Graves Disease

Question 1

Definition of Graves’ disease

Answer 1

Is an autoimmune thyroid condition associated with hyperthyroidism
• Caused by the presence of TSH receptor autoantibodies

Question 2

Aetiology of Graves’ disease

Answer 2

• An autoimmune condition that is characterised by thyroid hormone overproduction due to stimulation of the thyroid by anti-TSH antibodies

• Graves is the most common cause of thyrotoxicosis

Question 3

Risk factors for Graves’ disease

Answer 3

• Female
• Smoking
• Family history
• High iodine intake

Question 4

Pathophysiology of Graves’ disease

Answer 4

• Many patients have overlapping autoimmunity (anti-TPO antibodies would hence also be present in Graves)

• The anti-TSH receptor antibodies cause the thyroid hormone overproduction as well as thyroid hypertrophy and hyperplasia -> leading to goitre

• TSH receptors are also found at extrathyroidal sites (e.g retro-orbital and dermal tissue)

Question 5

History and Examination of Graves’ disease

Answer 5

• Heat intolerance: increased metabolism leads to higher body temperature
• Sweating
• Weight loss
• Palpitations
• Tremor
• Diffuse goitre
• Exophthalmos
• Irritability
• Moist, velvety skin
• Pretibial myxoedema
• Oligomennorhoea
• Thyroid acropachy
• Sexual dysfunction
• Anxious
• Diarrhoea
• Muscle weakness

Question 6

Investigations for Graves’ disease

Answer 6

• TSH: Suppressed due to increased thyroid hormone
• TSH receptor antibodies: would be positive, and is a DIAGNOSTIC TEST for Graves’ disease
• T3 and T4: would elevated

Consider thyroid uptake scan

Question 7

Management of Graves’ disease

Answer 7

Thyroid storm:
1) High dose anti thyroid medication, corticosteroids, beta blockers and iodine solution: presents with volume depletion, congestive heart failure, confusion, nausea and vomiting and extreme agitation

Symptomatic:
1) Prolonged anti thyroid drug therapy:
◦ Treatment should continue for 12-18 months
◦ Skin rash side effects
◦ CARBIMAZOLE, thiamazole

+ Symptomatic therapy: Give beta blocker for tachycardia, tremor and anxiety (e.g propranolol)

OR

1) Radioactive iodine: Ablates the thyroid tissue, then thyroid hormone replacement is needed (can also be used as salvage therapy after medication to ensure its all clear or if medical treatment fails)

OR

1) Thyroidectomy: risk of recurrent laryngeal nerve injury ->hoarseness of voice. Give iodine doses beforehand to reduce vascularisation of the gland

Question 8

Complications and prognosis of Graves’ disease

Answer 8

• Bone mineral loss
• AF
• Congestive heart failure: type of high output failure

• Untreated would increase the risk of mortality
• Prognosis of hyperthyroidism post anti thyroid medication therapy is excellent