Thyroid disorder

Question 1

What does high iodine levels do to TH?

Answer 1

Wolff-Chaikoff: Thyroid gets stunned and stops production temporarily as a protective behavior. Begins again after a few days. #: seen with cardiac catheterization and CT with contrast.

Jod-Basedow effect: overproduction of thyroid hormone causing overt hyperthyroidism in the presence of large amounts of iodine in persons who fail to manifest the Wolff-Chaikoff effect.

Question 2

What happens to TH levels in pregnancy?

Answer 2

Change- non thyroid disease can adjust appropriately, otherwise increase hormone drug

Question 3

What is the test of choice to screen for abnormal thyroid function?

Answer 3

TSH

Question 4

When does the fetus start making its own TH? What happens before that?

Answer 4

week 10/11. Before, TH crosses placenta and the placenta regulates how much TH baby gets

Question 5

TH affect on pulmonary system?

Answer 5

modulates the way the brain responds to CO2. Doesnt respond to hypercapnea- seen in long standing disease. Would result in respiratory acidosis?

Question 6

T3 functions (4 Bs)#

Answer 6

B: brain maturation
B: bone growth
B: beta adrenergic effects
B: basal metabolic rate increases

Question 7

Thyroid hormone effects on CV system.

Answer 7

Increased B1 receptors in the heart so there is more responsiveness to epinephrine. 
#: increased contractility, SV, HR--> inceased CO

Question 8

Thyroid hormone effects on bones#

Answer 8

TH facilitates growth by stimulating GH gene expression in somatotrophs of the anterior pituitary. TH also stimulates calcification and closure of cartilaginous plates throughout the body.

Question 9

Effects of thyroid hormone on GI?

Answer 9

Hyper: diarrhea
Hypo: constipation

Question 10

Effect of thyroid hormone on lipids and carbs?

Answer 10

Lowers cholesterol . Stimulates fuel mobilization and catabolism

Question 11

Explain hypothyroidism in babies and why its bad.

Answer 11

: Cretinism: mental retardation, short stature, coarse features, umbilical hernia.

Usually do to agenesis. Worldwide problem due to iodine deficiency. Preventable. Bone age, height, and mental age won’t normalize if not treated in first few days.

Question 12

Symptoms of hypothyroidism

Answer 12

fatigue, weakness, dry skin, feeling cold, hair loss, memory, constipation, weight gain with poor appetite, menorrhagia,

Question 13

Signs of hypothyroidism

Answer 13

also goiter

dry, coarse skin, puffy face, hands, and feet, diffuse allopecia, bradycardia, peripheral edema, carpal tunnel syndrome, serous cavity effusions, delayed tendon reflex relaxation.

Question 14

Symptoms of hyperthyroidism

Answer 14

fatigue, weakness, hyperactivity, irritability, dysphoria, heat intolerance, sweating, palpitations, weight loss with increased appetite, diarrhea, oligomenorrhea, loss of libido

Question 15

Signs of hyperthyroidism

Answer 15

tachycardia, a fib in elderly, goiter, tremor, warm, moist skin, muscle weakness, proximal myopathy, lid retraction

Question 16

T or F. Goiters are always associated with elevated TH levels.

Answer 16

False

Question 17

Clinical manifestations of Grave’s disease #

Answer 17

diffuse, nontender goiter with or without a bruit.

Infiltrative opthalmopathy, pretibial myxedema.

Question 18

What type of hypersensitivity reaction is Graves?#

Answer 18

Type 2

Question 19

Oncholysis is associated with _____.

Answer 19

Hyperthyroidism

Question 20

When is TSH NOT a reliable test?

Answer 20

Hyperthyroidism (you would expect a low TSH unless…) TSH secreting pituitary adenoma, isolated pituitary resistance to TH
Hypothyroidism (would expect HIGH) central hypothyroidism
Euthyroid- systemic illness, generalized resistance to thyroid hormone, assay interference

Question 21

What is thyroid storm/thyrotoxicosis?#

Answer 21

life-threatening, presents with high fever, tachyarrhythmia, psychosis, confusion, diarrhea, and liver dysfunction. Manage with ICU support, antithyroid meds, and B blockers.

Dont wait for test results before starting therapy!!!!!!

Question 22

Which TH hormone level will respond quicker to changes?

Answer 22

T3

Question 23

What is a toxic multinodular goiter?#

Answer 23

hyperfunctioning areas that make Increase T3/T4 and patchy uptake on thyroid scan. Due to a mutation in TSH receptor and is more common in elderly. Presents like Graves but less sever.

PAINLESS goiter.

Question 24

8 endogenous causes of hyperthyroidism

Answer 24

Graves, toxic multinodular goiter, toxic adenoma, GOF TSH receptor mutation, GOF Gs (GPCR) mutation, struma ovarii, thyroiditis, secondary hyperthyroidism

Question 25

What drugs can cause primary hypothryoidism?

Answer 25

lithium, amiodarone, interferon alpha

Question 26

Etiology of primary hypothyroidism

Answer 26

Thyroiditis, RIA tx for Graves disease, Thyroidectomy, Excessive iodine intake, Iodine deficiency, Inborne errors of TH synthesis, Drugs (lithium, amiodarone, interferon-alpha)

Question 27

Etiology of secondary hypothyroidism

Answer 27

destruction of pituitary gland, hypothalamic dysfunction, peripheral resistance

Question 28

What might you see in an acute/subacute thyroiditis?#

Answer 28

Can go both ways and follows an upper respiratory illness
1. Hyperthyroidism, PAINFUL goiter, fever, elevated ESR, radiating pain to ears, neck, arm
Hypothyroidism: usually follows hyper.
2. Hypothyroidism: self-limited, may have elevated ESR, jaw pain, tender gland, granulomatous inflammation

Question 29

How does Riedel’s thyroiditis present?#

Answer 29

Rare disease in which thyroid tissue is chronically replaced by fibrosis.
Rock-hard, fixed, PAINLESS goiter

Question 30

What are causes of a painful goiter?#

Answer 30

Subacute thyroiditis

Question 31

What are causes of a painless goiter?#

Answer 31

Hashimotos, graves, toxic multinodular goiter, iodine def, riedels thyroiditis

Question 32

Someone comes in with a “rock hard” goiter. You should be thinking- #

Answer 32

Riedel’s

Question 33

Risk factors for thyroid cancer

Answer 33

childhood radiation exposure, male, young age, family history

radiation, 45 y/o, nodule >4 cm, new or enlarging mass, male gender, hoarse voice/vocal cord paralysis, nodule fixed to adjacent structures, extra-thyroidal extension, suspected lymphnode involvement, iodine def, family history (MEN2)