Chapter 103- Hyperthyroidism Flashcards
__________ has been noted in the settings of chronic lymphocytic (Hashimoto’s) thyroiditis, subacute (granulomatous) thyroiditis, and postpartum thyroiditis.
Transiet hyperthyroidism
Graves Disease, toxic multinodular goiter, toxic adenoma (nodule), excessive ingestion of thyroid hormone, and Jod-Basedown phenomenon are all well recongnized causes due to ___________.
hyperthyroidism
Is hyperthyroidism more common in men or women?
women
___________ is due to mechanisms responsible for this excess include stimulation of thyroid-stimulating hormone, autonomous thyroid hormone production, increased release of thyroid hormone without increased production of TSH, and intake of exogenous hormone.
hyperthyroidism
______ hormone stimulates calorigensis and catabolism and enhances sensitivity to catecholamines.
Thyroid
What will patients with excessive amounts of thyroid hormone experience?
- heat intolerance; nervousness; hyperactivity; tremor; increased appetite; weight loss; excessive sweating; palpitations, lid lag; stare; and muscle weakness.
- Diarrhea, or more precisely, frequent defecation, may also ensue
What will patients with chronic hyperthyroidism experience?
* along with all the manifestations listed on the previous card
- muscle weakness and SEXUAL DYSFUNCTION
* a DOC better not ever MISS a diagnosis of HYPERTHYROIDISM in BRITT!!!!!!!!! fockerFord wouldnt be possible hahaha
A reversible picture of left ventricular dysfunction may emerge, and the risk of _______ is increased in patients with hyperthyroidism.
atrial fibrillation/flutter
Elevations in __________ and ___________ may accompany thyrotoxicosis and persist even after treatment.
alkaline phosphatatse and angiotensin-converting enzyme
In an ELDERLY thyrotoxic patient, the characteristic systemic manifestations of hyperthyroidism may be absent, INSTEAD you commonly see _______, _______, and _______.
Apathy
Weight Loss
Unexplained Atrial Fibrillation
**The condition can mimic depression depression and occult malignancy.
Hyperthyroidism increases sensitivity to catecholamines. What are 5 things that result in a patient because of this?
- Tachycardia
- Tremor
- Sweating
- Stare
- Lid Lag
_______ is due a deficiency of thyroid specific suppressor T cell lymphocytes, which allows a thyroid-stimulating immunoglobulin G antibidy (Tsab) to form; resulting in toxic hyperthyroidism
***Tsab (also called thyrotropin-receptor antibody) binds to TSH receptors on the surface of thyroid cells and triggers the synthesis of excess thyroid hormone.
Graves Disease
______ disease is the most common form of hyperthyroidism.
seen in 90% of cases younger than 40 yrs.old
& 70% of cases older than 60 yrs. old
Graves Disease
What are the eye characteristic manifestations associated with Graves’ disease?
- Patients can have the “thyroid stare”
- Patients can orbital edema and proptosis due to inflammatory infiltrate producing swelling of tissue, which compresses veins
- Inflammation can cause DIPLOPIA
- usually develops CONCURRENTLY in MOST with the onset of hyperthyroidism & change little once established
Manifestations range from lid retraction and stare, mild periorbital edema, and conjunctival inflammation. to extraocular muscle dysfunction, corneal injury, and optic nerve damage in _______ disease.
*Other associated ocular symptoms include pain, diplopia, proptosis, and blurred vision.
Graves
_________ is characterized by the appearance of NONPITTING swelling, indurated nontender plaques (thickening of the skin) with brownish, reddish, dark pink, or purple color and an “orange skin” primarily LOCATED primarily to the skin of the pretibial area.
**Rarely the LOWER LEG can be extensively involved, giving the appearance of ELEPHANT TIASIS!
Pretibial Myxedema - Thyroid Dermapathy
________ is characterized by CLUBBING and soft tissue swelling of the distal fingers and toes, is also rare.
*associated with Graves’ disease, but very rare
Thyroid acropachy
________ = Thyroid gland in Graves’ disease that is DIFFUSELY ENLARGED and a BRUIT may be heart (unusual sound that blood makes when it rushes past an obstruction). The skin is VELVETY and the hair is SILKY. Onycholysis, vitiligo, and gynecomastia are found in some cases and may suggest diagnosis.
Thyrotoxicosis
T/F The clinical course of Graves Disease is one in which if left along it will spontaneously improve.
YEAHHH RIGHT!! NO GIRL NO!
- usually worsens if it untreated
- although patients with mild diseases may have exacerbations and remissions of unpredictable duration
- After many years mild HYPOTHYROIDISM may ensue, especially in patients with small Goiters and mild hyperthyroidism at the time of onset.
_________ = results from diffuse hyperplasia of thyroid follicular cells whose activity becomes independent of TSH regulation. It is MOST COMMON in areas of IODINE deficiency.
Toxic Multinodular Goiter (Plummer’s Disease)
What do most patients present to the clinic with upon diagnosis of Toxic Multinodular Goiter?
- Heart Failure, Atrial Fibrillation, Palpitations, or Angina
- Some patients present with constipation and anorexia
- Lid Lag may be noted on few, BUT EXOPHTHALMOS DOES NOT OCCUR
- **Sometimes, APATHY & WEIGHT LOSS are the most prominent clinical features and can be so profound as to suggest occult malignancy or severe depression
______ = active nodule surrounded by suppressed gland on radioiodine thyroid scan. The LARGER the nodule the GREATER is its propensity to cause thyrotoxicosis. NON CANCEROUS
***OFTEN th eonset of toxicity is FIRST manifested by an isolated increase in ______; later ______ levels rise.
Single Toxic Nodule (HOT NODULE)
T3 serum levels rise first; later T4 rise at onset of toxicity
The larger the SIngle Toxic Nodule (HOT NODULE) the greater is its propensity to cause thyrotoxicosis, with the risk quite high once the nodule reaches ______ in diameter.
3 cm
In Single Toxic Nodule (“HOT” Nodule), sometimes _________ TERMINATES the overproduction of hormone and limits the progression of thyrotoxicosis.
Hemorrhagic Infarction
_________ = very important to consider when patients with clinically apparent hyperthyroidism have NORMAL T4 LEVELS. This condition has been reported with both DIFFUSE & NODULAR GOITERS. Clinical presentation is NO different than that of hyperthyroidism caused by elevations in T4.
Triiodothyronine Toxicosis
Graves’ disease is characterized by a continuous elevation in Thyroid hormones. BUT There are 3 diseases that are characterized by TRANSIET hyperthyroidism. What are they?
*What is the transient hyperthyroidism caused by?
- Subacute (granulostomatous)
- Chronic (lymphocytic) thyroiditis
- Postpartum thyroiditis
* *The mechanism causing transient hyperthyroidism = uncontrolled release of of hormone from an inflamed gland.
_______ is described as iodine uptake reduced; mild clinical manifestations of hyperthyroidism; the course is self limited; hypothyroidism often follows as intrathyroidal stores of the hormone are depleted.
Transient Hyperthyroidism
Britt is taken to get a CT w/ contrast after tripping in the tRaiLeR ;).
He later found that there was Iodine excess in his body
*which can result in unregulated thyroid hormone production especially in glands that have underlying pathology.
What disease is this?
Jod-Basedow - Iodine Induced Hyperthyroidism
What are two ways that Iodine-Induced Hyperthyroidism (Jod-Basedow) can develop?
- after an iodine load - for example contrast agents for angiography or computed tomography scanning.
- Iodine containing drugs - AMIODARONE
What is the drug that can result in Jod-Basedow?
Amiodarone
Which age has the greatest risk of Jod-Basedow disease?
elderly patients with large nontoxic nodular goiters who come from areas where iodine intake is low (europe) lol
*im sure we will be asked where in the World is iodine intake low haha u will know the answer EUROPE!! haha
Iodine - Induced Hyperthyroidism (Jod-Basedow) can also occur in nonendemic cases of _______ and ______ , in which the mechanism involves INCREASED RELEASE OF STORED HORMONE.
multinodular goiter and thyroid adenoma
What are the characteristic laboratory findings of Iodine-Induced Hyperthyroidism (Jod-Basedow)?
low uptake of radioactive iodine and an absence of antithyroid antibodies
__________ = a form of iodine-induced thyrotoxicosis, occurs in patients with underlying thyroid underlying thyroid disease, (Graves Disease, nodular goiter) and results from overproduction of thyroid hormone using iodine as a substrate.
Type 1 amiodarone induced thyrotoxicosis
*Amiodarone, an iodinated drug with antiarrhythmic and antitianginal properties, which can precipitate hyperthyroidism
_______ = a destructive thyroiditis, occurs in normal thyroids, and the hyperthyroidism is due to EXCESS RELEASE, NOT SYNTHESIS of thyroid hormone.
Type 2
Distinguishing between type 1 and type 2 amiodarone-induced thyroiditis. What is one characteristic that could aid in this distinction?
Type 1- enlarged gland, because it occurs in patients with nodular goiters
Type 2 - a small goiter or a small gland may be present.
* Color-Flow Doppler studies have shown that blood flow is increased in type 1 and decreased in type 2.
What is an iodinated drug with antiarrhythmic and antianginal properties that can precipitate hyperthyroidism?
Amiodarone
_______ typically follows a viral illness, producing a TENDER, MULTINODULAR gland.
Subacute Thyroiditis
Describe the onset of Subacute Thyroiditis
abrupt onset characterized by thyrotoxic symptoms
What is the erythrocyte sedimenation rate in Subacute Thyroiditis?
Rate is high
How will Subacute THyroiditis show up on a Thyroid scan?
charactisitically shows little or NO UPTAKE of Radioiodine
_________ = resulting in hyperthyroidism that is believed to be an uncommon variant of Hashimoto’s disease. In some cases it may be caused by coexisting Graves’ disease. High tiders of antibodies to microsomes and thyroglobulin are present. The prevalence is highest in middle aged women and among the elderly. The gland FEELS RUBBERY and is ENLARGED, sometimes ASYMMETRICAL. Hypothyroidism eventually develops in a substantial number of cases.
Lymphocytic Thyroiditis
_________ = transient mild hyperthyroidism, onset is within 3-6 months of delivery, and the condition is often mistaken for anxiety associated with the stress of caring for a new baby. A low uptake of radioactive iodine and the detection of antithyroid antibodies suggest an immunologic mechanism.
Postpartum (Subacute Lymphocytic) Thyroiditis
T/F Postpartum (Subacute Lymphocytic) Thyroiditis is characterized with tender gland and may resemble Hashimoto’s thyroiditis.
FALSE!!!
NONTENDER GLAND
T/F Postpartum (Subacute Lymphocytic) Thyroiditis may persist for months before resolving. A period of hypothyroidism may occur. It does not tend to recur with subsequent pregnancies.
FALSE!!
it DOES tend to recur with subsequent pregnancies.
a small number of pituitary adenomas produce excessive _______. The result is a diffusely enlarged gland simulating that of Graves’ disease, BUT ophthalmopathy does NOT occur. A similar clinical picture may be caused by tumor proudcing hyman chorionic gonadotropin (hCG), such as *hydatidiform mole or *choriocarcinoma.
TSH
**The thyroid stimulating activity of hCG is weak, but when it is produced in massive quantities it can cause hyperthyroidism
When the source of excess thyroid hormone is extrathyroidal, the thyroid gland will appear ___________ because of the absence of _________.
small; absence of TSH
A ________ with elements of thyroid like tissue, is the only neoplasm regularly capable of synthesizing excessive amounts of thyroid hormone.
dermoid tumor of the ovary = Struma Ovarii
T/F Rarely, thyroid cancers can cause hyperthyroidism, but only in the context of massive tumor burden.
true
The inteake of thyroid hormone in excess of daily requirements (_______ micrograms of ________ per day) may make a person hyperthyroid. Sometimes the intake is surreptitious. The gland is small and THS is absent.
> 200 micrograms of levothyroxine per day
**Topic = Ectopic Thyroxine Production & Intake of Exogenous Hormone
_______ = low or undetectable levels of TSH in the setting of normal (usually high-normal) levels of free T4 & T3.
Subclinical Hyperthyroidism
What is the most common causes of Subclinical Hyperthyroidism?
- *****excess intake of thyroid hormone
1. either for the treatment hypothyroidism
2. for suppressing the growth of a goiter
What are the two risks associated with Subclinical Hyperthyroidism?
- A moderately increased frequency of atrial fibrillation in the elderly’
- Osteoporosis in postmenopausal women
What is the difference in exogenous and endogenous Subclinical Hyperthyroidism?
- In exogenous disease, T3 tends to be normal, but thyroxine levels are either at the upper-normal range or frankly elevated.
- In endogenous disease, both T3 and thyroxine levels are at the upper-normal range.
What are the 2 diseases that cause hyperthyroidism due to autonomous hormone production?
Toxic Multinodular goiter
Toxic adenoma
What are the 3 diseases that cause hyperthyroidism due to increased hormone release?
Subacute thyroiditis
Lymphocytic (Hashimoto’s Thyroiditis)
Iodide exposure
What are the 3 diseases that cause hyperthyroidism due to increased glandular secretion?
Graves’ disease
Functioning Pituitary Adenoma
Choriocarcinoma (hCG)
T/F Exogenous hormone (Levothyroxine) intake of >200 micrograms per day causes hyperthyroidism.
true
What are 2 diseases that cause hyperthyroidism due to extraglandular production?
Struma Ovarii
Metastatic thyroid cancer
T/F The most common causes of hyperthyroidism is Graves’ disease, followed by multinodular goiter, toxic adenoma, thyroiditis, and exogenous thyroid hormone.
true
What is the best way to test for hyperthyroidism?
Determination of serum TSH levels - looking for the absence of TSH
- pt’s with less than 0.05 microU/mL = hyperthyroidism
- as long as the hypothalamic-pituitary axis is intact
A normal TSH level by radioimmunoassay virtually rules out hyperthyroidism, unless a rare ___________ is present.
TSH- secreting pituitary adenoma is present
A very low TSH level may result from which drugs that suppress TSH response to thyroid hormone?
glucocorticosteriods
________ is suggested by a very low or undetectable TSH and thyroid hormone levels that are normal, typically at the upper end of the normal range.
Subclinical hyperthyroidism
What is the most useful and consequently the preferred determination of circulation thyroid hormone? This test helps to confirm the diagnosis and determine the severity of the disease.
free T4 index
an excellent proxy for the free T4, calculated by multiplying the serum T4 by the T3 resin uptake
What would be the results when measuring circulation thyroid hormone using the Free T4 Index?
The serum TOTAL T3 concentration is elevated along WITH T4
As useful as thyroid hormone levels are for diagnosis, over reliance on them and failure to use the TSH assay can be misleading. ________ occurs when an increase in thyroid-binding globulin (pregnancy, estrogen use, liver disease) produces an increase in total T4, whereas the free T4 remains normal.
Euthyroid hyperthyroxemia
An unexpectedly normal or low T3 level in a patient who is clinically euthyroid but has elevated T4 and free T4 levels should suggest the possibility of _________.
Euthyroid Hyperthyroxemia
**T3 level helps in the differentiation
low = eurthyroid
high T3 = most hyperthyroid conditions
Antithyroid antibodies are increased in both _____ and ______, so their diagnostic utility is limited. _________ can be measured to help in identifying persons with Graves’ disease.
- Graves Disease & lymphocytic (Hashimoto’s) thyroiditis
- Thyroid stimulating immunoglobulin G antibody, also referred to as thyrotropin-receptor antibody
_______ levels serve as an elegant yet simple means of detecting a patient who is surreptitiously taking thyroid hormone-exogenous hormone.
Determination of THYROGLOBULIN LEVELS -
*taking thyroid hormone-exogenous hormone will result in SUPPRESSION OF THYROGLOBULIN SYNTESIS
_________ can help to distinguish between excess endogenous thyroid synthesis (high uptake) and increased release of preformed hormone due to inflammation or glandular destruction or an extrathyroidal source (low uptake).
24 hour RADIONUCLIDE THYROID SCAN
A ______ is characteristic of a toxic adenoma, with little uptake of iodine by the rest of the gland.
hot nodule
Uptake of iodine is _____ in patients with thyroiditis, exogenous hormone intake, extraglandular hormone production, and iodine exposure.
Uptake of iodine is _____ in patients with Graves’ disease or a functioning pituitary adenoma.
low; diffusely increased
_________ can identify the rare cases of extrathyroidal hormone synthesis, such as occurs in struma ovarii or a metastasis from a thyroid malignancy.
whole body scanning
Once patient has confirmation of hyperthyroidism, ________ follows by inquiry made into goiter, thyroid nodule, use of iodides or thyroid hormone, eye changes, recent pregnancy, or viral illness and known ovarian, pituitary, or thyroid neoplasms.
Identify the underlying cause
Patient with hyperthyroidism: During the physical evaluation, Holly finds a diffusely enlarged, non-tender thyroid gland. What does this suggest?
-also a Bruit may accompany the diffusely enlarged gland
Graves Disease
**in rare instances a TSH secreting tumor may be responsible for such diffuse glandular stimulation, but not for the Bruit
A patient with hyperthyroidism: During the physical examination, Stephanie finds an exquisitely tender, diffusely enlarged gland occuring in the context of a viral illness point to ________.
Subacute thyroiditis
Patient with hyperthyroidism: During the physical examination Heather finds a nontender and diffusely, but only modestly enlarged thyroid gland. Whats ur diagnosis?
lymphocytic thyroiditis
?Hashimoto’s disease
A small gland indicates an ______ source of hormone.
extrathyroidal source
Multinodularity is consistent with a _____________and also occurs in patients with ______________.
toxic multinodular goiter
Hashimoto’s thyroiditis
An otherwise atrophic gland with a single nodule, especially if larger than 3 cm in diameter = ________
toxic adenoma
Extrathyroidal findings should always be noted.
What are the eye manifestations associated with Graves Disease?
- True proptosis (eye protrusion of greater than 20 mm from the orbital bone)
- Eye muscle disfunction, periorbital and conjunctival edema, lid lag, and stare are also seen
- Pretibial myxedema is also a hallmark (remember this from a card in the begining) :)
Excessive amounts of _______ are associated with an increased risk for osteoporosis, especially in cortical bone, because of increased bone turnover.
thyroid hormone
The risk for thyroid-induced osteoporosis and hip fracture is greatest in ________ with a history of hyperthyroidism or thyroid-suppressive therapy.
postmenopausal women
In patients with thyroid induced osteoporosis, where should u screen?
screening bone density examination of the hip or wrist (sites with a predominance of cortical bone)
