Page 261 - TNFlipTest

Toronto Notes 2019 Pituitary Gland
Clinical Features
• hypogonadism,amenorrhea,erectiledysfunction(seeUrology,U32),lossofbodyhair,fineskin, testicular atrophy, and failure of pubertal development
Treatment
• combinedFSH/LHhormonetherapy,humanchorionicgonadotropin(hCG),rFSH,orpulsatileGnRH analogue if fertility desired
• symptomatictreatmentwithestrogen/testosterone
HYPERGONADOTROPIC HYPOGONADISM
• hypogonadismduetoimpairedresponseofthegonadstoFSHandLH
Etiology
• congenital:
■ chromosomal abnormalities (Turner’s syndrome, Klinefelter syndrome, XX gonadal dysgenesis)
■ enzymedefects(17α-hydroxylasedeficiency,17,20-lyasedeficiency)
■ gonadotropinresistance(Leydigcellhypoplasia,FSHinsensitivty,pseudohypoparathyroidismtype1A)
• acquired:
■ gonadal toxins (chemotherapy, radiation)
■ drugs (glucocorticoids, antiandrogens, opioids, alcohol)
■ infections (STIs, mumps)
■ gonadal failure in adults (androgen decline and testicular failure in men, premature ovarian failure
and menopause in women)
Clinical Features
• hypogonadism,amenorrhea,erectiledysfunction(seeUrology,U32),lossofbodyhair,fineskin, testicular atrophy, failure of pubertal development, low libido, and nfertility
Treatment
• hormonereplacementtherapyconsistingofandrogen(formales)andestrogen(forfemales) administration
Antidiuretic Hormone
DIABETES INSIPIDUS
Definition
• disorderofineffectiveADH(decreasedproductionorperipheralresistance)resultinginpassageof large volumes of dilute urine
Etiology and Pathophysiology
• centralDI:insufficientADHduetopituitarysurgery,tumours,idiopathic/autoimmune,stalklesion, hydrocephalus, histiocytosis X, trauma, familial central DI
• nephrogenicDI:collectingtubulesinkidneysresistanttoADHduetodrugs(e.g.lithium), hypercalcemia, hypokalemia, chronic renal disease, hereditary nephrogenic DI
• psychogenicpolydipsiaandosmoticdiuresismustberuledout
Clinical Features
• passageoflargevolumesofdiluteurine,polydipsia,anddehydration;hypernatremiacandevelopwith inadequate water consumption or secondary to an impaired thirst mechanism
Diagnostic Criteria
• fluiddeprivationwilldifferentiatetrueDI(highurineoutputpersists,urineosmolality<plasma osmolality) from psychogenic DI (psychogenic polydipsia)
• responsetoexogenousADH(DDAVP)willdistinguishcentralfromnephrogenicDI
Treatment
• hormonereplacementtherapyconsistingoftheadministrationofandrogen(formales)andestrogen (for females) (plus progesterone if uterus intact)
SYNDROME OF INAPPROPRIATE ADH SECRETION
Diagnostic Criteria
• hyponatremiawithcorrespondingplasmahypo-osmolality,urinesodiumconcentrationabove40mEq/L, urine less than maximally diluted (>100 mOsm/kg), euvolemia (edema absent), and absence of adrenal, renal, or thyroid insufficiency (Bartter-Schwartz criteria)
Etiology and Pathophysiology
• stress(pain,nausea,post-surgical)
• malignancy(lung,pancreas,lymphoma)
• CNSdisease(inflammatory,hemorrhage,tumour,Guillain-Barrésyndrome)
Endocrinology E19
Diagnosing Subtypes of DI with DDAVP Response
Concentrated urine = Central
No effect = Nephrogenic