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Flashcards in Thyroid Disease Deck (73)
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1
Q

If a thyroid condition is described as Primary, what is actually affected by the disease process?

A

affecting thyroid gland itself

2
Q

Can thyroid disease occur both WITH and WITHOUT a goitre?

A

Yes

goitrous or non-goitrous

3
Q

What type of disease process is usually responsible for types of thyroid disease?

A

Autoimmune

4
Q

If there is a problem in the hypothalamus or pituitary gland, what is this referred to in terms of thyroid disease?

A

Secondary Thyroid disease

5
Q

What is the other name for Thyroid Stimulating Hormone (TSH)?

A

thyrotropin

6
Q

Where is TSH or Thyrotropin released from?

A

Thyrotroph cells in anterior pituitary

Released in response to Thyrotropin Releasing Hormone (TRH)

7
Q

Describe the levels of Free T3/T4 and TSH found in Primary Hypothyroidism?

A
Free T3/4 low
TSH high (body's reaction to low circulating hormone)
8
Q

Describe the levels of Free T3/T4 and TSH found in Primary Hyperthyroidism?

A

Free T3/4 high

TSH low

9
Q

What is the difference in the level of TSH between primary and secondary Hypothyroidism?

A

TSH low (or ‘normal’) in secondary hypothyroidism

Due to problem being in pituitary/hypothalamus
=> less able to sense body’s required response

10
Q

What is the difference in the level of TSH between primary and secondary Hyperthyroidism?

A

TSH high (or ‘normal’) in secondary hyperthyroidism

11
Q

What name is given to the condition which is a severe form of hypothyroidism causing a medical emergency?

A

Myxoedema

12
Q

What disease does Pretibial Myxoedema usually indicate?

A

rare clinical sign of Graves’ disease

13
Q

Incidence of thyroid disease is higher in White Caucasian populations than in ethnic minorities. TRUE/FALSE?

A

TRUE

higher in areas of high iodine intake

14
Q

What conditions could cause Goitrous Primary Hypothyroidism?

A
  • Chronic thyroiditis (Hashimoto’s)
  • Iodine deficiency
  • Drug-induced (e.g. amiodarone, lithium)
  • Maternally transmitted (e.g. antithyroid drugs)
15
Q

What conditions can cause Primary Hypothyroidism that presents without a goitre?

A
  • Atrophic thyroiditis
  • Post-ablative therapy (e.g. radioiodine, surgery)
  • Post-radiotherapy (e.g. for lymphoma treatment)
  • Congenital developmental defect
16
Q

What forms of Primary Hypothyroidism can be self-limiting?

A
  • Following withdrawal of antithyroid drugs
  • Subacute thyroiditis with transient hypothyroidism
  • Post-partum thyroiditis
17
Q

What are the usual characteristics in Hashimoto’s Thyroiditis?

A
  • Antibodies against thyroid peroxidase (TPO)

- microscopic T-cell infiltrate and inflammation

18
Q

What clinical signs of Hypothyroidism can occur in the skin?

A
  • Coarse, sparse hair
  • Periorbital puffiness
  • Pale cool skin that feels doughy to touch
  • Vitiligo
  • Hypercarotenaemia (Yellowing Skin)
19
Q

Patients experiencing hypothyroidism become intolerant to the heat. TRUE/FALSE?

A

FALSE
They become cold all the time
Patients with HYPERthyroidism become intolerant to the heat

20
Q

What cardiac symptoms and complications can a patient with Hypothyroidism experience?

A
  • Reduced heart rate
  • Cardiac dilatation
  • Pericardial effusion
  • Worsening of heart failure
  • Hyperlipidaemia
21
Q

Patients with hypothyroidism find it easy to put on weight. TRUE/FALSE?

A

TRUE

can cause easy weight gain

22
Q

Describe the GI symptoms experienced in both hypothyroidism and hyperthyroidism

A
HYPO = Constipation
HYPER = Diarrhoea
23
Q

What respiratory symptoms can be experienced in hypothyroidism?

A
  • Deep hoarse voice
  • Macroglossia (unusally large tongue)
  • Obstructive sleep apnoea
24
Q

What neurological symptoms can arise from Hypothyroidism?

A
  • Depression/psychosis/neuro-psychiatric
  • Muscle stiffness, cramps
  • Peripheral neuropathy
  • Prolongation of the tendon jerks
  • Carpal tunnel syndrome
25
Q

Does Hypothyroidism cause heavier or lighter periods?

A
  • Menorrhagia (heavier periods)

- Patients can also experience irregular periods or no periods at all

26
Q

What is the starting dose for hypothyroid patients beginning on levothyroxine?

A

Younger patients = 50-100 μg daily

Elderly with Hx of IHD: start 25-50 μg daily, adjusted every 4 weeks according to response

27
Q

How long after a dose change should a patient’s TSH levels be checked?

A

2 months after any dose change

28
Q

Once TSH is stabilised, how often should it be checked?

A

TSH should be checked every 12-18 months

29
Q

Why is T3 therapy not often used in hypothyroidism?

A

T3 effects develop within a few hours and disappear within 24-48 hours of discontinuation

30
Q

Dose requirements in hypothyroidism may increase in pregnancy. TRUE/FALSE?

A

TRUE

Due to increased TBG

31
Q

What group of people are most affected by Myxoedema coma?

A

Elderly females with frequently unrecognized or untreated hypothyroidism

32
Q

What symptoms of a myxeoedema coma can be found on an ECG?

A
  • bradycardia
  • low voltage complexes
  • varying degrees of heart block
  • T wave inversion
  • prolongation of the QT interval
33
Q

What respiratory symptoms can be seen in myxoedema coma?

A

Type 2 respiratory failure:

=> hypoxia, hypercarbia, respiratory acidosis

34
Q

What percentage of patients with myxoedema coma also experience adrenal failure?

A

10% of patients

35
Q

How should myxoedema coma be treated and monitored?

A
  • Intensive care ( A, B, C, D, E )
  • Passively rewarm (slow rise in body temp.)
  • Cardiac monitoring for arrhythmias
  • Broad spectrum antibiotics
  • Thyroxine cautiously

Monitor:

  • urine output
  • fluid balance
  • central venous pressure
  • blood sugars
  • O2
36
Q

What is the definition of thyrotoxicosis

A

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

37
Q

Describe the difference between Hyperthyroidism and thyrotoxicosis

A

Hyperthyroidism = conditions where overactivity of the thyroid gland leads to thyrotoxicosis

38
Q

What are the potential cardiac symptoms of thyrotoxicosis?

A
Palpitation, atrial fibrillation (AF)
Cardiac failure (very rare)
39
Q

Thyrotoxicosis causes what effect on the sympathetic nervous system?

A

Tremor

Sweating

40
Q

What CNS symptoms can be caused by thyrotoxicosis?

A

Anxiety
nervousness
irritability
sleep disturbance

41
Q

Constipation can be a sign of thyrotoxicosis. TRUE/FALSE?

A

FALSE

Thyrotoxicosis usually results in frequent, loose bowel movements

42
Q

What are the common features of thyrotoxicosis which present in the eye?

A

Lid retraction (not specific to Graves’)
Double vision
Proptosis (Eyes bulging forward - only really seen in Grave’s)

43
Q

What hair and nail changes can be noticed in thyrotoxicosis?

A

brittle, thin hair

Rapid fingernail growth

44
Q

Patients with thyrotoxicosis usually experience heavier periods. TRUE/FALSE?

A

FALSE

lighter bleeding and less frequent periods

45
Q

In what areas do patients with thyrotoxicosis experience muscle weakness?

A

thighs and upper arms

46
Q

Patients with thyrotoxicosis usually gain weight easily. TRUE/FALSE?

A

FALSE

can experience weight loss regardless of increased appetite

47
Q

Are patients with thyrotoxicosis usually intolerant to the heat or to the cold?

A

Heat intolerant

48
Q

What causes of thyrotoxicosis are related to hyperthyroidism?

A

Excessive thyroid stimulation
=> Grave’s DIsease
=> Hashitoxicosis
=> Cancer

Thyroid nodules with autonomous function
=>Toxic solitary nodule
=> Toxic multinodular goitre

49
Q

What causes of thyrotoxicosis are NOT associated with hyperthyroidism?

A

Thyroid inflammation (thyroiditis)
=> Sub acute (de Quervains)
=> Post partum

Exogenous thyroid hormones
=> overtreatment with levothyroxine

Ectopic thyroid tissue
=> Metastatic thyroid cancer

50
Q

What age do patients usually develop Grave’s Disease?

A

Younger (20-50yrs)

51
Q

Smoking is an important factor in Grave’s Disease. TRUE/FALSE?

A

TRUE

major risk factor especially for developing Grave’s related thyroid disease

52
Q

Aside from TSH and free T3/T4 levels, what other lab results can be seen in a patient with Grave’s disease?

A

Hypercalcaemia
↑Alkaline phosphatase
Leucopenia (↓white cell count)
TSH receptor antibody (TRAb)

53
Q

What clinical signs are extremely specific to Grave’s Disease?

A

Pretibial Myxoedema
Thyroid acropathy (severe finger clubbing)
Thyroid Bruit (Associated only with large goitres)
Grave’s Opthalmopathy

54
Q

A nodular goitre is more likely to present in younger people. TRUE/FALSE

A

FALSE

older patients

55
Q

A nodular goitre usually has an insidious onset. TRUE/FALSE?

A

TRUE

56
Q

What type of Goitre may be seen in nodular disease?

A

Assymetrical

57
Q

Will nodular thyroid disease be TRAb positive or negative?

A

Negative

58
Q

What is Thyroid Storm? (also known as Thyroid Crisis)

A

Severe hyperthyroidism!

  • Respiratory and cardiac collapse
  • Hyperthermia
  • Exaggerated reflexes
  • May require mechanical ventilation
59
Q

How should Thyroid Storm/crisis be treated?

A
Lugol’s Iodine,
glucocorticoids
Propylthiouracil (PTU)
β-blockers
fluids
60
Q

When does thyroid storm/crisis usually occur?

A

Hyperthyroid patients with:

  • acute infection/illness
  • Recent thyroid surgery
61
Q

What is the 1st line anti-thyroid drug?

A

Carbimazole

62
Q

What anti-thyroid drug is used in the first trimester of pregnancy and why?

A

Propylthiouracil (PTU)

Risk of Carbimazole causing aplasia cutis in early pregnancy

63
Q

What are the differences between giving Carbimazole and Propylthiouracil?

A

Carbimazole:
Once daily dosing
Less side effects
10x more potent

Propylthiouracil:
Twice daily dosing
10x less potent
Side effects more common (e.g. liver failure)

64
Q

What are the main side effects of anti-thyroid drugs?

A

allergic type reactions – rash, urticaria, arthralgia

Cholestatic jaundice/ Liver failure

Agranulocytosis

65
Q

What drugs provide immediate relief from thyrotoxic symptoms?

A

Beta Blockers

Propanolol preferred

66
Q

If a patient is asthmatic and cannot tolerate Beta Blockers, what drug should be given instead to manage Thyrotoxic symptoms?

A

Calcium Channel Blockers

e.g. Diltiazem

67
Q

What is Radioiodine used for?

A

1st choice treatment for relapsed Graves’ disease and nodular thyroid disease

can cause Patient to have HYPOthyroidism

68
Q

When would a thyroidectomy be indicated?

A

If radioiodine was contraindicated

69
Q

What complications can arise during a thyroidectomy?

A

recurrent laryngeal nerve palsy
Hypothyroidism/ Hypoparathyroidism
Anaesthetic Risk
Permanent Scar

70
Q

What are the most common causes of thyroiditis?

A
  • Hashimoto’s
  • De Quervain’s/subacute (viral)
  • Post-partum
  • Drug-induced (e.g. amiodarone)
  • Radiation
  • Acute suppurative thyroiditis (bacterial)
71
Q

Who is most likely to get Subacute thyroiditis?

A

Females

Ages 20-50 years

72
Q

Is subacute thyroiditis usually self limiting?

A

Yes

Over a few months

73
Q

What is meant by non-thyroidal illness?

A

impact of intercurrent illness (e.g. severe infection) on the Hypothalamic-Pituitary axis

TSH = suppressed initially then rises during recovery