Download clinical aspects of thyroid disorders

CLINICAL ASPECTS OF THYROID DISORDERS
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A 30-year-old woman
 Her eyes bulge.
Nervousness, irritability, palpitations and heat
 Diffuse enlargement thyroid gland.
intolerance.
 Carbimazole and propranolol are prescribed.
 Lost 9.1 kg despite a good appetite.
WHAT ARE HORMONES?
 Chemicals That Are Released Into the Bloodstream
 Regulators of Specific Body Functions
 Two main hormones: Tetraiodothyronine (Thyroxin) T4 & Triiodothyronine T3
Where to look for Thyroid Gland?
CLINICAL EXAM. OF THYROID
 Have patient seated on a chair
 Inspect neck before & after swallowing
 Examine with neck in relaxed position
 Palpate from behind the patient
 Remember the rule of finger tips
 Use the tips of fingers for palpation
 Palpate firmly down to trachea
Aspects That Will Be Addressed
• Hyperthyroidism
• Hypothyroidism
• Thyroiditis
Clinical Anatomy of Thyroid
GOITRE
A swollen thyroid gland
Assessment;
 how big, how quickly has it
developed, is it smooth or nodular, is
it painful, any associated lymph
nodes, any sudden changes, is it big
enough to cause local symptoms (e.g.
breathing problems)
HYPERTHYROIDISM
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SYMPTOMS
Hyperactivity/ irritability
Heat intolerance and sweating
Palpitations
Fatigue and weakness
Weight loss with increase of appetite
Diarrhoea
Polyuria
Oligomenorrhoea, loss of libido
Most common causes
 Graves disease
 Toxic multinodular goiter
 Autonomously functioning nodule
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SIGNS
Tachycardia (AF)
Tremor
Goiter
Warm moist skin
Proximal muscle weakness
Lid retraction or lag
Gynecomastia
CAUSES
Rarer causes
 Thyroiditis or other causes of destruction
 Thyrotoxicosis factitia
 Iodine excess (Jod-Basedow phenomenon)
 Secondary causes (TSH or ßHCG)
GRAVES DISEASE
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Autoimmune disorder
Abs directed against TSH
receptor with intrinsic
activity. Thyroid and
fibroblasts
Responsible for 60-80%
of Thyrotoxicosis
More common in
women
HYPERTHYROID EYE DISEASE
HYPERTHYROIDISM (ANY
TRUE GRAVES’ OPHTHALMOPATHY
CAUSE)
 Proptosis
 Lid lag, lid retraction and
 Diplopia
stare
 Inflammatory changes
 Due to increased adrenergic
1. Conjunctival injection
tone stimulating the levator
2. Periorbital edema
palpebral muscles.
3. Chemosis
Due to thyroid autoAb’s that cross-react
w/ Ag’s in fibroblasts, adipo-cytes, +
myocytes behind the eyes.
Periorbital edema and chemosis
Occular muscle palsy
EYE SIGNS(OPHTHAMOPATHY)
N - no signs or symptoms
O - only signs (lid retraction or lag) no symptoms
S - soft tissue involvement (peri-orbital oedema)
P - proptosis (>22 mm)(Hertl’s test)
E - extra ocular muscle involvement (diplopia)
C - corneal involvement (keratitis)
S- sight loss (compression of the optic nerve)
 Signs of Graves’s ophthalmopathy are divided into two
components:
SPASTIC:
MECHANICAL:
Stare, lid lag and lid  Proptosis of varying degrees
retraction which
 Ophthalmoplegia
account for the
 congestive occulopathy characterized by
“frightened” facies.
chemosis, conjunctivitis, periorbital
swelling
 the potential complications of corneal
ulceration,optic neiritis and optic
atrophy
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DERMOPATHY
Usually occurs over the dorsum of
the legs or feet and is termed
localized or pretibial myxedema.
It is usually a late phenomenon
The affected area is usually
demarcated from the normal skin
by being raised and thickened and
having a peau d’ orange
appearance;it may be pruritic and
hyperpigmented.
The most common presentation is
non pitting oedema,but lesions
maybe plaque like,nodular or
polypoid.
Clubbing of the fingers and toes
accompanies and is termed thyroid
acropachy
INVESTIGATIONS
Thyroid function test:
• TSH- Undetectable
• T4 - Raised
• T3 - Raised
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TSH-receptor antibodies (TRAb)
elevated in Graves’s disease
Isotope scanning- Increased
uptake
THYROTOXICOSIS- TREATMENT
Three modalities: Radioactive iodine, Antithyroid drugs & Surgery
1) β-blockers
2) 131-RAIA
(symptom control)
(70% thyroidologists prefer)
• Pregnancy should be deferred
• Dosing
for at least 6 months following
1. Graves: 10-15 mCi
therapy with radio-active 131
2. Toxic MNG/Adenoma: 20-30 mCi • It is advisable to avoid 131-Rdio• Absolute contraindications
active iodine therapy in patients
- Pregnancy and lactation
with active moderate severe
(excreted in breast milk)!
Graves’ ophthalmopathy.
3) Antithyroid Drugs
4) Surgery
(30% thyroidologists prefer)
(sub-total thyroidectomy)
Indications
1. Propylthiouracil (PTU)
– Patient preference
– Large or symptomatic goiters
 100 mg bid-tid to start
– When there is question of malignancy
2. Methimazole
– Need to be euthyroid prior to surgery
 10X more potent the PTU
– To ↓ the risk of arrhythmias during induction of
 10 mg bid-tid to start
anesthesia
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To ↓ the risk of thyroid storm post operatively
Complications of ATD’s
– ATD’s + β-blockers
1. Agranulocytosis (1/200-500)
2. usually presents w/ acute pharyngitis/ tonsilitis
Risks
or pneumonia.
– Permanent hypoparathyroidism
3. Rash
– Recurrent laryngeal nerve problems
4. Hepatic necrosis, Cholestatic jaundice
– Permanent hypothyroidism
Arthralgia
Propranolol (Inderal ®)
HYPOTHYROIDISM
SYMPTOMS
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Tiredness and weakness
Dry skin
Feeling cold
Hair loss
Difficulty in concentrating
and poor memory
 Constipation
SIGNS
 Weight gain with poor
appetite
 Hoarse voice
 Menorrhagia, later oligo and
amenorrhoea
 Paresthesias
 Impaired hearing
CAUSES
 Dry skin, cool extremities
 Puffy face, hands and feet
 Delayed tendon reflex
relaxation
 Carpal tunnel syndrome
 Bradycardia
 Diffuse alopecia
 Serous cavity effusions
LAB INVESTIGATIONS
 TSH , free T4 
 Ultrasound of thyroid – little
value
 Thyroid scintigraphy – little
value
 Anti thyroid antibodies –
anti-TPO
 S-CK , s-Chol , sTrigliseride 
TREATMENT
 Normochromic or macrocytic
Levothyroxine
anemia
 If no residual thyroid function 1.5 μg/kg/day
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ECG: Bradycardia with small
 Patients under age 60, without cardiac disease can be started on
QRS complexes
50 – 100 μg/day. Dose adjusted according to TSH levels
 In elderly especially those with CAD the starting dose should be
much less (12.5 – 25 μg/day)
 Autoimmune
hypothyroidism
(Hashimoto’s, atrophic
thyroiditis)
 Iatrogenic (I123treatment,
thyroidectomy, external
irradiation of the neck)
 Iodine deficiency
 Drugs: iodine excess, lithium,
antithyroid drugs.
 Infiltrative disorders of the
thyroid:
1. amyloidosis,
2. sarcoidosis,
3. haemochromatosis,
4. scleroderma
THYROIDITIS
ACUTE
rare and due to suppurative
infection of the thyroid
SUB ACUTE
also termed de Quervains thyroiditis/
granulomatous thyroiditis – mostly viral origin
CHRONIC THYROIDITIS
mostly autoimmune
(Hashimoto’s)
 The most common form of thyroiditis is Hashimoto thyroiditis, this is also the most common
cause of long term hypothyroidism
 The outcome of all other types of thyroiditis is good with eventual return to normal thyroid
function