CNS

Question 1

Edema of Brain

Answer 1

Types

• Vasogenic: cases of abscess & neoplasm
  
  • _{Fluid accumulation in the interstitial space ^{(BBB disrupted)}}
  • _{^{Ex. Trauma, Tumor, Arterial HTN}}
• Cytotoxic: Intracellular fluid accumulation due to hypoxic injury ex. Stroke ^{<strong>(BBB intact)</strong>}
  
  • _{^{Loss of cellular metab impairs fnx of Na/K pump}}
• Morphology-Gyri are flattened & Sulci narrowed
• Complication of severe edema=Hernation of brain matter

Question 2

Brain Herniation

Answer 2

• Causes (mass effect):
• _{^{Tumor, trauma-Blood clot (Vasogenic) ORInfection induced edema (Cytotoxic)}}
• Decorticate Posturing-Flexor posture
• Decerebrate Posturing-Extensor posture _{^{(Serious damage)}}
  
  • _{^{<strong>Assoc w/Transtentorial or Tonsillar</strong>}}
• Subfalcine = Cingulate gyrus (frontal lobe)
• Compression on Ant cerebral artery-
  
  • _{^{Weakness & Sensory loss to <em><strong>legs</strong></em>}}
• Transtentorial = Uncal gyrus _{^{(temporal lobe-tentorum cerebri)}}
• Compression on Post. cerebral artery-
  
  • _{^{Occipital infarct-ischemic<strong> injury to visual</strong>}}
  • _{^{Ipsilateral <strong>dilated pupil</strong>-stretching of <strong>CN 3 (oculomotor)</strong>}}
• Tonsillar = Cerebellar tonsils _{^{(severe issues)}}
  
  • _{^{Compression of vital resp center <strong>(foramen magnum)</strong>}}
• _{^{<strong>Duret hemorrhage-</strong>Kinking of median/paramedian pontine arteries<strong><u> (branch of basilar artery)</u></strong>}}

Question 3

Hydrocephalus

Answer 3

• Abnormal collection of CSF in the ventricles
• Choroid plexus lining Lateral vent=CSF production
• Hydrocephalus ex-Vacuo (low pressure)
  
  • _{^{Ex. stroke/Alziemers decrease brain matter<u>=Enlarged ventricles</u>}}
• Before closure of c. sutures ^{(increased head circumference)}
  
  • _{^{<em><strong>Cerebral aqueduct stenosis</strong></em> (3rd/4th ventricles)}}
• Normal pressure (Wet, whacky, whobbly):
  
  • Idiopathic _{^{(decreased reapsorbtion to arachnoid granulation)}}
  • Secondary ^{(infection, tumors, subarachnoid hem)}
  • ^{_{Symptoms Due to stretching of <u><strong>corona radiata</strong></u>}}
• Duret hemorrhage-Increase Intracranial pressure
  
  • Tonsillar herniation or Gilomas

Question 4

Cerebral Infarction (Stroke)

Answer 4

• Caused by local obstuction in blood vessels
  
  • ^{<strong>Thromboembolism & HTN</strong>}
  • _{^{<strong>Artherosclerosis-rupture of plaque <u>(pale infarct-ischemia)</u></strong>}}
  • _{^{<strong>Embolic-mural thrombus lysed <u>(hemorr infact of MCA-Reperfusion injury)</u></strong>}}
• High Risk-History of HTN, smoking, Diabetes
• Pt male in 70’s
• Histo:
• 12 hours- red neuron _{^{(Ischemic injury)}} & neutrophils _{^{(inflammation)}}
• 24hrs-2 weeks-_{^{<strong>Keratin found in necrosis</strong>}}
  
  • _{^{Liquifactive necrosis<strong> (10 days</strong>}<strong>^{in the presence of macrophages/microglial cells)}</strong>}
  • _{^{Vascular prolif/<u>Reactive gilosis</u><strong> (overall healing by Astrocytes w/cystic cavity)</strong>}}
• 1-6 months-Cystic cavity will form w/remote infarcts

Question 5

Stroke Clinical

Answer 5

• TIA _{^{(transient ischemia attack)}}=Less than 24 hours
  
  • Related to angina
• Stroke=Greater than 24 hours
  
  • Sudden onset:
  • _{numbness/weakness on 1 side of face, arm, or leg}
  • _{Trouble speaking or understanding}
  • _{Trouble seeing}
• Middle cerebral artery-
• Contalateral hemiparesis _^(weakness) & spasticity
• Visual field abnormality
• Speech aphasia _^(Broca’s)

Question 6

Aphasia

Answer 6

• Broca’s _{^{(expressive aphasia)}}-associated w/right-sided weakness/paralysis arm or leg
  
  • _{^{Ventral temporal & Medial insular cortex}}
• Wernicke’s _{^{(Sensory aphasia)}}-No body weakness due to no assoc w/frontal lobe
  
  • _{^{<strong>Temporal lobe <u>(post. temp artery)</u></strong>}}

Question 7

Thrombo-embolism

Answer 7

• Common of MCA
• Source-
• Mural thrombus of left vent of heart
• Atherosclerotic plaque from proximal arteries
  
  • Carotid arteries

Question 8

Intracranial Hemorrhage (Spontaneous)

Answer 8

Non-traumatic

• Intracerebral-Intraparenchymal _{^{(inside brain)}} Hypertensive
• Subarachnoid-Aneurysmal (Berry)
• Mixed-Rupture of arteriovenous malformations
  
  • _{^{Abnormal collections between arteries/veins}}
• Accounts for 50% of hemorrhages
• Age-middle to late adult life (60 years)
• Causes:
• Acute raise in BP
• Chornic raise in BP-_{^{Rupture of Charcot-Bouchard microaneurysm}}

Question 9

Non-traumatic-Hypertensive

Answer 9

• Sudden loss of consciousness
• Vomiting & Headache _{^{(increase intracranial pressure)}}
• Hyaline arthreoscelrosis-weakening of vessel wall
• Assoc. w/Diabetes-Lacunar infarcts=_{^{Small vessel deep brain}}
• Brain stem compression (charcot-Bouchard):
• Irregular respiration followed by Apnea-_{^{Cheyne-Stoke breathing}}
• Dilated non-responsive pupil
• Spasticity
• Tonsilar hernation-cerebellar “C”

Question 10

Non-traumatic-Subarachonoid Bleed

Answer 10

• Rupture of “saccular aneurysm” _^(Berry) following HTN
• Size-6-10 mm @ circle of Willis _{^{(Ant communicating artery)}}
  
  • _{^{Asymptomatic <u>less than 3mm</u>}}
• Arise from weakness in MEDIA of artery-
  
  • Marfan syndrome _{^{(disorder of Fibrillin-1)}}
  • Ehler Danlos _{^{(Disorder w/type 3 collagen)}}
  • Adult polycystic kidney _{^{(dominant PKD1/2)}}
• Blood in between arachnoid & pia
• LP-CSF-will show blood=_{<u>^{<em><strong>Xamthochromia </strong></em>(breakdown of Bilirubin)}</u>}
• Worst headache, vomiting, heriation-
  
  • _{^{<strong>Acute hydrocephalous <u>(communicating/no CSF reabsorption @SSS)</u></strong>}}
• Can be associated w/Trauma
• Menigial irritation present-
  
  • _{^{Neck rigidity w/blood CSF (Xamthochromia)}}

Question 11

Non-traumatic-Mixed

Answer 11

• Due to vascular malformations-
• Arteriovenous
• Capillary telangectasis _{(abnormal dialated caps)}
• Venous angioma _{<strong>(tangle of abnormal veins)</strong>}
• Cavernous angioma _{<strong>(blood filled spaces)</strong>}
• Seen in cerebral hemispheres **males 10-30 **

Question 12

Charcot-Bouchard Micro

Answer 12

• Non-traumatic or Traumatic
• Branches of basilar artery=“Kinked”
• Appear in Ventral-dorsal spread
• Affects Midbrain/Pons
• Outpouching of abnormal small vessels-
• Bassal ganglia or Deep structures -Lacunar infarcts
• Wall of vessel is made of collagen _{^{(blue-trichrome stain)}}

Question 13

Traumatic-Concussion

Answer 13

• Result from head strikes against an object
  
  • _{^{Produce<u><strong> unconsciousness or bleeding</strong></u>}}
• Damage to reticular activating system=^{unconsciouness}
• Minimum Morphological change

Question 14

Contusion

Answer 14

• Contusion:
• Injury to superficial brain parenchyma (Blunt trauma)
• Bleeding + Edema
• Coup _{^{(no skull fracture)}}=Hit to immoble head or site of impact
• Counter-coup=injury due to opposite area of impact
  
  • _{^{Brusing of brain BOTH can present}}
• Traumatic intracerebral Hemmorrhage-_{^{Contusion + Edema}}
• Laceration:
• Contusion + Tear of superfical layers of brain

Question 15

Trauma Hematomas

Answer 15

• Epidural:
• Clots underneath the skull _{^{(Dura mater-Skull)}}
• Disruption from middle meinigeal artery _{^{(dura peeled off skull)}}
  
  • _{^{Lateral skull fracture-Temporal bone}}
  • _{^{Low HB}}
  • _{^{Lucid period sudden & Loss of con}}
• Subdural:
• Clots between outer & middle layers ^{<strong>(arachnoid/Dura)</strong>}
• Rupture of bridging veins **_{^{(dura still attached)}} **
• Caused by rapid change in head velocity
• Morphology: Small brain big skull ^{(more brain mobility)}
  
  • Acute - Child & Chornic - Adult

Question 16

Subdural Hematomas (acute/chronic)

Answer 16

• Head injury/trauma-2 weeks/months:
  
  • ​_{^{Headache, dizziness, loss of consciousness}}
• _^​Chronic:
• Slow progress-Contain venous blood
• Assoc. w/Brain atrophy-brain more mobility
  
  • _{^{Make the vein more vunerable to trauma}}
• Acute-Risk for re-bleeding:
• Seen in infants
• Cause-More space in cranium w/less brain matter
  
  • _{^{Excess brain mobility & Hemorrhage minor trauma}}

Question 17

Diffuse Axonal injury

Answer 17

• Cause: Post-traumatic dementia & Vegetative state
• Injury to white matter
• Damage to axon @ node of Ranvier
• Common sites-
  
  • Corpus collosum, periventicular, Hippocampus
• Clinical-coma after trauma w/o evidence of parenchymal injury
• Histo: Axonal swelling-either side of node

Question 18

Neural tube defects

Answer 18

• Associated w/def of folate prior to conception
• Anencephaly-
  
  • Absence of skull/brain-froglike _{^{(orbital bone)}}
• Diagnosis:
• Ultrasound-Polyhydraminos later stage of 1st tri _{^{(22-28 day)}}
  
  • _{^{<strong>Increased conc of alfa-feto & acetylcholinesterase</strong>}}
• Encephalocele-
  
  • _{^{Common in southeast Asia}}
  • _{^{Protrusion of brain matter through skull}}
• Cranial meningocele-
• CSF & meninges come out through cranial defect

Question 19

Spina Bifida

Answer 19

• Location: Lumbosacral
• Myelomeningocele: Sac or cyst contains CSF, nerves, & spinal cord
• Meningocele: Def of vert and CSF cyst
• Occulta (hidden): Slight def in formation of 1 vert
• Dimple or small hair patch-**Giant naevus **

Question 20

Arnold-Chiari Malformation

Answer 20

• Related Non-communicating hydrocephalus
• Cerebellar tonsil downard displacement through foramen magnum
• Morphology: elongation & flattening of cerebellum & medulla
• Type 2 can be life threatening-Spriomylegia (C8-T1)

Question 21

Dandy-Walker Malformation

Answer 21

• Defect in forming Cerebellar vermis
• Can also result in COMPLETE absence of cerebellum
• Massive dialtion of 4th ventricle-Hydrocephalus
• X-ray-Enlargement in post fossa

Question 22

Holoprosencephaly

Answer 22

• Forebrain development disorder
• Cleavage failure of embyonic prosencephalon (below Telencephalon)
• Associated w/Trisomy 13 _^(pattau) & 15 _{^{(Prader-willi/Angelman)}}
• Morphology:
• Midline facial defects (cleft lip/palate & cyclopia)

Question 23

Neurocutaneous Syndome (Neurofibromatosis)

Answer 23

• NF-2
• Von-Recklinghausen disease (Ch 17)
• Symptoms:
• Optic giloma _{<strong>^{(tumor pressing on optic nerve)}</strong>}
• Multiple neurofibroma, schwanoma, meningioma
  
  • _{^{Transform to malignant schwann cell tumors}}
  • _{^{<u>Cafe-au-lait spots:</u> pigmented areas adj to <u>neurofibromas</u>}}
• Lisch nodules of iris _{^{(Hemartoma of eye)}}

Question 24

Neurocutaneous Syndome (Von-Hippel-Lindau)

Answer 24

• Hemangioblastomas _{^{(benign BV tumors)}} in brain, SC, & retina
• “Cerebellar blastomas=Ataxia”-VHL gene
• Associated with:
  
  • Retinal angiomata
  • Pulmonary hemangiomas
  • Liver hemangiomas
  • Pancreatic hemangiomas
  • Pheochromocytoma
  • **Renal cell carcinoma **
• Diagnose: Slit lamp test _{^{(retinal detachment)}}

Question 25

Neurocutaneous Syndome (Sturge-Weber)

Answer 25

• Cong vascular malformation affecting head, face, brain
• Clinical presentation:
• @ birth w/port-wine nevus (reddish-brown/pink dicoloration of face)
• Follows distrubution of CN V (trigeminal)-^{<strong>Sturge-weber</strong>}
  
  • _{^{Motor & sensory}}

Question 26

Neurocutaneous Syndome (Tuberous Sclerosis)

Answer 26

• “Cortical Tubers”
• Autosomal dominant - ^{w/mental retardation & seizures}
  
  • Starts early in life
• Pts can present with Cardiac rhabdomyomas
  
  • _{^{Fatty foci in myocardium}}
• Facial angiofibromas “Butterfly pattern”
• Multisystemic=Non-malignant tumors
  
  • _{^{Brain, kidneys, heart, eyes, lungs, & Skin}}

Question 27

Germinal matrix hemorrhage

Answer 27

• Cause: Fragile portion of brain damaged _{^{(2nd tri abortions)}}
• Common in pre-term infants (before 35 weeks)
  
  • _{^{Associated w/hyaline membrane & necrotizing renal issues}}
• Germinal matrix highly cellular & highly vascularized
  
  • _{^{Source of<u> neurons &amp; glial cells</u> migrate out to other regions of brain}}
• Most active during 8-28 weeks gestation
• _Morphology: _Intraventricular hemorrhage (IVH)
  
  • _{^{Origin subpendymal region (“germinal matrix”)}}
• Baby presents w/seizure = obstructive hydrocephalus
  
  • ^{<strong>_{Increased cranial circumferance}</strong>}

Question 28

Cerebral Palsy

Answer 28

• Disorder of movement-Causes:
• Grey matter necrosis-Hypoxic/ischemic injury _{^{(Red neuron)}}
  
  • _{^{Makes holes/cystic cavity in brain}}
• Symptoms _{^{(motor problems-paralysis)}}:
  
  • Spastic diplengia _{^{(affects symmetrical parts of body)}}
  • Spastic hemiplegia _{^{(affects one side of body)}}
• Presents in infancy to childhood
• Non-progressive due to developing brain plasticity

Question 29

Meningitis-Lab

Answer 29

• Inflammation of Pia/Arachnoid
• Acute bacterial/pyogenic:
  
  • _{^{Low glucose}}
  • _{^{Pressure increase}}
  • _{^{Increase in<strong> neutorphils</strong>}}
  • _{^{+ Culture}}
• Acute viral:
  
  • _{^{<strong>Glucose Normal</strong>}}
  • _{^{Slight increase in pressure}}
  • _{^{Slight increase in <strong>lymphocytes</strong>}}
  • _{^{<strong>- Culture</strong>}}

Question 30

Bacterial Meningitis

Answer 30

• Neonates: Ecoli, Group B strep _{^{(Birthing process)}}
• Babies: H. influ _{^{(non-vacinnated)}} & Strep pneumo
• Epidemics amongst adults: Neisseria men
  
  • _{^{Pathogens enter through Nose}}
  • _{^{Associated w/”<u>Waterhouse Fredrichson syndrome</u>“-Bilateral adrenal insuff/DIC}}
  • Septicemia can present w/_purpuric rash does NOT lose colo_r when pressed
• Infection following surgery: Staph aureus _{^{(IV drug user)}}
• Morphology: Opaque meninges _^(exudates)
• Histo: Neutrophils in subarachnoid space
• Acute hydrocephalus _{^{<strong>(high pressure)</strong>}}-_{^{Headache & Papilledema <strong><u>(optic swell)</u></strong>}}

Question 31

Viral Meningitis/Encephalitis

Answer 31

• General properties:
• Perivascular inflammatory infiltrates (lymphocytes)
  
  • _{^{<strong>Stain pink/blue in histo</strong>}}
• Microglial nodules _{^{(microglial cells surrounding necrotizing tissue)}}
• Inclusion bodies _{^{(viral replication in bacterium or host cell)}}
• Progressive multifocal leukocephalopathy:
• JC virus will stain brown-Polyomavirus _{^{similar to BK-SV40}}
• Glial cells/white matter progressive inflammation
  
  • Similar to MS BUT more rapid
• Herpes simplex-Attacks Temporal Lobe

Question 32

Toxoplasma & Fungal

Answer 32

• Toxoplasma-“*Cat Stratch Disease*“
  
  • Retinits _{<strong>^{(cause blindness)}</strong>} in new born
  • MRI: Calcification in brain
  • Lead to Brain abscess
• Fungal meningitis:
• Cryptococcus-_{^{present in<u><strong> HIV or Lymphandenopathy</strong></u> pts (cancer of lymph)}}
• Use indian ink stain
• Found in Virchow-Robin spaces:
• Perivascular, fluid filled canals surround perforating arteries/veins in parenchyma _{^{(inside brain)}}
  
  • Regulate CNS movement & Drainage

Question 33

Transmissible Spongiform Encephalopathies

Answer 33

• “Prion Disease”
• Transmission:
  
  • Blood/Sputum
  • Fatal familial insomnia _{^{(mutation PrPsc gene)}}
  • Kuru (humans)
  • Eating infected food or cannibalism
• Clinical: ^{Changes in memory & behavior w/rapid dementia}
  
  • Startle myoclonus _{^{<u>(brief muscle spasm)</u>}}
  • Average survival 7 months from onset
• PrPc _{^{<strong>(Alpha-helices)</strong>}} & PrPsc _{^{<strong>(beta sheets)</strong>} <u>^{differ in 3D confirmation}</u>}
  
  • _{^{PrPsc goes back to PrPc to make more PrPsc}}
• Histo: Amyloid rich kuru plaques ^{_{<strong>(intra-vacoule)</strong>}}

Question 34

Demyelination Disease (MS)

Answer 34

• Sporadic chronic relapsing & remitting diease
• Genetics-HLA DR2
• Morphology-Plaque in CNS white matter _{^{(Brain/spinal cord)}}
  
  • Plaques = Astrogliosis
• Autoimmune-caused by CD4 Tcell mediated injury to myelin sheath _{^{(oligodentrocytes)}}
• CSF-High lympocytes w/Oligoclonal IgG bands
• Clnical:
• Unilateral visual impairment _{<strong>^{(optic neuritis)}</strong>} few days
• Brainstem-_{^{CN signs, Ataxia, Nystagmus, Slurred speeach}}
• Spinal cord-_{^{Motor/sensory impairment (spasticity)}}
• Difficulty w/voluntary control of bladder

Question 35

Demyelination disease (Guillain)

Answer 35

• Acute ascending polyneuritis (PNS)
• Segmental myelin loss of PNS-Schwann cells
• Spontaneous or due to Viral/Mycoplasma infection
• Symptoms:
• Rapid ascending motor weakness over weeks
• Lead to respiratory failure-death
  
  • _{^{Begins in feet & hands migrates toward trunk}}

Question 36

Alzheimers Disease

Answer 36

• Changes seen in hippocampus (CA1 region)
  
  • _{^{Imaging will show shrinkage w/<u>Hydrocephalus ex vacuo</u>}}
• Symptoms _{^{(cortex/gray matter degeneration)}}:
• Impaired memory, loss motor skills, incontenence, & immobility/mute (late)
• Genetics-Chrom 19 Tau protein ^(ApoE) & 21 _{^{(increase in APP)}}
• Generation of Amyliod-B
  
  • ​_{^{2 sequential extracelluar <strong>cleavages of APP</strong> by <strong><u>BACE/A-secretase</u></strong>}}
  • _{^{<em><strong>Alpha-secretase</strong></em> prevents generation of Amyloid-B <em><strong><u>(cannot be brokendown)</u></strong></em>}}
• Histo: Neuritic Plaque stain
  
  • Tau protein (Brown)-_{^{proteins that stabalize microtubules}}
  • Beta-Amyloid-_{^{<strong>E4 upregulated</strong>}} (Red Dot)
  • Neufibrillary tangles _{^{(Hyperphospho Tau)-}}
    
    • _^​Bielschowsky silver stain

Question 37

Pick’s Disease

Answer 37

• FrontoTEMPORAL lobar degeneration
• Early behavior & language symptoms-Dementia
• Spares parietal/occipital lobes
  
  • _{^{<strong>Rare neurodegenerative disease</strong>}}
• Progresses to destruction of nerve cells
• Histo: Round Tau protein aggregates

Question 38

Parkinson’s Disease

Answer 38

• Paralysis agitans
• Autosomal dominant-_{^{mutations in <u><strong>alpha-synuclein</strong></u> gene}}
• Autosomal recessive-_{^{mutations in <u><strong>ubiquitin-protein ligase</strong></u> (parkin gene)}}
• Loss of doperinergic _{^{(catecolaminergic)}} neurons in pars-compacta of substantia nigra
• Symptoms (damage basal ganglia)-
• Shuffling gait
• Cogwheel-rigidity of limbs
• Pill-rolling tremor @ rest _{^{(absent w/movement)}}
• Histo: Lewy body in abnormal neuron _{^{(Alpha sy)}}
  
  • Pigment melanine

Question 39

Hutington’s Disease

Answer 39

• Chorea-Unopposed muscle contrations
• Trinucleotide repeat disorders-caused by length of repeated section of gene exceeding normal range
• HTT gene-p Chromosome 4/13
• 3 DNA bases-CAG repeated several times _^(Glutamine)
  
  • Early HT affects Extrapyramidal motor
• Late atrophy of caudate nuclei w/enlargement of frontal horns of lat vet _{^{(hydrocephalus ex-vacuo)}}
  
  • _{^{<strong>Degeneration of GABA neurons <u>(caudate nucleus)</u></strong>}}
• Psychiatric Symptoms-
  
  • _{^{Irraitability, Apathy, Aniety, Depressed mood<strong> (suicide)</strong>}}

Question 40

Lou Gehrig’s (Amyotrphic lateral sclerosis)

Answer 40

• Motor neuron disease ^{(upper & lower of pyramidal system)}
  
  • _{^{Overall nerve atrophy}}
• Rapidly progressive weakness w/*muscle atrophy*-
• Gliosis in motor cortex, pallor of lateral cortico w/neuronal loss in ant horns (motor)
  
  • Fasiculations _{<strong>^{(muscle twitching)}</strong>}
  • Muscle spasticity _{<strong>^{(impaired muscle coordination)}</strong>}
  • Diffculty speaking _{<strong>^(dysathria)</strong>}
  • Diffculty swallowing _{<strong>^(Dysphagia)</strong>}
  • Difficulty breathing _{<strong>^(dyspnea)</strong>}