Thyroid disorders

THYROID DISORDERS
-
HYPOFUNCTION AND
HYPERFUNCTION

Presented by Dr. Hrudi Sundar
Sahoo

INTRODUCTION

 Largest endocrine gland.
 Located inferior to cricoid cartilage.
 Butterfly shaped organ comprising of two
lobes
- lobus dexter(right)
- lobus sinister(left)
 Weighs 18-60gms in adults.
 Histologically it is made up of follicular and
parafollicular cells.

 Blood supply
Arterial supply - superior thyroid artery
- inferior thyroid artery
Venous supply - superior thyroid vein
- inferior thyroid vein
 Nerve supply
- Superior laryngeal nerve
- Recurrent laryngeal nerve
 Lymphatic drainage
- Lateral deep cervical lymph node
- Pretracheal/para tracheal lymph nodes

 Functions
Produces thyroid hormones.
Produces calcitonin.

Physiology

Hypothalamus

Thyroid releasing hormone(TRH)

Pituatary

Thyroid stimulating hormone(TSH)

Thyroid gland (target site)

Tyrosine(target hormone)

MIT/DIT

T3 T4

THYROID DISORDERS

• GRAVE’S DISEASE
• THYROID STORM
HYPERTHYROIDISM • TOXIC THYROID NODULE

• HASHIMOTOS THYROIDITIS
• CRETINISM
• MYXOEDEMA
HYPOTHYROIDISM • POSTPARTUM THYROIDITIS
• SUBACUTE THYROIDITIS
• SICK EUTHYROIDISM

NEGATIVE FEEDBACK

Thyroid hormones on pituitary

T3 & T4 T3 & T4

TSH TSH

THYROTOXICOSIS

 Hypermetabolic clinical syndrome resulting
from serum elevation of thyroid hormone
levels(T3 & T4).
 Causes are GRAVE’ S disease, multinodular
goitre and toxic adenoma.
 GRAVE’S DISEASE is the most common

form.

GRAVE’S DISEASE

Introduction

 Autoimmune disease.
 Female : Male ratio – 5:1 or 10:1

 Has a strong hereditary component.

 Diagnosis is mainly made by the

symptoms

Signs and symptoms

 Skin is warm and moist, palms are warm,moist
and hyperemic and Plummer’s nails are seen.
 Pretibial myxedema.
 Alopecia and vitiligo.
 Severe cases proptosis maybe seen.
 Excessive sweating and heat intolerance.
 CVS symptoms: palpitations, CCF, isolated
systolic hypertension.
 Metabolic symptoms: weight loss despite of
increased in apetite.

 GIT symptoms: hyperdefecation.
 Exacerbate bronchial asthma.
 CNS symptoms: nervousness, irritability,
tremor, insomnia, proximal muscle weakness.
 In females: amenorrhea/ oligomenorrhea.
 In males: impotence and loss of libido.

Eye signs

 VON GRAEFE’S SIGN – Lid lag.
 JOFFROY’S SIGN – Absence of wrinkling of
forehead on looking up.
 STELLWAG’S SIGN – Decreased frequency of
blinking.
 DALRIMPLE’S SIGN – Lid retraction exposing
the upper sclera.
 MOBIUS SIGN – Absence of convergence.

Investigations

 T3 & T4 levels.

 Thyroid uptake of radio iodine.

 Presence of antibodies: TSH receptor antibody
Antimicrosomal antibody
 CT orbits thyroid scans.

Management

 Immediate control: Propranolol 40mg/6hr orally.
 Long term control:
Anti thyroid drugs – Carbimazole 15mg tid
initially and then reducing it to 5mg tid for
12-18 months.
Radio iodine ablation – Postmenopausal women
and elderly men.
In recurrence following surgery.
Given to fertile women conception postponed to
1
year.
Surgery – Presence of large goitre.
Poor drug compliance.

 Exopthalmos: Corticosteroids.
Tarsorrhaphy.
Orbital decompression.
 Cardiac arrythmias: ß- blockers.
In euthyroid state,
cardioversion is done.

MULTINODULAR GOITRE

 Excess production of thyroid
hormones from functionally
autonomous thyroid nodules which
do not require the stimulation from
TSH.
 Second common cause.

 Occurs in individual over 60 years of

age and females are mostly affected.

Symptoms

 Large goitre with or without tracheal
compression.
 Goitre is nodular or lobulated, often

palpable.
 Large goitre cause mediastinal

compression with stridor, dysphagia and
obstruction of superior vena cava.
 Hoarseness

Management

 Small goitre : No treatment.
Annual review.
 Large goitres : Partial thyroidectomy.
131
Radioactive iodine I
 Recurrence is common after 10-20 years.

THYROID STORM
 Rare but life threatening sudden severe
exarcerbation of hyperthyroidism.
 Causes: Precipitated by stress or infection with
either unrecognized thyrotoxicosis or
inadequately treated thyrotoxicosis.
Following subtotal thyroidectomy/radio
active iodine.
Trauma.
Pregnancy.
Emotional stress.

Signs

 Elevation of temperature.
 Increase in heart rate.
 Irritable.
 Delirius/comatose.
 Hypotension.
 Vomiting.
 Diarrhoea.

Management
 Treatment started immediately with
Propranolol 80mg/6hrs orally(dose of 1-5mg/6hrs
given IV).

Potassium iodide 60mg daily orally/ sodium
iopodate 500mg daily orally.

Carbimazole 60-120mg daily

Dexamethasone 2mg/6hrs IV.

Fluid replacement.

Antibiotics.

Emergency management in dental
office

 Terminate all treatment.
 Have someone summon medical assistance.
 Administer oxygen.
 Monitar all vital signs.
 Initiate basic life support if necessary.
 Start IV line with drip of crystalloid
solution(150mL/hr).
 Transport patient to emergency care facility.

HYPOTHYROIDISM

 Insufficiency synthesis of thyroid hormones.
 Female : Male ratio is 6 : 1.
 Causes : Hashimoto’s thyroiditis
Thyroid failure following radio iodine.
surgical treatment of thyrotoxicosis.
Drugs like carbimazole, amiadarone.
Iodine deficiency.

HASHIMOTO’S THYROIDITIS

 Primary condition of
hypothyroidism

 Autoimmune.

 Described by Hakaru Hashimoto

Signs and symptoms

 Weight gain.
 Enlarged thyroid gland.

 Depression.

 Sensitivity to heat/cold.

 Fatigue.

 Hypoglycemia.

 Increased cholestrol level.

Diagnosis

 T3 & T4 levels.

 Presence of TPO antibodies.

 Positive ANF.

Treatment
 Thyroxine therapy.

LEVOTHYROX
INE
 Helps in both hypothyroidism and goitre
shrinkage

CRETINISM
 Hypothyroidism dating from birth.
 Tyroxine is essential for growth and development of
brain during the first three years.
 Earlier onset greater is the brain damage.
 Causes : - Congenital developmental defects.
- Radio iodine/surgery.
- Post radiation.
- Iodine deficiency.
- Drug induced.
- Hashimoto’s thyroiditis.
- Recurrent hypothyroidism.

Signs and symptoms

 Dry, cool, mottled skin, hoarse cry, broad flat
nose, puffy face.
 Protruberant abdomen, umblical hernia,
hypotonia.
 Large posterior fontanelle.
 Lethargy, delayed stooling, poor
feeding/sucking.
 Cold to touch.
 Delayed dentition.
 Mental retardation.

Management

 Investigation : Cord blood T4, TSH.
Serum T4, TSH
RAIU
X-ray of knee, foot and skull.
 Treatment
Medication : levothyroxine (initial dose of 10-
15mcg/kg/dl).
Diet : iodine rich foods.
Follow up.

MYXOEDEMA

 Severe hypothyroidism in which there is
accumulation of hydrophilic
mucopolysaccharides in the skin and other
tissues.
 Common in women.
 Two variants – Hyperthyroid myxoedema
– Hypothyroid myxoedema.
 Cause : Increased deposition of glycosamine
glycans
Hashimoto’s thyroiditis.

MYXOEDEMA COMA
 Uncommon but life threatening form of
untreated hypothyroidism with physiological
decompensation.
 Occurs in patients with long standing
hypothyroidism.
 Precipitated by a climate induced hypothermia,
infection, drug therapy and other systemic
conditions
.

Symptoms
 Lethargy
 Stupor,
 Delirium.
 Hypotension.
 Convulsions.
 Hypoglycemia.
 Hyponatremia.
 Hypoventillation.
 Coma.

Investigations

 Free T4 and TSH
 T3 & T4 levels are decreased and TSH
are elevated or normal.
 Serum electrolyte and serum osmolality.

 Serum creatinine.

 Serum glucose.

 Differential blood count.

 Pan culture for sepsis.

Treatment

 Hyperventilation if respiratory acidosis is
significant.
 Immediate IV levothyroxine given
 Loading dose of 500 - 800mcg followed by 50
– 100mcg daily.
 Hydrocortisone 5 – 10mg/hr.
 Treatment of associated infection.
 Correction of hyponatremia with saline.
 Correction of hypoglycemia with IV dextrose.

Thyroid tests

 T3, T4 and TSH levels.
 Presence of TPO antibodies.

 Thyroid scan.

 Thyroid uptake test.

Thyroidectomy

 Surgical removal of all or a part of the gland.

 Indications: Thyroid carcinoma.
Hyperthyroidism.
Very enlarged thyroid.
Symptomatic obstruction.

Complications
 Hypothyroidism.
 Laryngeal nerve injury.
 Hypoparathyroidism.
 Infection.
 Chyle leak.
 Surgical scar.

Conclusion
A self assessment of thyroid gland is
necessary for earliar detection of thyroid
disorders.

Thyroid disorders

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Thyroid disorders