Endocrine disorders Flashcards

Question

Genetic causes of hypertrophic hypogonadism

Answer 1

Noonan syndrome Klinefelter syndrome Turner syndrome

Answer 2

NOONAN SYNDROME Affectation: males and females Karyotype: Normal Clinical: short stature, webbing of the neck, low hairline, pectus carinatum/excavatum, right-sided CHD (mainly valvular, pulmonic stenosis), cardiomypathy, cubitus valgus, hypertelorism, downward slanted palpebral fissures, ptosis, micrognathia Subnormal IQ, high frequency sensorineural hearing loss cryptochordism, small testes, delayed puberty Management: Human GH

Answer 3

KLINEFELTER affects males Karyotype: 47 XXY 48 XXXY, 48 XXYY, 49 XXXYY *diagnosis rarely made before puberty due to paucity of signs and symptoms in childhood *behavioral or psychiatric disorders *anxious, immature, or excessively shy), learning disabilities, verbal cognitive defects, deficits in executive function *tall, slim, long legs disproportionate to the arms *small testes and phallus, cryptochordism, low testosterone, delayed puberty, gynecomastia, sparse facial hair, azoospermia, infertility *increased incidence of metabolic syndrome, breast cancer, leukemia, lymphoma Management: replacement therapy with testosterone preparation

Answer 4

TURNER SYNDROME affects females Karyotype: 45, X * recognizable at birth: edema of dorsa of the hands and feet, loose skin folds at the nape, low birth weight, decreased length *short stature (cardinal finding), webbed neck, low posterior hairline, small mandible, high arched palate, prominent ears, epicanthal folds, broad chest with illusion of widely spaced nipples, cubitus valgus, hyperconvex fingernails *cardiac defects (mainly bicuspid aortic valve), renal malformations, IBD *nearly all oocytes are gone by 2 years (ovaries described as "streaks" *breast development fails to occur but adrenarche normally present Management: Human GH Estrogen replacement therapy

Answer 5

Girls: o Thelarche (breast bud) --> pubarche (6-12 mos later) --> menarche (2-2.5 yrs from thelarche) o Peak height velocity: breast stage 2-3 Boys: o Growth of testes (>4ml) and thinning of scrotum --> growth of penis and pigmentation of scrotum --> pubarche o Peak height velocity: genital stages 4-5

Answer 6

Etiopatho - onset of secondary sexual characteristics (breast devt or testicular devt) before: o 8 yo in girls o 9 yo in boys - classification based on primary source of hormonal production

Answer 7

Hypothalamus secretes GnRH (gonadotropin releasing hormone) --> pituitary releases LH and FSH --> gonads secrete sex steroids (testosterone from testes, estradiol and progesterone from ovaries) Females - FSH – ovarian production of estrogen, in puberty causes formation and support of corpus luteum Males – LH – production of testosterone from Leydig cells, later FSH stimulates development and support of seminiferous tubules Sex steroids and inhibin (produced by gonads) – both suppress the secretion of gonadotropins GnRH released in episodic pulses vary during development and menstrual period - onset of puberty, increased at night than during the day - Adrenarche then Gonadarche

Answer 8

CENTRAL PRECOCIOUS PUBERTY Etiology: Idiopathic (most frequent cause among females), brain lesions (hypothalamic hemartoma, tumor, hydrocephalus, trauma, myelomeningocele, abscess, radiation), untreated hypothyroidism Labs: elevated LH and FSH serial blood samples during sleep reveals pulsatile LH secretion Pubertal levels of testosterone or estradiol GnRH or GnRH agonist (leuprolide) stimulation test leads to "pubertal" LH response or pubertal levels of estradiol Imaging: advanced osseous maturation Pelvic UTZ in girls; progressive enlargement of ovaries and uterus MRI: physiologic enlargement of pituitary gland as seen in normal puberty Tx: GnRH agonist PERIPHERAL PRECOCIOUS PUBERTY Etiology: ovarian tumors, Leydig cell tumor, adrenal tumo, CAH, teratoma, Mc-Cune-Albright syndrome Labs: Supressed LH, FSH Elevated estradiol or testosterone No response to GnRH or leuprolide stimulation test Imaging: Advanced osseous maturation polyostotic fibrous dysplasia in McCune-Albright syndrome Tx: Aromatase inhibitors: letrozole, testolactone Anti-estrogen: Tamoxifen Anti-androgens: spinorolactone, flutamide, bicalutamide Inhibitor of testosterone synthesis: ketoconazole

Answer 9

Incomplete (partial) precocious puberty - isolated manifestations of puberty without devt of other pubertal signs

Answer 10

-transient isolated breast -development without other pubertal changes -most often occurs in the first 2 yrs of life -infrequently may progress to precocious puberty

Answer 11

-early apperance of pubic hair -early increase in adrenal androgen production -increased prepubertal growth velocity but decreased pubertal growth, so adult height is not affected -may herald disorders of androgen synthesis

Answer 12

-majority will have only 1-3 episodes of bleeding -puberty occurs usual time

Answer 13

Delayed puberty - No physical changes of puberty by age: o 13 yo in girls o 14 yo in boys - No menarche by 16 yo in girls who developed secondary sexual characteristics - Dx: LH/FSH, Bone aging, TFT, Karyotyping - Mgt: hormonal replacement

Answer 14

Parathyroid hormone (PTH) – stimulates activity of 1alphahydroxylase in kidneys, increases serum Ca by enhancing bone resorption and facilitates phosphorous excretion Vitamin D deficiency – low Ca, normal Ph

Answer 15

Etiology - Neonatal, congenital, postsurgical/radiation destruction, hypo/hyperMg, VitD deficiency, Ca deficiency, drugs (furosemide, aminoglycosides, calcitonin, bisphosphonates, anticonvulsants, ketoconazole, antineoplastic agents), sepsis, acute pancreatitis - Destruction/aplasia/impaired synthesis of parathyroid gland à dec PTH à hypoCa, hyperPh

Answer 16

CM 1. Muscular pain and cramps (early), numbness, stiffness, tingling of hands and feet of hands and feet 2. (+)Chvostek or Trousseau sign or laryngeal and carpopedal spasms 3. Abdominal pain --> tonic rigidity, head retraction, cyanosis --> Sz w/ or without LOC

Answer 17

Dx 1. Serum PTH – dec 2. Serum Ca, Ph, 1,25(OH)2D, Mg - dec Ca, elev Ph 3. ECG – prolonged QT

Answer 18

Mgt 1. Calcium gluconate 10% IV 5-10mL at 0.5-1 ml/min with HR monitoring 2. Calcitriol 0.25ug/d 3. Calcium gluconate or calcium glubionate 800mg daily

Answer 19

1. Pseudohypoparathyroidism (PHP) or Albright Osteodystrophy – elev PTH but dec Ca - Due to PTH receptor defect - Short child, stocky build, round face with dimpling of hands - Tetany – usual presenting sign 2. Pseudohypoparathyroidism – have the usual anatomic stigmata of PHP - Slightly elevated PTH but normal Ca and Ph - Hypocalcemia occurs with increasing age

Answer 20

HYPERPARATHYROIDISM - Usually manifest after 10yo - MEN type I – hyperplasia of pancreas + ant pituitary + parathyroid gland

Answer 21

Patho - May be from adenoma or hyperplasia of parathyroid gland (primary) or a compensatory increase from a hypocalcemic state (secondary) --> inc PTH --> hyperCa, hypoPh

Answer 22

CM 1. Muscle weakness, fatigue, headache 2. anorexia, abdominal pain, nausea, vomiting, constipation 3. polydipsia, polyuria, weight loss, fever 4. renal calculi (chronic) 5. osseous changes – pain in back/ext, gait disturbance, genu valgum, fractures, tumors 6. parathyroid crisis – serum Ca >15mg/dL + progressive oliguria, azotemia, stupor, coma 7. cognitive impairment, sz, blindness 8. depression, confusion, dementia, stupor, psychosis

Answer 23

Dx 1. Elev PTH 2. elev Ca (>12 mg/dl), dec Ph (<3mg/dl), dec Mg 3. XR – resorption of subperiosteal bone: most consistent and characteristic finding - Best seen along the margins of the phalanges of the hands

Answer 24

Mgt 1. Surgical exploration – indicated in all instances: excision of adenoma/ total parathyroidectomy 2. Bisphosphonates, calcimimetics 3. High Ca and Ph diet

Answer 25

CH 568: HYPERTHYROIDISM - Excessive secretion of thyroid hormone - Graves disease: MC cause in childhood (95%)

Answer 26

GRAVES DISEASE Etiopatho - Autoimmune disorder of thyrotropic receptorstimulating binding Ab (TRSAb) production - F>M (5:1) - MC of pedia hyperthyroidism - Peak 11-15yo - Most have FHx of autoimmune thyroid ds

Answer 27

CM 1. Finger tremors 2. Nervousness, headaches, difficulties with sleep, poor concentration 3. Voracious appetite with weight loss or no increase in weight 4. Flushed skin with excessive sweating, heat intolerance 5. Earliest sign: emotional disturbance with motor hyperactivity 6. Diffuse enlarged thyroid (goiter) 7. Exophthalmos – due to Ab vs Ag shared by the thyroid and eye ms 8. Retraction of upper eyelid (Dalrymple sign), lagging of upper eyelid on downward gaze, infrequent blinking, impairment of convergence 9. Tachycardia, weight loss, palpitations, dyspnea, HTN, widened pulse pressure

Answer 28

Dx 1. TFT – inc T4 and T3, low TSH 2. Thyroid Ab – TRSAb confirms dx 3. Thyroid UTZ and scintigraphy – diffusely enlarged thyroid gland - Often homogenous with normal or hypoechogenicity - RAI uptake measured in scintigraphy if hx, PE, & lab tests cannot establish dx - Inc uptake of 99mTc

Answer 29

Antithyroid drugs-1st line of tx for pregnant and children PTU MOA: inhibit iodine organification and coupling in the thyroid; also inhibits peripheral conversion of T4 to T3 heavily protein bound, less able to cross placenta and pass into breastmilk; preferred drug during pregnancy and lactation administration: administered 3x daily AE: transient granulocytopenia transient urticarial rashes agranulocytosis hepatitis, lupus-like polyarthritis syndrome, glomerulopnephritis METHIMAZOLE/CARBIMAZOLE blocks the organification of iodide needed to synthesize the thyroid hormone more potent than PTU Carbimazole: is the prodrug of methimazole consensus is to use methimazole for children clinical response is evident within 2-4 months Admin: initial dose 0.5-1 mg/kg/day given OD or BID AE: transient granulocytopenia transient urticarial rashes agranulocytosis hepatitis, lupus-like polyarthritis syndrome, glomerulopnephritis

Answer 30

2. Radioactive iodine ablation/ thyroidectomy - Indications: o Inadequate cooperation for medical mgt o Medical mgt failed to result in permanent remission o Severe SE preclude use of antithyroid drugs - Px should be in euthyroid state prior to radiofrequency ablation or surgery - Thyroidectomy – if with coexisting suspicious nodule - Consequence = permanent hypothyroidism - Complications: o Radiofreq ablation: worsen ophthalmopathy o Thyroidectomy: laryngeal nerve damage, hyperparathyroidism

Answer 31

THYROID STORM - Acute life-threatening surge of thyroid hormone in the blood usually precipitated by surgery, trauma, infection, or radioactive iodine tx - Fever, tachycardia, high output CF, GI dysfunction (vomiting, diarrhea, jaundice), neuro changes (confusion, agitation, obtundation) - Rapid progression to delirium, coma, death

Answer 32

Mgt 1. Inhibition of TH formation and secretion – PTU, saturated solution of potassium iodide (only after PTU to avoid potential inc in TH synthesis) 2. Sympathetic blockade – propranolol: treat exaggerated adrenergic sx. Inhibits peripheral conversion of T4 to T3 3. Tx for relative glucocorticoid insufficiency – prednisone

Answer 33

CH 559: DIABETES INSIPIDUS Etiopatho - From vasopressin deficiency (central DI) or vasopressin receptor insensitivity (nephrogenic DI) - Vasopressin – principal regulator of tonicity o Secreted in the posterior pituitary gland o Antidiuretic and vascular pressor activity

Answer 34

CM 1. Polyuria and polydipsia (>2L/m2/d) – cardinal fx 2. dehydration

Answer 35

Dx 1. Serum osmolality 2. BUN, crea, Na, K, Ca 3. Glu 4. Urine osmolality, specific gravity, urine glu DI = serum osmolality > 300 mOsm/kg and Urine osm < 300 mOsm/kg Serum Osm 270-300 --> perform water deprivation test to establish dx and differentiate central from nephrogenic DI Hyponatremia – usual reason for referral - Then check UO, is px polyuria (DI) /oliguria (SIADH)? - For DI: then check USg --> If <1.010 = DI

Answer 36

SIADH Cerebral salt wasting Central DI Nephrogenic DI

Answer 37

Serum Na: low Serum osmolality: low Urine Na: High Urine output: normal or low Intravascular volume status: high Vasopressin level: high Management: limit oral fluid intake

Answer 38

Serum Na: low Serum osmolality: low Urine Na: VERY HIGH Urine output: HIGH Intravascular volume status: low Vasopressin level: low Management: NaCl and H2O replacement

Answer 39

Serum Na: HIGH Serum osmolality: HIGH Urine Na: low Urine output: HIGH Intravascular volume status: low Vasopressin level: low Management: fluid therapy; vasopressin

Answer 40

Serum Na: HIGH Serum osmolality: HIGH Urine Na: low Urine output: High Intravascular volume status: low Vasopressin level: high Management: Thiazides +- indomethacin or amiloride

Answer 41

etiology: congenital trauma(deceleration injury) Tumors (craniopharyngioma, lymphoma, leukemia( Autoimmune Infection (meningitis, TB) Drugs: Ethanol, phenytoin, opiate antagonists, alpha-adrenergic agents) Vascular (bleed or infarction) Idiopathic in 10% Management: Fluid therapy' long-acting vasopressin analog DDAVP acute onset after neurosurgery: vasopressin with a total fluid intake limited to 1L/m2/ day during antidiuresis

Answer 42

etiology: congenital hypercalcemia,hypokalemia renal disease (polycystic kidney disease, Chronic renal failure, ATN, obstructive uropathy) Drugs (lithium, ciplatin, methoxyflurane, democlocycline) Infiltrating lesions vascular (sickle cell anemia) Solute diuresis (glucose, mannitol, Na, radiocontrast dyes Management: treat underlying disorder thiazides(decrease overall urine output by enhancing Na excretion at the expense of water and by causing decrease in GFR Indomethacin and amiloride +/- thiazides to further reduce polyruria Ensure intake of adequate calories for growth & to avoid severe dehydration