Hypoparathyroidism Flashcards
What is primary hypoparathyroidism?
It is characterized by decreased PTH secretion, often secondary to thyroid surgery, resulting in low calcium and high phosphate levels.
Treated with alfacalcidol.
What are the main symptoms of hypoparathyroidism?
Symptoms are secondary to hypocalcaemia and include tetany, perioral paraesthesia, Trousseau’s sign, and Chvostek’s sign.
Chronic symptoms may include depression and cataracts.
What is Trousseau’s sign?
It is carpal spasm induced by occluding the brachial artery with a blood pressure cuff and maintaining pressure above systolic.
What is Chvostek’s sign?
It is facial muscle twitching caused by tapping over the parotid gland.
What ECG finding is associated with hypoparathyroidism?
Prolonged QT interval.
What is pseudohypoparathyroidism?
It is a condition where target cells are insensitive to PTH due to an abnormality in a G protein, associated with low IQ and short stature.
It presents with low calcium, high phosphate, and high PTH.
How is pseudohypoparathyroidism diagnosed?
Diagnosis is made by measuring urinary cAMP and phosphate levels following a PTH infusion. In hypoparathyroidism, both levels increase; in pseudohypoparathyroidism type I, neither increases, while in type II only cAMP rises.
What is pseudopseudohypoparathyroidism?
It has a similar phenotype to pseudohypoparathyroidism but with normal biochemistry.
