Hypoparathyrodism

Question 1

Primary Hypo PT:

What is the primary cause?

2 blood tests done?

Answer 1

Gland failure - leads to low PTH

They may also have co-existing autoimmune disease.

Calcium and phosphate

Question 2

Primary Hypo PT:

You’d get hypocalcaemia.

Presentation:

• What is an umbrella phrase to describe a number of the symptoms and signs seen in hypocalcaemia?
• What is a carpopedal spasm?
• What is chvostek’s sign?
• What is trousseau’s sign?
• What 2 things could happen to the airway?
• Where do they get paraesthesia (numbness)?

Answer 2

Tetany (involuntary contraction) of feet or hands

Facial twitch on parotid tap

Carpal tetany in response to tightened BP cuff

Laryngospasm
Bronchospasm

Peripheries (hands and legs)
Tongue
Mouth

Question 3

Primary Hypo PT:

You’d get hypocalcaemia.

Presentation:

Why does hypocalcaemia cause tetany (involuntary contractions)?

Answer 3

Hypocalcemia is the primary cause of tetany. Low ionized calcium levels in the extracellular fluid increase the permeability of neuronal membranes to sodium ion, causing a progressive depolarization, which increases the possibility of action potentials.

Question 4

Primary Hypo PT:

You’d get hypocalcaemia.

Presentation (chronic disease):

• What happens to the lens of the eye in chronic disease?
• What happens to their skin?
• What may happen to their teeth if the patient is young?
• What CNS symptoms do they get?

Answer 4

Cataracts

Dry
Coarse
Puffy skin

Reduced tooth growth 
----
Seizures 
Papilloedema 
Dementia
Parkinsonism 
Anxiety 
Depression
Fatigue

Question 5

Primary Hypo PT:

What can be done to treat this?

What can be given IV if it is very severe (e.g. tetany, paraesthesia)?

Answer 5

Calcium supplements + Calcitriol

Calcium glutinate

Question 6

Secondary Hypo PT:

What are some causes of this?

What other electrolyte if low prevent PTH secretion also causing hypo PT?

Rx the same as primary!!!

Answer 6

Radiation
Surgery - post thyroidectomy, parathyroidectomy

Magnesium - hypomagnesaemia - needed for PTH secretion

Question 7

Pseudohypoparathyroidism:

What is happening in this case?

Signs:

• What happens to the fingers?
• What happens to their face?
• What about their stature?
• Why do they learning difficulties?

Rx the same as primary!!

Answer 7

PTH resistance - PTH is still being produced

They get short metacarpals (4th and 5th)

Round face

Short stature

Low IQ