Neuro XI Flashcards
hemangioblastoma path description
closely arranged, thin-walled capillaries with minimal intervening parenchyma.
classic location of schwannoma
cerebellopontine angle
schwannoma management
Resection or stereotactic radiosurgery
Schwanzoma tumor marker
S-100
most common site of oligodendroglioma
frontal lobes
other findings in oligodendroglioma
1) “chicken-wire” capillary pattern
2) often calcified
pilocytic astrocytoma prognosis
benign; good prognosis
pilocytic astrocytoma location
Posterior fossa (cerebellum). May be supratentorial
characteristic path findings in pilocytic astrocytoma?
Rosenthal fibers
Rosenthal fibers description
Eosinophilic, corkscrew fibers.
gross finding of pilocytic astrocytoma
cystic + solid
medulloblastoma personality
1) highly malignant
2) form of primitive neuroectodermal tumor
medulloblastoma pathology
1) Homer-Wright rosettes
2) small blue cells
Most common site of ependymal cell tumors?
4th ventricle
ependymoma pathology
1) Characteristic perivascular rosettes
2) Rod-shaped blepharoplasts
blepharoplasts?
(basal ciliary bodies) found near nucleus
craniopharyngioma histology
1) calcification common
2) cholesterol crystals found in “motor oil” like fluid within tumor
pinealoma presentation in males
precocious puberty due to beta-hCG preoduction
pinealoma histology
similar to seminoma (late cells in lobules with watery cytoplasm and “fried egg” appearance)
Downward (transtentorial) central herniation
Caudal displacement of brain stem leads to rupture of paramedic basilar artery branches –> duret hemorrhages. Usually fatal.
cingulate herniation complication
con compress ACA
cingulate/subfaciline herniation
Innermost part of the frontal lobe is scraped under part of the fall cerebra.
duret hemorrhage
Small lineal areas of bleeding in the midbrain and upper pons of the brainstem caused by a traumatic downward displacement of the brainstem.
central herniation AKA
transtentorial herniation
central herniation pathophys
Caudal displacement of brain stem –> rupture of paramedic basilar artery branches –> Duret hemorrhages. Usually fatal.
Uncal herniation pathophys
1) Compresses *ipsilateral CN III
2) compresses ipsilateral PCA (leading to contralateral homonymous hemianopia with macular sparing)
3) compresses contralateral crus cerebri at the Kernohan notch (leading to ipsilateral paresis; “false localization sign”)
what herniates with uncal herniations?
medial temporal lobe
tonsillar herniation pathophys
cerebellar tonsills herniate through foramen magnum leading to coma and death due to brain stem compression.
Brimonidine MOA
a2 agonist
epinephrine MOA for glaucoma?
Decreases aqueous humor synthesis via vasoconstriction.
brimonidine MOA for glaucoma?
Decreases aqueous humor synthesis
epinephrine contraindication
closed-angle glaucoma (mydriasis)
brominidine AE’s
1) blurry vision
2) ocular hyperemia
3) foreign body sensation
4) ocular allergic reactions
5) ocular pruritis
b-blockers used in glaucoma?
1) timolol
2) *betaxolol
3) carteolol
b-blockers AE’s in glaucoma
no pupillary or vision changes
acetazolamide MOA in glaucoma
decreases aqueous humor synthesis via inhibition of carbonic anhydrase
acetazolamide AE’s in glaucoma
no pupillary or vision changes
drug for use in glaucoma emergency’s? why?
pilocarpine (very effective at opening meshwork into canal of schlemm)
cholinomimetic MOA for glaucoma
Increase outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork.
cholinomimetic AE’s
miosis (contraction of pupillary sphincter muscles) + cyclospasm
cyclospasm
contraction of ciliary muscle
latanprost
PGF2alpha
prostaglandins for use in glaucoma?
1) bimatoprost
2) latanoprost
prostaglandin mechanism for glaucoma?
Increase outflow of aqueous humor
bimatoprost/latanoprost AE’s
1) darken color of iris (browning)
2) eyelash growth
diphenoxylate
opioid analgesic
pentazocine
opioid analgesic
mu receptor is for?
beta-endorphins
delta receptor is for?
enkephalins
kappa opioid receptor is for?
dynorphin
opioid mechanism
Open K+ channels, close Ca2_ channels –> decreased synaptic transmission + inhibit release of ACh + NE + 5-HT + glutamate + substance P.
opioid GI use
anti-diarrheal
other use for opioid analgesics?
Acute pulmonary edema
opioid AE’s
1) addiction
2) respiratory depression
3) constipation
4) miosis
5) additive CNS depression with other drugs
meperidine is unique in AE’s among opioid analgesics because….
Causes mydriasis rather than mitosis.
tolerance and opioids
does not develop to *miosis and constipation.
