Path

Question 1

most critical exposure period?

Answer 1

3-8wks b/c that’s when brain forms

Question 2

notochord development

Answer 2

day 17: notochord secretes signaling molec –> ectoderm becomes neuroderm –> produces neural precursors –> notochord = axis vertebral column

Question 3

primary vs secondary neurulation vs post neurulation d/o

Answer 3

day25-28: Neural tube become brain & spinal cord till S2 –> neural tube separates from ectoderm –> ectoderm becomes epidermis; ant/cranial & post/caudal neuropore close vs day28-wk7: Rod of mesenchymal cells differentiate to neural cells to make neural tube past S2, conus medullaris, filum terminale; post neural tube merges w/ ant neural tube vs herniation d/t disturbance of mesoderm development at cranial (encephalocele) or spinal level (meningocele) –> not considered NTD; CSF pressure –> hydrostatic pressure –> dural hernia

Question 4

genetic causes of NTDs

Answer 4

 MTHFR encodes methylene-tetrahydrofolate reductase –> converts 5,10-methylenetetrahydrofolate to 5-methylthrahydrofolate (5-MTHFA) –> convert homocysteine to methionine
 Homozygosity of C677C–>T variant

Question 5

Craniorachischisis vs rachisis vs anencephaly

Answer 5

anencephaly + open cleft spine –> exposed neural tissue vs entire spinal cord exposed but no skull defect –> chronic infxn, incont, motor/sensory deficits vs cranial neuropore doesn’t close day25; Tunica cerebrovasculosa = dark red nonneural vascular mass attached to abnl skull base

Question 6

open spina bifida: Myelomeningocele vs myelocele vs Chiari II w/ clinical sxs

Answer 6

Sac containing meninges, spinal cord, CSF; neural placode; neurological defects, bladder/bowel, weak LE vs neural plates did not fold edges –> neural placode lying level of skin, incomplete central canal spinal cord; neurological defects, bladder/bowel, paralysis LE vs open spina bifida + small post fossa –> displaced hindbrain

Question 7

closed spina bifida: lipomyelomeningocele vs hydromyelia vs split cord vs tethered cord vs thick filum

Answer 7

Midline lipoma attached to dorsal neural placode extending thru defect vs Dilated, filiform shaped central canal of thoracic spinal cord; fluid cavity lined by ependymal cells, no neuro deficits vs Diastematomyelia & diplomyelia vs anchored by inelastic structure –> taut –> stretched; Abnl conus medullaris below L2-L3 vs >2mm, Incomplete involution of distal spinal cord –> lipoma, cyst in filum

Question 8

herniation defects: encephalocele vs meningocele

Answer 8

sin: glabella, forehead, orbits
bas: nasal cavity, cribriform plate, sphenoid, ethmoid
occ: occ bone
vs
sac w/ CSF, spinal cord, meninges; U shaped –> tethered cord

Question 9

auto rec primary micro. isolated vs syndromic?

Answer 9

mutation in ASPM encoding ASPM protein in mitotic spindle poles of neuronal progenitors –> <3 stdev. no abnilities vs w/ abnlities (holo, liss, polymicrogyria) –> intellectual disability, generalized spasticity, epilepsy, fail to thrive

Question 10

anatomic vs benign familial vs metabolic megacephaly

Answer 10

inc size/number brain cells vs broad gyri, inc white/grey matter, avg or better intelligence vs excess deposits in brain –> lysosomal storage d/o, leukodystrophies

Question 11

holo: WK5 - pro divides to…via? a vs semi/lobar

Answer 11

tele (cerebral cortex, striatum) & di (hypo/thal, caudate/putamen) via sonic hedgehog gene. no separation –> 1 ventricle vs mild midline facial defect –> close set eyes, flat nose, cleft lip

Question 12

arrhinencephaly

Answer 12

no olfactory bulbs, tracts, trigone

Question 13

agen CC can be sporadic partial (>1 region) or complete (4 regions)

Answer 13

Callosal neurons fail to form in cerebral cortex; or callosal neurons form but can’t cross midline –> white matter tracts (Probst bundles) assume anteroposterior position –> separates lat ventricles

Question 14

cortical development. radial migration vs tangential migration

Answer 14

Neuronal progenitors in periventricular zone become neuroblasts –> move to overlying cortical plate –> pial surface –> cerebral cortex. wk12-16 to wk24: Cortical projection neurons from periventricular zone to pial surface guided by radial glial cells vs Interneurons from ganglionic eminence to cerebral cortex –> basal ganglia and amygdala

Question 15

liss. Classical LIS vs cobblestone

Answer 15

Too few neurons reach cortex –> 2-4 layer cortex –> abnl longitudinal band of thick grey matter deep to cerebral cortex separated by thin white matter. loss of fxn mutation in LIS1, DCX, TUBA1A encoding cytoskel microtubules –> abnl neuronal migration vs mutation in POMT1/2, FKPR encoding glycosyltransferases for glycosylation –> hypoglycosylation of dystroglycan –> disrupt glia limitans under pia mater –> neuronal overmigration –> dec sulcation –> bumpy/pebbly cortical surface

Question 16

polymicrogyria. bil sylvian PMG sxs

Answer 16

excess small and partly fused 2-3mm gyri separated by shallow sulci; either unlayered for 4 layered, thick 8-12mm cortex. developmental delay, mild spastic quadriparesis, impaired language development, epilepsy

Question 17

neuronal heterotropia. periventricular nodular heterotropia vs subcortical laminar heterotropia

Answer 17

grey matter in abnl locations d/t failed radial migration. Loss of fxn X-linked dom mutation in FLNA at Xq28 encoding filamin A crosslinking actin to cell membrane for mig –> interrupted radial migration –> sz, mild intellectual disability vs X-linked dom mutation in DCX at Xq23 for doublecortin for cytoskel microtubules for migration –> developmental delay, spastic quadriparesis, sz, fine motor deficits

Question 18

focal cortical dysplasia

Answer 18

Germline or somatic mutations in genes regulating PI3K/Akt/mTOR pathway –> loss of horizontal lamination of cerebral cortex –> epilepsy

Question 19

congenital vs acquired aqueduct stenosis

Answer 19

X-linked mutation in L1CAM on Xq28 encoding L1 cell adhesion molec for neuronal migration –> hydrocephalus, AS stenosis, ventriculomegaly, mental retard, spastic paraplegia (absence of corticospinal tracts), adducted thumbs vs intraut infxn, perinatal intraventricular hemorrhage d/t prematurity

Question 20

cerebellar malformations: cerebellar agen vs cerebellar hypoplasia vs Dandy Walker vs Joubert

Answer 20

brains develops w/o cerebellum but sm remnants remain –> poor movement, clumsy, intellectual & emotional problems vs dec cerebellar w/ small but nml shaped vermis, folia, fissures –> ataxia, dec muscle tone/hypotonia, developmental or language delay, nystagmus vs cystic dil of 4th v –> hydrocephalus, macrocephaly, irritability, emesis, developmental delay, hypotonia, bal & coordination vs auto rec mutation in AHI1 encoding jouberin in basal bodies of primary cilia –> block forming primary cilia –> hypoplasia of vermis –> episodic tachypnea and/or apnea, hypotonia, delay in motor, ataxia, oculomotor apraxia, nystagmus, intellectual disability

Question 21

Chiari 1 vs 2 vs 3

Answer 21

caudally placed tonsils + sm occ bone & post cranial fossa –> impacted vs inf brainstem displacement + myelomeningocele vs inf brainstem displacement + occ encephalocele

Question 22

spinal cord malformations: syringomyelia vs syringobulbar vs hydromyelia

Answer 22

CSF-filled gliosis-lined tubular cavitation of spinal cord; congenital = Chiari 1, tethered cord; acquired = hydrocephalus, meningitis, MS, post trauma, spinal cord tumors vs syrinx w/in brainstem that’s not lined by ependymal cells but lined by CSF; asx but if destroys spinothalamic tracts –> loss pain & temp; or destroys dorsal column –> loss fine touch, vibration, proprio; or destroys pyramidal tracts –> spastic paraparesis of UE or LE vs you know this

Question 23

Cerebral edema: gross vs micro appearance

Answer 23

inc fluid in brain –> enlarged brain, wide/flat gyri, narrow sulci, compressed ventricles; micro enlarged perivascular/neuronal spaces —> intracranial pressure –> brainstem herniation, HA, emesis, altered state of consciousness

Question 24

cytotox vs vasogenic edema

Answer 24

neural/glial cell injury –> early phase of anoxia/ischemia –> loss ATP –> inhibit Na/K ATPase, GluE also binds to neuronal & astrocyte receptors –> Na+, Cl-, H2O enter cells –> CNS cells swell –> intracellular fluid accumulation vs influx of fluid & blood solutes into brain –> dmg tight jxns & basement membrane by proteases & free radicals –> endothelial “permeability pores” –> incompetent BBB; MRI shows affecting white matter only

Question 25

what's inc ICP and caused by?

Answer 25

>/= 20mmHg pressure inside skull, brain tissue, CSF caused by intracranial mass; cerebral edema from acute ischemia/ischemic stroke/hepatic encephalopathy/traumatic brain injury; hydrocephalus; obstruct venous flow; idiopathic

Question 26

clinical pres of ICP (5)

Answer 26

o HA, N/V o Vision probs from papilledema (axon flow impeded by inc pressure around optic nerve) o Abnl posturing (decerebrate/corticate) o Impaired consciousness from pressure on midbrain reticular formation o Cushing reflex (late sign of ICP, warning sign of brain herniation)

Question 27

what if ICP > cerebral arterial perfusion?

Answer 27

no cerebral perfusion --> destroyed axons in periventricular pyramidal tracts & CC --> brain death

Question 28

ICP: subfalcine vs transtentorial vs tonsillar vs extracranial

Answer 28

Mass in frontal/parietal/temp lobe --> pushes ipsi cingulate gyrus under falx cerebri --> focal necrosis of cingulate gyrus; compressed CC/contralat cingulate gyrus/A2 pericallosal a --> contralat LE wk, abulia, dec verbal fluency vs uncal: uncus moves below tentorial notch --> midbrain & contralat cerebral peduncle against Kernohan notch --> oculomotor paresis, loss of consciousness, hemiparesis. central: thal & both temp lobes herniate thru tentorial notch --> compressed reticular activating system --> coma; Duret hemorrhage of basilar a vs tonsils herniate thru foramen magnum into cervical cord --> fora mag compromises resp/circ centers --> stiff neck, head tilt, resp/cardiac depression vs Comminuted skull fx --> swollen brain tissue herniating thru surgical defect/lacerated dura --> mushroom cap --> venous infarct

Question 29

what causes hydrocephalus?

Answer 29

CSF obstructed flow (obstructive/noncommunicating), inadeq CSF absorption, CSF overprod (nonobstructive/communicating) --> dil ventricles, inc ICP

Question 30

* CSF prod * CSF circ * CSF absorption * CSF pressure

Answer 30

-by choroid plexus in ependyma lining of ventricles (mostly lat ventricles) -ventricular system -into cerebral venous system by arach gran adjacent to sup sag sinus via pressure-dependent grad -7-13mmHg when pt on side, 15-22mmHg when pt sitting

Question 31

how does inadeq CSF absorption vs CSF overprod cause hydrocephalus?

Answer 31

o Immature arach gran/villi --> can’t absorb CSF continuously o Inflamm/scar of arach villi, meningitis, subarach hemorrhage --> clog CSF reabsorption o High venous pressure sinus --> impair CSF translocation to venous circ vs from choroid plexus papilloma

Question 32

congenital vs acquired hydrocephalus

Answer 32

o Aqueduct stenosis: X linked mutation in L1CAM encoding L1 cell adhesion molec o Chiari II o Dandy Walker --> atresia of apertures o Arachnoid cysts: meningeal maldevelopment --> split arachnoid membrane --> intraarach sacs filled w/ CSF --> Asx unless too big --> mass effect o CSF overexcretion --> choroid plexus papilloma/carcinoma --> communicating hydrocephalus o Intraut infxns vs o meningitis --> obstructed CSF flow in Syl or 4th --> block subarach spaces --> impede CSF absorption o Traumatic brain injury: posttraumatic intraventricular hemorrhage, subdural hematoma --> block CSF flow at Syl, 4th; or obliterated arach gran d/t inflamm or RBCs --> hemorrhage in subarach space or ventricular system

Question 33

clinical pres of hydrocephalus in infants vs older kids/adults

Answer 33

sutures haven’t closed; CSF accumulation --> enlarged head, ant fotanelle bulge, splay cranial sutures, Setting Sun eyes vs no enlarged head; inc ICP --> HA, N/V, drowsy, sunsetting eyes; blurred vision from papilledema & optic n atrophy; unsteady gait, dementia

Question 34

hydrocephalus ex vacuo vs benign external hydrocephalus

Answer 34

Alzheimer’s --> degen brain vol loss --> compensatory enlarged ventricles & subarach spaces; nml ICP vs infants w/ inc head circumference + enlarged subarach spaces or ventricles --> immature arach gran/villi --> can’t absorb CSF continuously

Question 35

nml pressure hydrocephalus. how to dx?

Answer 35

nml LP but enlarged ventricles o Form of communicating hydrocephalus caused by intraventricular hemorrhage, subarach hemorrhage, meningitis o Triad: gait disturbance, dementia, urin incont o MRI: ventriculomegaly w/ maintained cerebral parenchyma - o Imging: US for infants if ant fontanelle = open  mono/bi/tri/panventricular hydrocephalus o LP: assess CSF pressure & presence of biochemical abnlities but risk cerebral herniation

Question 36

mild vs mod vs severe traumatic brain injury sxs

Answer 36

* Mild = loss of consciousness <1hr or amnesia <24h; GCS 13-15 * Moderate = loss of consciousness 1-24h or amnesia 1-7d; GCS 9-12 * Severe = loss of consciousness >24h or amnesia >1wk; GCS 3-8

Question 37

linear vs depressed vs basilar vs ring skull fx

Answer 37

single fx going thru entire calvarium --> little to no clinical sxs unless going thru middle meningeal groove or venous sinus --> epidural hematoma or venous thrombosis vs part of skull = displaced below adjacent skull --> dmg brain parenchyma --> CNS infxn, sz, death vs linear fx at base of skull w/ dural tear --> retroauricular or mastoid ecchymosis/Battle sign; periorbital ecchymosis/raccoon eyes; CSF leaks like clear rhinorrhea/otorrhea; hemotympanum vs fall --> cervical spine move up to foramen magnum & occ bone --> basilar fx of skull --> fatal

Question 38

cerebral concussion vs contusion

Answer 38

direct blow to head --> quick rotational accel to brainstem --> temporary paralysis of brainstem reticular formation neurons --> GCS 13-15; transient loss of consciousness <30min; amnesia; HA, N/V confusion, dizzy vs mechanical force dmg blood vessels, neurons, glial cells of brain parenchyma --> bruise brain

Question 39

mild vs mod vs greater contusion locations

Answer 39

* Mild force = outer layer cortex & gyri crests * Moderate force = large areas of cortex, confluent hemorrhagic lesion in subcortical white matter & subarach space * Greater force = tear cortex --> intraparenchymal hemorrhage; bruised necrotic tissue phag by macs; astrocytosis --> scar

Question 40

cerebral contusion clinical pres (know the lobe). CT?

Answer 40

o Unconscious for few min or longer, drowsy, vomit, sz, impaired bal o Ant temp lobe --> delirium; orbitofrontal --> disinhibited behavior, impulsiveness; med temp lobe --> mem loss; convexity --> focal defects (aphasia, hemiparesis). patchy hyperdense hemorrhagic foci w/ hypodense edema (salt & pepper)

Question 41

diffuse axonal injury

Answer 41

unrestricted head movement from injury --> rotation accel or brain shaking --> shear effect --> stop fast axonal flow --> mito & vesicles build up --> dmg axons --> coma, veg state, contusion, lesion

Question 42

Axonal varicosities vs Axonal swellings

Answer 42

* Axonal varicosities = axonal elongation w/ rupture; enlargements then shrunken areas * Axonal swellings = round/elliptical eos masses * Both found via immunostain w/ ab to beta-amyloid precursor protein

Question 43

Chronic traumatic encephalopathy. gross vs micro?

Answer 43

degen dz d/t rpt concussions & traumatic brain injury --> bal, Parkinson’s sxs, behavior/mood changes, mem loss. Reduced brain wt, enlarged ventricles, front & temp lobe atrophy v Neuronal loss & gliosis in hippo, sub nigra, cerebral cortex, accumulation of phosphorylated tau protein; neurofibrillary tangles in layers 2/3

Question 44

sxs of epidural hematoma. characteristics of acute vs subacute vs chronic subdural hematoma

Answer 44

initial unconsciousness, transient complete recovery --> neuro deterioration (N/V, contralat hemiparesis, brady, arterial HTN, apnea, death. 3d, fresh & jelly clot, loss of consciousness vs 3-21d, blood clot & fluid d/t fibrinolysis, altered mental state/hemiparesis vs >21d, fluid, altered mental state/hemiparesis

Question 45

Spinal cord injury caused by? lower thoracic vs cervical vs C1-C4

Answer 45

from vertebral fx/dislocation, tearing lig, disrupt/herniate intervertebral discs. paraplegia vs quadriplegia vs paralyzed diaphragm

Question 46

4 cause mechanisms for spinal cord injury

Answer 46

o Vert fx: impact + compression injury o Neck hyperextension injury: impact + transient compression o Distraction injury: 2 adjacent vertebrae pull apart --> spinal column stretches and tears o Laceration & transection injuries from sharp bone frag, severe dislocation, missile injuries

Question 47

complete cord injury vs incomplete cord injury vs central cord syndrome vs ant cord syndrome vs transient paralysis & spinal shock

Answer 47

spared sensation & motor above not below v various motor fxn below injury, sensation preserved below injury v motor deficits UE > LE, blad & sensory loss below v : dmg to ant spina a by retropulsed disc or bone frag --> spare DCML v loss spinal cord fxn above injury --> flaccid paralysis, anesthesia, blad/bowel incont, loss reflexes

Question 48

hypoxic ischemic encephalopathy vs perinatal stroke vs encephalopathy prematurity

Answer 48

placenta/ut abrupt, prolonged labor w/ transverse arrest, cord prolapse --> dec O2, CO2, lactic acidosis --> nec of neocortex, hippo, thal, basal ganglia; infarcts b/w MCA & PCA --> sz, hypotonia, poor feeding, dec consciousness 7-14d vs lg cyst in R MCA --> meningitis + arteritis or phlebitis, trauma, congenital arterial malformation or heart dz, hypercoag, placental thrombosis --> sz vs in premies <32wks w/ birth wt <1500g; maternal chorioamnionitis, neonatal resp distress syndrome --> perinatal inflamm/infxn, hypoxia-ischemia --> necrosis in white matter w/ loss of cellular elements => periventricular leukomalacia --> sz, weak LE, inc tone in neck extensor muscles, apnea, brady

Question 49

germinal matrix hemorrhage. what is germinal matrix?

Answer 49

no cerebral autoreg --> fluctuation in cerebral blood flow --> vessels rupture --> hemorrhage b/w thal & caudate --> ruptures into ventricles --> subarach hemorrhage --> sz, resp depression, apnea, abnl posturing, bulging fontanelles. layer of primitive neuroectodermal cells under ependyma b/w thal & caudate --> migrate & melt away by wk36-37

Question 50

origin sites of CNS primary tumors. 4 major types of tumors?

Answer 50

brain, spinal cord, meninges. gliomas, neuronal tumors, meningiomas, embryonal tumors

Question 51

most common brain tumors in adults vs children

Answer 51

gliomas, meningiomas vs embryonal tumors/medullobastoma, high grade glioma, pilocytic astrocytoma

Question 52

where can gliomas arise from?

Answer 52

multipotent progen --> astrocytes, oligodendrocytes, ependymal cells

Question 53

describe astrocytes

Answer 53

multipolar, star like cells w/ eos cyto; has glial fibrillary acidic protein for cytoskel

Question 54

astrocytomas: diffuse astrocytic tumors

Answer 54

invades subcortical white matter & can progress into higher grades: diffuse astrocytoma II (inc cell density) anaplastic astrocytoma III (inc cells density + nuclear pleomorphism & atypia), glioblastoma IV (anaplastic + necrosis, glomeruloid microvasc prolif)

Question 55

clincal pres of diffuse astrocytic tumors?

Answer 55

dull constant HA, sz, muscle wk/vision/lang deficit, personality change; mass effect, edema if big enough

Question 56

genetic causes for diffuse astrocytic tumors

Answer 56

hetero point mutation in IDH1>2 --> can't turn isocit to alpha ketoglutarate --> makes 2-HG --> inc expression of ca genes. ATTR mutation --> mutation in TP53 gene --> no reg in transcpxn. TERT promoter mutation --> cell prolif by oncogenes

Question 57

astrocytomas: circumscribed astrocytic tumors

Answer 57

don't invade brain; pilocytic astrocytoma, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma

Question 58

pilocytic astrocytoma

Answer 58

cerebell > optic n/chiasm > hypothal. biphasic appearance of compact pilocytic w/ microcystic areas; dense piloid astrocytes w/ long bipolar processes; thick long eos rosenthal fibers; eso granular bodies

Question 59

clinical pres of pilocytic astrocytoma. genetic causes?

Answer 59

depends on location: HA, N/V, ataxia > bad vision. BRAF mutation (fusion gene) --> activate Ras --> activate MEK then ERK --> MAPK; or val to glu point mutation --> activate MEK w/o Ras. both lead to prolif & tumorigenesis

Question 60

how to dx astrocytic tumors?

Answer 60

GFAP stain: stronger in circumscribed but dec w/ higher tumor grade --> anaplastic & glioblastomas = neg GFAP

Question 61

oligodendroglioma II vs anaplastic oligodendroglioma III

Answer 61

hyperchromatic nuclei/fine chromatin pattern w/ small nucleoli; perinuclear haloes; in sheets & lobular groups surrounded by vasc like "chicken wire". GFAP neg vs more cellular & nuclear pleomorphism and atypia, more mitotic activity & vasc prolif

Question 62

clinical pres of oligodendrogliomas. genetic cause?

Answer 62

sz, HA. IDH1>2 mutation + whole arm chrm del of 1p & 19q

Question 63

ependymomas

Answer 63

glial tumors from ependymal cells in ventricles & central canal; also from fetal ependymal cell crest mig from periventricular areas

Question 64

classic ependymomas II

Answer 64

circumscribed. true ependymal rosettes = elongated tubules lined by ependymal cells around empty lumen like ependymal canals; perivascular pseudorosette = spoke wheel of ependymal cells w/ central processes around blood vessel

Question 65

classic ependymomas II: subependymoma vs myxopapillary ependymoma

Answer 65

slow growing pearly white nodules on wall of lat/4th ventricle --> can cause hydrocephalus vs slow growing cuboid cells surrounding basophilic mucus in con med, cauda equina, filum terminale

Question 66

anaplastic ependymoma

Answer 66

hypercellular, cellular & nuclear pleomorphism, freq mitosis, necrosis; perivascular rosettes

Question 67

clinical pres of ependymoma. genetic cause?

Answer 67

depends on location. in ventricle --> HA, N/V, ataxia, papilledema, vertigo; in spinal cord --> back pain, paraparesis. hypermethylation in CpG-rich promoters --> in post fossa; fusion of RELA & C11orf95 --> supratentorial; NF2 somatic mutation --> intramedullary spinal

Question 68

choroid plexus papilloma I vs choroid plexus carcinoma III

Answer 68

circumscribed pink cauliflowers from ventricle; cuboid cells w/ fibrovasc stalk in finger like projections vs lobulated cystic & necrotic areas w/ loss of papillary architecture; hypercellular, pleomorphic, inc mitosis, necrosis

Question 69

clinical pres of choroid plexus tumors

Answer 69

nonspecifc & depends on location. hydrocephalus & ICP

Question 70

gangliocytoma I. clinical pres? tx?

Answer 70

benign & slow growing, GFAP neg tumors in supratentorial, frontal, temp lobes. depends on locaton; sz, ICP, focal sxs. surgical removal

Question 71

gangliogliomas I. genetic cause? clinical pres?

Answer 71

mix of lg dysplastic multipolar neurons + lg/sm dysplastic glial cells in temp > front > occ > par; GFAP & chromogranin A pos. BRAF activating mutation. chronic intractable epi

Question 72

dysembryoplastic neuroepithelial tumor I

Answer 72

mixed neuronal-glial tumor in cortical grey matter in temp > front/par-occ; Alcian blue pos mucin

Question 73

embryonal tumors

Answer 73

high mal/undifferentiated tumors of neuroepithelial origin in peds; most common = medulloblastoma

Question 74

medulloblastoma IV. how to tx?

Answer 74

soft pink/gray tumors w/ hemorrhage & nec in vermis > cere hemi; hypercellular, basophilic hyperchromatic nuclei, little cyto, mitosis. radiosensitive --> multi modality therapy

Question 75

3 variants of medulloblastoma IV: classic vs desmoplastic nodular vs lg cell/anaplastic variant

Answer 75

small round blue cells w/ mito & apop, Homer Wright rosettes vs pale nodules, reticulin-rich undifferentiated cells w/ hyperchromatic & mild pleomorphic nuclei vs lg anaplastic cells w/ hyperchromatic nuclei, prominent nucleoli, brisk mito, apop, nec

Question 76

4 genetic causes of medulloblastoma IV

Answer 76

overactive sonic hedgehog pathway; upreg of Wnt pathway; amp MYC protooncogene; amp MYCN & CDK6 protooncogene

Question 77

what are lymphomas? primary vs secondary?

Answer 77

neoplasms from lymph nodes or lymphocytes. originate from CNS (brain, spinal cord, leptomeninges, eye) vs from systemic lymph nodes

Question 78

primary CNS lymphoma. risk factor? clinical pres? tx?

Answer 78

subcortical white matter in front lobe, periventricular white matter, cerebellum, basal ganglia; most from B cells w/ hemorrhage & nec. immunodefic. HA, focal neuro deficits, behavior changes. chemo then whole brain radiotherapy

Question 79

meningioma

Answer 79

benign from meningothelial cells of arachnoid attached to inner surface of dura --> intracranial but extraaxial neoplasms. in convexity & parasagittal regions of brain; tent cerebelli, sphenoid wings, olf groove, tuberculum sellae

Question 80

risk factors of meningioma: genetics vs radiotherapy

Answer 80

NF2 mutation --> abnl merlin in actin-cytoskel organization --> abnl tumor suppressor protein --> auto dom d/o leading to mult neoplasm; TRAF7 mutation --> E3 --> MAPK --> NFkB --> tumor at skull base; chrm losses vs from tx of other brain tumors

Question 81

key features of meningioma

Answer 81

yellow/tan globular rubbery tumor w/ whorls, concentric lamellated calcified psammoma bodies, intranuclear pseudoinclusions (target-like nuclei w/ central clearing & periph chromatin margination)

Question 82

4 variants of meningiomas: meningothelial vs fibroblastic vs transitional vs psammomatous meningiomas

Answer 82

epith cells w/ indistinct cell borders --> syncytial appearance surrounded by collagen or fibrous septa vs spindle shaped cells in parallel bundles w/ collagen & reticulin vs mixed meningothelial & fibroblastic features vs excess whorls w/ psammoma bodies in centers

Question 83

meningioma I vs II vs III

Answer 83

benign tumors w/ any 4 variants & no anaplastic vs atypical growths w/ inc cellularity & prominent nucleoli --> surgery and/or radiation vs malig de novo or from lower grade meningiomas --> invade brain, inc mito & nec

Question 84

clinical pres of meningioma (7)

Answer 84

depends on location: convex --> HA, sz, motor/sensory deficits; parasagittal --> mem & behavior change; middle --> wk legs, urin incont; posterior --> homonymous hemianopsia; parasellar & orbital --> vision; cerebellopontine angle --> hearing; spinal --> cord compression

Question 85

imging vs tx for meningioma

Answer 85

CT/MRI showing calcification + prominent vasc; dural tail sign to show it's really extraaxial vs surgery resection, rad if can't do resection; II/III do resection but incomplete --> adjuvant external beam rad + stereotactic radiosurg

Question 86

metastatic brain tumors

Answer 86

more common than primary CNS tumors. from pulm > br > skin melanoma > GI > renal via hematogenous route --> HA, sz, focal neuro sxs, ataxia

Question 87

most common sites for brain metastasis generally vs in cerebrum. meningeal carcinomatosis

Answer 87

cerebrum > cerebellum > brainstem; usually at GW jxn vs front > par > temp > occ. when metastasis infiltrate meninges --> subarach, ventricles --> CSF

Question 88

paraneoplastic neurologic syndromes

Answer 88

autoimmune affect any part of nervous system not caused by metastasis; from sm cell lung ca, lymphoma or mal myeloma

Question 89

paraneoplastic cerebellar degen w/ ab

Answer 89

loss Purkinje; from sm cell lung ca (anti Hu), ov/ endomett/br ca (anti Yo), Hodgkin lymphoma (anti Tr)--> gait ataxia, truncal & limb ataxia, dysarthria/phagia, nystagmus

Question 90

paraneoplastic limbic encephalitis w/ ab

Answer 90

involve limbic system --> behavior change, short term mem, complex-partial sz, cog dysfxn; from sm cell lung ca (anti Hu), testes ca (anti Ta), br ca, Hodgkin lymphoma, thymoma (CV2/CRMP5)

Question 91

Paraneoplastic opsoclonus-myoclonus with ab

Answer 91

chaotic syncrhonus eye movments, spont muscle jerks, ataxia; from sm cell lung ca, br/gyn ca, neuroblastoma in kids; sometimes w/ encephalitis in cerebell or brainstem; anti Ri for br/gyn ca against Nova proteins for reg synaptic proteins