Disorders of the Parathyroid Flashcards
Parathyroid Glands are located
on the posterior surface of the thyroid
Parathyroid Glands are responsible for secretion of
PTH (parathyroid hormone) - regulating serum calcium levels
Increase in PTH causes an increase in
serum calcium
Decreased PTH causes a decrease in
serum calcium
PTH acts on several targets to alter serum calcium levels by
bones
kidneys
GI tract
Vit D metabolism is necessary for
calcium homeostasis and absorption
no vit D = no calcium absorption
Vit D is activated in the kidneys
PTH stimulates activation
Calcitonin functions to lower
serum calcium
Calcitonin is secreted by the
thyroid in response to elevated serum calcium
Hyperparathyroidism is
overactive parathyroid –> excess levels of PTH
Two types of Hyperparathyroidism
Primary and secondary
Primary = problem is the parathyroids themselves
Secondary = problem is outside of the parathyroid
Most common cause of Primary Hyperparathyroidism
single gland adenoma
associated with MEN 1, 2, 4, other risks = head and neck radiation
Primary Hyperparathyroidism sxs
presents related to hypercalcemia:
bones, stones, abdominal groans, psychic moans, fatigue overtones
Primary Hyperparathyroidism dx starts with
serum calcium
> 14 or PTH > 5x normal think cancer
urinary calcium to confirm - should be normal or high
low = kidney
Imaging not necessary for dx but used for preop (Hyperparathyroidism)
US
SPECT CT
Primary Hyperparathyroidism treatment
mainstay is parathyroidectomy
caution = transient hypocalcemia post-op
potentially take too much parathyroid = hypoparathyroidism
Primary Hyperparathyroidism alternative treatment
Osteoporosis medications
DEXA every 1-2 years
Maintain hydration to prevent kidney stones
physical activity to maintain bone strength
AVOID thiazides diuretics, lithium
Loop diuretics to decrease calcium levels
Secondary Hyperparathyroidism treatment
treat underlying cause if secondary
increase calcium if low (diet, supplements)
decrease phosphorus if high
increase Vit D if low
Hemodialysis if due to CKD
Hypocalcemia may cause
secondary hyperparathyroidism
low serum Vit D
Hypoparathyroidism is
reduced function of the parathyroid
can be due to surgical removal of the parathyroid(s) and/or thyroid glands
can also be due to autoimmune disorders or genetic mutations
Hypothyroidism presentation
may be asymptomatic
sxs related to hypocalcemia:
paresthesias (hands, feet, perioral) - muscle spasms/ cramps - seizures
arrhythmias, wheezing, SOB, stridor
Hypothyroidism PE findings/ signs
Chovstek’s sign - tap on facial nerve -> ipsalateral grimace
TRousseau’s sign - involuntary movement of wrist/hand with BP cuff inflation
Hyperreflexia
Pts with Hypothyroidism are also more prone to
cataracts
Hypothyroidism workup
reduced serum calcium
increased serum phosphorus
reduced PTH
no imaging necessary
Hypothyroidism treatment
mainstay treatment is calcium and activated Vit D supplement - lifetime treatment
major side effects - constipation, caution for hypercalcemia, esp in CKD
if low magnesium - supplement
Thiazide diuretics to treat hypercalciuria
