MBBS 4TH YR

1. Hyperthyroidism

2. Objectives
• To understand types ,clinical features ,
investigation and management of
hyperthyroidism

3. Overview
• Definition
• Types
• clinical features
• Investigation
• Treatment

4. Hyperthyroidism
Disease process associated with increased
thyroid secretion result in predictable hyper
metabolic state

5. • Types:
Primary thyrotoxicosis
1. Diffuse toxic goitres- graves disease
Secondary thyrotoxicosis
2. Toxic nodular goitre
3. Toxic nodule
4. Hyperthyroidism due to rare cause
Hyperthyroidism

6. Diffuse toxic goitre (graves)
• Most common cause of hyperthyroidism
• Irish physician-Dr Robert Graves in 1835
• Common-young females(20 to 40)
• Whole gland involved
• 50% family h/o autoimmune endocrine disease
• Hypertrophy and hyperplasia-abnormal TSH –R
Ab bind to TSH receptor disproportionate and
prolonged effect
• Genetic susceptibility

7. Toxic nodular goitre
• Middle aged/elderly
• Eye signs –rare
• Secondary TT
• Nodules-inactive
• Internodular tissue - overactive
• Toxic adenoma-autonomous

8. Toxic nodule
• Solitary overactive nodule
• Part of generalised nodularity or two toxic
adenoma
• Autonomous
• TSH- suppressed by high T3 and T4
• Normal surrounding thyroid tissue –
suppressed and inactive

9. Histology
• Normal acini- with flattened cuboidal
epithelium and filled with homogenous colloid
• Hyperthyroid – acini hyperplasia
- lined by high columnar epi
- empty or vacuolated colloid
- characteristic scalloped pattern
adjacent to thyrocytes

10. Clinical Features
• Symptoms
– Tiredness
– Emotional liability
– Heat intolerance
– Weight loss
– Excessive appetite
– Palpitation
– Diarrhoea
– Amenorrhoea
– Blurring of vision or double vision

11. • Signs
– Tachycardia
– Hot moist palms
– Exophthalmos
– Lid lag retraction
– Agitation
– Thyroid swelling
– bruit

12. • Cardiac rhythm
• - Increased sleeping heart rate( sinus tachycardia)
- Arryhthmias, multiple extra systoles, paroxysmal
atrial tachycardia
- Paroxysmal atrial fibrillation
- Persistent atrial fibrillation, no response to digoxin
• Myopathy
– Proximal limb muscle weakness ( thyrotoxic
myopathy)

13. Eye Signs
• Exophthalmos
– Unilateral or bilateral
– Infiltration of retrobulbar tissue with fluid and
round cells
• Retraction/spasm of upper eyelid
• Levator palpabre superiaris supplied partly by
sympathetic fibers
• Graves ophthalmopathy is autoimmune
disease

14. • Diplopia –weakness of elevator (inferior
oblique
• Papilloedema and corneal ulcer
• Malignant exophthalmos
• Graves ophthalmopathy-autoimmune disease-
Ab mediated effects on the ocular muscles

15. • Von Graefe's sign (lid lag sign)
• Dalrymple's sign
• Joffroy sign (absent creases in the forehead on
superior gaze)
• Möbius sign (poor convergence)
• Stellwag sign (incomplete and infrequent
blinking

18. • Pretibial myxoedema
thickening of skin –mucin like deposit

19. • Thyroid acropathy

20. • Thyrotoxicosis factitia:
thyroxine induced (0.2 -0.3 mg)
• Jod - basedow thyrotoxicosis
jod = iodine (german)
• Neonatal thyrotoxicosis : increased TSH Ab
subsides : 3-4 weeks

21. Diagnosis
1. Clinical
2. Thyroid profile
3. Thyroid scan-autonomous nodule
4. –children with growth spurt ,behaviour
problems or myopathy
- tachycardia /arryhthmia in elderly
- unexplained diarrhoea
- loss of weight

23. Treatment
1. Rest , Sedation
2. Antithyroid drugs
3. Surgery
4. Radioiodine

24. Drugs
1. Antithyriod drugs- <45yr small goitre
- carbimazole
- propylthiouracil
- oxidation and binding of Iodine to tyrosine
2. B Adrenergic blockers
-propranolol,nadolol
3. Iodides

25. • Advantages : no surgery
rapid control of thyrotoxicosis
• Disadvantages : treatment is prolonged
failure rate-50%
• SE : agranulocytosis / aplastic anemia
Dose :10mg 3-4 times/day
• Replacement – thyroxine 0.1 mg – 0.15 mg

26. Surgery
• <45 yr large goitre
• Toxic nodule
• Toxic nodular goitre
• Advantage: goitre removed
Cure rapid
Cure rate-high

27. • Disadvantage : recurrence - 5%
- risk of surgery
- hypothyroidism-20-45%
- hypoparathyroidism

28. Radio iodine
• Indictions : >45 yr
rec thyrotoxicosis after surgery
• Advantages : no surgery ,no drug
• Disadvantages : isotope facility must be
available

29. THANK YOU