Problem based learning case study

Thyroid disorder

• 23 year old female student came to the doctor complaining of weight loss and she felt her heartbeat was very fast.

• Her symptoms began about 2 months ago• Her friends also noticed that her eyes had become prominent and that the patient

was very irritable and anxious.• She would often have an argument with her friends because she felt too hot and

wanted the air conditioner to be cooler even though the rest of her friends felt fine• On taking a detailed history the patient mentioned that her menstrual periods had

become infrequent• Her mother had a similar problems and had taken treatment from the doctor after

which she had improved

Case study

• While seated on the chair, the doctor noticed that the patient was rather fidgety and could not keep still.

• Her heart rate was 104 beats per minute• The doctor also noticed a small swelling in the anterior aspect of the patient’s neck

that moved upwards when the patient was asked to swallow some water in a cup.

• The doctor asked the patient to stretch her hands out and put her fingers apart. On doing so the doctor noticed fine tremors of the fingers

• The patient did have prominent eyes and the upper part of the sclera was visible• The doctor looked for lid lag and extraocular muscle weakness.• The skin over the anterior aspects of the lower part of the legs was examined and

found to be abnormal

• Blood tests were ordered• Her Free Thyroxine(FT4) and Free Tri-iodothyronine levels (FT3) were high and the

Thyroid Stimulating Hormone (TSH) level was very low.• TSH receptor antibodies were positive

Case study

Important Terms

• Goiter:A goiter is a swelling in the thyroid gland, which can lead to a swelling of the neck. Goiter rarely occurs when the thyroid gland is functioning properly.

Worldwide, over 90% cases of goiter are caused by iodine deficiency. but Hashimoto's thyroiditis is the most common cause.

Important Terms

• Heat Intolerance:Heat intolerance is the inability to be comfortable in normal temperature.

often produces a feeling of being overheated and can cause heavy sweating.

Important Terms

• Thyrotoxicosis:The state produced by excessive quantities of endogenous or exogenous thyroid hormone.

Important Terms

• Primary hyperthyroidism:Is a hyperthyroidism due to a disorder originating within the thyroid gland, in contrast to one of pituitary origin.

Important Terms

• Thyroiditis:Is the inflammation of the thyroid gland.

Thyroiditis is a group of disorders that all cause thyroidal inflammation. e.g. Postpartum thyroiditis, sub-acute thyroiditis, silent thyroiditis, drug-induced thyroiditis, radiation-induced thyroiditis, and acute thyroiditis

Important Terms

• Lid lag:lid lag is the inability of the upper eyelid to follow the eye’s downward movements.

• Exophthalmos:Is the protrusion of one or both eyeballs.

Important Terms

• Pretibial Myxedema:Pretibial myxedema or, more appropriately, thyroid dermopathy is a term used to describe localized lesions of the skin resulting from the deposition of hyaluronic acid, usually as a component of thyroid disease.

Although the condition is most often confined to the pretibial area, it may occur anywhere on the skin.

What is the likely disorder in a patient presenting with this cluster of symptoms?

Based on the elevation of Free Thyroxine(FT4), Free Tri-iodothyronine (FT3) levels & the reduction of (TSH) with the positive test of TSH receptor antibodies. We say it’s Graves’ disease

What are the symptoms of hyperthyroidism ?

• 1- Wt. loss despite normal or increased appetite.

• 2-Hyperdefecation (increased stool frequency).

• 3- Diarrhea.• 4- Anorexia (decreased

appetite).• 1-Palpitations.• 2-Atrial Fibrillations ( a type of

cardiac arrhythmias involves both chambers of atrium).

• 3-Increased pulse pressure.• 4-Dyspnea on exertion.

• GIT

• Cardiorespiratory

What are the symptoms of hyperthyroidism ?

• 1-Increased sweating, pruritus.

• 2-Palmar erthem.• 3-loss of hair (Alopecia).• 4- Pigmentation.

• 5-Clubbing fingers.

• Dermatological

• 1-Nervousness, irritability.• 2- Tremors.• 3-Hyper-reflexia.

• 4-Muscle weakness.

• Neuromuscular

What are the symptoms of hyperthyroidism ?

• Reproductive• 1- Amenorrhea.• 2-Infertility, spontaneous

abortions.

Others• 1- Thirst.• 2- Heat intolerance,

• 3-Fatigue, apathy.• 4-Osteoprosis

• Ocular• 1-Lid retraction, lid lag.• 2-excessive lacrimation.• 3-Exophthalmous

Mention few causes of hyperthyroidism with goiter

•Thyroid nodules usually represent benign lumps or tumors in the gland. These nodules sometimes produce excessive amounts of thyroid hormones (TNG)

Hyper functioning

thyroid nodules(single nodule )

• Autoimmune disorder in which antibodies produced by our immune system stimulate thyroid to produce too much T-4

• The most common cause of hyperthyroidism

Graves' disease

(entire thyroid gland is

enlarged)

Mention few causes of hyperthyroidism with goiter

Drugs

This is a particular problem in patients who take forms of

thyroid medication that contains T3

• Inflammation of the thyroid gland can lead to the release of excess amounts of thyroid hormones

Thyroiditis

Hyperthyroidism (the presence of too much

thyroid hormone)

exophthalmos (protrusion of the eye balls)

Dermopathy with skin lesion

What is the triad of Graves’ disease ?

How do you practically examine for Goiter ?

• ASK the pts to drink his glass of water as you apply very gentle pressure

• The gland should slide beneath your fingers while it moves upward along with the cartilagenous rings

• The two main lobes are connected by a small isthmus

• slide the three fingers of both hands to either side of the rings

Stand behind the pts (use M 3 finger)

Move down (T.C)

Move down (horiz.

Groove)

Continue walking down

( next well defined T

ring)

• Landmarks used in the examination of the Thyroid gland

• Ask the patient to hold their arms out in front of him with palms facing up , then put a paper on his/her hands and WATCH the paper directly if there is any movement .

How do you practically examine for Fine tremors?

Asking the patient to follow with their eyes an object moving slowly from their upper to lower field of vision

Notice that the eyelid will lags behind the upper edge of the iris as the eye moves downward

A lag is indicated by white sclera appearing between eyelid and limbus.

A similar phenomenon is seen with the lower edge, when the eye moves upwards

How do you practically examine for Lid lag?

Bring the upper & lower orbital margin in the same plane by titling the face , and see whether you can see eyeball or cornea coming out of plane , if yes it is known as exophthalmos.

How do you practically examine for Exophthalmos?

Discuss the feedback mechanisms of the hypothalamic-pituitary-thyroid axis.

What is Hashitoxicosis ?

Hashitoxicosisis a transient hyperthyroidism caused by inflammation associated with Hashimoto's thyroiditis disturbing the thyroid follicles, resulting in excess release of thyroid hormone

What is Sub-acute thyroiditis ?

Sub-acute thyroiditisis a self-limited thyroid condition associated with a tri-phasic clinical course of hyperthyroidism, hypothyroidism, and return to normal thyroid function.

It is thought to be caused by a viral infection. The condition often occurs after a viral infection of the upper respiratory tract, such as influenza.

Mention the role of biochemical investigations, radiological and nuclear scans in the evaluation of a

patient presenting with thyrotoxicosis

We measuring the level of (TSH), produced by the pituitary glands.

We measuring specific antibodies, such as anti-TSH-receptor antibodies in Graves' disease, or anti-thyroid-peroxidase in Hashimoto's thyroiditis

We measuring the level of T3, Free T3, T4, and/or Free T4.

The diagnosis of Graves' disease is confirmed by blood tests that show a decreased (TSH) level, elevated T4 and T3 levels & elevated level of anti-TSH-receptor antibodies.

Biochemical Investigations:

Mention the role of biochemical investigations, radiological and nuclear scans in the evaluation of a

patient presenting with thyrotoxicosis

Nuclear Scan:

Thyroid nuclear test is a useful test to distinguish between causes of hyperthyroidism, and this entity from thyroiditis.

This test procedure typically involves two test: an iodine uptake test and a scan (imaging) with a gamma camera. The uptake test involves administering a dose of radioactive iodine, typically Iodine-123, which is the most suitable isotope of iodine for the diagnostic study of thyroid diseases.

Mention the role of biochemical investigations, radiological and nuclear scans in the evaluation of a

patient presenting with thyrotoxicosis

Radiological Investigations:

e.g. We use ultrasound scan to investigate thyroid enlargement, & the blood flow of the thyroid gland.

What is the treatment of Graves’ disease ?

We treat graves’ disease via three different methods:

The use of ant-thyroid drugs e.g.Methimazole and propylthiouracil

Partial or complete destruction of the thyroid gland by ingestion of radioactive iodine

Partial or complete surgical removal of the thyroid gland (thyroidectomy).