Endocrine: Graves Disease

Question 1

Pathophysiology of Graves disease

Answer 1

Body produces IgG antibodies TSH receptor.
These antibodies bind to TSH receptors causing chronic stimulation.

Question 2

What does hyperstimulation of the thyroid follicular cells cause?

Answer 2

Excessive production of T3 and T4
Hypertrophy of the thyroid gland
Hyperplasia of thyroid follicular cells

Question 3

Extrathyroidal manifestations of graves

Answer 3

Eye disease (30%)
Pretibial myxoedema (3%)
Thyroid acropachy (1%)

Question 4

Investigations for graves (2 Steps)

Answer 4

Step 1 is to test for thyroid dysfunction
- TSH low, T3/T4 high
Step 2 if step 1 positive: further testing for Graves’ disease
- TSH receptor antibodies (TRAbs): present in Graves’ disease.
- Technetium scan of thyroid gland: considered if TRAbs are negative.

Question 5

How to assess for eye involvement?

Answer 5

Examine visual fields, acuity and eye movements.
MRI or CT scans can confirm the diagnosis (especially if subclinical).

Question 6

Management of Graves?

Answer 6

Radioactive Iodine
Anti-thyroid drugs e.g. carbimazole
Surgery

Question 7

Indications/Contraindications for radioactive iodine

Answer 7

NICE recommend first line unless CI

Indications:
- First-line definitive treatment, unless anti thyroid drugs are likely to achieve remission or it is unsuitable

Contraindications:
- pregnancy
- attempts to conceive within the next 4-6 month
- presence of active eye disease
- concerns about compression or malignancy.

Question 8

Indications for anti-thyroid drugs

Answer 8

Indications:
- If it is likely to achieve remission, or if radioactive iodine and surgery are unsuitable.

Question 9

When is surgery used for management/ complications?

Answer 9

• Concerns about compression or malignancy
• Radioactive iodine and antithyroid drugs unsuitable
• antithyroid drugs have been tried but hyperthyroidism persisted or relapsed.

Risks: recurrent laryngeal nerve damage, hypoparathyroidism.

Patients become hypothyroid, thus require replacement therapy.

Question 10

Side effects of radioactive iodine?

Answer 10

Patients often become hypothyroid so replacement required.

Question 11

How long do you give anti-thyroid drugs?

Answer 11

12-18 months

Question 12

What indicates remission when using anti-thyroid drugs? when is it more likely?

Answer 12

Euthyroid status after withdrawal of antithyroid drugs
Occurs in around 50% of Graves’ patients.

Remission is more likely in mild and uncomplicated Graves’ disease.