Parathyroid

Question 1

Function of PTH

Answer 1

The four parathyroid glands, located in the neck next to the thyroid, sense serum levels of ionized calcium by the calcium-sensing receptor and regulate calcium through parathyroid hormone (PTH) release

Question 2

Primary hyperparathyroidism

Answer 2

inappropriate secretion of PTH in the setting of hypercalcemia.

Question 3

Secondary hyperparathyroidism

Answer 3

appropriately increased secretion of PTH in the setting of low or normal serum calcium concentration and can be caused by vitamin D deficiency or renal failure

Question 4

Tertiary hyperparathyroidism

Answer 4

prolonged secondary hyperparathyroidism in which hypercalcemia develops; it is an initially appropriate secretion that later becomes inappropriate

Question 5

Hypoparathyroidism

Answer 5

primarily a consequence of thyroid and parathyroid surgery,

Question 6

Causes of excess PTH

Answer 6

Single parathyroid adenoma

Question 7

PTH Effects

Answer 7

Causes kidney to increase calcium reabsorption and increase phosphorus loss

Question 8

Presentation of parathyroid disorders

Answer 8

Asymptomatic hypercalcemia is common
primary hyperparathyroid = sings of calcium levels too high - weakness, depression, insomnia, kidney stones
Common sign is white cloudiness as nasal borders of cornea (band keratopathy)

Hypoparathyroid - signs of low calcium - tetany, excitability, seizures, cardiac arrthymia

Question 9

Diagnostics

Answer 9

PTH, calcium, albumin, 25-hydroxy D, phosphorus level
Bone mineral and x-rays may be helpful to look for damage
EKG
Neck ultrasound or CT of PT glands

Question 10

PT disorder management

Answer 10

Hyperparathryoid = primary requires surgery but can result in low calcium

Cinacalet may help normalize calcium

Hypoparathyroid requires PTH replacement and vitamin supplements (not easy)

Question 11

Differential PT types

Answer 11

High PTH, Calcium High - primary hyperparathyroid (tumor)
High PTH, Low/Normal Calcium - secondary hyperparathyroid (Vit D deficient)
High PTH, Calcium normal/high - May be tertiary if no tumor exists and Vit D is normal

High PTH, Calcium very low - possible hypoparathyroid (early)
Low PTH - always hypoparathyroid

Question 12

Hypocalcemia Signs

Answer 12

Confusion
Muscle spams / tetany
Numbness
Muscle cramps
Chvostek / Trousseau signs

Question 13

Hypercalcemia Signs

Answer 13

Depression
Weakness in muscles
Delayed reflexes
Cardiac arrthymia
Seizures

Question 14

PTH in Renal Patients

Answer 14

PTH may be elevated in renal failure as kidney cannot reabsorb Vitamin D so calcium is not absorbed from GI without enough Vitamin D and the glands secrete more PTH in response to low calcium. This is secondary hyperparathyroid