Parathyroid Disorders

Question 1

What are the functions of parathyroid hormone

Answer 1

PTH is released in response to low blood calcium / high phosphate

PTH acts on:

1. Catalysing VITAMINE D3 Activation ->Calcitriol
   Calcitriol acts on intestines to increase Abdo Ca2+ absorption + kidney to reduce Ca2+ excretion
   2.Increase bone resorption: Indirectly increase osteoclast activity + Directly inhibit osteoblast activity
2. Decrease phosphatase resorption

Question 2

Which hormone opposes the action of PTH?

Answer 2

Calcitonin released by Thyroid gland oppose PTH and reduce blood calcium levels by

Inhibiting Bone resorption

Question 3

What are the different types of hyperparathyroidism and associated causes>

Answer 3

Primary Hyperparathyroidism - Parathyroid adenoma (MC), Hyperplasia
Secondary Hyperparathyroidism - Low VITD (CKD/DEFICIENCY)
Tertiary Hyperparathyroidism - Autonomic secretion following long term 2o causes

Question 4

Which serum levels is to be taken when assessing parathyroid function and how would it look for each type of hyperparathyroidism?

Answer 4

Also ALP will be up in all of them

Question 5

What signs and symptoms will present in hyperparathyroidism?

Answer 5

Sx is associated with hypercalcemia - BSGM

Bones - Bone pain / Osteoperosis
Stone - Renal Stones, Haematuria; due to renal stones
Abdo groan - Abdo pain
Psychic moans - Anxiety/depression

+polyuria/polydispsia

Question 6

hyper Parathyroid DX

Answer 6

PTH profile - indicates which source
ECG - Hypercalcaemia ~ Short QT (primary)

other
Dexa Scan - Assess bones
CT KUB - Kidney Urethra Bladder- Assess kidney function and stones

Question 7

Hyperparathyroid TX

Answer 7

Parathyroidectomy
+
Bisphosphonates - bone protection
Calcimimetics - Calcitrol - Reduce PTH=Ca2+

2o:
Tx underlying cause - CKD - renal transplant / vit d def - vit supplements
+
Ca2+ Suuplements

Question 8

What are the causes of hpoparathyroidism

Answer 8

Iatrogenic - MC Neck surgery
Metabolic - Hypo magnesium (MG need for secretion)
Autoimmune - Isolated autoimmune hypoparathyroidism
Congenital: DiGeorge syndrome: 22q11

Question 9

What the associated signs with DiGeorge syndrome: 22q11

Answer 9

22q11 deletion leads to failure to develop the 3rd and 4th pharyngeal arches.

Features can be summarised by the mnemonic, CATCH22

CATCH22: cardiac abnormalities, abnormal facies, thymic aplasia, cleft palate, hypoparathyroidism, 22q11 deletion

Question 10

How would hypo parathyroid present?

Answer 10

Hypocalcemia - CATS go numb

CONVULSION
ARRYTHMIAS
TETANY - SPASM
and
numbness/ Paresthesia

+ Signs
Chvostek’s sign
Trousseau’s Signs

Question 11

FACIAL NERVE TAP CAUSES FACIAL TWITCHING

Answer 11

CHVOSTEK’S SIGN

Question 12

BP CUSS CAUSES WRIST/HAND SPASM

Answer 12

TROUSSEAU’S SIGNS

Question 13

Hypoparathyroidism Dx

Answer 13

PTH profile
U/E - Ca2+/Mg and Vit D
ECG - PROLONGED QT

Question 14

Hypoparathyroidism TX

Answer 14

IV calcium gluconate
Calcitrol (vitd3)
thiazides