Hypoparathyroidism

Question 1

Epidemiology

Answer 1

Rarer than hyperparathyroidism

Question 2

Risk factors

Answer 2

Thyroid surgery
Hypomagnesaemia
Autosomal dominant conditions
Metastatic cancer

Question 3

Aetiology

Answer 3

Primary - PTH gland failure
- Autoimmune destruction
- Di Georges syndrome -> familial, PTH glands don’t develop (22q11del)
- Idiopathic
Secondary
- After surgery (parathyroid/thyroidectomy)
- Radiation
- Decrease in Mg (needed for PTH secretion)
Pseudo parathyroid
- Peripheral PTH resistance
- SHORT STATURE + SMALL 4th/5th MTP

Question 4

Pathophysiology

Answer 4

Disorder is caused by relative or absolute deficiency of plasma parathyroid hormone (PTH) synthesis + secretion
Leads to low albumin - corrected serum total calcium + elevated phosphate

Question 5

Signs

Answer 5

Chevosteks - facial nerve tap induces spasm
Trousseau’s sign - BP cuff causes wrist flexion and fingers to pull together

Question 6

Symptoms

Answer 6

C - Convulsions
A - Arrhythmias
T - Tetany
S - Spasm
N - Numbness

Question 7

Diagnosis

Answer 7

Blood - bone profile
- Ca2+ = Low
- Phosphate = Increase
- PTH = Low
ECG = Prolonged QT + ST segment

Question 8

Treatment

Answer 8

IV Calcium
Adcal D3 - Calcitriol
Synthetic PTH if required