Parathyroid Disease Flashcards
Describe lab results of primary hyperparathyroidism
PTH - Elevated/normal
Calcium - High
Phosphate - Low
What are the lab results of secondary hyperparathyroidism?
PTH - Elevated
Calcium - Low/normal
Phosphate - Elevated
Vitamin D - Low
what are the lab results for tertiary hyperparathyroidism?
PTH - elevated
Calcium - normal to high
Phosphate - decreased or normal
Vitamin D - normal to low
ALP - Elevated
What are the causes of primary, secondary and tertiary hyperparathyroidism
Primary - Parathyroid adenoma
Secondary - Parathyroid gland hyperplasia due to chronic low calcium due to chronic renal disease or vitamin D deficiency (due to vitamin D deficiency)
Tertiary - Occurs due to prolonged secondary hyperparathyroidism once it has been treated as there is resultant hyperplasia of the glands
What is the function of phosphate?
It binds to calcium to reduce the amount of free calcium in the blood. Therefore when calcium rises, phosphate falls
What is the presentation of primary hyperparathyroidism?
Moans (abdo pain due to pancreatitis or renal colic), groans, stones and psychiatric moans.
- Polyuria and polydipsia,
- Depression,
- Anorexia, constipation,
- Peptic ulceration,
- Pancreatitis,
- Bone pain,
- Renal stones,
- Hypertension
What is the presentation of secondary hyperparathyroidism?
- Muscle cramps and bone pain,
- Signs of hypocalcaemia: perioral tingling, Chvostek’s sign and Trousseau’s sign
- Eventually develop bones disease, osteitis fibrosis cystica and soft bone calcifications
what is Chvostek’s sign?
Tapping on the face anterior to the ear causes twitching of the muscles around the mouth. Demonstrates neuromuscular excitability
What is Trousseau’s sign?
Inflating BP cuff above diastole for 3mins causes flexion of the wrist, hyperextension of the fingers and flexion of the thumb
What is an important differential for hyperparathyroidism?
Benign familial hypocalciuric hypercalcaemia - High calcium in the blood and low urine calcium
What are the investigations for hyperparathyroidism?
- Bloods: Calcium, phosphate, PTH, ALP.
- Ultrasound scan of neck
- X-ray (pepperpot skull and osteitis fibrosa cystica)
- Parathyroid MIBI scan, SPEC CT
What is the treatment of primary hyperparathyroidism
- Definitive management is total parathyroidectomy.
- If not suitable for surgery then treatment is with cinacalcet (calcimimetic - mimics action of calcium)
What is the management of secondary hyperparathyroidism?
- Treat the underlying cause
- Give vitamin D supplements
- May need to give phosphate binders
What is the treatment of tertiary hyperparathyroidism
- Cinacalcet
- Total or subtotal parathyroidectomy
What is the function of the parathyroid gland?
- Increasing osteoclast activity to release calcium from the bones
- Increase calcium reabsoprtion from the kidneys
- Increase vitamin D activity
