In what order are the pituitary hormones lost in pituitary insufficiency?
- GN (LH/FSH)
What is the acronym for the causes of anterior pituitary failure?
- Infection/Infiltrative diseases
- Neoplastic disorders
- Degenerative/deficiency states
- Idiopathic (empty sella)
- Congenital/Famillial/genetic disorders
- Endocrine/metabolic disorders
What are the 6 things (two underlined) Darrow lumped into the vascular causes of anterior pit. failure?
- Pit. apoplexy
- carotid aneurysms including SAH
- Ischemic strokes
- SS disease
Infective causes of anterior pituitary failure includ syphilis, TB, bacterial abcess, fungi and parasites. What are the infiltrative diseases Darrow mentioned that cause ant. pit. failure?
7, two underlined
- Langerhans cell histiocytosis
What are the neoplastic disorders Darrow highlighted that cause ant. pit. failure?
- optic glioma
- nasopharyngeal carcinoma
- pineal dysgerminoma
What are the Congenital, familial or genetic disorders Darrow mentioned that cause ant. pit. failure?
Kallman Syndrome - Gnrh
PROP 1 gene mutation
DAX1 gene mutation Prader-willi syndrome
What is an example of allergic/autoimmune causes of ant. pit failure?
What are the major causes of trauma to the pituitary?
- post CABG
- Head trauma
You should assume that GH is low if you find what on lab work?
3 other pituitary hormones are low
If a patient's 8 a.m. cortisol is under what level, do they have a deficiency?
If a patient with an 8 a.m. cortisol of 2.9 ug/dL what should be done to further the differential?
What would the abnormal result be?
Use ACTH stimulation to test for adrenal insufficiency.
If in 45 minutes the serum cortisol is less than 18 ug/dL, then the dx is made as adrenal insufficiency.
What is normal TSH?
.35 - 5 mIU/L
What is normal testosterone?
280 - 1100 ng/dL
What is normal ACTH?
9 - 52 pg/mL
What is normal serum cortisol?
3- 23 ug/dL
Why am I bothering you with all these normal value q's?
hahaha - June/July
If a patient loses cortisol d/t adrenal insufficiency, what other hormones will become deregulated?
So many, but lets focus on...
- CRH and ADH will both become unchained and run wild since they are co-secreted.
- Also, epinephrine cannot be produced in the absence of cortisol
If you have a euvolemic patient with hyponatremia and a urine osmolality greater than 150 - 200 mOsm/L then what should you be thinking?
How does hypothyroidism lead to hyponatremia?
Hypothyroidism leads to decreased cardiac output and ECV, which leads to increased ADH to retain water and dilution of plasma.
Similar to decreased cortisol levels but without the CRH/ADH cosecretion mechanism
What are four counterregulatory hormones used to keep blood glucose from dropping too low?
If lab testing confirms hypopituitarism, what should be ordered?
Lets say we have a patient with general hypopituitarism... what four replacement hormones should we give them?
If they recover with this treatment but have polyuria, what does this mean?
Posterior Pituitary failure - cortisol increases the GFR via cardiac output and ECV, leading to an absence of ADH manifesting as polyuria.
Central diabetes insipidus does not usually occur with anterior pituitary failure. When it does however, what are three things you should consider?
- metastatic cancer
What are some presentations that accompany hemochromatosis? 5
- Gray skin
- joint pain
- dilated cardiomyopathy
- heart rhythm disturbances
A female patient with headaches is noticed to have enlargement of the
Sella tursica on Xray. Periods are normal. BP and sugars are normal.
Complexion and skin are normal. This patient most likely has?
Empty Sella syndrome - sella is filled with CSF
Where are the ADH receptors?
V1 - In systemic vasculature
V2 - nephron collecting ducts
A patient complains of craving ice water, has hyponatremia and serum uric acid is increased. What should come to mind for you?
What is the pneumonic for causes of polyuria and polydipsia?
Recovery from renal failure
Ions - hypo K and hyper Ca, Iv Infusions (mannitol)
Enzyme - vasopressinase (autoimmune DI)
Drugs - Lithium, demeclocycline
What would allow you to differentiate between psychogenic polydipsia and DI?
Psychogenic polydipsia would come with hyponatremia d/t excessive fluid intake.
DI would hypernatremia d/t the failure of ADH to stimulate H2O reuptake.
Which ADH receptors cause uric acid secretion?
If after water restriction a patient's Uosm/Posm remains less than 1 then what are the only two options?
Complete central DI
Complete renal DI
What will be observed on MRI of a patient with central diabetes insipidus?
- Pituitary Stalk thickening
- Loss of the bright spot (ADH somehow makes the posterior pituitary show up as a bright spot on MRI)
What are some conditions where thickening of the pituitary stalk may be observed?
Autoimmune (apparently just in general)
What is the treatment for DI?
What should you watch out for?
Desmopressin acetate 0,05 mg BID orally or nasally to 0,4 mg q 8 hours.
Plus hydrochlorthiazide 50-100 mg daily
Watch out for suicide with the use of desmopressin acetate.
After water restriction the Uosm/Posm for both partial central and partial nephrogenic DI will be greater than 1.
What improvements would be seen in both cases with addition of DDAVP?
Nephrogenic = no change
Central = 10 - 50% improvement
He tossed up the Vindicated thing three times, so I guess he thinks that's pretty good shit. Although in the past his memory devices have been occasionally worth not so much. Regardless, what does it stand for?
Also, give examples of each wherever you are able.
•Vascular (SS disease, ATN)
•Infectious (pyelonephritis) or Infiltrative (amyloid, Sjögrens, myeloma, sarcoid)
•Neoplastic (myeloma, polycystic kidneys)
•Degenerative or Deficiency
•Congenital, familial or genetic (X-linked defective X-linked V2 receptor or aquaporin (AQP2) water channels –adults have hyperuricemia as well)
•Allergic or Autoimmune
•Endocrine (corticosteroids) or metabolic (potassium depletion, Mg depletion, hypercalcemia)
•Drugs (lithium, demeclocycline, foscarnet, methicillin, amphotericin b) or Depression
What are the causes of a positive Tinel's sign?
Which one would apply in this class?
Mnenonic is "Median Trap"