ALL ABOUT THYROID IN MRCP PACES

ALL ABOUT THYROID IN MRCP PACES


Based on the instruction given, you may decide on where you going to start your examination first. For example, if the instruction given, 'to assess thyroid status', you can start at the peripheries than onto the thyroid gland. Or if the instruction given, ' to examine the patient's neck', then you may want to start at the neck first and then go onto peripheral when you have extra time.


1. GENERAL INSPECTION
Basic step is ALWAYS your general inspection, inform the patient that you want to stand at the edge of the bed to have a general look first:
-> patient may appeared anxious, fidgeting, myxedema facies (dull, puffy, sparse hair with loss of 1/3 of eyebrow)
-> if you shake patient hands, the palms are warm and sweaty in hyperthyroid patient
-> brief look at the eye and neck , you may noticed exopthalmos or large goitre


2. HANDS
If you start from peripheries, begin with the hands for:
-> sweaty and warm palm
-> check for the pulse for bounding tachycardic and sometime irregular (in AF) pulse
-> nail clubbing ('thyroid acrophachy')
-> stretch the arm to look for tremor
-> Tinels and phalen's test for carpal tunnel syndrome
->  +- Pemberton's sign: ask patient to raise the arms above their head and look for suffusion of face (signs of retrosternal goitre)


3. EYES
-> check for lid lag, lid retraction
-> proptosis
-> corneal involvement with conjunctivae chemosis and redness
-> EOM - assess for diplopia which often due is complex opthalmoplegia  from swelling of intra-ocular muscle


4. NECK
-> check for goitre (assess for size, texture- is it smooth or nodular, is it a solitary of multiple nodule) or thyroidectomy scar
-> check mobility with swallowing (versus with sticking out tongue to differentiate from thyroglossal cyst)
-> palpate for cervical LN
-> listen for bruits
-> check for retrosternal extension


5. LIMBS
-> test power to look for proximal myopathy
-> brisk or slow deep tendon reflxes
-> pretibial myxoedema (waxy, non-pitting oedema with hyperpigmentation and induration due to to stimulation of fibroblast and large amounts of glycosoaminoglycan)


Investigation:

-> Thyroid function test (including T3, T4 and TSH)
-> thyroid antibodies (TSH receptor Ab, Tg Ab, thyroid peroxidase)
-> US thyroid for goitre
-> Radio-isotope scan, if 'cold nodule' -> FNAC
-> CT/MRI neck for retrosternal extension
-> CT scan of orbit, Hertel's exopthalmometer  for eye involvement
-> Serum calcitonin (MEN-2)


Causes of hyperthyroidsm:

1. Graves disease
2. Toxic adenoma
3. Multi-nodular goitre
4. Viral/post-partum thyroiditis
5. Iodide-induced
6. Iatrogenic- over replacement of thyroxine in hypothyroid patient


Causes of hypothyroidsm:

1. Hashimoto thyroiditis
2. Recovery from thyroiditis
3. Iodide- deficient
4. Iatrogenic- over-treatment from anti-thyroid meds in hyperthyroid patient


Management of thyroid patient:

-> Anti-thyroid medication (Carbimazole, PTU). Carbimazole is preferred as once/daily dosing, PTU is preferred as safer in pregnancy but thrice/daily dosing). Risks of agranulocystosis, hepatitis, rashes including Steven Johnson Syndrome. Inform patient, if  develop fever, sore throat, so seek treatment immediately in view of risk of neutropenia.
-> Beta -blockers (ie: Propranolol to help with palpitation and aid to reduce T4-T3 conversion)
-> thyroxine replacement for hypothyroid patient (lower dose in elderly and patient with known heart disease)
-> for hyperthyroid patient, aim for treatment with anti-thyroid medication for 18 months and monitor for relapse. In patient with frequent relapse, other treatment to consider include RAI  (may worsened thyroid eye disease, in mild eye disease, oral steroid should be use as prophylaxis) and thyroidectomy


Management of thyroid opthalmopathy:

-> stop smoking
-> mild: eye drops, elevate the head at night, diuretic to reduce oedema, tinted glass for protection
-> moderate: tarsorraphy surgery, prism put in front of spectacle to help with diplopia
-> severe: treated immediately with high dose steroids, orbital irradiation and plasma exchange as adjunct, if there is no improvement within 72-96 hrs, to consider orbital nerve decompression by surgical removal of the floor and medial wall of the orbit


The end