Download Hyperthyroidism - Texas Tech University Health Sciences Center

GENERAL MEDICINE CONFERENCE
HYPERTHYROIDISM
Selim Krim, MD
Assistant Professor
Texas Tech University Health Sciences Center
SIGNS AND SYMPTOMS
Skin: Increased Sweating and heat intolerance, onycholysis,
hyperpigmentation, pruritus and thinning of the hair.
Eyes: Stare and lid lag, exophtalmos if graves disease
Cardiac: Palpitations, exertional dyspnea, anginal-like chest pain,
tachycardia, atrial fibrillation, CHF
GI: Weight loss, diarrhea
Neuro-psych: Anxiety, restlessness, irritability, emotional lability, psychosis,
agitation, and depression
Metabolic/Endocrine: Hyperglycemia, low serum total and high-density
lipoprotein (HDL) cholesterol
GRAVES’ DISEASE
Signs and symptoms of hyperthyroidism
Exopthalmos, proptosis, lid lag, orbital edema
Diffuse goiter
TSH receptor antibodies
Increased RAI uptake
MUST KNOW
T4 and T3 are produced in thyroid gland but T3 is the active
component.
T3 can also come form T4.
T4-to-T3 conversion is stopped by starvation, liver disease and
certain drugs (propylthiouracil, propranolol, prednisone)
T4 and T3 are circulating as bound proteins-TBG (thyroid binding
globulin)
If TBG goes up-T4 and T3 would go up. If TBG goes down-T4 and
T3 would go down.
GENERAL RULE
Hyperthyroidism with a high radioiodine uptake indicates
de novo synthesis of hormone.
Hyperthyroidism with a low radioiodine uptake indicates
either inflammation and destruction of thyroid tissue with
release of preformed hormone into the circulation, or an
extrathyroidal source of thyroid hormone.
FACTITIOUS VS. SUBACUTE
THYROIDITIS
FACTITIOUS
HYPERTHYROIDISM
SUBACUTE
THYROIDITIS
THYROID GLAND
Painless gland
Painful gland
SERUM
THYROGLOBULIN
Low/Normal
High
SEDIMENTATION RATE
Normal
High
DIFFERENTIATING THE THREE TYPES OF
THYROIDITIS
Subacute thyroiditis/Viral
thyroiditis/de Quervain’s
thyroiditis
Silent or painless thyroiditis
(Chronic lymphocytic)
Hashimoto’s thyroiditis
(Painless goiter)
Viral
Idiopathic mainly in women,
typically 3-12 months after
pregnancy (Postpartum
thyroiditis)
Autoimmune. Multinodular
goiter is the outstanding
feature.
High ESR with fever
Normal ESR
High or normal ESR
High T4 and T3 early onlater low T4 and T3. Low
RAIU
Anti-thyroglobulin antibodies
are usually elevated. TPO
antibodies usually normal.
High T4 and T3 with low
TSH initially, then Low
RAIU, low T4 and T3.
Anti-thyroglobulin antibodies
may or may not be
elevated. TPO elevated in
75% of cases.
Initially eu, hyper- or hypo,
eventually hypothyroid.
Low RAIU.
Anti-thyroglobulin antibodies
are present in 85% of
cases.
TPO in 95% of cases.
Aspirin/Steroids
Beta-blockers if needed
Levothyroxine if needed
INDICATIONS FOR SURGERY
Patients with very large goiters
Goiters causing upper airway obstruction or severe dysphagia
In a patient who also has a nonfunctional thyroid nodule, which can be a
thyroid cancer, surgery can both cure the hyperthyroidism and remove the
nodule.
Moderate to severe Graves' ophthalmopathy,
Pregnant women who are allergic to antithyroid drugs and/or are tolerating
hyperthyroidism poorly
Case 1
A 27-year-old woman is evaluated for palpitations and heat intolerance that develop
3 months after a successful pregnancy. She is breastfeeding. The patient's older
sister has Graves' disease, but the patient herself has no history of thyroid disease.
On physical examination, the blood pressure is 128/70 mm Hg, and the pulse rate is
104/min. Eye examination reveals stare and lid lag, but no proptosis. The thyroid
gland is moderately enlarged and nontender. She has moist palms and brisk deep
tendon reflexes. Serum free T4 is 2.7 ng/dL (34.2 pmol/L), free T3 46.22 ng/dL (7.1
pmol/L), and thyroid-stimulating hormone (TSH) is undetectable. Which one of the
following is the most appropriate next step in this patient's management?
A- Serum anti-thyroid peroxidase antibodies
B- Serum thyroglobulin level
C- Serum TSH immunoglobulins
D- An empiric trial of antithyroid drugs
E- Radioiodine (I-131) uptake and thyroid scan
Case 2
A 27-year-old male athlete is evaluated for frontal headache, palpitations,
and heat intolerance and an elevated serum thyroid-stimulating hormone
(TSH) level. On physical examination, the blood pressure is 147/78 mm Hg,
a pulse rate of 88/min, and a mildly enlarged thyroid gland. He has a fine
tremor, moist palms, and deep tendon reflexes are brisk. On laboratory
testing, serum free T4 is 2.9 ng/dL (38.0 pmol/L) and TSH is 6.8 µU/mL (6.8
mU/L). Antithyroid peroxidase and antithyroglobulin antibodies are negative.
Which of the following is the most appropriate next test in the evaluation of
this patient?
A- MRI of the pituitary
B- Thyroid function testing of family members
C- Radioactive iodine uptake and thyroid scan
D- Serum thyroglobulin level
E- Thyroid stimulating immunoglobulins
Case 3
65-year-old man with refractory atrial fibrillation begins therapy with
amiodarone. Baseline thyroid hormone levels are normal. One month later,
the patient is asymptomatic but has the following laboratory findings: total
T4, 13.4 µg/dL (172.46 nmol/L); free T4, 2.7 ng/dL (34.2 pmol/L); free T3,
11.72 ng/dL (1.8 nmol/L); TSH, 3.9 µU/mL (3.9 mU/L). Which of the
following is the most likely explanation for these findings?
A- Amiodarone-induced thyroiditis
B- Iodine-induced hyperthyroidism
C- Expected changes in euthyroid patients taking amiodarone
D- Spurious laboratory results caused by amiodarone
E- Euthyroid sick syndrome
Case 4
A 24-year-old woman is evaluated for palpitations and sweating that began 4
weeks after she delivered her first child 8 weeks ago. She has had
occasional loose stools. Otherwise, she has felt generally well. She nursed
her baby for 6 weeks but decided to stop 2 weeks ago. Her family history is
unremarkable. She is taking multivitamins but no other supplements. On
physical examination, the blood pressure is 110/60 mm Hg, pulse rate
92/min, and BMI 23.7. The thyroid gland is normal size, slightly firm in
consistency, and nontender. Thyroid-stimulating hormone<0.01µU/mL, free
T4=3.4ng/dL, total T3=315ng/dL, radioiodine uptake<1%. Thyroid scan not
visualized. Which of the following is the most appropriate therapy for this
patient?
A- Radioactive iodine (I-131)
B- β-Blocker
C- Prednisone
D- Propylthiouracil
E- Aspirin
Case 5
A 59-year-old woman is evaluated for a 2-week history of diffuse arthralgias,
malaise, anorexia, and left-sided neck pain and swelling. The pain radiates
upwards towards the left ear. She has no fever, chills, palpitations, or
nervousness. On physical examination, the temperature is 37.3 °C (99.2
°F), and the pulse rate is 92/min. Thyroid examination shows warmth,
tenderness, and moderate enlargement of the left lobe of the gland, without
fluctuance. Laboratory testing shows a leukocyte count of 12,300/µL (12.3 ×
109/L), with 82% segmented cells and 3% bands; erythrocyte sedimentation
rate is 113 mm/h. Serum free T4 is 3.0 ng/dL (38.6 pmol/L), and TSH is 0.04
µU/mL (0.04 mU/L). CT scan of the neck shows no evidence of abscess.
Which of the following is the most appropriate therapy at this time?
A- Propylthiouracil 100 mg three times daily
B- Radioiodine ablation therapy
C- Thyroidectomy
D- Systemic antibiotic therapy
E- Prednisone 40 mg once daily
Case 6
A young female has weight loss, irritability, diarrhea, very high T4, low TSH,
and a low RAIU. O/E thyroid gland is painless. Serum thyroglobulin level is
low. TPO antibodies are normal. What is your diagnosis?
A- Graves disease.
B- Subacute thyroiditis.
C- Chronic lymphocytic thyroiditis
D- Factitious hyperthyroidism
E- Hashimoto’s thyroiditis.
Case 7
A 33 year old female gave birth to a healthy child 6 weeks ago. She
complains of tremors and anxiety. T4 is elevated while TSH is low normal. In
addition to prescribing beta-blockers, which of the following would you order
to confirm your diagnosis?
A- Lugol iodine
B- Radioactive iodine
C- RAU uptake
D- Observation
Case 8
A 32 year old, 4 months post-partum nurse comes to you for depression.
O/E thyroid is enlarged but painless to palpation. Blood tests reveal high T3
and low TSH. What is your next step in the management of this patient?
A- Free T4
B- RAI uptake
C- A trial of propylthiouracil
D- Propranolol
E- Observation
Case 9
2 months later she comes back with continued symptoms of depression.
The previously ordered RAIU was low. Blood tests now reveal low T3 and
high TSH. What is your next step in the management of this patient?
A- No medication, reassurance, and to return for rechecking thyroid function
test in 3 months
B- Give synthroid for short term and reassure that she will be fine soon
C- refer her to a psychiatrist
D- Check for spurious intake of thyroid hormone
Questions?