Thyroid Dysfunction

Question 1

What attaches the thyroid gland to the trachea and larynx?

Answer 1

pre-tracheal fascia

Thus the thyroid moves upwards on swallowing

Question 2

What is usually used for a thyroid uptake scan

Answer 2

Technetium 99

Question 3

What is a thyroglossal duct cyst?

Answer 3

Embryological anatomical structure forming an open connection between the initial area of development of the thyroid gland and its final position. Forms swelling in anterior part of neck, always in the midline.

Question 4

TSH and free thyroxine (T4) in hypothyroidism and hyperthyroidism

Answer 4

Hypothyroidism

• TSH increased
• T4 decreased

Hyperthyroidism

• TSH decreased
• T4 increased

Question 5

Who are autoimmune endocrine diseases more common in and why?

Answer 5

Women, we don’t know

Question 6

Types of goitre

Answer 6

Diffuse
Multinodular
Single nodule

Question 7

When can physiological goitre occur?

Answer 7

Menarche, pregnancy, menopause

Question 8

Commonest causes of goitre globally

Answer 8

Iodine deficiency - reduced thyroxine levels, increased TSH, severe cases may become hypothyroid

Multinodular goitre - aetiology unknown, normal thyroid function, may develop into toxic multinodular goitre

Question 9

Effects on child from iodine deficient pregnancy

Answer 9

• Mental retardation
• Abnormal gait
• Deaf mutism
• Short stature
• Goitre
• Hypothyroidism

Question 10

Symptoms of hypothyroidism

Answer 10

• Excessive tiredness
• Memory problems, depression, psychosis (myxoedema madness)
• Weight gain
• Cold intolerance
• Gruff voice, croaky voice
• Puffy eyes , face hands and feet
• Dry, flaky skin
• Hair loss, particularly outer third of eyebrows
• Symptoms of carpal tunnel syndrome
• Constipation
• Menorrhagia (heavy bleeding)
• Muscle weakness and cramps
• Pallor
• Bradycardia
• Hyporeflexia and delayed relaxation
• Non pitting oedema
• Ascites

Question 11

Hashimoto’s disease

Answer 11

• Ten times commoner in women
• Antibodies to thyroglobulin and thyroid peroxidase
• Thyroid gland may initially enlarge and then shrink in size, or may not enlarge at all

Question 12

Treatment for hypothyroidism

Answer 12

Oral thyroxine, not destroyed by gastric acid

Question 13

Symptoms of thyrotoxicosis

Answer 13

• Overactivity, tiredness
• Nervousness, anxiety, insomnia
• Shaking, trembling
• Heat intolerance
• Increased sweating – warm sweaty hands
• Palpitations. Rarely angina
• Weight loss in spite of increased appetite
• Diarrhoea
• Amenorrhea
• Proximal muscle weakness
• Tachycardia, atrial fibrillation
• Proximal myopathy
• Lid lag
• Staring eyes

Question 14

Causes of thyrotoxicosis

Answer 14

• Graves disease
• Toxic multinodular goitre
• Toxic adenoma

Question 15

Graves’ Disease

Answer 15

• Exopthalmus and pre-tibial myxoedema are signs

- Caused by thyroid stimulating immunoglobulin (TSI), which attaches and stimulates TSH receptor

Question 16

Why is the rest of the gland suppressed in toxic adenoma?

Answer 16

Adenoma produces thyroxine autonomously so rest of gland is suppressed as thyroxine levels in the body are high

Question 17

Treatment of thyrotoxicosis

Answer 17

• Carbimazole - prevents thyroid peroxidase form coupling and iodinating the tyrosine residues on thyroglobulin, thereby reducing production of T4
• Surgical excision of thyroid
• Ablative dose of radioactive iodine

Question 18

Thyroid cancer

Answer 18

Very uncommon, do not cause metabolic disturbance, present as thyroid nodule, prognosis - 97% cure rate