Parathyroid disease

Question 1

Parathyroid physiology

Answer 1

PTH secreted in response to ↓Ca2+

• ↑osteoclast activity
• ↑Ca2+ and ↓PO4 reabsorption in kidney
• Activates Vitamin D

Question 2

Hypercalcaemia presentation

Answer 2

Stones:
- Renal stones - polyuria and polydipsia (nephrogenic DI)

Bones:

• Bone pain
• Pathological fractures

Moans: depression

Groans

• Abdo pain
• n/v and constipation
• Pancreatitis
• Peptic ulcer disease (↑gastrin secretion)

Other:
↑ BP

Question 3

Primary Hyperparathyroidism Causes

Answer 3

• Solitary adenoma: secreting PTrP
• Hyperplasia
• Parathyroid Ca

Question 4

Ix for hyperparathyroidism

Answer 4

Abdominal examination 
Obs 
Bloods
- ↑Ca2+
-  ↑ or inappropriately normal PTH
- ↑ALP
- ↓PO4
- U+Es
- Vit D

ECG: ↓QTc → bradycardia → 1st degree block

X-ray: osteitis fibrosa cystica → phalangeal erosions

DEXA: osteoporosis

Question 5

Tx of hyperparathyroidism

Answer 5

General:

• ↑ fluid intake
• Avoid dietary Ca2+ and thiazides (↑ serum Ca)

Surgical: excision of adenoma

Question 6

Complications of surgical incision of adenoma

Answer 6

• Hypoparathyroidism

- Recurrent laryngeal N. palsy

Question 7

Secondary Hyperparathyroidism

Causes

Answer 7

Vitamin D deficiency

Chronic renal failure

Question 8

Mx if secondary hyper PTH

Answer 8

Correct causes:
• Phosphate binders
- With or without Ca: 
- Vit D: calcitriol (active)
- cholecalciferol (innactive Vit D)

Cinacalcet: ↑ parathyroid Ca-sensitivity

Question 9

Tertiary Hyperparathyroidism

Answer 9

Prolonged secondary hyper PTH → autonomous PTH secretion

Question 10

Hypoparathyroidism

Answer 10

↓PTH due to gland failure

Question 11

Presentation of hypocalcaemia

SPASMODIC

Answer 11

Spasms (carpopedal = Trousseau’s sign)
Perioral paraesthesia
Anxious, irritable
Seizures
Muscle tone ↑→ colic, wheeze, dysphagia
Orientation impaired (confusion)
Dermatitis
Impetigo herpetiformis (↓Ca + pustules in pregnancy)
Chovsteks, cardiomyopathy (↑ QTc → TdP)

Question 12

Causes of hypo pTH

Answer 12

Autoimmune
Congenital: DiGeorge
Iatrogenic - Surgery or radiation

Question 13

DiGeorge Syndrome

Answer 13

Cardiac abnormality: Fallot’s
Abnormal facies
Thymic aplasia
Cleft palate
Hypocalcaemia
Chr 22

Question 14

Ix for hyp PTH

Answer 14

↓Ca
↑PO4
↓PTH
Normal ALP

Question 15

Mx of hypo PTH

Answer 15

Calcium supplements

Calcitriol

Question 16

Pseudohypoparathyroidism

Answer 16

Failure of target organ response to PTH
- Symptoms of hypocalcaemia
- Short 4th and 5th metacarpals, short stature
Ix: ↓Ca, ↑PTH
Rx: Ca + calcitriol

Question 17

Treatment of hypercalcaemia

Answer 17

Rehydration with normal saline
Bisphosphonates
IV pamidronate

Others:

• calcitonin can be used
• steroids in sarcoidosis

Question 18

Causes of hypercalcaemia

Answer 18

Hyperparathyroidsim 
Malignancy - melanoma, bone mets, PTHrP 
Sarcoidosis 
Acromegaly 
Thiazides 
Dehydration
Addison’s

Question 19

Bisphosphonates

Answer 19

Inhibit osteoclasts

Used in:

• osteoporosis prevention
• hypercalcaemia
• Paget’s disease
• pain from bone mets

S/E

• oesophageal reactions - therefore take in the morning 30 mins before food while sitting up
• osteonecrosis of the jaw

Question 20

X-ray head finishing for primary parathyroid disease

Answer 20

Pepper pot skull