Hypoparathyroidism

Question 1

Primary hypoparathyroidism

Answer 1

Decrease PTH secretion e.g. secondary to thyroid surgery

Low calcium, high phosphate

Question 2

Treatment of primary hypoparathyroidism

Answer 2

Alfacalcidol

Question 3

Symptoms of hypoparathyroidism

Answer 3

Tetany (muscle twitching, cramping and spasm)

Perioral paraesthesia

Trousseau’s sign

Chvostek’s sign

If chronic- depression, cataracts

Question 4

Trousseau’s sign

Answer 4

Carpal spasm if the brachial artery is occluded by inflating the blood pressure cuff and maintaining pressure above systolic

Question 5

Chvostek’s sign

Answer 5

Tapping over parotid causes facial muscles to twitch

Question 6

ECG in hypoparathyroidism

Answer 6

Prolonged QT interval

Question 7

Psuedohypoparathyroidism

Answer 7

Target cells being insensitive to PTH due to abnormality in a G protein

Associations: low IQ, short stature, short 4th/5th metacarpals

Low calcium, high phosphate, high PTH

Question 8

Diagnosis of pseudohypoparathyroidism

Answer 8

Measure urinary cAMP and phosophate levels following an infusion of PTH

In hypoparathyroidism this will cause increase in cAMP and phosphate levels

In pseudohypoparathyroidism type I neither cAMP no phosphate increase

In pseudohypoparathyroidism typeII only cAMP rises