hypopituitarism Flashcards
approach to dx and management
-The goal is always to maintain homeostasis
-Using physiology and pathophysiology to explain the symptoms and signs.
-What if any, are the risk factors, that might result in the pathology?
-How would you approach treating the symptoms and signs?
-What does follow up entail?
-How would you explain it to the patient?
hypopituitarism dx + tx
Diagnosis:
-Imaging tests: ideally MRI
-Measurement of pituitary hormone levels -> Basally and after various provocative stimuli
Treatment:
-Removal of any tumor/suppression medications
-Administration of replacement hormones
Hypopituitarism is a ______ syndrome, with _______ of anterior pituitary function +/______
Endocrine deficiency syndrome
Partial or complete loss of ANTERIOR pituitary function
With or without associated mass lesions
Causes of Primary Hypopituitarism causes
Pituitary tumors
-adenoma
-craniopharyngioma (MCC in kids)
infarction or ischemic necrosis:
-hemorrhagic infarction (pituitary apoplexy)
-shock- sheehan’s syndrome
-vascular thrombosis or aneurysm
infiltrative disorders
-Hemochromatosis
-Langerhans’ cell histiocytosis- (Hand-Schüller-Christian disease)
inflammatory processes
-Meningitis
-Pituitary abscess
-Sarcoidosis
Iatrogenic
Autoimmune
primary hypopituitarism causes just list the major categories
-Pituitary tumors
-Infarction or ischemic necrosis
-Inflammatory processes
-Infiltrative disorders
- Iatrogenic
-Autoimmune dysfunction
“PIIIIA”
secondary hypopituitarism
-Hypothalamic tumors
-Neurohormone deficiencies of the hypothalamus
-Trauma
-Inflammatory diseases
-Iatrogenic
“HNT II”
Mortality Morbidity of Hypopituitarism. Which hormone is most urgent?
ACTH»> MOST URGENT WITHOUT YOU WILL DIE**
next TSH» GH» FSH/LH
ACTH → Adrenal Crisis = Life-Threatening
- especially if its sudden loss of production rather than slowly progressive
TSH → Myxedema Coma = Life-Threatening
GH deficiency is more morbid in children than adults
FSH/LH Deficiency with Hypogonadism is more insidiously morbid
Congenital hypopituitarism has greater morbidity effects
With hypopituitarism - what order do we lose hormones?
MC GH is lost first **
- then gonadotropins -> then TSH and ACTH
GH → FSH/LH → TSH → ACTH **
The body tries to preserve the hormones needed for survival
–panhypopituitarism:
ADH deficiency = rare in primary pituitary ds
- common with stalk and hypothalamic lesions
Onset of hypopituitarism is usually
insidious - may not be recognized by pt
-occasionally onset is sudden or dramatic
other presenting features of hypopituitarism if its space occupying
Pt with SPACE occupying lesion may present with headaches or visual field deficits: optic chiasm lesion
-BITEMPORAL HEMANOPSIA
Pt with large lesions involving the hypothalamus:
- may present with polydipsia and syndrome of SIADH
investigation/dx of hypopituitarism
ideally MRI***
- HRCT w/wo contrast to r/o structural abnormalities
T4, TSH in generalized hypopituitarism vs primary thyroid deficiency
Generalized hypopituitarism/secondary:
- LOW in BOTH T4, TSH
Primary hypothyroidism:
- INCREASED TSH
- LOW T4
acute adrenal insufficiency: urgent treatment
NEED IMMEDIATE TX W GLUCOCORTICOIDS
-100 mg hydrocortisone IV, then 50-100mg every 6hr and fluid replacement
-immediate referral for visual field loss is required -> bitemporal hemianopsia
-refer immediately to an experienced neurosurgeon
Pituitary Apoplexy complications
- Catastrophic adrenal failure
- visual field loss
- raised ICP
Pituitary Apoplexy tx
Needs Immediate treatment with Glucocorticosteroids!!!!!
If visual field loss = Referral to neurosurgery
- bitemporal hemianopsia
Immediate surgery warranted if:
-Visual field disturbances
-Oculomotor palsies
-Somnolence progresses to coma because of hypothalamic compression
-Although management with high-dose corticosteroids and general support may suffice in a few cases, transsphenoidal decompression of the tumor should generally be undertaken promptly
tx of hypopituitarism
Goal: Hormone replacement of hypo-functioning target glands
If tumor:
Transsphenoidal removal or irradiation
Prolactinoma: Dopamine agonist is given as initial tx
DDx of generalized hypopituitarism
-anorexia nervosa- maintenance of secondary sexual characteristics despite amenorrhea -> increased levels of basal growth hormone and cortisol
-alcohol liver disease of hemochromatosis- evidence of liver disease -> lab testing
-myotonia dystrophica- progressive weakness, premature balding, cataracts, facial features of accelerated aging -> lab testing
-polyglandular autoimmune disease
hypopituitarism in children -Presentation
-Height is below the 3rd percentile, and growth velocity
-Skeletal maturation > 2 yr behind chronologic age
-Fails to begin pubertal development
Hypopituitarism in children: causes
MCC is craniopharyngioma- pituitary tumor**
Other causes
Langerhans’ cell histiocytosis
Midline defects- Cleft Palate
Radation of CNS, idiopathic (5%), hereditary
Hypopituitarism in children: work up and tx
Work-up:
-Assess bone age: X-ray of the left hand
-Skeletal maturation usually delayed to the same extent as height
-CT or MRI of brain
-R/o calcifications & tumors
-Mid to late childhood: IGF-1 levels measured
Treatment:
-Surgery
-GH replacement + other hormones (Cortisol, Thyroid, gonadal sex steroids)
GH deficiency: adults vs kids
Adults
- undetectable
-usually asymptomatic
-decreased energy
-?? accelerates atherosclerosis
Children:
-abnormally slow growth
-short stature with NORMAL proportions
ACTH deficiency sx
aka Hypoadrenalism
Sx:
-fatigue
-weakness
-wt loss
-hypotension
-hypoglycemia
-intolerance to stress and infection
-decreased axillary and pubic hair
-NO hyperpigmentation
- low plasma and urinary STEROID levels ( will become normal after ACTH replacement)
ACTH deficiency can lead to _______. how do you treat it?
Hypoadrenalism
-tx is with cortisol replacement
ACTH investigations
Standard ACTH simulation test **
-Safe & less labor intensive
-Synthetic ACTH (cosyntropin) is administered IV/IM
-Plasma cortisol response measured 30 and 60 min later
Normal:
- Cortisol levels ↑↑↑ (> 21 g/dL) and Aldosterone ↑ (>4 ng/dL above baseline)
Insulin Tolerance Test: Hazardous do in pts with severe
-Panhypopituitarism
-Diabetes mellitus
-Elderly
-Contraindicated in those:
-Coronary artery disease
-Epilepsy
lack of LH and FSH: children, premenopause women and men
Children:
- delayed puberty
-short stature
Premenopausal women:
-amenorrhea
-reduced libido
-regression of secondary sexual characteristics
-infertility
men:
-ED
-testicular atrophy
-reduced libido
-regression of secondary characteristics
-decreased spermatogenesis with infertility
kallmann’s syndrome associated factor and s+s
GnRH deficiency:
- Associated with midline facial defects
S/S:
Anosmia: cannot smell
Cleft Palate/Lip
Color Blindness
hypogonadism: reduced sex hormones -> infertile, no puberty
-1/2 of these pts have unilateral renal agenesis (kidney fails to develop)
-some pts also exhibit cryptorchidism (undescended testes), micropenis, sensorineural deafness, cerebellar ataxia (affecting coordination and balance), cognitive problems, bimanual synkinesis (mirror movements of hands), and a high arched palate.
-some affected women have menarache followed by secondary amenorrhea
Kallmann’s syndrome is lack of what hormone?
Lack of gonadotropin-releasing hormone (GnRH)
simmond’s syndrome
aka Panhypopituitarism:
- involvement of ALL pituitary hormones
Often: only 1+ pituitary hormones involved resulting in partial hypopituitarism
“Simms game = PAN; you can control the whole world”
Sheehan’s syndrome
Pituitary necrosis from hypovolemia and shock
- Due to increased blood demand from pituitary and decreased blood supply lost during pregnancy
S/S:
- Lactation does not start after childbirth
- Fatigue
- Loss of secondary sex characteristics (pubic and axillary hair loss)
Who does Sheehan’s syndrome affect and what is it
Affects postpartum women *
- aka: postpartum pituitary gland necrosis
-rare condition that can occur in women who experience severe blood loss (hemorrhage) or hypovolemic shock during or after childbirth
pituitary apoplexy sx
Symptoms:
-severe headache
-stiff neck
-fever
-visual field defects: bilateral hemi
-oculomotor palsies
- CSF ± Blood
May present with edema which if compresses hypothalamus:
- Risk of Somnolence or Coma
Varying degrees of hypopituitarism may develop suddenly:
- many present with vascular collapse bc of deficiency ACTH and cortisol
Pituitary apoplexy definition + diagnostic studies
Sudden enlargement of pituitary caused by:
- pituitary tumor*
- hemorrhagic infarction of pituitary gland
- medical emergency!!! - ACUTE hormonal deficiencies
need MRI** to assess hemorrhage
