1 / 29

Thyroid Disease

Thyroid Disease . Lottie Wright. Thyroid Anatomy. -2 lobes, Isthmus -Formed from diverticulum of floor of pharynx -Follicular cells -C5-T1 -2 Arteries -3 Veins -PSNS – vagus nerve -SNS – cervical trunk -Recurrent laryngeal nerve -4 parathyroid glands.

kareem
Télécharger la présentation

Thyroid Disease

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thyroid Disease Lottie Wright

  2. Thyroid Anatomy -2 lobes, Isthmus -Formed from diverticulum of floor of pharynx -Follicular cells -C5-T1 -2 Arteries -3 Veins -PSNS – vagus nerve -SNS – cervical trunk -Recurrent laryngeal nerve -4 parathyroid glands

  3. Quick note on the Parathyroid glands • 4 • Posterior to thyroid • Secrete parathyroid hormone in response to low ionised calcium levels (-ve feedback) • PTH – increase osteoclast activity  releases calcium and phosphate from the bones • Increase calcium and decreased phosphate reabsorption in the kidney • Increase active vitamin D3 production • OVERALL INCREASE CALCIUM AND DECREASE PHOSPHATE.

  4. Hormone Pathway Hypothalamus TRH Anterior Pituitary TSH Thyroid -ve feedback T3 and T4

  5. T3, T4, TBG?! • T4 = Thyroxine = PROHORMONE (80%) • T3 = Triiodothyroxine = ACTIVE (20%) • Iodine containing modified amino acids • T4  T3 in peripheral tissues by: • beta-deiodination • STRESS e.g. acute/chronic sickness, post-surgery, high cortisol, diabetes T4  reverse T3 (rT3), no endocrine action. Regulation of T4 levels e.g. to conserve energy.

  6. Plasma Proteins • T3 & T4 bound to Plasma Proteins in the bloodAlbumin, Thyroxine Binding Globulin • 0.05% T4 free, 0.5% T3 free • Total plasma hormone concentration is dependent on concentration of binding protein. • TBG = pregnancy • TBG = liver and kidney disease

  7. Action of thyroid hormone • Work via intracellular receptors and DNA • Increase basal metabolic rate • Increase number of adrenergic B-receptors in tissuesTissues more responsive to catecholamines • In FETUS – responsible for maturation of bones, lungs, brain.Lack thyroid function  ‘cretinism’low IQ, poorly formed bones

  8. Case 1 – 37 year old female Sally • 4 week history of: • Weight loss despite increased appetite • Irritability • ‘Feeling hot and clammy’ • Diarrhoea • Palpitations • Tremor • Examination: • Fast pulse • Fidgeting • Thin hair • Palmar erythema • Eye signs…

  9. HYPERTHYROIDISM • Prevalence 2% • M:F = 5:1 • Most common in middle age. • Causes:99% intrinsic thyroid disease rather than pituitary origin. • Graves’s DiseaseToxic Nodular GoitreToxic Adenoma

  10. Investigations • TSH – undetectable (0.5-5.7mU) • Free T4 – 40pmol/L (10-25 pmol/L) • Free T3 – 20 pmol/L (3.5 – 7.5 pmol/L) • Thyroid Peroxidase Antibody +ve(Don’t routinely test for TSH receptor Antibodies) • ImagingThyroid Uptake Scan

  11. Grave’s Disease (75%) T4 TSH • A cause of ‘thyrotoxicosis’ • Autoimmune IgGantibodies to TSH receptor on thyroidStimulates  increased T4 production-ve feedback  decreased TSH, therefore undetectable • DiffuseGoitre • 20-50% concordance MZ twins • Environmental triggers:High Iodine IntakeSmokingStress

  12. Thyroid Eye Disease Pretibial myxoedema Thyroid Acropachy

  13. Toxic Multi-nodular Goitre (15%) • More common in elderly & iodine deficient areasLow T4 production  Increased TSH  hyperplasia of thyroid tissue (multinodular)  predisposition to TSHr mutation • Thyroid hormone secreting nodules • Nodular goitre

  14. Hyperthyroid treatment • Beta-blockers for rapid symptom control • 2 treatments, equally effective • Titration of carbimazole for 4/52, reduce based on TFTs every 1-2 months • ‘Block and replace’ – carbimazole + levothyroxineReduced risk of iatrogenic hypothyroidism • 12-18 months of treatment • 50% relapse and require... • Radioiodine – thyroid traps iodine, destroys cells • Surgery –thyroidectomy +/- replacement therapy.Euthyroidpts onlyComps: vocal cord palsy

  15. Differential Diagnosis of Hyperthyroidism • VAGUE! • Difficult to distinguish mild case from anxiety states • Use clinical signsEye signs, goitreetcWeight loss despite normal/increased appetite.

  16. Thyroid Eye Disease (Thyroid orbitopathy) • Affects whole orbit- 6 extra-ocular muscles- lacrimal gland- fatty tissues • Target cells express TSHrAutoantibodies attack fibroblasts  proliferate, secrete glycosaminoglycans, form collagen • Diagnosis based on clinical features80% have been hyperthyroid20% ‘euthyroid’ • RFS: SMOKING, female, radioactive iodine

  17. Clinical features • Soft tissue inflammationConjunctivaloedema& redness, eyelid oedema, lacrimal gland enlargement • Proptosis • Eyelid changesLid lag, lid retraction, lateral flare • Radiological featuresfusiform swelling, sparing of tendons, inflammed tissues – shows up white. • MyopathyInflammed extra-ocular musclesDIPLOPIA • Compressive optic neuropathyreduced visual acuity, reduced colour vision, visual defect

  18. Case 2 – 46 year old female Brenda • 6 month history of: • Weight gain • Dry hair and skin • Constipation • Always feeling cold • Fatigue • Low mood • On Examination: • Puffiness of face • Pallor • Slow pulse • Coarsening and shedding of hair BRADYCARDIC Reflexes slow to relax, Ataxia (cerebellar), Dry thin hair/skin, Yawning/drowsy, Cold hands/cold intolerance, Ascites + non-pitting oedema, Round puffy face and hand/obese, Defeated demeanour, Immobile +/- Ileus, Congestive cardiac failure.

  19. HYPOTHYROIDISM • Prevalence 1-5% • Incidence 2/1000 • M:F = 1:5 • Most common middle age • Causes:Primary (thyroid)Secondary (pituitary gland)Autoimmune/ Radio-iodine treatment for hyperthyroidismWorldwide- - iodine deficiency

  20. Investigations • TSH – 23.0 (0.5-5.7 mU/L) – Important for 1’/2’ cause • Free T4 – 2.0 (10-25 pmol/L) • Free T3 – 3.0 (3.5-7.5) • TPO antibodies +ve

  21. Hashimoto’s Thyroiditis T4 TSH • Autoimmune • Autoantibodies to thyroid peroxidase enzyme (TPO) • Diffusegoitre • Decreased T4 production by disease thyroid, feedback to pituitary leads to increased TSH production.

  22. Atrophic Hypothyroidism T4 TSH • Autoimmune • Anti-thyroid Auto-antibodies  lymphoid infiltration  atrophy and fibrosis • No goitre present • Associated with other autoimmune conditions • Pernicious anaemia, vitiligo

  23. 2’ hypothyroidism due to 1’ hypopituitarism • Failure of anterior pituitary gland to produce TSH • Understimulation of thyroid to produce T4 • Biochemistry:Low T4, Low TSHTreat pituitary! T4 TSH

  24. Hypothyroid Management • Replacement therapyfor life • Levothyroxine, Starting dose dependent on age, fitness and cardiac performance. • 6/52 reviewOnce normal, check TSH yearlyEnzyme inducers increase metabolism of thyroxine

  25. Complications • Thyroid Crisis (<2%) • Rapid deterioration of hyperthyroidism • 10% mortality • Fever, anxiety, agitation, confusion, tachycardia • Treat before biochemistry results return. • Often provoked by minor stress/infection/surgery • May require ICU admission • B-blockers, carbimazole, iodine, IV glucocorticoids to stop thyroxine production

  26. Myxoedema Coma (rare) • >50% mortality • Hypothermia, confusion, coma • Treat before biochemistry results • IV T3 • Full supportive therapy

  27. Prognosis • Hyperthyroidism: Untreated = 30% mortality • Post treatment = 3x increased risk of osteopaenic # 1.5 x increased risk of CV disease • Hypothyroidism

  28. OSCE: Thyroid Examination • Introduce and wash hands • General ExaminationAppropriately dressed/ behaviour, Skin, Hair, Body shape, • HandsThyroid Acropachy, sweating, onycholysis, palmar erythema, tremor, pulse • EyesPeriorbitaloedema, Exophthalmos from sides and behind, assess CN 2,3, 6, lid lag by following finger • NeckSwelling, scars, hyperaemia, venous distention, stick out tongue • PALPATE Temperature, swallowing, stick out tongue *, swelling (describe!), lymph nodes, tracheal deviation • Thyroid Bruit, percuss for retrosternal goitre • Offer to assess Pretibial myxoedema, tendon reflexes, review ECG • Review any biochemistry available

  29. QUIZ • 2 causes of hyperthyroidism? • Graves’s Disease, Toxic MultinodularGoitre • 2 causes of hypothyroidism? • Atrophic Hypothyroidism, Hashimoto’s thyroiditis • 3 Treatments of Hyperthyroidism • Carbimazole +/- Levothyroxine, Radio-iodine, Sub-total Thyroidectomy • Feature of thyroid eye disease (SPERMC) • Soft tissue inflammation, Proptosis, Eyelid changes, Radiological Changes, Myopathy, Compressive Optic Neuropathy • What happens to TSH & T4/T3 in the following:Grave’s DiseaseHashimoto’s ThyroiditisSecondary hypothyroidism • GD: Low TSH, Raised T4/T3HT: High TSH, Low T4/T3SH: Low TSH, Low T4/T3

More Related