Hypoparathyroidism

Question 1

Definition

Answer 1

Occurs when the parathyroid glands dont produce enough PTH.

Uncommon condition

The low production of PTH leads to abnormally low calcium levels in the blood and an increase of phosphorus in the blood

Question 2

Clinical Presentation

Answer 2

Usually related to low calcium levels:
– tingling or burning in the fingertips, toes and lips
– muscles aches or cramps in the legs, feet, stomach or face
– twitching or spasms of muscles, particularly around the mouth, but also in the hands, arms and throat
– fatigue or weakness
– heart failure
– irregular heart beat
– low blood pressure
– seizures

long term low calcium can cause:
– cataracts
– dental problems
– movement disorders like tremors
– hair loss and brittle nails

Question 3

Aetiology

Answer 3

Neck surgery (most common)- develops after accidental damage to or removal of the parathyroid glands during surgery

Autoimmune disease (autoimmune polyendocrine syndrome type I)- in some cases, the immune system attacks parathyroid tissues as if they were foreign bodies. In the process, the parathyroid glands stop producing their hormone.

Hereditary hypoparathyroidism- born without an or with parathyroid glands that dont work properly

Low levels of magnesium in the blood- low magnesium levels can affect the function of the parathyroid glands

Extensive cancer radiation treatment of the face or neck- radiation can result in the destruction of the parathyroid glands

DiGeorge syndrome- 3rd and 4th pharyngeal pouch doesn’t form, leading to improper formation of PT glands

Infiltrative diseases:
– Wilson’s disease- copper infiltrating the PT gland, leading to decreased function
– Haemochromatosis- infiltration of iron into the PT gland, leading to decreased function

Question 4

Risk factors

Answer 4

Recent neck surgery

Family history

Certain autoimmune or endocrine conditions, such as Addison’s disease- which causes a decrease in the hormones the adrenal glands produce

Question 5

Complications

Answer 5

Can be reversible or irreversible

Reversible complications:
- cramp like spasms
- muscle pain and twitches
- tingling or burning sensations
- seizures
- problems with kidney function
- abnormal heart rhythms and fainting

Irreversible complications:
- hardening and changes in the shape of bones, and poor growth
- delayed mental development in children
- calcium deposits in the brain, which can cause balance problems, movement disorders and seizures
- clouded vision due to cataracts
- teeth that dont form properly

Question 6

Investigations

Answer 6

Blood tests:
– low blood-calcium level
– low parathyroid hormone level
– high blood-phosphorus level

Urine test:
– PTH acts on kidneys to prevent too much calcium from being wasted in the urine. A urine test can tell whether your body is getting rid of too much calcium.

Other tests:
- ECG (electrocardiogram)

Question 7

Treatment

Answer 7

Oral calcium supplements- as tables, chews or liquid

Vitamin D- generally in the form of calcitriol, to help your body absorb calcium and eliminate phosphorus

Magnesium- magnesium supplement

Thiazide diruetics- can decrease the amount of calcium lost through urine

PTH replacement