - B-blockers
3 - Levothyroxine
4 - Carbimazole

Answer 11

4 - Carbimazole

Can be used to treat hyperparathyroidism, but De Quervain’s Thyroiditis is typically self limiting. This may cause Hypothyroidism, which may then become long term

Question 12

When trying to diagnose primary hyperthyroidism, T3 and T4 will typically be high. Will TSH be high or low?

Answer 12

• low

TSH is coming from antibodies and NOT TSH from pituitary gland

Question 13

Which of the following may be most useful in diagnosing secondary hyperthyroidism?

1 - ultrasound
2 - MRI
3 - radioactive iodine uptake test
4 - X-ray

Answer 13

3 - radioactive iodine uptake test

If TSH is HIGH or normal, this suggest a pituitary tumour

Question 14

What is the 1st line management for a patient with primary hyperthyroidism?

1 - Carbimazole
2 - Riiodothyronine
3 - Levothyroxine
4 - Teriparatide

Answer 14

1 - Carbimazole

• Inhibits thyroid peroxidases (TPO)
• TPO catalysed iodination of tyrosine residues in thyroglobulin and the oxidative coupling of iodinated tyrosines forming T3 and T4

Question 15

Carbimazole is the 1st line management for a patient with primary hyperthyroidism. Jow long is this drug typically taken for?

1 - 2-4 weeks
2 - 3-6 months
3 - 6-12 months
4 - 12-18 months

Answer 15

4 - 12-18 months

Typically titrated down after this

Question 16

A severe side effect of a patient taking Carbimazole is severe epigastric pain radiating to the back, which is most likely to be what?

1 - cholelithiasis
2 - peptic ulcer
3 - acute pancreatitis
4 - cholestasis

Answer 16

3 - acute pancreatitis

Question 17

What is the 2nd line management for a patient with primary hyperthyroidism?

1 - Carbimazole
2 - Propylthiouracil
3 - Levothyroxine
4 - Propanalol

Answer 17

2 - Propylthiouracil

Rare, but can cause severe liver reactions, including death, hence why Carbimazole is 1st choice

Propanalol can be used for adrenalin-related symptoms of hyperthyroidism, which helps control symptoms while treatments work

Question 18

Carbimazole and Propylthiouracil are used to treat primary hyperthyroidism. Which of the following can both of these drugs cause?

1 - severe liver reactions or death
2 - acute pancreatitis
3 - retinopathy
4 - agranulocytosis

Answer 18

4 - agranulocytosis

• Low WBCs essentially
• Patient may present with sore throat on one of these drugs
• Treat aggressively as this is dangerous

Question 19

Radioactive iodine treatment is an alternative treatment for primary hyperthyroidism. This involves a single dose of radioactive iodine, taken up by thyroid gland and radiation destroys some thyroid cells. Can this cause an underactive or overactive thyroid gland?

Answer 19

• under active

Patients typically given Levothyroxine to help

Question 20

Radioactive iodine treatment is an alternative treatment for primary hyperthyroidism. Which of the following is NOT a strict rule that must be followed in order to receive Radioactive iodine treatment?

1 - Not be pregnant or breastfeeding and must not get pregnant within 6 months of treatment
2 - Men must not father children until >4 months after treatment
3 - No travelling in a confined space for 6 months
4 - Limit contact with people after the dose, particularly children and pregnant women

Answer 20

3 - No travelling in a confined space for 6 months

Question 21

What is the definitive approach to treating primary hyperthyroidism?

1 - Thyroidectomy
2 - Radioactive iodine treatment
3 - Life long Carbimazole
4 - Low iodine diets and lifestyle change

Answer 21

1 - Thyroidectomy

Patients will become hypothyroid and require life-long levothyroxine.