Hyperthyroidism/ hypothyroidism/thyroiditis

Question 1

primary thyroid disease

Answer 1

disease affecting thyroid gland itself
can occur with or without goitre

Question 2

secondary thyroid disease

Answer 2

hypothalamic or pituitary disease
no thyroid gland pathology

Question 3

what is TSh released by

Answer 3

thyrotroph cells in anterior pituitary

Question 4

what is TSH released in reponse to

Answer 4

TRH

Question 5

what is another name for thyroid stimulating hormone

Answer 5

thyrotropin

Question 6

hormone characteristiscs in primary hypothyroidism

Answer 6

free t3/t4 low
TSH high

Question 7

hormone characteristics in primary hyperthyroidism

Answer 7

free t3/t4 high
TSH low

Question 8

secondary hypothyroidism hormone characteristics

Answer 8

free t3/t4 low
TSH low or normal

Question 9

secondary hyperthyroidism hormone charcateristcs

Answer 9

free t3/t4 high
TSH high or normal

Question 10

myxoedema

Answer 10

severe hypothyroidism
medical emergency
when hypothyroidism goes untreated for a long time

Question 11

pretibial myxoedema

Answer 11

localized skin condition associated with Graves’ disease

characterized by thickened, waxy, and discolored skin on the shins, though it can also occur on other areas like the feet or dorsa of the toes

Question 12

goitrous primary hypothyroidism causes

Answer 12

Chronic thyroiditis (Hashimoto’s thyroiditis)
Iodine deficiency
Drug-induced (e.g. amiodarone, lithium)
Maternally transmitted (e.g. antithyroid drugs)
Hereditary biosynthetic defects

Question 13

non goitrous primary hypothyroidism causes

Answer 13

Atrophic thyroiditis
Post-ablative therapy (e.g. radioiodine, surgery)
Post-radiotherapy (e.g. for lymphoma treatment)
Congenital developmental defect

Question 14

self limiting primary hypothyroidism caueses

Answer 14

Following withdrawal of antithyroid drugs
Subacute thyroiditis with transient hypothyroidism
Post-partum thyroiditis

Question 15

secondary hypothyroidism causes

Answer 15

Infiltrative
Infectious
Malignant
Traumatic
Congenital
Cranial radiotherapy
Drug-induced

Question 16

hashimotos thyroiditis

Answer 16

autoimmune destruction of thyroid gland and reduced thyroid hormone production

Characterised by
Antibodies against thyroid peroxidase (TPO)
T-cell infiltrate and inflammation microscopically

Question 17

hypothyroidism clinical features

Answer 17

Hair and skin
Coarse, sparse hair
Dull, expressionless face
Periorbital puffiness
Pale cool skin that feels doughy
to touch
Vitiligo may be present
Hypercarotenaemia

Thermogenesis
Cold intolerance

Fluid Retention
Pitting oedema

Cardiac
Reduced heart rate
Cardiac dilatation
Pericardial effusion
Worsening of heart failure

Metabolic
Hyperlipidaemia

Metabolic rate
Decreased appetite
Weight gain

GI
Constipation
(Megacolon and intestinal obstruction)
(Ascites)

Respiratory
Deep hoarse voice
Macroglossia
Obstructive sleep apnoea

Neurology/CNS
Decreased intellectual and motor activities
Depression, psychosis, neuro-psychiatric
Muscle stiffness, cramps
Peripheral neuropathy
Prolongation of the tendon jerks
Carpal tunnel syndrome
(Cerebellar ataxia, encephalopathy)
Decreased visual acuity

Question 18

abnormslities in blood tests of primary hypothyroidism

Answer 18

Macrocytosis (↑MCV)
↑Creatine kinase (CK)
↑LDL-cholesterol
Hyponatraemia
↓renal tubular water loss
Hyperprolactinaemia
↑TRH leads to ↑PRL (often mild)

Question 19

thyroid auto antibodies

Answer 19

anti-TPO
anti- thyroglobulin
TSH receptor antibody

Question 20

most common auto antibodies in autoimmu e hypothyroidism

Answer 20

anti-top= 95%
anti thyroglobulin= 60%
tsh receptor antibody= 10-20%

Question 21

hypothyroidism drug management

Answer 21

levothyroxine
children- 50-100
elderly- 25-50

Question 22

treatment of myxoedema coma

Answer 22

Intensive care, remember – A, B, C!
Passively rewarm: aim for a slow rise in body temperature
Cardiac monitoring for arrhythmias
Close monitoring of urine output, fluid balance, central venous pressure, blood sugars, oxygenation
Broad spectrum antibiotics
Thyroxine cautiously (hydrocortisone)

Question 23

findings in myxoedema coma

Answer 23

ECG: bradycardia, low voltage complexes, varying degrees of heart block, T wave inversion, prolongation of the QT interval
Type 2 respiratory failure: hypoxia, hypercarbia, respiratory acidosis
Co-existing adrenal failure is present in 10% of patients

Question 24

who does myxoedma usually affect

Answer 24

elderly women with long standing but frequently unrecognized/ untreated hypothyroidism

Question 25

thyrotoxicosis

Answer 25

clinical physiological and biochemical state arising when the tissues are exposed to excess thyroid hormone

Question 26

hyperthyroidism in compairson to toxicosis

Answer 26

conditions in which overactivity leads to thyrotoxicosis

Question 27

symptoms and signs of thyrotoxicosis

Answer 27

Cardiac Palpitation, atrial fibrillation (AF) Cardiac failure (very rare) Sympathetic Tremor Sweating CNS Anxiety, nervousness, irritability, sleep disturbance GI Frequent, loose bowel movements Vision Lid retraction (not specific to Graves’) Double vision (diplopia) Proptosis (Graves’) Hair and skin Hair change – brittle, thin hair Rapid fingernail growth Reproductive Menstrual cycle changes, including lighter bleeding and less frequent periods Muscles Muscle weakness, especially in the thighs and upper arms Metabolism Weight loss despite increased appetite Thermogenesis Intolerance to heat

Question 28

tests in nodular thyroid disease

Answer 28

↑fT4/3, ↓TSH Antibody negative (TRAb) Scintigraphy: high uptake Thyroid US

Question 29

nodular thyroid disease

Answer 29

presence of one or more discrete lumps (nodules) within the thyroid gland

Question 30

first line drug for hyperthyroidism

Answer 30

carbimazole ocne daily dosing

Question 31

propythiouracil

Answer 31

1st line only in 1st trimester of pregnancy Twice daily dosing 10x less potent compared to carbimazole Inhibits DIO1 (↓T4 to T3 conversion)

Question 32

side effcts of atds

Answer 32

Generally well tolerated drugs 1-5% will develop allergic type reactions – rash, urticaria, arthralgia Cholestatic jaundice, ↑liver enzymes, fulminant hepatic failure (PTU) Agranulocytosis 0.1-0.5% of patients ATDs cannot be used again Risk highest in first 6 weeks No evidence for monitoring of FBC Warn patient verbally and in writing to stop drug and have urgent FBC checked in event of fever, oral ulcer or oropharyngeal infection

Question 33

Useful drug for immediate symptomatic relief of thyrotoxic symptoms

Answer 33

beta blockers propanolol is drug of choice

Question 34

first choice treatment for relapsed graves disease and nodular thyroid disease

Answer 34

radioiodine

Question 35

what is radiodine contraindicated in

Answer 35

pregnancy active thyroi eye disease

Question 36

thyroiditis

Answer 36

inflammaton of thyroid ashimoto’s De Quervain’s/subacute (viral) Post-partum Drug-induced (amiodarone, lithium) Radiation Acute suppurative thyroiditis (bacterial)

Question 37

subacute thyroiditis

Answer 37

May be triggered by viral infection May be associated with neck tenderness, fever, or other viral symptoms Usually self limiting (over a few months) Scintigraphy scan – low uptake throughout ages 20-50

Question 38

where does hypothyroidism tend to occur

Answer 38

in iodine rich areas

Question 39

where does hyperthyroidism tend to occur

Answer 39

in iodine deficient areas

Question 40

subclinical thyroid disease

Answer 40

increased TSH with normal t3/t4 subtle, noticed in blood tests

Question 41

non thyroidal illness

Answer 41

in unwell patient tsh typically suppressed initially then rises during recovery

Question 42

type 1 amiodarone induced thyroiditis

Answer 42

usually due to pre existing thyroid issue amiiodarone consitss of lots of iodine so causes iodine overload leading to excessive thyroid hormone production

Question 43

type 2 amiodarone induced thyroiditis

Answer 43

direct damage to thyroid tissue usually self limitting so managed with corticosteroids to reduce inflammation

Question 44

is carpal tunnel syndrome assoc with hypo or hyper

Answer 44

hypo

Question 45

thyrotoxicosis

Answer 45

thyroid storm administer PTU as more rapid than carbimazole, prevents t4 into t3