Hypoparathyroid/Hyperparathyroid Flashcards
1
Q
Causes of hypoparathyroid
A
- decreased PTH secretion
e.g. secondary to thyroid surgery - low calcium
- high phosphate
- alfacalcidol treatment
2
Q
Features of hypoparathyroidism
A
Many are secondary to low Ca2+
- tetany
- perioral paraesthesia
- Trosseau’s/Chvostek’s signs
Chronic: depression, cataracts
3
Q
What ECG change can occur in hypoparathyroid?
A
prolonged QT interval
(same as hypocalcaemia)
4
Q
What is meant by pseudohypoparathyroidism?
A
- target cells insensitive to PTH
- abnormality in a G protein
- low calcium, high phosphate, high PTH
5
Q
Describe the phenotype seen in pseudohypoparathyroidism
A
- low IQ,
- short stature
- shortened 4th and 5th metacarpals
6
Q
How is peudohypoparathyroidism diagnosed?
A
Infusion of PTH then check
- urinary cAMP
- phosphate levels
In hypoparathyroidism
= Increase in cAMP + phosphate
In pseudohypoparathyroidism
Type 1 - neither rises
Type 2 - only cAMP rises
7
Q
What is Pseudopseudohypoparathyroidism
A
Similar phenotype to pseudohypoparathyroidism
but normal biochemistry
