Hypoparathyroidism

Question 1

What are the main causes of hypoparathyroidism?

Answer 1

Surgical removal of parathyroid gland
Autoimmune destruction of the parathyroid gland

Question 2

What is the pathophysiology of hypoparathyroidism?

Answer 2

Decreased PTH production or function leads to decreased calcium absorption from the intestines, reduced bone resorption, and impaired renal reabsorption of calcium

Question 3

What is the clinical presentation of hypoparathyroidism?

Answer 3

Hypocalcaemia related symptoms:
- Muscle cramps
- Paraesthesia
- Tetany

Neuropsychiatric symptoms:
- Anxiety
- Depression
- Cognitive impairment

Dental enamel hypoplasia and tooth discolouration

Question 4

What are the differentials of hypoparathyroidism?

Answer 4

Hypocalcaemia due to other causes e.g renal failure
Vitamin D deficiency
Neuromuscular disorders
Psychiatric conditions

Question 5

What investigations are performed in the diagnosis of hypoparathyroidism?

Answer 5

Serum calcium - low
Serum phosphate - high
PTH levels - low/inappropriately normal
Vitamin D levels
Urinary calcium - low
ECG - detection of long QT due to hypocalcaemia

Question 6

What is the management of hypoparathyroidism?

Answer 6

Calcium and vitamin D supplementation
Regular monitoring of calcium levels and PTH

Question 7

What is the management of acute severe hypocalcaemia?

Answer 7

IV calcium

Question 8

What are the complications of hypoparathyroidism?

Answer 8

Seizures
Cardiac arrhythmias
Kidney stones - increased urinary calcium excretion
Impaired renal function
Cataracts

Question 9

What is pseudohypoparathyroidism?

Answer 9

A rare genetic disorder where the bone, kidney and gut fail to respond to normal levels of PTH

Question 10

What is the pathophysiology of psudoparathyroidism?

Answer 10

A mutation of the FNAS1 gene lead to defects in the PTH receptor.