Thyroid Dysfunction

Question 1

What is the most common way that the thyroid is imaged?

Answer 1

Ultrasound

Can also look at radioactive substances being uptaken into the thyroid- v rare

Question 2

Where does the thyroid gland begin development?

Answer 2

In the foramen caecum of the tongue

Then moves down

Question 3

What is a lingual thyroid?

Answer 3

When the thyroid doesn’t migrate fully/ at all and remains at the back of the tongue

Question 4

What is a thyroglossal (duct) cyst?

Answer 4

A thyroglossal cyst is a fibrous cyst that forms from a persistent thyroglossal duct. Thyroglossal cysts can be defined as an irregular neck mass or a lump which develops from cells and tissues left over after the formation of the thyroid gland during developmental stages.

As the thyroid migrants down some gets left behind further up the neck

Question 5

What is the cause of most of the metabolic thyroid diseases? (Ie hypothyroidism and hyperthyroidism)

Answer 5

Primary abnormality of the thyroid gland itself

Question 6

What is the difference between thyrotoxicosis and hyperthyroidism?

Answer 6

Hyperthyroidism is an overactive thyroid gland and so may result in thyrotoxicosis

But thyrotoxicosis is just as excess of thyroid hormone in the body, this may not necessarily be as a result of hyperthyroidism. There may be another source of the hormone (ie a drug)

Question 7

What is the most important hormone to look at when looking for hyperthyroidism and hypothyroidism? Why?

Answer 7

TSH because it works as part of a negative feedback system to control the thyroid. Thryoid hormone levels within the body may not reflect the activity of the thyroid

*TSH level tell us what the patient’s brain thinks of the patient’s thyroid function

Question 8

What are the TSH and free T4 levels if someone has hypothyroidism?

Answer 8

TSH increased

free T4 decreased

Question 9

What are the TSH levels and the free T4 levels when someone has hyperthyroidism?

Answer 9

TSH decreased

Free T4 increased

Question 10

Why does the thyroid gland move up on swallowing?

Answer 10

Because it is invested by the pre-tracheal fascia

Question 11

Upon what movement would a thyroglossal cyst move up?

Answer 11

Tongue protrusion

Question 12

What are the different appearances that a goitre can have?

Answer 12

Diffuse (all over)
Multinodular (nodules)
Single nodule (lopsided)

Question 13

Physiological goitres can occur, at what points in life would they occur?

Answer 13

Menarche (when you start your period)
Pregnancy
Menopause

Question 14

What are the commonest causes of goitre?

Answer 14

1. Iodine deficiency- reduced thyroxine levels lead to an increased TSH which leads to generalised thyroid enlargement, usually nodular. In cases of severe iodine deficiency the person may become hypothyroid (most common in mountainous regions)
2. Multinodular Goitre (in the UK)- normal thyroid function, however after many years a tiny percentage of people may go on to develop hyperthyroidism which will equal a toxic multi doula role goitre

Question 15

What is iodine deficiency a concern during pregnancy?

Answer 15

Cretinism:
Mental retardation 
Abnormal gait
Deaf-mutism 
Short stature
Goitre
Hypothyroidism

Question 16

What can a retrosternal multinodular goitre cause?

Answer 16

Tracheal compression because the goitre enlarges and pushed inferiorly into the superior mediastinum

Question 17

what are the signs of hypothyroidism?

Answer 17

Weight gain
Dry skin, coarse brittle hair, loss of outer third of eyebrow
Pallor- ‘peaches and cream’ face
Coarse facial features and periorbital puffiness
Bradycardia
Hyporeflexia with delayed relaxation
Non pitting oedema - myxoedema (due to deposition of mucopolysaccharides particularly around the eyes, hands and feet)

Question 18

How do you treat hypothyroidism?

Answer 18

Oral thyroxine 
(Adjust does to normalise serum TSH)

Question 19

What are the symptoms of thyrotoxicosis?

*hyperthyroidism is thyrotoxicosis due to over production of thyroxine by the thyroid gland

Answer 19

Overactivity, tiredness
Nervousness, anxiety, insomnia 
Shaking, trembling 
Heat intolerance 
Increase sweating-warm sweaty hands
Palpitations. Rarely angina 
Weight loss in spite of increased appetite 
Diarrhoea 
Amenorrhea (light periods)
Proximal muscle weakness

Question 20

What are the signs of thyrotoxicosis?

Answer 20

Weight loss
Warm sweaty hands
Fine hand tremor (use piece of paper to see this)
Tachycardia, AF?
Bounding pulse, wide pulse pressure 
Proximal myopathy
(Always) Staring eyes 
(Always) Lid lag (when the eyelid doesnt move quickly with the eye)

Question 21

What are the common causes of thyrotoxicosis due to hyperthyroidism?

Answer 21

1. Hyperthyroidism due to Graves’ disease
2. Toxic multinodular goitre (not autoimmune therefore no exopthalmos or pretibial myxoedema)
3. Toxic adenoma (produced thyroxine- causes TSH to go down and rest of thyroid gland is suppressed)

Question 22

How do you treat thyrotoxicosis?

Answer 22

Give Carbimazole

Surgical excision of thyroid (thyroidectomy)

Ablative dose radioactive iodine

Question 23

How do thyroid cancers present and do they cause metabolic changes?

Answer 23

Single nodule

Have no metabolic disturbances

Question 24

Which of the following signs in hyperthyroidism is SPECIFIC to Graves' disease:
A. Staring eyes
B. Exopthalmos
C. Lid lag
D. Pre-tibial myxoedema 
E. Goitre

Answer 24

B and D