disorders of the parathyroid - mcgowan

Question 1

what are the parathyroid glands

Answer 1

four pea sized glands
located on posterior surface of thyroid
responsible for secretion of parathyroid hormone (PTH)
primary regulator of serum calcium levels

Question 2

what is secreted in response to serum calcium levels

Answer 2

PTH
low serum calcium -> PTH secretion-> increased serum calcium
high serum calcium -> reduce PTH secretion - > dec serum calcium

Question 3

what are the targets of PTH

Answer 3

bones- release or store calcium
Kidneys -excrete or conserve calcium
GI trac t- absorb or not absorb

Question 4

what is necessary for calcium homeostasis and absorption

Answer 4

vitamin D

Question 5

where is vitamin D activated

Answer 5

kidneys

Question 6

what stimulates the activation of vitamin D

Answer 6

PTH

Question 7

what lowers serum calcium

Answer 7

calcitonin

Question 8

what secretes calcitonin

Answer 8

thyroid in response to elevated serum calcium

Question 9

what is primary hyperparathyroidism

Answer 9

problem is the parathyroids themselves
m/c cause is parathyroid adenoma
W>M (3:1), age 60-70
AA > Caucasians > other races
associated with MEN types 1,2 and 4 (NOT 3)
+FH

Question 10

what is secondary hyperparathyroidism

Answer 10

problem is outside of the parathyroids
-hyperphosphatemia, renal failure, malabsorption of Vit D

Question 11

what is the presentation of primary hyperparathyroidism

Answer 11

bones, stones, abdominal groans, psychic moans and fatigue overtones
paraesthesias, muscle cramps/weakness, reduced DTRs, malaise, etc

Question 12

what is the workup for primary hyperparathyroidism

Answer 12

dx starts with serum calcium
if calcium > 14 of PTH > 5x normal = think cancer
urinary calcium to confirm
genetic testing if < 40yo
adjunctive testing: vitamin D, DEXA scan, renal function testing/imaging

Question 13

what is the treatment of primary hyperparathyroidism

Answer 13

mainstay is parathyroidectomy
non-operative: Cincalcet really only direct pharamcotherapeutic option of hypercalcemaia

Question 14

what is the surgical criteria for parathyroidectomy

Answer 14

calcium > 11.5
DXA < -2.5
+ kidney stones
+hx fragility fracture
Age <50
or other based on shared decision making

Question 15

what is the treatment of secondary hyperparathyroism

Answer 15

treat underlying cause if secondary
increase calcium if low
decrease phosporus if high
increased vitamin D if low
hemodialysis if due to CKD

Question 16

what can cause hypocalcemia

Answer 16

may be causing secondary hyperparathyroism
low serum Vit D
HYPOparathyroidism

Question 17

what is hypoparathyroisism

Answer 17

reduced function of parathyroid
can be due to surgical removal of parathyroid(s) and/or thyroid glands
can be due to autoimmune disorders or genetic mutations
M=W
can affect any age

Question 18

what is the presentation of hypoparathyroidism

Answer 18

may be asymptomatic
CATS: convulsion, arrhythmias, tetany, stridor and spasms

Question 19

what is Chovstek’s sign

Answer 19

tap on facial nerve - ipsilateral grimace

Question 20

what is Trousseau’s sign

Answer 20

involuntary movement of wrist/hand with BP cuff inflation

Question 21

what can be seen on PE with Hypoparathyroidism

Answer 21

Chovstek’s sign
Trousseau’s sign
hyperrreflexia

Question 22

what are patients with hypoparathyroidism more prone to

Answer 22

cataracts

Question 23

how do you workup hypoparathyroidism

Answer 23

reduced serum calcium
increased serum phosphorus
reduced PTH
+/- low serum magnesium
+/- low serum Vit D
+/- renal dysfunction (elevated creatinine)