Management of thyroid disorder

Question 1

What is thyrotoxicosis?

Answer 1

• Excess in T3 and T4 concentration in serum, due to the release of intrathyroidal thyroid hormone
• Excess thyroid hormone exposure and action on tissues

Question 2

What is hyperthyroidism?

Answer 2

Excess thyroid hormone production and release

Question 3

What is overt hyperthyroidism?

Answer 3

Hyperthyroidism + thyrotoxicosis

• Thyrotoxicosis is the term used when there is an excess amount of T3 and T4 in the blood regardless of the cause/ origin – the body manifests signs and symptoms due to this increased level

Question 4

What is subclinical hyperthyroidism?

Answer 4

hyperthyroidism without thyrotoxicosis

Question 5

What is a thyroid storm (thyrotoxic crisis)?

Answer 5

• Extreme exacerbation of thyrotoxicosis
• Medical emergency characterized by a severe acute exacerbation of the signs and symptoms of hyperthyroidism
• Fever, tachycardia out of proportion to the fever, altered mental status, diarrhea, vomiting, and cardiac arrhythmia
• It could also cause shock, stupor, coma, and death

Question 6

What is hypothyroidism?

Answer 6

• When the thyroid gland does not produce enough thyroid hormone
• Abnormally low level of circulating thyroid hormones

Question 7

What are the thyroid function tests?

Answer 7

1) TSH

2) Thyroid hormone (T3 & T4)

3) Anti-TSH

4) Anti-TPO

5) Thyroid ultrasound

6) Thyroid scan

7) Thyroid uptake

8) Fine needle aspiration

Question 8

What are the thyroid function tests?

Answer 8

1) TSH (increased in case of hypothyroidism when T3 & T4 levels levels are decreased)

2) Thyrotropin-releasing hormone (BLOOD LEVELS OF IT ARE RARELY USED, TRH is not a routine test – he said in the exam if one of the choices he puts as TRH do not choose it)

3) T3 & T4 (thyrotoxicosis is detected when they are both elevated)

Question 9

What are the levels of the thyroid hormones in secondary hyperthyroidism?

Answer 9

1) Increased TSH and T3 & T4

Question 10

What are the thyroid hormone blood levels in case of tertiary hyperthyroidism?

Answer 10

Increased T3 & T4, TSH and TRH

Question 11

What are the different investigations of autoantibodies for the thyroid gland?

Answer 11

1) Thyroglobulin antibody (TGAb)

2) Thyroid peroxidase antibody (TPOAb)

3) Anti-TSH receptor antibodies (TSHrAb)

• Stimulating one is (TSAb)
• The blocking one is (TBAb)

Question 12

Which thyroid autoantibodies is used in case of graves disease?

Answer 12

TSAb (thyroid-receptor-stimulating antibody)

• TRAb

Question 13

Which thyroid autoantibodies is used in hashimotos?

Answer 13

TPOAb (Thyroid peroxidase antibody)

• Anti-TPO

Question 14

What are the imaging investigations?

Answer 14

1) US (opportunity for fine needle aspiration)

2) Thyroid scan

3) Thyroid radioactive iodine uptake

Question 15

What is a thyroid scan?

Answer 15

• Nuclear medicine test
• This thyroid scan (nuclear medicine test) is required to distinguish the subtypes, tells the underlying disease that causes the conditions
• On administering pertechnetate both lobes of the thyroid gland should diffusely glow up in the imaging as both the lobes take up the nuclear dye
• If it is darker than normal – suggests the thyroid gland is over-working
  It can be irregular with hot spots (areas that take up more dye) – so they are over-working
• This test can help us distinguish between diffuse hyperthyroidism (A) or a particular hot spot (D) – both of which will cause primary hyperthyroidism
• If in the scan the thyroid takes up the dye but there is a focal area that does not take up the dye (cold nodule) - this could be thyroid cancer

Question 16

Describe the thyroid radioactive iodine uptake test

Answer 16

Measuring the amount of iodine (radioactive tracer) uptake by the thyroid gland

• The radiotracer is given to the patient IV or Oral

Question 17

Describe the thyroglobulin test

Answer 17

Thyroglobulin is a substrate for the synthesis of thyroid hormone (T4 & T3), AS WELL AS THE STORAGE OF INACTIVE FORM OF THYROID HORMONE AND IODINE WITHIN THE FOLLICULAR LUMEN O A THYROID FOLLICLE

• Mostly used as a tumor marker (A reliable marker to see if there is a recurrence of cancer)

Question 18

Which investigation is used as a tumor marker?

Answer 18

Thyroglobulin test

Question 19

What classification of thyroid hormone disorders is based on increased thyroid stimulating hormone levels?

Answer 19

• Increased TSH:

1) Decreased T4 will be primary hypothyroidism (like in autoimmune thyroiditis)

2) Normal TSH will be subclinical hypothyroidism

3) Increased TSH will be secondary hyperthyroidism (like in a pituitary-secreting adenoma)

Question 20

What classification of thyroid hormone disorders is based on normal thyroid stimulating hormone levels?

Answer 20

• Normal TSH:

1) Decreased T4 will be secondary hypothyroidism (like in non-secreting pituitary adenoma)

2) Normal TSH will be normal

3) Increased TSH will be secondary hyperthyroidism (like in TSH secreting pituitary adenoma)

Question 21

What classification of thyroid hormone disorders is based on decreased thyroid stimulating hormone levels?

Answer 21

• Decreased TSH:

1) Decreased T4 will be secondary hypothyroidism (like in non-secreting pituitary adenoma)

2) Normal, T3 toxicosis

3) Increased TSH will be primary hyperthyroidism (like in graves disease)