CNS 2,3,4

Question 1

• Neurosyphilis:

Answer 1

o Treponema pallidum invades CNS, 20% 3rd infx
o progressive ↓ mental and physical fxn, life-threaten
o micro: Silver stain, spirochete
o 4 types: asx neuro, meningovascular, paretic, tabes dorsalis
o asx neuro: precedes sx syphilis, 15% w latent (hidden) syphilis

Question 2

• Meningovascular neurosyphilis:

Answer 2

o perivascular inflam in brain
o mc stroke-like in young adult
o usu middle cerebral a or branches of basilar a
o brain base → CN palsies
o encephalitic Prodrome: HA, vertigo, psych abn (ie personality change, emotional lability, insomnia, ↓memory)

Question 3

• Paretic syphilis:

Answer 3

o progressive meningoencephalitis → ongoing loss of cortical fxn
o 20-30 years after initial exposure
o widespread parenchymal invasion
o → chronic perivascular, meningeal inflame, meningeal fibrosis
o → individual brain cell death, brain atrophy

Question 4

• Paretic syphilis ssx:

Answer 4

o Personality change (cog, behavior impair) 33%
o Ataxia 28%, Stroke 23%
o Ophthalmic sxs (ie blurred vision, ↓color perception, ↓acuity, photophobia) 17%
o Urinary sxs (eg incontinence) 17%
o HA 10%, Dizzy 10%, HL 10%, Sz 7%

Question 5

• Tabes dorsalis neurosyphilis:

Answer 5

o damage to sensory nerve dorsal roots
o slowly progressive degeneration of posterior columns (demyelination) and posterior roots (inflam, fibrosis) of spinal cord
o ssx: ataxia, ↓pain sensation , proprioception bladder incontinence, loss DTRs

Question 6

• neurosyphilis gumma:

Answer 6

o meningeal granulomas, well-circumscribed, dt immune response to Treponema (3rd)
o soft, non-cancerous
o anywhere in brain, spinal cord (usu dura), wide variety neuro deficits
o mc liver (gumma hepatis)
o heart, skin, bone, testis, etc

Question 7

• Jarisch-Herxheimer reaction:

Answer 7

o Several hrs after tx early stage syphilis
o Ssx: Fever, chills, HA, N, arthralgias, myalgias
o Usu disappear in 24 hrs

Question 8

• Progressive multifocal leukoencephalopathy (PML):

Answer 8

o Dt JC virus, a polyomavirus (papovavirus)
o rare demyelinating dz, progressive, loss of oligodendrocytes
o ssx: memory loss, loss of coordination, mentation problems, vision problems, eventual vegetative state
o gross: irregular areas of granularity in white matter

Question 9

• Subacute sclerosing panencephalitis (SSPE):

Answer 9

o rare (dt vaccine) complication of measles (rubeola), 1-20+ yrs later
o measles usu ↓2 yo → dormant
o reactivated → gradual, progressive neuro deterioration
o white matter of cortex in both hemispheres and brainstem
o personality changes, szs, ataxia, photosensitivity, spasticity, coma
o death usu in 3yrs

Question 10

• SSPE path, micro, dx:

Answer 10

o Path: virus defective, no M protein, don’t “bud,” cell fusion to spread thru nervous system
o widespread perivascular cuffing, neuronal loss, patchy demyelinization, white matter hemorrhage, gliosis
o Micro: Eosinophilic inclusion bodies in nuclei/cyto of neurons and glia
o EM: inclusions look like measles nucleocapsids, stain w fluorescent anti-Rubeola
o Dx: diff, normal CSF profile
o But, CSF: ↑ Rubeola IgG Ab

Question 11

• Poliomyelitis

Answer 11

o Poliovirus = RNA virus
o via oral-fecal route or ingest contaminated water
o replicate in nasopharynx, GI, invade lymphoid tissues → blood (viremia)
o inc 5-35 d → neurotropic
o destruction of motor neurons in anterior horn and brainstem
o → flaccid paralysis, atrophy, hyporeflexia of affected mm

Question 12

• Post-polio syndrome:

Answer 12

o recover from polio, mb → recurrent bouts mm weakness (usu initially affected)
o mb 20-50 yrs later

Question 13

• rabies, incubation:

Answer 13

o zoonotic dz, via salvia of animals (bite)
o affects all warm blooded wildlife, raccoons (44%), skunks (28.5), bats (12.5), foxes (5.5) & pets (dogs, cats)
o via peripheral nerves from site of bite to brain (1-3 mos)
o ssx usu 30-60 d post-exposure (up to 1 yr w/o vaccine)
o quicker if bite closer to brain, or deeper

Question 14

• rabies ssx:

Answer 14

o w/o vaccine, → flu-like
o severe HA, fever, irritability, painful mm spasm of throat, dilated pupils
o ↑ saliva*
o Sens to sound, light, temp change
o *Fear of water (hydrophobia)
o Violent, uncoordinated movements
o If survive past 5-7 d, usu ↑ skeletal muscle paralysis
o alt mental status from anxiety, severe irritability, confusion, finally stupor, coma
o Death from cardiac or resp failure usu in 1 wk sxs

Question 15

• Rabies micro, dx:

Answer 15

o Micro: Round or oval shaped inclusion bodies, Negri bodies, in brain. Temporal lobe neurons and cerebellar Purkinje cells common sites
o Dx: st w PCR on saliva, urine, CSF
o PCR or viral culture on brain after death
o Negri bodies 100% dx, only 20% cases

Question 16

• AIDS dementia complex (ADC), ssx:

Answer 16

o Freq ↑ w adv dz, ↓CD4+ cell ct
o LC early HIV dz, mc immune-compromised, adv ssx
o early: Diff concentrate, ↓ memory, Irritability, ↓balance, gait, ↓hand coordination, handwriting, Depression
o later: Slowness (eating, writing), Diff speak, mm weak (drop things)
o adv: Lose bladder, bowel control, Spastic gait, diff walk, Psychosis, mania, Apathy, bed-ridden

Question 17

• ADC path, image:

Answer 17

o Unk mechanism
o First targets CNS M0s
o HIV-infx M0s carry HIV into brain from blood
o → infx brain M0s (prevalent)
o M0 release toxic substances to brain (in excess)
o quinolinic acid, cytokines, etc bind nerve cells → dysfxn, death
o M0 can shed part of ingested HIV outer coat (gp120), damage nerve cells
o MRI: cortical atrophy, marked ventricular enlargement

Question 18

• Reye’s syndrome:

Answer 18

o Assoc prior viral infx (flu, colds, varicella), not contagious
o Assoc aspirin used to tx sxs
o Ssx: fever, V, fatty infiltration of liver, swelling kidneys, brain
o Recovery: complete, mild-severe effects, motor or learning disabilities, profound brain injury

Question 19

• Slow virus dzs:

Answer 19

o Or prions, of CNS
o Ssx: mult neuro, wide array
o Spongiform encephalopathy
o Scrapie in sheep

Question 20

• (transmissible) Spongiform encephalopathy:

Answer 20

o Brain infx w prion, Kuru (New Guinea), CJD (linked to bovine SE, mad cow)
o Spread via eat infx brain
o Incubation mb years
o rapidly progressive dementia, death usu in 1 yr
o gradually destroy brain → full of holes, no immune response
o 250 cases of Iatrogenic CJD
o Dt contaminated human GH, dura mater, corneal grafts, neurosurgical equip

Question 21

• Cerebrovascular disease

Answer 21

o Mc neuro do w ↑ of morbidity and mortality
o 3rd mc cause death in US
o 3 types: Thrombotic, Embolic, Hemorrhagic
o 2 processes:
o 1) Hypoxia, ischemia, infarction
o 2) Hemorrhage

Question 22

• cerebral: ischemia:

Answer 22

o Cell survival depends on: collateral circulation, Duration ischemia, Magnitude & rapidity of ↓flow
o Mb focal or global
o Mb transient or prolonged

Question 23

• Focal vs global cerebral ischemia:

Answer 23

o Focal: local, usu dt embolus or thrombosis in a large vessel, or vasculitis in medium or small sized vessels, → infarction, well circumscribed necrosis in distribution of artery
o Global: generalized, usu cardiac arrest or severe sustained hypotension; outcome depends on health status of brain before event

Question 24

• Transient and prolonged cerebral ischemia:

Answer 24

o Transient: hypotension → ischemia, mb LOC w/o sequelae, or temp alt mental status (confusion, mins)
o Global: → mild-severe sequelae
o Prolonged: eventually → cell death

Question 25

• Micro and macro cerebral ischemia:

Answer 25

o Micro: don’t stain well w vital stains, H&E (dead cells)
o Macro: brain edema, swollen gyri, narrow sulci
o cut surface shows poor demarcation bw gray and white matter
o Global hypoxia: border zone infarcts, border of areas of anterior and middle cerebral arteries
o laminar necrosis, at short, penetrating vessels

Question 26

• Cerebral infarction:

Answer 26

o aka stroke, sudden loss of circulation to brain → loss neuro fxn (by area)
o 3rd mc cause death, #1 cause major disability in US
o 50% all stroke deaths in first 48 hrs
o Usu dt thrombosis, embolism, or hemorrhage → inflame → cell damage, death
o Risk factors: →age, HTN, DM, ↑cholesterol, tobacco, A-fib, African-American
o 2 types: ischemic and hemorrhagic

Question 27

• Ischemic vs hemorrhagic stroke:

Answer 27

o	Hem: dt intracerebral, subarachnoid, subdural, or epidural hemorrhage; ↑morbidity and mortality (40-80% 30d mortality rate)
o	Isch (80%): dt thrombosis, embolus, or systemic hypoperfusion

Question 28

• Ssx stroke:

Answer 28

o Similar ssx, but hem: N/V, HA, change LOC
o abrupt onset monoparesis, hemiparesis, or quadriparesis
o U/BL ↓vision, diplopia, dysarthria, ataxia, vertigo, aphasia
o sudden change LOC (also include stroke in ddx of acute neuro deficit)
o usu mult sxs

Question 29

• non/dominant hemisphere stroke:

Answer 29

o dom usu L: classic syndrome, R hemiparesis, R hemisensory loss, L gaze preference, R visual field cut, aphasia
o non usu R: opposite (not aphasia?), L-sided inattention or neglect (completely ignore L side body)

Question 30

• Cerebral infarction event, timeframe:

Answer 30

o Important to establish timeframe, for tx
o US: usu 4-24 hrs from sx onet to ER
o Factors in delay: many asleep, too incapacitated to call for help
o St unrecognized by pt, family, etc

Question 31

• Stroke histo, chronological:

Answer 31

o 12-24 hrs: neurons vacuolated, cyto eosinophilia (red), edema, blurred grey-white jxn
o 24 hrs: neutrophil infiltration begins at edges, where vascular supply intact
o 1-14 d: necrosis, ↑M0s, Ns and reactive gliosis
o 2 wks: scar (dense fibrous network of neuroglia)

Question 32

• Gliosis:

Answer 32

o In response to CNS damage, No fibrosis, dt fibroblasts in brain only near vessels
o Instead, gliosis= reactive proliferation and hypertrophy of astrocytes, microglia, oligodendrocytes
o in many CNS dzs, inhib axonal regeneration both beneficial and detrimental effects
o many inhibs secrete, prevent complete recovery of CNS
o but no glial scar assoc w ↓repair of BBB

Question 33

• Gliosis process:

Answer 33

o Extreme → glial scar Series of events over several days:
o In hrs: ↑M0s, microglia (microgliosis)
o 3-5 d: oligodendrocyte precursors →remyelination
o 2 wks: Finally astrogliosis, main constituents of glial scar

Question 34

• Micro/macro stroke:

Answer 34

o Macro: edema, narrow sulci, wide gyri, unclear Demarcation bw white and grey matter
o neurons die, disappear → gliosis
o micro: edema (pale, acellular)
o N infiltration, w vacuolar changes
o M0s, clear lipid debris from liquefactive necrosis → cystic space

Question 35

• Red neurons:

Answer 35

o	Neurons are most sensitive of all cell types to anoxic injury
o	Red (eosinophilia) = dying neurons dt sustained hypoxia

Question 36

• Ischemic stroke:

Answer 36

o Atherosclerosis mc cause thrombotic, mc at carotid bifurcation or vertebrobasilar
o Usu vessel most affected is middle cerebral a
o Complete occlusion → fleeting, transient neuro sxs (TIAs)

Question 37

• TIAs:

Answer 37

o = “mini” or “brief” stroke
o Neuro sxs resolve in 24 hrs
o mb clinical markers for ↑ risk subsequent cerebral infarction
o 10-15% another stroke in 1 yr (half of that risk in 1st mo, esp 1st 48 hrs)
o ↓ risk: aspirin, etc to inhibit platelets from clotting
o But may also ↑ risk and effects of hemorrhagic stroke

Question 38

• embolic Ischemic stroke, etio, gross:

Answer 38

o rapid onset
o Atherosclerotic plaques in coronary circulation, ascending aorta or carotid → cerebral emboli
o Valvular vegetations in SBE and thrombi in auricular appendages, assoc A-fib, can embolize to brain
o Occlude smaller intracranial arteries → infarcts in only part of distribution of major cerebral a
o emboli may reach mult vessels → mult small infarctions
o gross: punctate hemorrhages

Question 39

• Hemorrhagic stroke:

Answer 39

o Etio: intracerebral, subarachnoid, subdural, or epidural hemorrhage
o Intracerebral: 10-15% all strokes
o ↑mortality than ischemic, more acute sxs (but similar)
o intracerebral bleed: severe HA, alt mental status, ss, N/V, ↑ HTN (mc underlying cause)
o but sxs can’t reliably ddx from ischemic

Question 40

• complications of hemorrhagic stroke, px:

Answer 40

o ↑ ICP and herniation are most dreaded
o Early hemorrhage assoc neuro deterioration
o Mb Post-stroke szs
o Px: depends severity of stroke, size and location of hemorrhage, other medical problems

Question 41

• anticoagulants w hemorrhagic stroke, imaging (vs non-hem):

Answer 41

o anticoagulated pts mb massive hemorrhage into infarction
o → CT scan immediately (even though edema not seen until 10-12 hrs)
o if none, can start anticoagulation tx w/o Cis
o hem: intracerebral may → midline shift
o non: also mb midline shift

Question 42

• Cerebellar and brainstem stokes:

Answer 42

o Usu dt pathology in vertebral or basilar arteries
o edema in cerebellum or brainstem → ↑risk brainstem herniation and compression
o Herniation → rapid ↓LOC, apnea, death
o Ssx: Gait or limb ataxia, Vertigo or tinnitus, N/V, Hemiparesis or quadriparesis
o Abn Eye movt → diplopia or nystagmus
o Oropharyngeal weakness or dysphagia

Question 43

• Berry aneurysm

Answer 43

o Aka saccular
o = thin wall out-pouching in circle of Willis
o few mm to 2-3 cm (↑ size ↑ risk rupture)
o > 10 mm, 50% risk bleeding per yr
o etio usu unk

Question 44

• ruptured berry aneurysm:

Answer 44

o mc comp, may occur any time, usu after physical strain
o mc cause clinically signifigant SAH
o Blood under pressure empties into subarachnoid space
o Vasospasm after bleed → additional ischemic injury
o Mc sx: sudden onset excruciating HA, immediate LOC
o Mortality 25-50% after initial rupture
o Rebleeding common

Question 45

• Mc locations of berry aneurysms:

Answer 45

o 40%: just posterior to anterior communicating a
o 34%: just lateral to split of middle cerebral a
o 20%: just anterior to posterior communicating a
o 4%: jxn of L&R posterior communicating a

Question 46

• Vascular malformations of brain:

Answer 46

o 4 groups: AVMs, cavernous angiomas, capillary telangiectasias, venous angiomas
o AVM mc type of clinically significant

Question 47

• AVMs:

Answer 47

o Dx 10-30, presents as sz do, intracerebral hemorrhage, or SAH
o Mc middle cerebral artery, esp posterior branches
o or anywhere along midbrain, cerebellum, spinal cord
o mb small or large
o if hemorrhage, usu ↓blood loss, unlike HTN hem (stroke)
o ↓ neuro fxn depends on location and amount of bleeding
o involve vessels in subarachnoid space extending into brain parenchyma or exclusively in brain
o macro: tangled vascular channels; prominent, pulsatile AV shunt, ↑blood flow thru malformation

Question 48

• Acute hypertensive encephalopathy:

Answer 48

o HTN → cerebral dysfxn: HA, confusion (MS), V, convulsions (sz), coma
o Need tx to ↓ICP, does not remit spontaneously
o Autopsy: edema brain, mb transtentorial or tonsillar herniation
o Micro: Petechiae, fibrinoid necrosis of arterioles in gray and white matter
o Lesions usu in posterior lobes, st frontal
o Also seen in: malig HTN, preeclampsia/eclampsia, CRF, HUS, SLE, Cyclosporine toxicity
o CT: Symmetrical translucent lesions, BL posterior parietal-occipital sub-cortical white matter

Question 49

• CNS trauma

Answer 49

o Depends on location, limited capacity of brain to repair itself
o Ex: skull fractures, parenchymal, vascular injury
o Mb Severe brain damage w/o signs external injury, or converse
o blow to head mb penetrating or blunt → open or closed injury
o depends on shape of object, force of impact, if head in motion

Question 50

• Concussion:

Answer 50

o Mb physiological or physical disruption in brain’s synapses
o Exact path unk: depolarization dt excitatory amino acid movt across cell membranes, ↓ ATP, alt vascular permeability
o instant onset transient neuro dysfxn: LOC, temporary respiratory arrest, loss reflexes
o usu full neuro recovery, st amnesia for actual event

Question 51

• aniscoria

Answer 51

o Unequal pupil size mb sign brain injury

o more serious than concussion

Question 52

• laceration and Contusion (2 types)

Answer 52

o Both assoc direct parenchymal injury of brain
o laceration= penetrating injury, tears brain tissue
o contusion= bruising, transmission of force to brain
o coup: cerebral injury at point of contact (a coup injury)
o contrecoup: damage to brain surface diametrically opposite contact, brain strikes opposite inner surface of skull after sudden deceleration

Question 53

• Skull fracture

Answer 53

o If fall while awake, usu occipital part of skull
o Fall dt LOC (syncope), usu frontal impact
o Autopsy of post-concussive syndrome: mb evidence of direct parenchymal injury or not

Question 54

• Types of skull fractures:

Answer 54

o Linear: mc, 69% w severe head injury; skull bends in, rest buckles out
o Diastatic: linear, cause bones of skull to separate at sutures, young children w skull not yet fused
o Comminuted: bone is shattered into many pieces, bits of bone mb driven into brain
o Displaced: skull indents into brain further than its thickness

Question 55

• Basilar/basal skull fracture

Answer 55

o linear, thru petrus part of temporal bone, leak spinal fluid from ear
o mb HL, instability of gait, vertigo
o Battle’s sign = mastoid ecchymosis
o Raccoon’s eyes = BL periorbital ecchymosis

Question 56

• Traumatic vascular injury:

Answer 56

o if fracture lines crosses blood vessel, esp temporal bone
o Vessels in dura, esp middle meningeal a, vulnerable to injury, esp fractures
o Epidural hematoma
o Sub-dural hematoma

Question 57

• Epidural hematoma:

Answer 57

o Dt rupture of a meningeal artery, usu dt skull fracture
o → accum arterial blood bw skull and dura (periosteum lining inner surface of skull)
o → focal biconvex shape, does not cross sutures
o 1-4% all head trauma, 10% w traumatic coma
o Classic (↓20%): lucid interval bw initial trauma and subsequent neuro deterioration
o Delayed development or enlargement in 10-30% of all EDHs, usu in 1st 24-48 hrs
o Late hematomas in 20% mod-severe head injuries w/o signs of cerebral contusions on CT

Question 58

• EDH locations:

Answer 58

o 85-95%, either fracture lacerates middle meningeal artery (MMA), or dural venous sinus
o 5-15%, venous “oozing” or MMA tear w/o fracture
o 95% are UL, supratentorial
o Posterior fossa uncommon, but ↑morbidity and mortality

Question 59

• subdural hematoma:

Answer 59

o damage veins bw brain and superior sagittal sinus (stretch, tear bridging cortical veins)
o → accum blood bw dura and arachnoid
o St arachnoid torn → blood and CSF in subdural space
o more extensive than EDHs

Question 60

• SDH appearance:

Answer 60

o look like ‘currant jelly’
o classic: crescent-shaped, homogeneously hyperdense extraaxial collection
o spreads diffusely over affected hemisphere
o 40% have mixed hyper/hypodense areas of non-clotted blood, serum extruded during clot retraction, or CSF in hematoma dt arachnoid laceration

Question 61

• Injuries that cause SDH:

Answer 61

o risk: ↑age, alcoholism, dt changes in vessel resilience
o often dt direct head injuries, or angular acceleration of head such (whiplash or blast injuries)
o 10-20% all head traumas, 30% of fatal injuries
o 5% no hx head injury, esp elerly
o 10-30% chronic SDH show evidence repeat hemorrhage

Question 62

• SDH locations:

Answer 62

o Usu fronto-parietal convexities, middle cranial fossa
o may cross suture lines but not dural attachments
o 85% UL
o Isolated interhemispheric and parafalcine SDHs in non-accidental trauma

Question 63

• Brain death:

Answer 63

o All brain fxn stops, irreversible, including brain stem fxn
o Global cerebral ischemia → neuron death → permanent vegetative state
o Dx criteria: no resp drive, brain perfusion, or reflexes
o Ddx: hypotensive shock, hypothermia (temp >32 C), drug intoxication or neuromuscular blockade causing coma
o Don’t need EEG, CT, MRI to dx (legal definition)

Question 64

• Degenerative diseases of CNS:

Answer 64

o Dementias
o PD
o Demyelinating diseases

Question 65

• Dementia:

Answer 65

o = loss intellectual fxn, interfere w daily functioning
o Ssx: changes in personality, mood, behavior
o ↓ short-term memory w age is normal
o Mc older, but not dt aging
o 1/10 >65 in US

Question 66

• Causes of dementia:

Answer 66

o 2 mc: AD, vascular dementia
o irreversible if dt brain injury or primary do like AD
o reversible if dt infx (meningitis, encephalitis), drugs, alcohol, metabolic/ hormone (hypothyroid)/ vitamin imbalances, depression

Question 67

• AD:

Answer 67

o Mc cause dementia, mc reason for nursing home
o progressive neurodegenerative dz, neuron death in several areas of brain
o → sx loss mental fxn, memory, learning
o Gross: deep sulci, narrow gyri, ↓brain mass

Question 68

• Types of AD:

Answer 68

o Late-onset: onset dementia >65, mc form AD, 45% ppl > 85
o Early-onset: dx ↓65. ↓10%. Genetic, chrom 1, 14, 21
o Familial: early; one type, 50% all relatives get AD ↓50

Question 69

• AD etio:

Answer 69

o Amyloid plaque; protein deposits, norm assoc tissue degeneration
o Healthy: protein fragments broken down, eliminated
o but in AD, accum to form hard, insoluble plaques
o micro: numerous plaque formations in field of neurons is seen.
o Neurofibrillary tangles: inside neurons, insoluble twisted fibers of tau protein.
o Normally, tau forms part of cellular microtubule systems
o In AD, tau is abn → microtubular structures collapse

Question 70

• vascular dementia:

Answer 70

o aka multi-infarct dementia (MID)
o micro-infarctions, ↓CBF, damage brain cells, ↓neuronal fxn
o severity depends on location, #micro-infarctions, underlying health
o gross: mult cystic infarcts, various locations, may take place over several yrs
o CT: ↑ventricular size, ↓volume grey and white matter (all dementia)

Question 71

• Pick’s dz:

Answer 71

o uncommon cause dementia, ssx like AD
o esp frontal and temporal
o atrophy is lobar, “knife-like” in appearance

Question 72

• PD:

Answer 72

o affects pigmented neurons: SN, LC
o ↓voluntary movt, speech slurring, difficult gait, cogwheel rigidity of limbs, pill rolling type tremor at rest, mask-like facies
o Gross: SN is pale
o Micro: SN neurons pale, fewer

Question 73

• Lewy body dementia:

Answer 73

o Some PD pt also have dementia
o Lewy bodies= in neuron cytoplasm
o Ddx for AD
o Micro: rounded pink cytoplasmic body (H&E); immunoperoxidase stain w ubiquitin Ab

Question 74

• Demyelinating dzs:

Answer 74

o MS (mc), 1/1000 in US
o Progressive multifocal leukoencephalopathy
o Central pontine myelinosis

Question 75

• MS:

Answer 75

o F > M, 2:1, onset 20-40, rare, ↓15 or >60
o distinct episodes of neuro deficits
o etio: unk, mb environ, genetic, immune
o myelin destroyed, nerves fire slowly, less efficiently.
o Patches of scar tissue, plaques, over affected areas, further disrupt nerves
o Any part of CNS, wide variety ssx, and depend on stage

Question 76

• MS ssx:

Answer 76

o Initial: weak mm, diff walk, Loss coordination or balance, Numbness, “pins and needles”, other abn sensation, Visual disturbance, blurred or double vision
o Late: severe and debilitating fatigue, tremors, mm spasticity, paralysis
o Other: Pain, Vertigo, Speech or swallowing difficulty, Loss bowel and bladder control, Incontinence, Constipation, Cognitive changes

Question 77

• MS dx:

Answer 77

o no definitive dx test for MS
o MRI: plaques on brain, spinal cord. Gad can distinguish old and new plaques, correlate new plaques w new sxs
o Gad: correspond to breakdown BBB, acute inflame, M0 and L infiltration, edema, demyelination
o Mb Lumbar puncture: ↑ immune proteins

Question 78

• Progressive multifocal leukoencephalopathy (PML):

Answer 78

o Infx w JC virus (polyomavirus
o Micro: mult discrete areas of demyelination, dense infiltrates foamy M0s, scattered large oligodendrocytes, enlarged astrocytes
o 39% to 58% pop sero(+) for JCV Abs= current or previous infx
o persistent asx infx in 1/3 adult pop
o ↓ immunity → disease
o Before ARV, 5% AIDS pts got PML

Question 79

• Central pontine myelinolysis:

Answer 79

o usu iatrogenic, dt too rapid correction of hyponatremia
o myelin destroyed, neurons and axons spared (opp infarction/ stroke)
o no obvious accompanying inflammation (opp other demyelinating dzs)

Question 80

• CNS tumors:

Answer 80

o	1st: 10% all CA deaths
o	50% 1st, 50% mets
o	All ages, but differences
o	Kids: 70% below tentorium (in posterior fossa) 
o	Adults: 70% supratentorial

Question 81

• Mc brain tumors, complications:

Answer 81

o Kids: #1 astrocytic (glioblastomas), medulloblastomas, ependymomas, craniopharyngiomas
o Adults: #1 mets, astrocytic, meningiomas
o Benign: mb lethal dt mass effect
o Surgical resection difficult, may cause more problems
o Even highly malig seldom mets outside CNS

Question 82

• Primary brain tumors:

Answer 82

o 4 major classes:
o Meningiomas: mostly benign, adults, arise in arachnoid, well rounded masses, on external surface of brain (attached to dura), malig rare
o Gliomas: malig, from glial cells, 30-40% all 1st IC tumros, astrocytomas (mc), oligodendrogliomas, ependymomas; anywhere, mostly hemispheres, kids brainstem and cerebellum; spinal corf
o Neuronal tumors
o Poorly differentiated neoplasms

Question 83

• Astrocytomas:

Answer 83

o Grade 1: well differentiated fibrillary, 2: anaplastic, 3: glioblastoma multiforme
o Micro: Tumor cells resemble normal or reactive astrocytes. stellate, spindle-shaped w fiber-like processes, or plump w large eosinophilic cytoplasmic mass
o 80% all adult 1st brain tumors: Fibrillary astrocytomas and glioblastoma multiforme
o 40-60, usu cerebral hemispheres
o Ssx: sz, HA, focal neuro deficits related to site

Question 84

• Glioblastoma multiforme (GBM):

Answer 84

o most malignant form of astrocytoma
o usu live 8-10 mos after dx
o Usu middle age, Mc frontal and temporal lobes
o Or any age, any part of CNS
o Micro: ↑cellularity, cellular & nuclear anaplasia
o Butterfly lesion: infiltrates across corpus callosum, ddx: glioblastoma multiforme, lymphoma, demyelinating processes
o spreads from one hemisphere to another

Question 85

• Oligodendrogliomas:

Answer 85

o 5-15% all gliomas
o Mc 30-50
o Usu white matter of cerebral hemispheres
o Px better than astrocytomas, survive 5-10 yrs after tx

Question 86

• Ependymomas:

Answer 86

o ↓20: usu adjacent to ventricles, esp 4th
o >20: usu spinal cord
o → hydrocephalus if in posterior fossa near 4th ventricle
o slow growing, but px poor, survive 4 yrs after surgery

Question 87

• neuronal tumors:

Answer 87

o mature appearing neurons (ganglion cells)
o ganglioma = all cells arise directly from ganglion cells
o mc ganglioglioma= mixture of ganglion and glial cells
o → 10% all 1st brain tumors in kids
o Tx: 90% 10 yr survival
o slow growing, but glial part can become more aggressive, ↑ morbidity and mortality

Question 88

• medulloblastoma:

Answer 88

o so poorly differentiated, appear embryonal
o mc medulloblastoma
o 20% all brain tumors in kids (mc peds malig BT)
o arise exclusively in cerebellum
o 50-60% “cured” but lifelong relapse risk
o Highly malig, often spread throughout spinal cord

Question 89

• Medulloblastoma micro, imaging, tx, px:

Answer 89

o Micro: small, ovoid or slightly elongated, ↑N:C ratio
o MRI w contrast: enhancing cerebellar mass in midline
o highly radiosensitive, early dx & tx may ↑ life expectancy
o total excision and radiation: 75% 5 yr survival