Thyroid

Question 1

therapuetic effect Radioactive idoine

contraindicated

Answer 1

hyperfunction thyroid takes up and is ablated

most patients will develop lifelong hypothyroidism and require lifetime thyroid hormone

contraindicated in severes Grave’s orbitopathy, especially in smokers with eye involvement and in pregnancy

Question 2

secondary hypothyroidism =

tertiary =

Answer 2

inadequate secretion or production of TSH from pituitary

inadequate secretion or production of TRH from hypothalamus

Question 3

not always found in Grave’s patients, but a very specific finding

Answer 3

TSI thyroid stimualting imunnoglobulins

Question 3

for secondary hyperthyroidism

TSH

T4

TSI

Thyroid uptake

Thyroid Scan

Treatment

Answer 3

TSH high or high normal

T4 high

TSI negative

Thyroid uptake NA

Thyroid Scan NA

Treatment pituitary surgery (pituitary adenoma)

Question 4

TSH, T3/T4 levels in Graves

Answer 4

TSH low

high normal

Question 4

mechanism+indication methmazole

side effects

Answer 4

hyperthyroidism

inhbits synthesis of thyroid hormes by blocking oxidation of iodine in the thyroid gland

reversible agranulocytosis

rash, joint pain, headache

Question 5

driving force for thyrotoxicosis

Answer 5

thyroid stimualting immunoglobulin TSI

Question 6

first step in differentiating between causes of primary hyperthyroidism

findings

Answer 6

radioiodine uptake/scan

Graves = high uptake, diffuse, bilateral

Hashimotos, granulomatous thyroiitis = low uptake

Toxic nodule or multinodular goiter = focused intense uptake

Question 8

pathogenesis of lymphocytic (Hashimotos) thyroiditis

Answer 8

sensitization of lymphocytes to thryoglobulin, thyroid peroxidase, TASH receptor

cytokine release and inflammation ulitimately result in glandular destruction

Question 9

in secondary/tertiary hypopthyroidism

TSH

Free T4, T3

thryroid peroxidase, thyroglobulin antibodies

Answer 9

TSH low or low normal

Free T4, T3 low

thryroid peroxidase, thyroglobulin antibodies negative

Question 10

mxedema coma

Answer 10

severe hypothyroidism

multiorgan dysfunction

hypoventilation

hypotension

CNS changes

Question 12

for toxic multinodal goiter or solitary toxic nodule

TSH

T4

TSI

Thyroid uptake

Thyroid Scan

Treatment

Answer 12

TSH low

T4 high

TSI negative

Thyroid uptake high

Thyroid Scan nodular, focal

Treatment - Methimazole, PTU, radioactive iodide, resection

Question 13

Common symptoms hyperthyroidism

Answer 13

emotional lability
palpitations
weakness/fatigability
voracious apetit with weight loss
hyperkinesia, rapid speach
fine tremor
most skin
lid lag, state, proptosis
tachycardia, accentuated first heart sound, A-fib
heat intolerance

Question 14

halflife Levothyroxine (T4)

liothyronine (T3)

Answer 14

Levothyroxine T4 - 6-7 days

LiothyronineT3 -

Question 15

mechanism and indication propylthiouracil

Answer 15

adjunct for hyperthyroidism - refractory to methimazole or pregnant

inhibits synthesis of thyroid hormone by blocking oxiation of iodine, also partioanll inhibits periphera deiodination of T4 to T3

reversible agranulocytosis, hepatic failure

Question 16

secondary thyroidititis due to

Answer 16

TSH secreting pituitary adenoma

Question 17

Treatment for Hashimotos

Answer 17

Thyroid hormone (most often T4, levothyroxine)

(T3 liothyronine is also used, but has short half-life and requires rapid dosig)

Question 18

pathophys for orbitopathy in Graves

Answer 18

sentization of T lymphocytes or T killer cells to TSH-R antigen found in thyroid follicular cells and orbital fibroblasts

Question 19

most common causes of primary hyper thyroidism

Answer 19

Graves

toxic multinodal goiter

solitary toxic (follicular) adenoma

thyroitis - inflammation

Question 19

therapeutic effects of iodie

Answer 19

inhibits hormone release

decreasses vascularity, size,, fragility of hyperplastic glands (pre-op utility)

Question 20

first test for suspected thyroid disease,

if this is abnormal, high suspicion of ____ and follow-up test=

Answer 20

TSH

if abnormal, high suspicion for central process,

followed with free T4 testing

Question 21

for thyroiditis

TSH

T4

TSI

Thyroid uptake

Thyroid Scan

Treatment

Answer 21

TSH low

T4 high

TSI negative

Thyroid uptake low

Thyroid ScanNA

Treatment - beta blockers, supportive care

Question 23

other Rx for hyperthyroidism

Answer 23

Beta blocker (block adrenergic effects of thyroid hromone)

Lugols solution - oral iodine, Jod-basedow effect (hyperthyroidism following iodine admin)

Chlesturamine - binds thyroid hormone in gut during enterohepatic circulation

Question 24

in Euthyroid…

TSH

Free T4, T3

thryroid peroxidase, thyroglobulin antibodies

Answer 24

TSH - normal

Free T4, T3 normal

thryroid peroxidase, thyroglobulin antibodies negative

Question 25

in primary hypothyroidism

TSH

Free T4, T3

thryroid peroxidase, thyroglobulin antibodies

Answer 25

TSH elevated

Free T4, T3 low

thryroid peroxidase, thyroglobulin antibodies positive

Question 26

for graves

TSH

T4

TSI

Thyroid uptake

Thyroid Scan

Treatment

Answer 26

TSH low

T4 high

TSI positive

Thyroid uptake high

Thyroid Scan diffuse, homogenous

Treatment - methimazole, PTU, radioactive iodine, resection

Question 27

primary treatment options for Graves and other high uptake modalitiies of hyperthyroidism (toxic nodules)

Answer 27

Methimazole - inhibitor of thyroidal iodine organification,

propylthiouracil - inhibitor of thyroidal iodine organification,
(preferred in pregnancy, though hepatotoxicity possible)

Radioactive iodine

(generally preferred, longer dosing)

Question 28

most common casue of primary hypothyroidsm

Answer 28

lymphocytic thyroditis (Hashimotos)