Grave's Disease

Question 1

Grave’s disease

Answer 1

the most common cause of hyperthyroidism

autoimmune

serum IgG antibodies bind to TSH receptors in the thyroid, stimulating thyroid hormone production (behave like TSH)

Question 2

epidemiology

Answer 2

autoimmune - middle aged women commonly affected

interacting susceptibility genes, plus environmental factors

associated with other autoimmune diseases eg vitiligo, T1DM

Question 3

smoking

Answer 3

important

smokers tend to get a more severe form of the disease that is harder to treat

Question 4

thyroid hormone levels

Answer 4

T4 wil be raised, T3 may be high or in the normal region

TSH decreased

Question 5

what antibody is found in >95% of patients

Answer 5

TSH receptor antibody - TRAb

Question 6

WCC

Answer 6

often decreased, however mild and related to the disease rather than the treatment

Question 7

what bone disease is grave’s associated with

Answer 7

osteoperosis - reflective of increased bone turnover due to increased thyroid hormones

hypercalcaemia and raised alkaline phosphate

Question 8

hands and feet

Answer 8

• thyroid acropachy
• soft tissue swelling of the hands and finger and toe clubbing
• bilateral and symmetrical

Question 9

what is thyroid acropachy almost always associated with

Answer 9

pretibial myxoedema

Question 10

what can be heard over the neck in Grave’s

Answer 10

thyroid bruit - only in very large goitres

is reflective of the hypervascularity of the thyroid gland

Question 11

what is the main risk factor for thyroid eye disease

Answer 11

smoking

cessation is cruical

Question 12

what can be the first presenting sign of graves

Answer 12

eye disease

does not always correlate with thyroid disease, the patient may be euthyroid, hypo or hyper thyroid

Question 13

what drives the pathophysiology of thyroid eye disease

Answer 13

TRAb - there are receptors similar to TSH receptors in the tissues and muscles surrounding the eyeball and these are stimulated by circulating TSH

Question 14

clinical features of thyroid eye disease

Answer 14

water build up and retro orbital swelling - causes eyes to be pushed forward (bulging eyes = exophthalmos/proptosis) and for the eyes to become swollen and red

collagen fibre deposition in the tissue and muscle around the eyes causes muscle swelling and fibrosis leading to loss of function and lack of movement of the eyeball

- this can cause double vision (diplopia) or opthalmoplegia

lid lag, eyes feel gritty, loss of colour vision

Question 15

Ophthalmoplegia

Answer 15

weakness or paralysis of the eye muscles, especially of the upward gaze

Question 16

what other features occur in thyroid eye disease

Answer 16

eyes feel gritty

loss of colour vision

afferent pupillary defect can indicate optic nerve compression

Question 17

how severe does thyroid eye disease tend to be

Answer 17

most disease in mild, however it can be severe and life threatening

Question 18

how is thyroid eye disease treated

Answer 18

mild - topically

severe - steroids, radiotherapy and surgery

Question 19

pretibial myoxedema

Answer 19

(Grave’s dermopathy), a rare sign (<1%)

caused by TSH antibodies bind ing to and stimulating fibroblasts to increase glycosaminoglycan production

there is bilateral plaque formation usually on the anterior aspect of the lower legs, although it can be found on any skin surface

distinctive orange peel look and is non-pitting