Hypoparathyroidism

Question 1

What are the causes of hypoparathyroidism?

Answer 1

Decreased PTH secretion
2 to thyroid surgery
Low Ca, High PO4
Rx with alfcalcidol

Question 2

What are the features?

Answer 2

Perioral parasthesia 
Tetany - muscle spasm + cramp
CHOVESTEK'S sign
TROUSSEAU'S sign 
Prolonged QT

Question 3

What causes these SX/features?

Answer 3

Normally, the resting state of Na channels are stabilised by Ca and prevents spontaneous depolarisation

BUT

Hypoparathyroid = hypoCa
SO more excitable neurones

Question 4

What is Chovestek’s sign?

Answer 4

Tapping facial nerve over parotid gland = twitching of same side

Question 5

What is Trousseau’s sign?

Answer 5

Carpopedal spasm caused by inflating BP cuff 20 mmHg higher for 20 mins = occludes brachial A
= Wrist + metacaropphalangeal joints flex

Question 6

What are the Ix?

Answer 6

Clinical hx

Bloods:
Low Ca
High PO4
Low PTH
Normal ALP

Mg and vitamin D

U&E to exclude CKD

ECG

Question 7

How is it mx acutely?

Severe hypoCa sx

Answer 7

IV calcium

Question 8

How is it mx generally?

Answer 8

Calcium + Vit. D
Parathyroid autotransplant/ allotransplant
Diet rich in dairy containing calcium + vitamin D

Question 9

What is pseudohypoparathyroidism?

What features is it associated with?

What is the blood profile?

How is it dx?

Answer 9

Failure of target cells to respond to PTH due to G protein mutation

Low IQ, short stature, short 4/5th metacarpals, obesity

Low calcium, high PO4, high PTH

Dx made by measuring cAMP and phosphate levels

Question 10

What is pseudopseudohypoparathyroidism?

Answer 10

Similar phenotype as pseudohypoparathyroidism, but normal biochemistry