thyroid
thyroid
thyroid
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Guest Speaker<br />
Dr. Abhishek Agarwal M.D.<br />
Family Medicine
• Butterfly shaped<br />
gland in front of the<br />
neck<br />
• Uses iodine in the diet<br />
to make <strong>thyroid</strong><br />
hormones T3 & T4<br />
• Thyroid hormones<br />
regulate body<br />
metabolism
GRAVES DISEASE :<br />
• Generalized overactivity of the <strong>thyroid</strong> gland<br />
• Thyroid gland has lost the ability to to respond<br />
to the normal control by pituitary gland via<br />
TSH<br />
• Autoimmune disease with antibodies directed<br />
against the <strong>thyroid</strong> gland that make it produce<br />
excess <strong>thyroid</strong> hormone
GRAVES DISEASE<br />
• Triggers for graves disease :<br />
1. Stress<br />
2. Smoking<br />
3. Radiation to neck<br />
4. Viral infections<br />
• Diagnosed by <strong>thyroid</strong> scan (diffuse uptake)<br />
• Blood test show high TSI (<strong>thyroid</strong> stimulating<br />
immunoglobulin) antibody level
GRAVES DISEASE<br />
• May be associated<br />
with eye disease<br />
(ophthalmopathy).<br />
Eyes protrude out and<br />
double vision can<br />
occur. Stroids needed<br />
for treatment
FUNCTIONING ADENOMA & TOXIC<br />
MULTINODULAR GOITER<br />
• The gland gets lumps that do not produce any<br />
excess hormone and require no treatment<br />
• Occasionally one nodule gets “autonomus”<br />
and starts producing <strong>thyroid</strong> hormone. If there<br />
are many such nodules its called toxic MNG<br />
• These are easily detected on <strong>thyroid</strong> scan
THYROIDITIS (inflammation of the gland)<br />
• Fever, sore throat, pain with swallowing. The<br />
gland is tender to touch<br />
• Affects 8% of women after delivery. Self<br />
limiting<br />
• Initially patient gets hyper<strong>thyroid</strong> as the<br />
inflamed gland releases too much hormone.<br />
Later it gets hypo<strong>thyroid</strong>
EXCESSIVE INTAKE OF IODINE<br />
• Seen more in patients who already have an<br />
underlying abnormal <strong>thyroid</strong> gland.<br />
• Certain meds like amiodarone(Cordarone)<br />
have high iodine content and can lead to this
EXCESSIVE INTAKE OF THYROID HORMONE<br />
• Due to lack of f/u of patients taking <strong>thyroid</strong><br />
medicine<br />
ABNORMAL SECRETION OF TSH<br />
• Tumor in the pituitary – very rare
HASHIMOTO’S THYROIDITIS<br />
• Most common cause of hypo<strong>thyroid</strong>ism in the<br />
country<br />
• The <strong>thyroid</strong> gland is enlarged and has a<br />
decreased ability to produce <strong>thyroid</strong> hormone<br />
• Autoimmune disease where the body has<br />
antibodies that attack its own <strong>thyroid</strong> tissue!<br />
• Has a genetic basis. Can run in families<br />
• Blood tested for antibodies to enzyme TPO
HASHIMOTO’S THYROIDITIS<br />
• 10 times more common in women<br />
• Patient may have other autoimmune diseases<br />
like diabetes type 1 or pernicious anemia (Vit.<br />
B12 deficiency)<br />
• Diagnosed by detecting anti-TPO antibodies in<br />
blood and by <strong>thyroid</strong> scan
LYMPHOCYTIC THYROIDITIS FOLLOWING<br />
HYPERTHYROIDISM<br />
• When inflammation is due to lymphocyte<br />
which is a particular type of white blood cell<br />
• Common after pregnancy<br />
• Hyper<strong>thyroid</strong> stage at start followed by a<br />
hypo<strong>thyroid</strong> phase that lasts about 6 months<br />
after pregnancy and then gets better on its own
THYROID DESTRUCTION SECONDARY TO<br />
RADIOACTIVE IODINE OR SURGERY<br />
• Patients who have received radioactive iodine<br />
therapy or surgery for treatment of<br />
hyper<strong>thyroid</strong>ism may be left with no<br />
functioning <strong>thyroid</strong> tissue<br />
• If there is no significant activity 6 months after<br />
iodine treatment, it is assumed there will no<br />
longer be adequate functioning <strong>thyroid</strong>. The<br />
result is hyper<strong>thyroid</strong>ism
PITUITARY OR HYPOTHALAMIC DISEASE<br />
• If for some reason the pituitary or<br />
hypothalamus cannot signal the <strong>thyroid</strong> to<br />
produce the hormones hypo<strong>thyroid</strong>ism will<br />
result. Its is called secondary and tertiary<br />
hypo<strong>thyroid</strong>ism
MEDICATIONS<br />
• Methimazole and PTU are meds for<br />
hyper<strong>thyroid</strong>ism and can actually cause<br />
hypo<strong>thyroid</strong>ism<br />
• Lithium used as a psychiatric medicine can<br />
cause this as a side effect
• TSH (SCREENING<br />
TOOL)<br />
• T3<br />
• T4<br />
• ANTIBODIES :<br />
1. Antithyroglobulin<br />
Antibodies<br />
2. Anti TPO Antibodies<br />
3. TSH receptor<br />
stimulating antibodies
ULTRASOUND :<br />
1. If there is concern<br />
about structure of the<br />
gland<br />
2. To quantify size<br />
3. If there is suspicion of<br />
cancer<br />
4. Good to detect<br />
calcification and cysts<br />
5. Cannot tell benign<br />
from cancerous gland
RADIOIODINE<br />
SCANNING AND<br />
UPTAKE<br />
1. Radioactively labeled<br />
form of iodine used<br />
2. Thyroid is the only<br />
tissue in the body that<br />
takes up iodine<br />
3. Very specific for<br />
finding <strong>thyroid</strong> tissue
RADIOIODINE<br />
SCANNING AND<br />
UPTAKE<br />
1. If <strong>thyroid</strong> is not picking<br />
up iodine normally<br />
“spots” show up<br />
2. Cold spots are where<br />
the tissue is not picking<br />
up iodine (can be<br />
cancerous)<br />
3. Hot spots are where the<br />
tissue is picking up too<br />
much iodine (toxic<br />
nodule)
Cold nodules<br />
notorious for being<br />
cancerous!
• Best technique to rule out cancer<br />
• Performed in the doctor’s office and takes about 20<br />
minutes<br />
• Complications are rare, but include bleeding,<br />
bruising and infection.<br />
WHEN IS IT DONE?<br />
1. To make a diagnosis of <strong>thyroid</strong> nodule<br />
2. To help select therapy for <strong>thyroid</strong> nodule<br />
3. To treat a <strong>thyroid</strong> cyst by draining its contents via<br />
aspiration<br />
4. To inject a medicine to shrink a recurrent cyst
HYPOTHYROIDISM :<br />
• Usually requires<br />
lifelong <strong>thyroid</strong><br />
hormone therapy<br />
• Synthetic T4 is used in<br />
the form of a pill to be<br />
taken once daily in<br />
morning 30 minutes<br />
before food<br />
• Avoid iron containing<br />
meds and antacids with<br />
it
HYPOTHYROIDISM :<br />
• Started at a lower dose in patients with heart<br />
disease and gradually dose is increased at 6<br />
week intervals<br />
• Therapy is monitored at 6 weeks intervals until<br />
stable <strong>thyroid</strong> hormone levels are achieved.<br />
During these visits a blood test for TSH level is<br />
done (normal TSH 0.5-5.0 IU/ml)<br />
• Once stable TSH can be checked annually
TREATING THE SYMPTOMS :<br />
• Beta blockers immediately treat symptoms like<br />
palpitations and increased heart rate.<br />
• These meds do not affect the level of the<br />
<strong>thyroid</strong> hormone in the blood and are simply<br />
for symptomatic relief
ANTITHYROID DRUGS<br />
• Methimazole and PTU : accumulate in <strong>thyroid</strong><br />
tissue and block hormone production<br />
• As a serious side effect they can suppress the<br />
production of white blood cells that fight<br />
infection<br />
• Impossible to know if and when this would<br />
occur so regular testing of white blood cells is<br />
not useful. If patient gets any signs of infection<br />
the doctor needs to know immediately
ANTITHYROID DRUGS<br />
• The patient is seen monthly by the doctor till<br />
the <strong>thyroid</strong> level are stable and then every 3-6<br />
months<br />
• Long term anti<strong>thyroid</strong> meds are used only for<br />
patients with graves disease as it may go into<br />
remission with these meds thereby avoiding<br />
the radioactive iodine or surgery as treatment<br />
• Data shows remission rates of 40-70%<br />
• In remission the gland would not need<br />
anti<strong>thyroid</strong> meds
RADIOACTIVE IODINE THERAPY<br />
• Radioactive iodine isotope-123 used orally as a<br />
one time dose. Iodine being specific for <strong>thyroid</strong><br />
tissue ablates it.<br />
• The radioactive iodine is picked up by the<br />
active cells in the <strong>thyroid</strong> and destroys them<br />
• Radioactive iodine ablation has been safely<br />
used for over 50 years, and the only major<br />
reasons for not using it are pregnancy and<br />
breast feeding
RADIOACTIVE IODINE THERAPY<br />
• Treatment of choice for recurring Graves'<br />
disease, patients with severe cardiac<br />
involvement, those with multinodular goiter or<br />
toxic adenomas, and patients who cannot<br />
tolerate anti<strong>thyroid</strong> drugs<br />
• If a woman chooses to become pregnant after<br />
ablation, it is recommended she wait 8-12<br />
months after treatment before conceiving
RADIOACTIVE IODINE THERAPY<br />
• In general, more than 80% of patients are cured<br />
with a single dose of radioactive iodine. It takes<br />
between 8 to 12 weeks for the <strong>thyroid</strong> to become<br />
normal after therapy<br />
• Permanent hypo<strong>thyroid</strong>ism is the major<br />
complication of this form of treatment. While a<br />
temporary hypo<strong>thyroid</strong> state may be seen up to six<br />
months after treatment with radioactive iodine, if<br />
it persists longer than six months, <strong>thyroid</strong><br />
replacement therapy (with T4 or T3) usually is<br />
begun
SURGERY<br />
• Surgery to partially remove the <strong>thyroid</strong> gland<br />
(partial THYROIDECTOMY) was once a<br />
common form of treatment for<br />
hyper<strong>thyroid</strong>ism<br />
• If too much tissue is removed, hypo<strong>thyroid</strong>ism<br />
may result. In this case, <strong>thyroid</strong> replacement<br />
therapy is begun
SURGERY<br />
• The major complication of surgery is disruption of<br />
the surrounding tissue, including the nerves<br />
supplying the vocal cords and the four tiny glands<br />
in the neck that regulate calcium levels in the body<br />
(the para<strong>thyroid</strong> glands). Accidental removal of<br />
these glands may result in low calcium levels and<br />
require calcium replacement therapy<br />
• With the introduction of radioactive iodine<br />
therapy and anti<strong>thyroid</strong> drugs, surgery for<br />
hyper<strong>thyroid</strong>ism is not as common as it used to be