Thyroid Flashcards
A pt with fatigue myalgia proximal mm wkness sluggish reflexes elevated CK and normal ESR
LIKELY DX?
Hypothyroid myopathy
pt having sxs of hypothyroidism but elevated T3, T4 with normal or mildly elevated TSH levels
Generalized resistance to thyroid hormones
Additional metabolic abnormalities in hypothyroidism; name at least 4
Hyperlipidemia, hyponatremia, asymptomatic elevations of creatinine kinase, serum transaminases
Autoantibodies in hashimoto’s
Antithyroperoxidase (>90% of pts) and antithyroglobulin antibodies
Preferred Rx in graves and its side effects?
Radioiodine therapy
-side effects- hypothyroidism n exacerbation of ophthalmopathy.
Euthyroid sick syndrome is?
Cause is?
Pts with an acute severe illness may have abnormal TFTs the most common pattern being low T3 with normal T4 n TSH ( low T3 syndrome)
- primarily due to impaired peripheral DEIODINATION( conversion of T4 to T3) which can b secondary to high endogenous cortisol, inflammatory cytokines, drugs like steroids, amiodarone
- late stage- May present with central hypothyroidism features.
- no Rx needed as it improves by itself when the pt recovers from the underlying illness
Autoantibodies in Graves’ disease
Thyroid stimulating immunoglobulins.
Pt taking herbal med for wt loss, presented with sxs of hyperthyroidism - diarrhea,…
What happens to her TFT including thyroglobulin?
Factitious thyrotoxicosis
Elevated thyroid hormones, low TSH
- the diagnostic test is low serum thyroglobulin due to suppression of native thyroid gland
Methimazole Vs PTU
- which one is preferred? What r the 2 exceptions?
Methimazole Is preferred
PTU:-
- pregnancy- MMI is teratogenic
- thyroid storm
Focal Vs diffuse radioactive iodine uptake
Focal- toxic nodule
Diffuse- graves
A pt presenting with inability to comb her hair with difficulty holding her arms up and hyperthyroid sxs
Dx is ?
Myopathy
Pathophysiology of graves ophthalmopathy
Stimulation of orbital fibroblasts by the anti-TSH receptor autoantibodies-> orbital tissue expansion
Untreated Hyperthyroid pts r at increased risk for rapid bone loss
Mechanism is?
Increased osteoclastic activity
Mechanism of hypertension in hypo Vs hyperthyroidism
Hypo- increase in systemic vascular resistance
Hyper- actually causes a decrease in SVR; htn is due to increased inotropic n cronotropic effect
A pt with fatigue, myalgia, proximal mm wkness, sluggish reflexes, elevated CK and normal ESR. The likely Dx is?
Hypothyroid myopathy
Thyroid lymphoma is 60times more common in pts with a preexisting thyroid hormonal disorder, which is?
Typical presentation?
Hashimoto’s thyroiditis
- rapid enlargement of the thyroid gland in pts with preexisting hashimoto’s
In a hypothyroid pt taking levothyroxine, how would oral estrogen preparations affect the free thyroxine, TSH levels? Levothyroxine dose should b?
Estrogen causes increased production of thyroid binding globulin—> hypothyroid pts, as they can’t produce thyroxine, they r dependent on exogenous thyroxine to saturate TBG binding sites—> decreased free thyroxine n increased TSH
Therefore, higher dosing of levothyroxine may b neede
Fever, neck pain, tender goiter following an upper respiratory tract infection is?
-inflammatory markers, radioiodine uptake?
Subacute thyroiditis( de Quervain thyroiditis) - elevated ESR, low radioiodine uptake
