Treatment of Thyroid Disorders

Question 1

what hormones does the thyroid gland secrete

Answer 1

• Thyroxine (T4)
• Triiodothyronine (T3)
• Calcitonin

Question 2

• The main steps of synthesis, storage and secretion of the thyroid hormones

Answer 2

• Uptake of plasma iodide by the follicle cells
• Oxidation of iodide and iodination of tyrosine residues in the thyroglobulin of
the colloid
• Secretion of the thyroid hormone

Question 3

Hypothyroidism

Answer 3

(‘underactive’ thyroid)
• Inadequate production and secretion of thyroid hormones (T3 and T4)

• Low free T4
• Possibly low T3
• Raised thyroid stimulating hormone (TSH)

cardiovascular complications

Question 4

hyperthyroidism

Answer 4

(‘overactive’ thyroid)
• Excessive production and secretion of thyroid hormones (T3 and T4)

• Raised T3 and T4 and low TSH
• About 10 times more common in women than men • Typically affects people aged 20-40 years old

Question 5

what are the causes of hypothyroidism

Answer 5

• Congenital
• Autoimmune thyroiditis (Hashimoto’s)
• Iatrogenic (e.g. post thyroidectomy or radio-iodine treatment)
• Drug induced (e.g. anti-thyroid medications, lithium, amiodarone)
• Pituitary disease

Question 6

Newborns with congenital hypothyroidism

Answer 6

May have few or no clinical manifestations of thyroid deficiency
• All babies screened at birth (heel prick test)
• Untreated CHT can result in impaired brain development and low IQ
• If treatment started before the baby is 2-3 weeks old the likelihood of significant longterm problems is low

Question 7

congenital causes of hypothyroidism

Answer 7

• Absent thyroid (agenesis)
• Under-developed thyroid (dysgenesis) – more common in girls
• Familial enzyme defects (dyshormonogenesis)
• Iodine deficiency
• Intake of goitrogens during pregnancy
• Pituitary defects
• Idiopathic

Question 8

hashimotos

Answer 8

most common cause of hypothyroidism

• autoimmune lymphocytic thyroiditis
• an antibody against thyroglobulin is produced or one which has an antagonist effects at follicular TSH receptors

MORE COMMON IN FEMALES

Question 9

Amiodarone

Answer 9

is a free base containing iodine

• longterm treatment is associated with 4 fold increases in plasma and urinary iodide levels
• patients can develop amiodarone induced hypothyroidism or thyrotoxicosis therefore monitoring of TFTs is important

Question 10

causes of hyperthyroidism

Answer 10

• Autoimmune – Graves’ disease (60-80% of cases in UK) • Toxic multinodular goitre
• de Quervain’s – (subacute) thyroiditis
• Medication (overtreatment with levothyroxine)
• Pituitary adenoma (tumour producing excess TSH)
• Transient neonatal thyrotoxicosis (mother with Graves’)
• Thyroid adenoma (rare)

Question 11

graves disease

Answer 11

autoimmune disorder mediated by antibodies that stimulate TSH
- most common in women aged 30-60 years old

• diffuse goitre
• pretibial myxoedema
• thyroid eye disease
• acropachy = swelling of distal digits with overgrown nail plates

Question 12

Toxic multinodular goitre

Answer 12

• Small benign nodules within the thyroid gland. Cells within the nodules are unresponsive to secretory control mechanisms and secrete excessT3 andT4
• Worldwide, iodine deficiency is the most common cause

Question 13

de Quervain’s – subacute thyroiditis

Answer 13

• Painful swelling of the thyroid gland
• Triggered by a viral infection
• Most commonly seen in women aged 20-50

Question 14

hyperthyroidism symptoms

Answer 14

• Anxiety
• Palpitations
• Weight loss
• Goitre
• Hair loss
• Fatigue
• Diarrhoea
• Sweating
• Muscle weakness
• Insomnia
• Periods lighter/infrequent

Question 15

surgery for hyperthyroidism

Answer 15

total thyroidectomy for adults with graves disease

Question 16

potencial complications of thyroid surgery

Answer 16

• haemorrhage
• infection
• damage to laryngeal nerve
• hypothyroidism
• hypocalcaemia
• hypoparathyroidism