Thyroid & Parathyroid Disease Flashcards
(111 cards)
1
Q
Primary disorders of the thyroid are of what origin?
A
The gland itself
2
Q
All thyroid diseases are goitrous, true or false?
A
False
3
Q
TSH is released by which cells & where?
A
Thyrotroph cells in the anterior pituitary
4
Q
T4/T3 represents the majority of thyroid hormone produced?
A
T4 (80%) AKA “thyroxine”
5
Q
What are the thyroid-binding plasma proteins? (3)
A
1) TBG
2) TTR
3) Albumin
6
Q
True/false: fT3 is the active form of thyroid hormone?
A
True
7
Q
T4 or T3 influences a negative feedback loop?
A
T3
8
Q
Where is T4 principally converted to T3?
A
Liver
9
Q
In primary hypothyroidism, free T3/T4 is what? What is TSH?
A
Free T3/T4 = low
TSH is high
10
Q
In secondary hyperparathyrodism, the free T3/T4 is what & what is the TSH?
A
T3/T4 is high
TSH is inappropriately high or normal
11
Q
What’s the clinical term for a severe hypothyroid emergency?
A
Myxoedema
12
Q
What’s the rare classical skin sign for Graves’ disease?
A
Pretibial myxodema
13
Q
What is the TSH and thyroxine profile in subclinical hypothyrodisim?
A
Thyroxine is just borderline normal while TSH i shigh
14
Q
Hypothyroidism is more common in African populations than whites? true or false?
A
False
15
Q
Iodine uptake positively or negatively correlates with thyroid disease?
A
Positively (more common in higher uptake areas)
16
Q
Hashimoto’s thyroiditis is a condition of hypo/hyper-thyroidism? Does it usually cause goitre?
A
Hypothyroidism & yes goitre present (if not it’s termed atrophic thyroiditis)
17
Q
Iodine deficiency usually induces a goitrous/non-goitrous form of thyroid disease?
A
Goitrous
18
Q
Name 2 drugs which can cause a goitrous hypothyroidism
A
- Amiodarone
- Lithium
19
Q
Atrophic thyroiditis is another term for what
A
Hashimoto’s thyroidits WITHOUT goitre
20
Q
The most common cause of hypothyroidism in the west is…
A
Autoimmune hypothyroidism (e.g. Hashimoto’s or atrophic thyroiditis)
21
Q
Hypothyroidism is more common in women/men?
A
Women
22
Q
What are the defining traits of autoimmune hypothyroidism? (2)
A
1) Antibodies against TPO
2) T-cell infiltrate of thyroid
23
Q
List the main features of hypothyroidism (8)
A
1) Coarse, sparse hair
2) Dull, expressionless face
3) Reduced thermogenesis leading to cold intolerance
4) Cardiac dilation
5) Reduced HR
6) Metabolic hyperlipidaemia (xanthelasma)
7) Decrease in appetite but weight gain
8) Megacolon
24
Q
What neurological signs are associated with hypothyroidism? (3)
A
1) Decreased intellect and motor activity
2) Depression, psychosis
3) Carpal tunnel syndrome
25
Hypothyroidism has no influence on reproduction, true or false?
False - causes painful period, can cause hyperprolactinaemia (excess TRH leads to excess PRL)
26
The cardinal abnormalities in hypothyroidism are (2)
1) Elevated TSH
| 2) Reduced fT4/T3
27
Hyponatremia is present in hypothyroidism, true or false?
True (but rare)
28
Macrocytosis is a feature of hypothyroidism, true or false?
True
29
TRAb antibodies are present in which % of Graves' cases?
70-100%
30
Anti-TPO antibodies are present in which % of autoimmune hypothyroid cases?
95%
31
Which type of respiratory failure is common in myoxedma coma?
Type 2 (hypoxaemia with hypercapnia)
32
Myxoedema coma is a complication of longstanding untreated hypothyroidism. How fatal is it with treatment?
60%
33
How should myoxedema coma be treated (3)?
1) Passive warming
2) Broad-spectrum antibiotics
3) Thyroxine cautiously (but NOT if adrenal failure is present)
34
Thyrotoxicosis is the condition occurring when tissues are exposed to...
Excessive thyroid hormone
35
List the major clinical signs & symptoms of thyrotoxicosis (cardiac, sympathetic, GI, vision, repro, muscles, metabolism)
-Cardiac (AF, palpitations)
-Sympathetic (tremor, sweating)
-GI (frequent, loose stools)
Vision (lid retraction, proptosis)
-Repro (lighter bleeding and less frequent periods)
-Muscles (proximal weakness)
-Metabolism (intolerance to heat, weight loss)
36
Hashitoxicosis refers mostly to what presentation of Hashimoto's?
The initial presentation, which can give rise to transient hyperthyroidism before hypothyroidism
37
Thyrotoxicosis is always associated with hyperthyroidism, true or false?
False
38
DeQuervain's Thyroiditis is a condition of resulting from what factor?
X = thyrotoxicosis
| Resulting from viral infection. Often self-limiting - but can indicate progression
39
Thyroiditis may be caused by amiodarone, true or false?
True
40
Thyrotoxicosis factitia describes what clinical case?
Self or deliberate poisoning
41
Struma ovarii is a condition of what
Ovary teratoma containing thyroid tissue
42
Overtreatment of levothyroxine can lead to thyrotoxicosis, true or false?
True
43
What % of HLA genes determines the risk of developing Graves?
70%
44
The cardinal abnormalities of Graves (biochemistry)
Low TSH, high fT4/T3
45
Hypercalcaemia is present in Graves, true or false?
True - it's a cause of osteoporosis
46
Thyroid acropachy is a sign of which condition?
Graves' Disease
47
What's a goitre sign specific to Graves?
Thyroid bruit
48
Graves' goitre is always bilateral, true or false?
False - can be unilateral
49
Nodular thyroid goitre tends to be symmetrical, true or false?
False
50
Thyroid storm is a medical emergency characterised by...
Severe untreated hyperthyroidism
51
The end-stage manifestation of thyrotoxicosis is...
Thyroid storm
52
How is thyroid storm treated (4)
1) Lugol's iodine
2) Steroids
3) PTU
4) Beta-blockers
53
What's the 1st line treatment for nodular thyroid disease & relapsing Graves?
Radioiodine
54
Radiodine increases risk of thyroid cancer, true or false?
False
55
Radiodine is contraindicated in (2)
Pregnancy & active thyroid disease
56
Which nerve is at risk in thyroidectomy?
Recurrent laryngeal
57
Sub-acute thyroiditis usually progresses to clinical disease, true or false?
False - usually self-limiting
58
Subclinical hypothyroidism does not need to be treated in pregnancy, true or false?
False
59
What's the biochemical profile of subclinical hyperthyroidism?(2)
Low TSH, normal fT4/T3
60
Subclinical thyroiditis is assoicated with which 2 conditions?
Osteoporosis, AF
61
Amiodarone only induces hypothyroidism, true or false?
False - can cause hyperthyroidism as well
62
Amiodarone works how?
Inhibiting DIO1
63
Sick euthyroid syndrome is a rare/common condition in the acutely unwell. It generally needs treated, true or false?
Common - does not often need treatment
64
Spot diagnosis:
- 68 year old female
- TATT, weight gain, goitre, slowness.
- Lab results: high TSH, fT4 low.
- DX: ?
-DX: Primary hypothyroidism
65
Spot diagnosis:
- 68 year old female
- TATT, goitre. FH of thyroid disease.
- Lab results: TSH high, fT4 normal, TPO antibodies present.
- DX: ?
-DX: Subclinical hypothyroidism (as fT4 is normal but TSH is high)
66
Spot diagnosis:
- 52 year old male
- Headache, visual field defect, dizziness, poor libido.
- Lab results: TSH low, fT4 low.
- DX: ?
-DX: Secondary hypothyroidism (secondary to a pituitary tumour - notice the lack of sexual characteristics)
67
Spot diagnosis:
- 32 year old female
- Weight loss, tremor, TATT, sleep disturbance.
- Lab results: TSH very low, fT4 very high.
- DX: ?
-DX: Graves Disease (not secondary as the TSH would be high in this case, indicating the gland is working)
68
Spot diagnosis:
- 70 year old female.
- Diagnosed with AF
- No symptoms
- Lab results: TSH low, fT4 high.
- DX: ?
-DX: Toxic multi-nodular goitre (associated with AF, TSH will be low but the nodules keep producing T4)
69
Spot diagnosis:
- 32 year old female.
- Sore throat & febrile illness. Weight loss, poor sleep.
- Lab results: TSH low, fT4 high.
- Six weeks later lab results change to TSH high, fT4 low.
- DX: ?
-DX: Subacute thyroiditis (DeQuervain's; can present with initial hyperthyroidism then transient hypothyroidism).
70
Principle symptoms of hypothyroidism (4)
1) Reduced BMR, puts on weight easy
2) Slow pulse
3) Fatigue, lethargy
4) Cold intolerance
71
In adults, hypothyroidism may lead to...
Myxoedema (puffy facial appearance)
72
Principle symptoms of hyperthyroidism (5)
1) increased BMR
2) Very fast pulse
3) Emotional lability
4) Sweating & heat intolerance
5) Exopthalmos
73
Which 3 signs are specific to Graves' disease?
1) Thyroid bruits
2) Pretibial myxoedema
3) Thyroid acropachy
74
Lactotroph cells (LH secretors) are under short/long-loop control & what's the mechanism of feedback?
Short loop negative feedback w/ dopamine
75
IGF-1 works on which organ?
Liver
76
No / low cortisol leads to an...
Addisonian Crisis
77
Cabergoline is what kind of drug & what is it used to treat?
Dopamine agonist - used to treat prolactinoma
78
Prolactinomas often require surgical excision, T/F?
False - drugs like cabergoline (dopamine agonists) usually control it well
79
Hypothyroidism can be a cause of raised prolactin, T/F?
True
80
Hypertension is an important feature of acromegaly, T/F?
True
81
The headache in acromegaly is usually treatable with drugs, T/F?
False - it's vascular in origin
82
Acromegaly is diagnosed using which test?
OGTT (looks for IGF-1, which should be suppressed as GH is a counter-regulatory hormone which is released in hypoglycaemia)
83
The first-line therapy for acromegaly is surgical/medical?
Surgical
84
Medical therapies for acromegaly include (3)
1) Dopamine agonists (cabergoline)
2) Somatostatin analogues (octreotide) - advantageous as they also treat headache
3) GH antagonist (Pegvisomant)
85
Pegvisomant (a GH-receptor antagonist) reduces tumour size, T/F?
False
86
Side-effects of somatostatin analogues include (3)
1) Local stinging
2) Flatulence
3) Diarrhoea
87
What drug can be used pre-operatively to improve outcome in GH-tumour surgery?
Somatostatin analogue (e.g. sandostatin) as they will reduce the tumour size
88
Common causes of hypocalcaemia (3)
Hypoparathyroidism, vitamin D deficiency, pseudohypopoarathyroidism
89
What is psuedohypoparathyroidism?
A mutation in GNAS causing a peripheral resistance to parathyroid hormone, giving elevated PTH
90
What is psuedo-psuedo-hypoparathyroidism?
Mutation in GNAS gene (AD) causing lack of peripheral action of PTH, but no resistance (unlike 1 psuedo) - often with normal calcium
91
Describe "CATS go numb" in hypocalcaemia
```
Convulsions
Arrhythmia
Tetany
Spasms
Numbness
```
92
All hypocalcaemia should be treated with IV calcium, T/F?
False - only severe. Mild/moderate can be treated with calcium supplements
93
What effect does PTH have? (3)
1) Bone resorption
2) Decreased calcium loss in urine
3) Enhanced calcium absorption from GI tract
94
Where does vitamin D production occur? (3)
Skin, liver and kidney
95
Where does the final step of vitamin D production occur?
Kidney
96
Which form of vitamin D is made by the kidney?
1, 25-OH vitamin D
97
What are the symptoms of hypercalcaemia?
Fractures (osteitis fibrosa cystica), renal stones, pancreatitis (and nausea& vomiting) and depression.
Painful Bones, Renal Stones, Abdominal Groans and Psychic Moans
98
What's the primary investigation for hyperglycaemia?
ALK-P (if high suggests bony mets, if low myeloma)
99
Causes of hypercalcaemia include (3)
Primary hyperparathyroidism, malignancy, certain drugs (e.g. Vitamin D, thiazides)
100
Treatment of acute hyperglycaemia is with (2)
1) Fluids and ONCE rehydrated 2) loop diuretics (not thiazides)
101
How long do bisphosphonates take to work & what condition are they useful in?
1 week and hypercalcaemia
102
Primary hypercalcaemia is often medically managed, T/F?
False - usually surgical excision required
103
Secondary hyperparathyroidism is a response to...
Low calcium (a physiological)
104
Tertiary hyperparathyroidism develops due to
Multiple years of secondary (parathyroid becomes autonomous)
105
If patient is hypercalcaemic & albumin is raised, what is the likely diagnosis?
Dehydration
106
Cinacalcet is useful in which condition?
Tertiary hyperparathyroidism
107
Hypocalciuric hypocalcaemia is inherited how? What's the defect?
AD and a defect in the calcium sensor (often benign & incidental)
108
Is calcium elevated in Paget's? What about PTH?
No (only ALK-P is elevated)
109
Looser's Zones is a classical X-ray sign of what disease?
Osteomalacia
110
Vitamin-D resistant Rickets is a genetic condition with which association?
X-linked hypophosphataemia (due to PHEX / FGF23 gene mutation)
111
FGF23 is secreted by which cell?
Osteocyte
