Thyrotoxicosis

The primary role of propranolol in thyrotoxicosis is to attenuate the effects of catecholamines, and it is also a weak inhibitor of extrathyroid conversion of T4 to T3. When given it is useful in reducing the heart rate, tremor, agitation, psychotic behavior, diarrhea, fever and diaphoresis. It doesn’t alter the metabolic rate.

Ans. is B. i.e. I 131 therapy

Radioactive Iodine therapy should not be given to patients wanting pregnancy within one year.

If pregnancy occurs inadvertently termination should be considered.

Initial investigation in a case of thyrotoxicosis includes estimation of TSH and unbound T4 levels.

 Ans. is ‘c’ i.e., Patients with distal muscle weakness

In hyperthyroidism there is proximal muscle weakness.

Thyrotoxicosis (Hyperthyroidism)

o Most common cause of thyrotoxicosis is diffuse hyperplasia of thyroid, i.e., Graves disease. Clinical features

o Hyperthyroidism is a hypermetabolic state.

o The effects are due to increased level of thyroxin as well as due to overactivity of the sympathetic nervous system. o Features are :

1. Metabolism –> T BMR, Intolerance to heat, weight loss, increased sweating, postprandial hyperglycemia, L cholesterol, phospholipd, triglyceride, T FFA, Increased appetite.
2. CVS T Systolic BP, Hyperdynamic precordium, wide pulse pressure, sinus tachycardia, mid systolic murmur, Means lerman scratch, atrial fibrillation, Angina & CHF.
3. Respiration —> T Respiratory rate.
4. GIT–> Diarrhoea
5. CNS Nervousness, anxiety
6. Musculoskeletal system -s Proximal muscle weakness, fine tremors, osteoporosis.
7. Others -s Extreme fatiguibility but inability to sleep, infertility.

o In Graves disease there is exophthalmos, and wide eyed, Staring gaze.

Ans. is ‘c’ i.e., Propylthiouracil

o Both carbimazole and propylthiourcil can be used during pregnancy, but propyl-thiouracil is the drug of choice because its greater protein binding allows low doses of propylthioracil to be transferred across the placenta and therefore less chance of hypothyroidism.

o Historically, prophylthiouracil has been preferred over methimazole because transplacental passage was thought to be lower; However, according to recent studies, both propylthiouracil and methimazole cross the placenta equally and either may be used safety in the pregnant patient.

Note : However, if you will have to choose one option, prophylthiouracil is still the best because all other books still mention prophylthiouracil as the DOC in pregnancy.

Ans. is ‘c’ i.e., Graves disease

Ans. is ‘c’ i.e., Carbimazole

o Most pediatric endocrinologists recommend initial medical therapy using antithyroid drugs rather than radioiodine or subtotal thyroidectomy.

o The 2 antithyroid drugs in widest use are methimazole and propylthiouracil.

Ans. is ‘a’ i.e., Early Diastolic Murmur

• Effect of thyroid hormone increases the heart rate and myocardial contractility. This along with decreased systemic vascular resistance in thyrotoxicosis, increases the stroke volume and cardiac output.
• CVS findings in thyrotoxicosis
• The most common cardiovascular manifestation is sinus tachycardia, often associated with palpitations. The restign heart rate is > 90/min
• Exertional dyspnea
• Hyperactive precordium with a loud first heart sound, an accentuated pulmonic component of the second heart sound, and a third heart sound.
• Systolic ejection click
• Midsystolic murmur along the left sternal border
• A systolic scratch also known as Means-Lerman Scratch, is occasionally heard in the 2″⁴ left intercoastal space during expiration (this is probably generated by the pleura and pericardium rubbing together).
• Systolic hypertension is common (diastolic hypertension can also occur).
• Atrial fibrillation (more common in elderly patients).

Ans is C 

Riedel’s thyroiditis

• It is a rare variant of thyroiditis also known as Riedel’s struma or invasive fibrous thyroiditis that is characterized by the replacement of all or part of the thyroid parenchyma by fibrous tissue, which also invades into adjacent tissues.
• Riedel’s thyroiditis also is associated with other focal sclerosing syndromes including
• mediastinal, retroperitoneal, periorbital, and retro-orbital fibrosis and sclerosing cholangitis.
• Patients may present with symptoms of hypothyroidism and hypoparathyroidism as the gland is replaced by fibrous tissue.
• Physical examination reveals a hard, “woody” thyroid gland with fixation to surrounding tissues

Diffuse Toxic Goiter-

• MC cause of hyperthyroidism, caused by stimulatory autoantibodies to TSH-R
• Hyperthyroid symptoms (heat intolerance, increased sweating, and thirst, weight loss despite adequate caloric intake). Graves’ disease includes thyrotoxicosis, goiter, exophthalmos, and pretibial myxedema
• MRI of orbits is useful in evaluating Grave’s ophthalmopathy.

Hashimoto’s thyroiditis-

• It is the most common inflammatory disorder of the thyroid and the leading cause of hypothyroidism.
• An elevated TSH and the presence of thyroid autoantibodies usually confirm the diagnosis.

Ans. is ‘d’ i.e. All 

Answer is D (Serial 24 hours test for catecholamines, metanephrines and vanillylamandelic acid excretion) :

Theochromocytoma, must be excluded by measurement of urinary catecholamines levels in all cases before embarking upon thyroid surgery to avoid the potential hazards^. of this condition’ – Bailey

Essays employed for diagnosis of pheochromocytoma include those for:

1. Vanillyl mandelic acid (VMA)
2. Metanephrines
3. Free catecholamines

The patient in question is a case of inherited Men II a syndromes

The presence of ‘headache and sweating’ in a patient with thyroid nodule warrants prompt investigation for a possible pheochromocytoma as part of MEN II syndrome, more so in a patient with a positive family history (as suggested by presence of renal calculi and thyroid nodule in mother).

Pheochromocytoma secrete large amounts of catecholamines, the secretion of which is further increased during surgery. This may result in large swings in blood pressure and arrhythmias, and increases the risk of surgical mortality. Stable a adrenergic blockage is essential before embarking on thyroid surgery.

Answer is A (Diastolic murmur) :

Thyrotoxicosis is associated with a systolic murmur. ur. It is not associated with any diastolic murmur.

Cardiovascular manifestations of thyrotoxicosis:

• Sinus tachycardia^Q is the most common^Q manifestation of Thyrotoxicosis.
• Midsystolic murmur^Qheard best at left sternal border with or without Systolic ejection click.
• Means lerman scratch^y: It is a systolic scratchy sound heard at the 2^nd left intercostal space during expiration. It is thought to result from rubbing of hyperdynamic pericardium against the pleura
• Angina and heart failure may be precipitated by hyperthyroidism in patients with underlying heart disease.

Answer is D (Oxygen consumption):

Betablockers do not correct the underlying metabolic abnormalities (i.e. does not affect the oxygen consumption^Q).

This is why propanolol should only be used as an adjunctive therapy.

Ans:B. Joffroy’s sign

Eye signs in thyrotoxicosis

• Stellwag’s sign: staring look, absent of normal blinking, first sign to appear(mild hyperthyroidism)
• von Graefe’s sign(Lid Lag sign): the inability of the upper eyelid to keep pace with the eyeball (mild)
• Joffroy’s sign: the absence of wrinkling on the forehead when the patient looks up (frowns) (moderate)
• Moebius sign: lack of convergence of eyeball(severe hyperthyroidism)
• Dalrymple’s sign: upper eyelid retraction, sclera visible
• Jellinek’s sign: increased pigmentation of eyelid margins
• Enroth sign: edema of eyelids and conjunctiva
• Rosenbach’s sign: tremor of closed eyelids
• Gifford’s sign: difficulty in everting upper eyelid in primary toxic thyroid. Differentiates exophthalmos from other causes
• Loewi’s sign: dilation of the pupil with weak adrenaline solution
• Knie’s sign: unequal dilation of the pupil
• Cowen’s sign: jerky papillary contraction to consensual light
• Kocher’s sign: when clinician places his hands-on patient’s eyes and lifts it higher, patient’s upper eyelid springs up more quickly than eyebrows
• Naffziger’s sign: with the patient in sitting position and neck fully extended, protruded eyeball can be visualized when observed from behind
• Proptosis due to infiltration of retrobulbar tissues with fluid and round cells
• The weakness of extraocular muscles(particularly inferior oblique) results in diplopia
• The most common ocular motility defect is a unilateral elevator palsy caused by the involvement of inferior rectus; next common – failure of abduction due to involvement of medial rectus.