1. Cause of 50-80% of all hyperthyroidism
1.1. form of type 2 hypersensitivity
1.1.1. stimulation of the thyroid by antibodies directed against TSH receptor
1.2. prevalent in women in their 30s and 40s.
2. Clinical manifestations
2.1. opthalmopathy
2.1.1. functional abnormalities
2.1.1.1. hyperactivity of sympathetic division of of autonomic nervous system
2.1.1.2. lag of globe on upward gaze
2.1.1.3. lag of upper lid on downward gaze
2.1.2. infiltrative changes
2.1.2.1. orbital fat accumulation
2.1.2.2. exophthalmos (eyeball protrusion)
2.1.2.2.1. can cause damage to optic nerve
2.1.2.3. periorbital edema
2.1.2.4. extraoccular muscle weakness
2.1.3. symptoms
2.1.3.1. double vision
2.1.3.2. pain
2.1.3.3. lacrimation
2.1.3.4. corneal ulceration
2.1.3.5. photophobia
2.2. pretibial myexedma
2.2.1. subcutaneous swelling on anterior portions of leg
2.2.2. indurated and erythematous skin
2.3. endocrine system (thyroid)
2.3.1. enlarged goiter
2.3.1.1. hyperactivity of thyroid gland
2.3.2. systolic bruit over thyroid
2.3.3. hypercalcemia
2.3.3.1. excess bone resorption leads to hypercalcemia
2.3.4. decreased PTH
2.3.5. diminished sensitivity to exogenous insulin
2.3.5.1. increased insulin degradation
2.4. reproductive system
2.4.1. oligomenorrhea or amenorrhea
2.4.1.1. related to hypothalamic and pituitary changes
2.4.2. erectile dysfunction
2.4.3. decreased libido
2.4.4. increased estrogen
2.5. GI
2.5.1. weight loss
2.5.1.1. increased metabolism, glucose absorption
2.5.2. frequent stools
2.5.3. N/V/D/A
2.5.4. abdominal pain
2.5.5. decreased lipid levels
2.5.5.1. increase in cholesterol expulsion in feces
2.5.6. decrease in tissue stores of vitamins
2.5.6.1. impaired conversion of B vitamins
2.6. cardiovascular
2.6.1. tachycardia
2.6.1.1. increased metabolism
2.6.2. loud heart sounds
2.6.3. dysrythmias
2.6.4. hypertrophy
2.7. nervous system
2.7.1. restlessness
2.7.1.1. increased cerebral metabolism
2.7.2. short attention span
2.7.3. fatigue
2.7.4. tremor
2.7.5. insomnia
2.7.6. increased appetite
2.7.7. emotional lability
2.8. respiratory
2.8.1. dyspnea
2.8.1.1. weakness of respiratory muscles
2.9. skin
2.9.1. sweating
2.9.1.1. Increased circulation related to increased metabolism
2.9.2. flushing
2.9.3. warm skin
2.9.4. heat intolerance
2.9.5. hair loss
3. Therapy
3.1. antithyroid drugs
3.1.1. methimazole is drug of choice
3.2. radioactive iodine
3.2.1. ablates thyroid gland
3.3. surgery
3.3.1. orbital decompression
3.3.2. partial thyroidectomy
3.4. Following treatment, hypothyroidism develops in most individuals. Thyroid hormone replacement may be required.
3.4.1. Hypothyroidism can lead to
3.4.1.1. Depression
3.4.1.2. Mental and physical sluggishness
3.4.1.3. Weight gain
3.5. comfort measures
3.5.1. prednisone to reduce eye swelling
3.5.2. tape eyes closed at night to prevent drying
3.5.3. sunglasses
3.5.4. eye drops
4. Diagnosis
4.1. increased serum thyroid hormone levels
4.1.1. TSH can be normal or elevated if thyrotoxicosis is TSH-driven
4.1.1.1. pituitary TSH-secreting adenoma
4.1.1.2. pituitary resistance to thyroid hormone
4.1.2. Elevated T4
4.2. decreased TSH levels
4.2.1. TSH should be 0 – .1 in thyrotoxicosis
4.2.2. Values of .1 – .3 seen in mild illness
4.3. presence of thyroid-stimulating immunoglobulins (TSI)
4.3.1. results are almost always positive