ENDOC- THYROTOXICOSIS Flashcards
_____________ is defined as the state of thyroid hormone excess and is not synonymous with hyperthyroidism , which is the result of excessive thyroid function.
Thyrotoxicosis
However, the major etiologies of thyrotoxicosis are _______________
hyperthyroidism caused by:
- Graves’ disease,
- toxic MNG,
- and toxic adenomas.
•state of thyroid hormone excess
•Thyrotoxicosis
•excessive thyroid function
•Hyperthyroidism
Causes of Thyrotoxicosis
- Primary Hyperthyroidism
- thyrotoxicosis without hyperthyroidism
- Secondary Hyperthyroidism
4.
Primary Hyperthyroidism
- Graves’ disease
- Toxic Multinodular goiter
- Toxic Adenoma
- Functioning thyroid carcinoma metastases
- ACtivating mutation of the TSH receptor
- Activating mutation of Galpha ( McCune-Albright syndrome)
- Struma ovarii
- Drugs: Iodine excess ( Jod- Basedow phenomenon)
Thyrotoxicosis without Hyperthyroidism
- Subacute thyroiditis
- Silent Thyroiditis
- Other causes of thyroid destruction; amiodarone, radiation, infarction of adenoma
- Ingestiopm pf excess thyroid hormone ( thyrotoxicosis factitia) or thyroid tissue
SEcondary Hyperthyroidism
- TSH-secreting pituitary adenoma
- Thyroid homrone resitance syndrome; occasional patient may have features of thyrotoxicosis
- Chorionic Gonadotropin-secrreting tumors
- Gestational thyrotoxicosis
What are the symptoms of Thyrotoxicosis in Descending Order of Frequency
- Hyperactivity, irritability, dysphoria
- Heat intolerance and sweating
- Palpitations
- fatigue and weakness
- Weightloss with increased appetite
- Diarrhea
- polyuria
- oligomenorrhea
- loss of libido
What are Thyrotoxicosis in Descending order of Frequency
- Tachycardia: atrial fibrillation in the elderly
- tremor
- Goiter
- Warm, moist skin
- Muscle weakness, proximal myopathy
- Lid retraction or lag
- Gynecomastia
Thyrotoxicosis
- Gravess Disease
- Thyroiditis
- acute
- subacute
- silent
- Toxic Multinodular Goiter
- Hyperfunctioning Solitary Nodule
_____________- accounts for 60–80% of thyrotoxicosis.
Graves’ disease
The prevalence of Graves’ disease varies among populations, reflecting _____________________.
genetic factors and iodine intake (high iodine intake is associated with an increased prevalence of Graves’ disease).
Graves’ disease occurs in up to 2% of women but is one-tenth as frequent in men.
Mas madami sa boys
Graves’ dse rarely begins before adolescence and typically occurs between ____________of age; it also occurs in the elderly.
20 and 50 years
What is the pathophysio of Graves’ Dse?
- a combination of environmental and genetic factors,
- including polymorphisms in HLA-DR, CTLA-4 , CD25 , PTPN22 (a T cell regulatory gene) and TSH-R , contribute to Graves’ disease susceptibility
- Smoking is a minor risk factor for Graves’disease and a major risk factor for the development of ophthalmopathy
GRAVES’ DISEASE
•TSI (thyroid stimulating immunoglobulins) that are synthesized in the thyroid gland as well as in bone marrow and lymph nodes•high levels of TSI can cross the placenta and cause____________-
•
•TPO antibodies occur in up to 80% of cases
•
•there is no direct correlation between the level of TSI and thyroid hormone levels in Graves’ disease
neonatal thyrotoxicosis
The hyperthyroidism of Graves’ disease is caused by_________that are synthesized in the thyroid gland as well as in bone marrow and lymph nodes.
Such antibodies can be detected by bioassays or by using the more widely available TBII assays.
Other thyroid autoimmune responses TPO antibodies occur
in up to 80% of cases and serve as a readily measurable marker of
autoimmunity
TSI
What are the clinical manifestation of Graves’ disease?
CLINICAL MANIFESTATIONS:
•clinical presentation depends on the severity of thyrotoxicosis
- ••features that are common to any cause of thyrotoxicosis
- –unexplained weight loss, despite an enhanced appetite, due to the increased metabolic rate
- –hyperactivity, nervousness, irritability
- –Fine tremor is a frequent finding
- •
In the elderly, features of thyrotoxicosis may be subtle or masked, and patients may present mainly with fatigue and weight loss, a condition known as_______________
apathetic thyrotoxicosis
CLINICAL MANIFESTATIONS:
•features that are common to any cause of thyrotoxicosis
- –Common neurologic manifestations include hyperreflexia, muscle wasting, and proximal myopathy without fasciculation
_________: most common CV manifestation
–Sinus tachycardia
–___________ ismore common in patients >50 years of age
–sweating and heat intolerance
–Women frequently experience oligomenorrhea or amenorrhea; in men, there may be impaired sexual function and, rarely, gynecomastia
Atrial fibrillation
The most common cardiovascular manifestation is _________________ often associated with palpitations, occasionally caused by** supraventricular tachycardia.**
sinus tachycardia,
Graves’ disease
CLINICAL MANIFESTATIONS:
•ELDERLY – “apathetic thyrotoxicosis”
_______________appear to play a major role in thyroid-associated ophthalmopathy.
There is infiltration of the extraocular muscles by activated T cells; the release of cytokines such as IFN-γ, TNF, and IL-1 results in fibroblast activation and increased synthesis of glycosaminoglycans that trap water, thereby leading to characteristic muscle swelling. Late in the disease, there is irreversible fibrosis of the muscles.
Cytokines
Onset of Graves’ ophthalmopathy occurs_____________________
within the year before or after the diagnosis of thyrotoxicosis in 75% of patients
_____________ occurs in <5% of patients with Graves’ disease (Fig. 341-7 B ) , almost always in the presence of moderate or severe ophthalmopathy.
Thyroid dermopathy
Where is Thyroid dermopathy most frequent _________________
over the anterior and lateraL aspects of the lower leg (hence the term pretibial myxedema )
In thyroid dermopathy, skin changes can occur at other sites, particularly after trauma.
The typical lesion is a _____________________ appearance. Nodular involvement can occur, and the condition can rarely extend over the whole lower leg and foot, mimicking elephantiasis.
- noninflamed,
- indurated plaque with a deep pink or purple color
- and an “orange skin”
Thyroid acropachy refers to a form of clubbing found in <1% of patients with Graves’ disease (Fig. 341-7 C ) . It is so strongly associated with _____________- that an alternative cause of clubbing should be sought in a Graves’ patient without coincident skin and orbital involvement.
thyroid dermopathy
Graves Disease
•COURSE
–Clinical features generally worsen without treatment
–mild Graves’ disease experience spontaneous relapses and remissions
–Ophthalmopathy: worsens @ ___________
•
1st 3-6 mos, plateau @ 12-18 mos
