1. Thyroid Disorders: Hyper and Hypothyroidism
Year II, Unit II
Unit-directed Activity
Thyroid Disorders: Hyper and Hypothyroidism
AMEL ARNAOUT, MD

2. Disclosure
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Unit II – Thyroid Disorders: Hyper and Hypothyroidism

3. Objectives Describe important signs & symptoms of hyperthyroidism
Describe important signs & symptoms of hypothyroidism
Discuss the use of thyroid function tests in the diagnosis of hypothyroidism
Discuss common causes of primary & secondary hypothyroidism
Discuss the use of thyroid function tests in the diagnosis of hyperthyroidism
Describe the pathophysiology of hyperthyroid Graves’ disease
Outline and describe acute, subacute & chronic thyroiditis
Describe the clinical course of postpartum thyroiditis
Describe the three phases of subacute thyroiditis
Unit II – Thyroid Disorders: Hyper and Hypothyroidism – D. Liu

4. Case 1
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

5. Ms. Lee is a 56-year old woman who has been your patient for 10 years.
Case 1: Ms. Lee
Ms. Lee is a 56-year old woman who has been your patient for 10 years.
She is normally healthy and active.
During a routine check-up, she complains of fatigue and 10 lb weight gain in 6 months.
Hypothyroidism is on the differential diagnosis. What other information will you ask for on history?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

6. Additional History: Case 1: Ms. Lee Chronic constipation
Hot flashes since menopause
Weight increased despite stable diet & activity
PMHx: Borderline HTN & dyslipidemia
Meds: Multivitamin, no other supplements
FHx: Hypothyroidism in aunts
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

7. Case 1: Ms. Lee What signs might you expect to find on physical exam?
General appearance:
Vitals:
Head & neck:
Resp:
CVS:
Abdo:
MSK:
Neuro:
BP 135/90, HR 65
Small, firm thyroid – no nodule
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

8. Which of the following tests would you order?
Case 1: Ms. Lee
Which of the following tests would you order?
TSH
Free T3
Total T3
Free T4
Total T4
Thyroid ultrasound
Thyroid uptake & scan
Anti-microsomal antibodies
Anti-thyroglobulin antibodies
Thyroxine binding inhibitory immunoglobulin (TBII)
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

9. What treatment would you recommend? What is your plan for follow up?
Case 1: Ms. Lee
Investigations
Test
Result
Reference Range
Units
TSH
34.3
0.35 – 5.0
mU/L
Free T4
5.7
pmol/L
Free T3
3.2
3.3 – 6.0
What is the diagnosis?
What treatment would you recommend?
What is your plan for follow up?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

10. Diagnosis: Primary hypothyroidism
Treatment: Levothyroxine (T4) titrated to achieve a normal TSH
Repeat blood work (TSH) 6 weeks after initiating treament

11. What if these were her lab results?
Case 1: Ms. Lee
What if these were her lab results?
Test
Result
Reference Range
Units
TSH
9.5
0.35 – 5.0
mU/L
Free T4
10.8
pmol/L
Free T3
4.3
3.3 – 6.0
What are the indications for treating subclinical hypothyroidism?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

12. Indications for treatment of SCH:
TSH >10
Significant symptoms of hypothyroidism
Hyperlipidemia
Depression
Women of childbearing age
Positive anti-TPO antibodies

13. Case 2
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

14. Surgeon advised she does not need surgery.
Case 2: Mrs. Healthnut
40 yr old female with small goitre (symmetric enlargement, no palpable nodules).
Surgeon advised she does not need surgery.
She read on the internet that taking kelp might shrink her thyroid gland.
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

15. Removed when converted to T3
Case 2: Mrs. Healthnut
What are possible consequences of taking kelp and the mechanisms involved? HO O
CH2 CH
COOH
NH2 I
T4: 4 iodine atoms
Removed when converted to T3
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

16. Kelp contains iodine which acts as a substrate for thyroid hormone synthesis
An increase in iodine in the diet MAY cause an increase in formation of thyroid hormones T4 and T3 which MAY cause a slight increase in circulating Free T4 and Free T3 levels which MAY suppress TSH.
A lower TSH causes gland to shrink

17. Case 3
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

18. Describe symptoms of thyrotoxicosis.
Case 3: Ms. Newmum
Ms. N has a 5-month old baby. She was coping well, but now has symptoms suggestive of thyrotoxicosis.
Describe symptoms of thyrotoxicosis.
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

19. Case3: Ms. Newmum
What signs might you expect to find on physical exam?
General appearance:
Vitals:
Head & neck:
Resp:
CVS:
Abdo:
MSK:
Neuro:
BP 140/80, HR 95
Eyes: Lid lag, no proptosis
Thyroid 2 x normal size, no nodule
S1 S2 & systolic flow murmur
Fine tremor in hands
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

20. Which of the following tests would you order?
Case 3: Ms. Newmum
Which of the following tests would you order?
TSH
Free T3
Total T3
Free T4
Total T4
Thyroid ultrasound
Thyroid uptake & scan
Anti-microsomal antibodies
Anti-thyroglobulin antibodies
Thyroxine binding inhibitory immunoglobulin (TBII)
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

21. What is the differential diagnosis? Which test(s) will you order next?
Case 3: Ms. Newmum
Investigations
Test
Result
Reference Range
Units
TSH
0.06
0.35 – 5.0
mU/L
Free T4 33
pmol/L
Free T3
10.4
3.3 – 6.0
What is the differential diagnosis?
Which test(s) will you order next?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

22. Case 3: Ms. Newmum 24 hr uptake: 47% (6-22%) Case 5: Mrs. New Baby
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

23. What is the pathophysiology of this condition?
Case 3: Ms. Newmum
What is her diagnosis?
What is the pathophysiology of this condition?
How can this condition be treated?
What are potential adverse effects of the treatment options?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

24. Thyroid Gland Periphery
Inorganic Iodine
Thyroid Gland
Iodine
PTU, MMI
MIT T T3
Po Po P
DIT T T4
Thyroglobin
MIT
I- DIT ID
Na Na+
I I-
Periphery
Iopanoic Acid, Ipodate
PTU
Steroids
T ’deiodinase T3
Periphery

25. Case 3: Ms. Newmum
With plans to have another pregnancy, Ms. N opted to be treated with 131-iodine. She is euthyroid on thyroid hormone replacement 4 months after thyroid ablation.
She is worried about how Graves’ disease will affect her pregnancy and baby. What would you advise?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

26. Case 4
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

27. Mr. Payne is normally stoic
Case 4: Mr. Payne
Mr. Payne is normally stoic
He presents with new neck pain, irritability, rapid weight loss in the last week, heat intolerance and palpitations.
What is the likely cause of his thyrotoxicosis?
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

28. THYROIDITIS Thyroiditis with pain and tenderness:
acute infectious (rare)
subacute granulomatous thyroiditis
(common)

29. SUBACUTE GRANULOMATIS
THYROIDITIS
subacute thyroiditis or DeQuervains’
thyroiditis, likely viral
three phases:
hyperthyroid,
hypothyroid
recovery phase
treatment: NSAID or prednisone for
pain, b-blocker for hyperthyroid
symptoms, L-T4 not usually necessary

30. Thyroiditis

31. What investigations are appropriate? Discuss the expected results.
Case 4: Mr. Payne
What investigations are appropriate?
Discuss the expected results.
What treatments would you consider recommending for this condition?
What is the expected clinical course for Mr. N?
Discuss the clinical course of acute and chronic thyroiditis.
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

32. Case 5
Unit II – Thyroid Disorders: Hyper and Hypothyroidism

33. Case 5
26 yr old woman with 6 wk history of agitation, tremors, palpitations, 20 lb wt loss, diarrhea
PHX: unremarkable
no meds
O/E
BP 170/62, HR 132 irreg irreg, RR 23, temp 39o
agitated, flight of ideas, tremulous
exophthalmus, lid lag, stare, chemosis
thyroid 4x normal, diffuse with bruit
few basilar crackles

34. Very rare high mortality (20-30%) When to suspect
Thyroid Storm
Very rare
high mortality (20-30%)
When to suspect
often have a history of thyroid disease
have all the usual features of thyrotoxicosis
often have very large goiter
often a ppting illness/event
surgery, infection, pregnancy, iodinated contrast dye

35. Thyroid Storm Life threatening exacerbation of the hyperthyroid state
Decompensation of organ systems
Fatal if untreated
Mortality rate of %
Most common in patients with thyrotoxicosis secondary to Graves disease

36. Thyroid Storm: Clinical Presentation
Features of thyrotoxicosis
History of thyroid disease, or symptoms consistent with prolonged thyrotoxicosis
Fever
Systolic Hypertension, widened pulse preassure
Tachycardia, Atrial arrythmias
Mental status change
GI, CVS or Neurologic symptoms may perdominate
Fever > 106 F
Mental status channges: psycho-motor agitation
confusion, agitation, stupor, coma, psychosis
Cause of Coma unclear: high density of thyroid receptors in the brain - alteration in cellular metabolism
? Hypoglycemia
? Tissue hypoxia - case reports of patient presenting as stroke
Cardiovascular, GI or Neurologic symptoms may perdominate:
may have unusual presentation
case reports of thyroid storm presenting as hypoglycemic coma, stroke, CHF, liver failure
Cause of Liver Failure: ? Hypoxia ( increased utilization, no change in Blood/O2 delivery)
? Autoimmune Phenomena ? In association with Graves

37. Thyroid Storm: Clinical Presentation
Precipitating event:
Infection
Surgery
Radioiodine Therapy
Iodonated Contrast Dyes
Withdrawal of Antithyroid drug therapy
Amiodarone
DKA
CHF
Hypoglycemia
Stroke
Trauma
Tooth extraction
Bowel infarction
Pulmonary embolism

38. THYROID STORM CLINICAL FEATURES Hyperpyrexia (>380C)
Tachycardia or cardiac dysrhythmia
Dehydration and dry skin
Restlessness, anxiety, or delirium
Goitre with or without exophthalmos
Stupor, coma or shock
Look for precipitating illness

39. Laboratory Elevated T3 and T4 Suppressed TSH Hyper or hypo glycemia
Leukocytosis
Elevated calcium
Increased transaminases, LDH, CK, Alk phos

40. Diagnosis of thyroid storm
A clinical diagnosis, no lab criteria
febrile
CNS effects
agitation, delirium, psychosis, extreme lethargy, seizure, coma
GI/hepatic effects
diarrhea, N, V, jaundice
CV effects
tachy, a fib, high output failure

41. Thermoregulatory Dysfunction Temperature 99-99.91 5 100-100.9 10
>=
CNS Effects
Mild 10
Agitation
Moderate 20
Delerium, Psychosis
Extreme lethargy
Severe 30
Seizure, Coma
Precipitant History
Negative 0
Positive 10
GI/Hepatic Dysfunction
Moderate 10
Diarrhea, N&V
Abd. Pain
Severe 30
Unexplained jaundice
CVS Dysfunction
Tachycardia
>=
CHF
Mild 5
Severe 15
Afib 10
Score > 45 Suggest thyroid storm
25-45 impending thyroid storm
< 25 unlikely thyroid storm
Reviewed littereture of all diagnostic criteria: found most had
- fever
- CNS dysfunction
- CVS dysfunction
- percipitating event
- GI dysfunction
Burch & Wartofsky

42. Treatment Monitored bed Correct the hyperthyroidism
PTU mg x 1 then 300 mg q. 4h
iodine after 1st dose of PTU
lugols 10 drops tid
block the effects of thyroid hormone
large doses of B-blockers
treat ppting event

43. THYROID STORM TREATMENT Lower temperature with cooling blanket,
acetaminophen, or chlorpromazine
SSKI 5-10 gtts po tid or qid, or Na I
I g iv infusion q12h
Propranolol 1 mg iv/min up to 2-10 mg, or
40-80 mg po q4-6h
PTU 800 mg po, and mg q6h, or
methimazole 80 mg po, and 40 mg q8h
Hydrocortisone 100 mg iv q8h or equivalent
Fluids and electrolyte replacement
Plasmaphoresis or peritoneal dialysis