Pituitary disorders

Question 1

Symptoms begin at 60 mg/dL, with brain function impairment at 50 (neuroglycopenia)

Sweating, palpitations, anxiety, tremulousness

Headache, lightness, confusion, slurred speech, dizziness, irritability, difficulty concentrating

Answer 1

hypoglycemia

Question 2

What are RF for hypoglycemia?

Answer 2

Post GI surgery
Occult diabetes (hyperglycemia → exaggerated response)

Autoimmune (postprandial hyperglycemia → hypoglycemia, 3-4 hours)

Question 3

Fasting (often due to secondary disorder - hypopituitarism, Addison’s, myxedema, liver failure, ESRD) vs. postprandial, or alcohol and medication-induced

Primary = hyperinsulinemia (insulin tumor, taking insulin or sulfonylurea)
can cause what?

Answer 3

hypoglycemia

Question 4

1 Document low glucose, symptoms, resolution
2 Measure glucose, insulin, C-peptide (resistance), proinsulin (precursor), beta-hydroxybutyrate (ketone body), oral hypoglycemic agents during spontaneous episode
3 Try recreating conditions if above not successful (fasting, fixed meal test)

Answer 4

hypoglycemia

Question 5

hyperinsulinemia with hypoglycemia can be caused by

Answer 5

insulinoma – check for antibodies

Question 6

how do you treat hypoglycemia?

Answer 6

<60 = oral glucose - fruit juice, hard candy

<45 = IV glucose, monitoring

Question 7

Headache, visual field defects, cranial nerve palsies (EOM), fatigue, dizziness/HOTN, confusion, cognitive dysfunction, sexual dysfunction, polydipsia, cold intolerance, pituitary apoplexy

Can compress the optic chiasm, cranial nerves → invasive, hemorrhage

Answer 7

pituitary adenoma

Question 8

pituitary adenomas are more common in

Answer 8

35-60

Question 9

MC: non-functioning
Larger = hypopituitarism

MC in anterior lobe - prolactinomas or non functioning, classified by type of hormone they produce (can secrete two)
Micro <1cm, macro >1cm

Answer 9

pituitary adenoma

Question 10

what’s the best diagnostic choice for pituitary adenoma?

Answer 10

MRI with contrast

Question 11

how do you treat pituitary adenomas

Answer 11

transsphenodial surgery

Question 12

Enlargement of hands, fingers, feet, head, facial features (increased ring, shoe, hat size), mandible, tongue, carpal tunnel, voice changes, snoring, OSA, HTN, cardiomegaly, weight gain, insulin resistance, arthralgias, arthritis, skin changes, polyps, hypogonadism

Headache, bitemporal hemianopsia, DM, glucose intolerance

Answer 12

somatotropic adenoma (Growth hormone)

Question 13

MEN1 or 4 (familial) can cause

Answer 13

anterior pituitary hyperpituitarism

Question 14

Acromegaly, gigantism by stimulation of IGF-1 release from liver

Prior to closure of epiphyses = gigantism
Adulthood = insidious, slow and progressing symptoms

Answer 14

somatotropic adenoma

Question 15

1 Screening: random serum IGF-1
2 Elevated → fasting labs of serum GH, IGF-1, PRL, glucose, LFTs, Cr/BUN, Ca, phosphate, T4, TSH (GF <1 = acromegaly can be excluded)
3 Glucose suppression test (GH <.4, acromegaly is excluded) - failure is considered positive
4 MRI in preparation for surgery

Answer 15

somatotropic adenoma

Question 16

how do you treat somatotropic adenoma?

Answer 16

Surgery – medical treatment if incomplete remission after surgery (somatostatin analogs, GH receptor antagonists)

Octreotide

Question 17

Women - dependent on pre or post menopausal
Hypogonadism: Amenorrhea, oligomenorrhea, infertility, decreased libido
Estrogen deficiency - vaginal dryness, irritability, anxiety, depression, galactorrhea

Men - decreased libido, ED, infertility, headache or visual changes

May also secrete growth hormone causing acromegaly or gigantism

Answer 17

prolactinoma

Question 18

what is the most common pituitary adenoma?

Answer 18

prolactinoma

Question 19

prolactinomas suppress what?

Answer 19

gonadotropin release, causing hypogonadism

Question 20

MCC - can suppress gonadotropin release and cause hypogonadotropic hypogonadism with similar symptoms

Answer 20

prolactinoma

Question 21

Confirm elevated prolactin and rule out other things - increased prolactin
Decreased FSH + LH

MRI if no other cause is found

PE: bitemporal hemianopsia

Answer 21

prolactinoma

Question 22

large tumors cause — while small tumors can adapt and cause —

Answer 22

hypopituitarism, hyperpituitarism

Question 23

only in large tumors do you see

Answer 23

blindness, headaches – because of hypopituitarism from compression of the optic chiasm. This can occur in non functioning and functioning but in non functioning this can be the only symptom and hypopituitarism.

Question 24

how do you treat prolactinoma/

Answer 24

Stop any medications causing this
Dopamine receptor agonists (cabergoline)

Surgery only for critical cases - apoplexy or compromised visual fields or those who cannot tolerate medications

Question 25

Moon face, acne, thin skin, weight gain, stretch marks, ulcers, osteoporosis, HTN, bruising, hypertrophy, poor wound healing, proximal muscle weakness

Answer 25

corticotropic adenoma

Question 26

Hypersecretion of cortisol from excess of ACTH From the pituitary = Cushing disease Hypercortisolemia = Cushing syndrome

Answer 26

corticotropic adenoma

Question 27

Establish confirmation for high cortisol → measure ACTH Increased baseline ACTH + suppression of cortisol on high-dose dexamethasone suppression test MRI

Answer 27

corticotropic adenoma

Question 28

How do you treat corticotropic adenomas?

Answer 28

surgery

Question 29

Most cases of what are from destructive processes: tumors/cysts, TBI & SAH, pituitary surgery or radiation Headaches or visual defects

Answer 29

anterior pituitary hypopituitarism

Question 30

Occurring when 75% of parenchyma is lost or absent – congenital or acquired Hypopituitarism with DI is almost always from hypothalamus

Answer 30

anterior pituitary hypopituriasm

Question 31

hypopituitarism with DI is almost always from the

Answer 31

hypothalamus

Question 32

anterior pituitary hypopituitarism is from

Answer 32

Either from hypothalamic dysfunction or direct pituitary dysfunction MCC = pituitary tumors

Question 33

how do you treat hypopituitarism?

Answer 33

Hormone replacement therapy

Question 34

Nonspecific, variable symptoms → fatigue, impaired sleep, concentration, memory Depression Dwarfism Reduced muscle mass, central obesity, increased LDL, atherosclerosis, HTN, reduced CO w/ exercise, insulin resistance, dyslipidemia, fasting hypoglycemia Chronic = fractures & osteopenia Congenital = hypoglycemia, jaundice, small penis, later short stature

Answer 34

growth hormone deficiency

Question 35

“Somatotropin” Genetic mutation, injury, idiopathic IGF-1 stimulated by GH, produced by the liver → signals cells to hypertrophy and divide, inhibiting cell apoptosis

Answer 35

growth hormone deficiency

Question 36

MRI including hypothalamus and pituitary In childhood = pituitary dwarfism with short stature (normal proportions), delayed dentition, delayed skeletal maturation)

Answer 36

growth hormone deficiency

Question 37

treat growth hormone deficiency with

Answer 37

GH injections

Question 38

TSH deficiency can lead to

Answer 38

hypothyroidism

Question 39

Women: amenorrhea, oligomenorrhea, infertility, loss of libido, dyspareunia, osteoporosis, premature atherosclerosis, hot flashes, vaginal dryness Men: loss of libido, impaired sexual function, decreased muscle + bone mass, decreased erythropoiesis and hair growth, gynecomastia

Answer 39

gonadotropin deficiency

Question 40

Hypogonadotropic hypogonadism – low LH and FSH → hypogonadism + infertility Congenitally = lack of pubertal development, abnormal genitalia, kidney abnormalities, craniofacial, neurological, MSK deficits

Answer 40

gonadotropin deficiency

Question 41

Acutely = fatigue, weakness, dizziness, nausea, vomiting, arthralgias, HOTN, hyponatremia, and hypoglycemia Chronic = tired, pallor, anorexia, weight loss, arthralgias, hyponatremia, hypoglycemia Thinning of hair, cognitive decline, pallor, impaired cardiac function, SOB, N/V/D

Answer 41

ACTH deficiency

Question 42

Central or secondary adrenal insufficiency with functional atrophy of adrenal cortex with diminished cortisol production 1 = adrenal dysfunction (defect, high K+, salt craving) ⅔ = hypothalamic or pituitary dysfunction with no defect

Answer 42

ACTH deficiency

Question 43

Low DHEA levels = irregular menstrual periods, decreased pubic/axillary hair, libido Primary → increased CRH, ACTH, with cortisol, DHEAS, and aldosterone are low Secondary → only CRH is high, ACTH, cortisol, DHEAS are low (aldosterone unaffected) Tertiary → everything is low (aldosterone unaffected)

Answer 43

ACTH deficiency

Question 44

secondary

Answer 44

double low

Question 45

primary

Answer 45

one (distal) low

Question 46

failure to lactate after childbirth is

Answer 46

prolactin deficiency

Question 47

panhypopituitarism can be all hormones affected or

Answer 47

some, and can be from an apoplexy as well from hemorrhage

Question 48

----- is usually a complication of nonfunctioning adenoma, causing an emergency with sudden onset of severe headache, visual disturbances, intracranial HTN, altered levels of consciousness, vomiting

Answer 48

apoplexy

Question 49

what is the most severe and life-threatening deficiency?

Answer 49

ACTH

Question 50

apoplexy is an

Answer 50

emergency! steroids, surgery, immediately

Question 51

hyposecretion of oxytocin causes

Answer 51

stopping of uterine contractions, milk ejection

Question 52

hypersecretion of oxytocin causes

Answer 52

oxytocin toxicity → overactive uterus, hypertrophy, limiting pregnancy

Question 53

intense thirst with copious amounts of water intake, polyuria, enuresis (unable to drink = hypernatremia and dehydration) Large amounts of dilute urine

Answer 53

vasopressin deficiency/central DI

Question 54

what's the difference between central vs nephrogenic DI?

Answer 54

Central diabetes insipidus – no production of ADH Nephrogenic DI = failure of kidney to respond to vasopressin (lithium, hypercalcemia)

Question 55

is primary or secondary vasopressin deficiency more common?

Answer 55

secondary from: hypothalamic or pituitary stalk damage (tumor, hypophysitis, infarction, hemorrhage, encephalopathy, surgery, trauma, infection, granuloma, pituitary metastases)

Question 56

24 hour urine – volume, Cr, hypernatremia (urine volume <2L/24hr w/o hypernatremia rules out DI) Plasma vasopressin, serum glucose, BUN, Ca, K, Na, uric acid Plasma osmolality high with urine osmolality low

Answer 56

vasopressin deficiency

Question 57

what is the vasopressin challenge?

Answer 57

1Measure UO for 12 hours 2Measure serum sodium 3Administer desmopressin 4Check serum Na and urine volume again -------Respond = central -------No response = nephrogenic

Question 58

what's the study of choice to find a cause to DI?

Answer 58

MRI

Question 59

how do you treat vasopressin deficiency?

Answer 59

Desmopressin - generally self-limited after surgery or head trauma OR long term treatment

Question 60

Clinical manifestations from hyponatremia: Acute: cerebral edema, increased risk of seizures or brain herniation - confusion, lethargy, disorientation, fatigue, N/V/watery diarrhea, muscle cramps Can cause acute renal injury Chronic: asymptomatic

Answer 60

SIADH

Question 61

----is more at risk in those with hospitalized, post-op, and older patients

Answer 61

SIADH

Question 62

Excess ADH – resorption of excessive amounts of water with hypervolemia + hyponatremia CNS disorders/infections, trauma, stroke, hemorrhage, malignant neoplasms (small cell of the lung) Meds - anticonvulsants, carbamazepine, hydrochlorothiazide, IV cyclophosphamide, ecstasy

Answer 62

SIADH

Question 63

Serum sodium low – high urine sodium >40 & osmolality >100 = SIADH

Answer 63

SIADH

Question 64

SIADH tx

Answer 64

Correct hyponatremia – hypertonic saline, fluid restriction, furosemide, oral salt tablets