Parathyroids

Question 1

What is the main function of parathyroid hormone ?

Answer 1

To increase Calcium concentrations

Question 2

What does PLC do?

Answer 2

Inhibits PTH release

Question 3

How is PLC controlled?

Answer 3

CASR calcium sensing receptor

Activation increases PCL secretion

Question 4

What is CASR

Answer 4

A G protein coupled receptor

Question 5

What are the four symptoms of Hypercalcaemia

Answer 5

Bones
Stones
Abdomina groans
Psychic moans

Question 6

Acute signs of Hypercalcemia

Answer 6

Thirst
Dehydration
Confusion
Polyuria

Question 7

Chronic signs of Hypercalcemia

Answer 7

Myopathy
Fractures
Osteopenia
Depression
Hypertension
Pancreatitis

Question 8

What drugs can cause Hyperparathyroidism?

Answer 8

Vitamin D supplements

Thiazides

Question 9

List some causes of Hyperparathyroidism

Answer 9

Malignacy
Granulomatous diseases
High bone turn over
Familial

Question 10

How does malignancy cause Hyperparathyroidism?

Answer 10

Metastatic bone destruction
PTHrp from solid tumours
Osteoclast activating factors

Question 11

How can a malignant hyperparathyroidism be diagnosed?

Answer 11

Increased Ca2+ and alkaline phosphatase

X ray CT or isotope bone scan

Question 12

What can lead to a high bone turn over?

Answer 12

Bed ridden
Pagets
Thyrotoxicosis

Question 13

What are the signs of a primary hyperparathyroidism?

Answer 13

Raised serum Ca2+
Raised Serum PTH
Increased urinary Ca2+ excretion

Question 14

What is the acute treatment for Hyperparathyroidism?

Answer 14

0.9% saline 4-6L in 24 hrs
Loop diuretics
Bisphosphonates
Steroids 
Sodium Calcitonin
Chemotherapy

Question 15

What diuretic should be avoided in the acute treatment of hyperparathyroidism?

Answer 15

Thiazide

Question 16

When are steroids used and what is the first line?

Answer 16

Used in granulomatous diseases like sarcoid

Prednisolone 40 mg

Question 17

Sodium calcitonin usage

Answer 17

Rarely used

Question 18

In what circumstances is a parathyroidectomy undertaken?

Answer 18

End organ damage

Serum Calcium over 2.85

Question 19

What is end organ damage in relation to Hyperparathyroidism?

Answer 19

Bone disease 
Brown Tumour
Pepper pot skull
Gastric ulcers
Renal stones

Question 20

Along with a high calcium what else must there be to undergo a parathyroidectomy?

Answer 20

Serum Calcium over 2.85
Under 50
eGFR <60ml/min

Question 21

What indicates a secondary Hyperparathyroidism

Answer 21

Low serum Ca2+

High PTH

Question 22

What is a secondary Hyperparathyroidism?

Answer 22

Physiological response to low Ca2+ or Vitamin D

Question 23

What indicates a tertiary Hyperparathyroidism?

Answer 23

High Ca2+ and PTH

Question 24

What is tertiary hyperparathyroidism?

Answer 24

Parathyroid has become autonomous due to chronic overactivity

Question 25

What genetic links does hyperparathyroidism have?

Answer 25

Links to MEN1/2

Question 26

Why will most people with MEN1/2 have Hyperparathyroidism?

Answer 26

Most will have a parathyroid adenoma

Question 27

As a result of the adenoma what will most MEN1/2 patients be affected by?

Answer 27

Hypercalcemia by a young age

Question 28

What is Hypocalciuric Hypercalcemia

Answer 28

Familial autosomal dominant | Usually benign asymptomatic

Question 29

What is the pathology behind Hypocalciuric Hypercalcemia?

Answer 29

Deactivation of the CaSR channels | No PLC release

Question 30

What are the symptoms of Hypocalciuric Hypercalcemia?

Answer 30

Mild Hypercalcemia Reduced Ca2+ urinary excretion PTH slightly elevated

Question 31

Signs of hypocalcaemia

Answer 31

``` Parasthesia - fingers toes personally Fatigue Fits Muscle weakness, cramps, Tetany Bronchospasm ```

Question 32

On an ECG how may hypocalcaemia manifest?

Answer 32

Prolonged QT

Question 33

What is the acute treatment for hypocalcaemia?

Answer 33

IV Calcium Gluconate

Question 34

Causes of hypoparathyroidism

Answer 34

Congenital - Digeorge syndrome Destruction- Surgery Radio/chemotherapy Autoimmune Hypomagnesaemia

Question 35

Management of hypoparathyroidism

Answer 35

>1-2g of Calcium supplement | Vitamin D supplement

Question 36

What Vitamin D supplements are there?

Answer 36

Alphacalcidol | Cholecalciferol- Injection 6 monthly

Question 37

Why does hypomagnesaemia cause low Ca2+ levels?

Answer 37

Ca2+ release from the parathyroid is dependent of Mg+

Question 38

Biochemically how does hypomagnesaemia present?

Answer 38

Intracellular Ca2+ is high | Low PTH

Question 39

What can cause hypomagnesaemia?

Answer 39

``` Thiazides PPI GI illness Pancreatitis Malabsorption ```

Question 40

What is diabetes insipidus?

Answer 40

Failure of the body to concentrate the urine | NO link to diabetes mellitus

Question 41

What are the two types of diabetes insipidus?

Answer 41

Nephrogenic - caused by fault within the kidneys | Neurogenic - caused by fault within the brain

Question 42

List some nephrogenic causes of diabetes insipidus

Answer 42

Lithium usage Electrolyte imbalance Kidneys unresponsive to ADH

Question 43

What electrolyte imbalance could lead to nephrogenic diabetes insipidus?

Answer 43

Low K+ High Ca+

Question 44

List some neurogenic causes of diabetes insipidus

Answer 44

Lesion Tumour Autoimmune Head injury

Question 45

How do you work out the serum osmolarity?

Answer 45

[Na+ + K+]² + urea + glucose

Question 46

What is the normal serum osmolarity of the urine?

Answer 46

275-295 mmol/L

Question 47

What is the definition of diabetes insipidus?

Answer 47

High plasma osmolarity + urine osmolarity is low

Question 48

What is the definitive test for diabetes insipidus?

Answer 48

Water deprivation test