Neuro - Infectious Diseases Of The Cns (Histo, Hickey)

Front 1

Prions (3 types of illnesses)

Back 1

Sporadic - No family hx
Genetic - Disease is in the genome and will occur in all generations of family.
Infectious - Individual exposed to infectious material in someone else's CNS.

Front 2

Prions - General

Back 2

No cell or DNA associated. Creates a subacute disease (progression over months)

The abnormal protein has notation PrP^(sc) - normal is PrP^c (and this one is normal in the CNS)

Prions can't replicate, but the abnormal prion can induce normal prions to be abnormal and gradual aggregation causes severe damage.

Front 3

Types of prion diseases

Back 3

Kuru
Creutzfeldt-Jakob Disease
New Variant CJD (AKA mad cow disease)
Gerstmann-Straussler
Scrapie...

Front 4

Histo features of prion diseases

Back 4

SPONGIFORM CHANGE (bubbles)

extensive neuronal loss, gliosis, kuru-like plaques, white matter changes

Front 5

If you see plaques with spongiform, you must think...

Back 5

new variant Creutzfeldt-Jakob disease!

Front 6

Virus - general

Back 6

Acute, rapidly progressive, serious and life-threatening.

Front 7

Herpes encephalitis

Back 7

Virus

Prefers temporal lobe - causes necrosis and edema.

Onset is quick and it can be grave.

Front 8

Histo characteristics of viruses

Back 8

Lymphocytes and macrophages diffusely through neuropil (inflammation)

Perivascular lymphocyte cuffs

Microglial nodules AKA neuronophagia (site where a neuron has died and has been eaten by microglial cells)

Inclusion bodies - In the nuclei there are big red things that push chromatin against the side of the nuclear membrane.

Front 9

Acute poliomyelitis

Back 9

Virus

Infects grey matter of spinal cord (motor neurons) - anterior horn area.

Front 10

HIV-1

Back 10

Mainlty affect immune system, and then CNS.

Non-transforming retrovirus of lentivirus family.

dsRNA

Front 11

How is CNS affected by HIV-1

Back 11

Macrophages carrying virus get to CNS within a week or two of primary infection. These secrete cytokines to damage the parenchyma and form nodules histologically (perivascular).

HAART (Highly active antiretroviral therapy) doesn't get to CNS that well so these pts die of a disease similar to Alzheimers.

Can progress to HIV encephalitis and the pt will die.

Will also see perivascular giant cells.

Front 12

4 CNS opportunistic infections seen in HIV immunodeficiency

Back 12

Toxoplasma gondii cerebral abscess/encephalitis

Cryptococcal meningitis or disseminated cryptococosis

Progressive multifocal leukoencephalopathy

B-cell lymphoma (cerebral or disseminated)

Front 13

CNS lymphoma

Back 13

Common with AIDS pts

Anaplastic B cells in parenchyma of brain.

Front 14

Progresive multifocal leukocencephalopathy (PML)

Back 14

Due to JC virus. Common in immunosupp (HIV)

Extensive oligodendo-->myelin loss.

Small demyelinating foci

Develops to an encephalopathic state and the pt drifts into coma and dies.

Oligos look huge, lose fried-egg appearance.

Won't have inflamm bc pt is immunosupp.

Front 15

Toxoplasmosis

Back 15

Intracellular parasite - not a virus.
Associated with AIDS and cats.

Cats play a role in spreading infection.

Pregnant women are in danger.

Hemorrhagic lesions. They replicate in cells, make them burst, and then go to other cells.

Can form toxoplasma pseduocyst - these are multiple organisms of the replicating toxoplasma in one cell.

Front 16

Bacteria CNS - 3 main categories

Back 16

Empyema

Meningitis

Abscess

Front 17

Empyema

Back 17

Collection of pus in a POTENTIAL space. Not in the tissue proper (this would be an abscess)

e.g. subdural

Front 18

Bacterial meningitis - agents affecting infants (0-2 months)

Back 18

E. Coli, Group B strep, Listeria

Front 19

Bacterial meningitis - agents affecting 2 months - 5 years

Back 19

Hemophlus, pneumococcus, meningococcus, m. tuberculosis

***"My Harry's Potty Trained

Front 20

Bacterial meningitis - agents affecting > 5 years

Back 20

Pneumococcus, meningococcus, m. tuberculosis

**Those my pencils!
(starting school)

Front 21

Bacterial meningitis - agents affecting elderly

Back 21

Listeria, hemophilus, pneumococcus, m. tuberculosis.

***Lavern and hokie potty train

Front 22

Pus in neonatal meningitis

Back 22

Creamy and white. May block CSF outflow.

Front 23

Adult bacterial meningitis - general features

Back 23

Pus along vessels over surface of the brain (this is the subarachnoid space)

Infection stays in subarachnoid space and neutrophils come in and secrete things to cause BV dilatation and edema.

Can cause infarcts or hydrocephalus

Front 24

Latest stage bacterial meningitis

Back 24

Pts if cured, may come back with big infarct bc the antigens of dead bacteria were in csf of subarachnoid space causing complement to be fixed and vasculitis.

Front 25

Post meningitis hydrocephalus

Back 25

Massively dilated ventricles bc scarring closes off CSF exit sites.

Front 26

M. Tuberculosis

Back 26

Can cause 1. diffuse BASAL meningitis (not rapidly progressive) or 2. localized tuberculoma (fibrotic mass).

typically, but not always, you will get one or the other.

Front 27

Diffuse BASAL meningitis from tuberculosis

Back 27

This is a fibrosing process in the brain stem that goes down to the spinal cord.

Front 28

Localized tuberculoma

Back 28

Fibrotic mass - causes granulomatous inflammation where fibroblasts lay down collagen and entrap BVs to cause infarctions.

Front 29

Brain abscess

Back 29

Presents like tumor.
Induces swelling (after rupture especially) and fibrosis (one of the few things that deposits collagen in the brain parenchyma).

Often due to staph or strep.

The rim on the outside of these abscesses in collagen.

Front 30

Typical pattern of brain abscesses

Back 30

Neutrophils - macrophages - b cells/plasma cells - necrosis - fibroblasts.

Front 31

Abscess rupture into ventricular system

Back 31

Will get REALLY bad edema

Front 32

Candida

Back 32

Yeast/fungi

Common only in immunosupp.

Necrotizing, non-hemorrhagic. Ischemic.

Can form fungus balls (colonies) in the brain parenchyma.

Minimal inflammation and yeast/pseudohyphal forms exist together.

Front 33

Cyyptococcus

Back 33

Yeast/fungi

Smoldering meningitis that progresses very slowly.

Common in non-immunosupp.

Produces large jelly-like masses, small ischemic lesions.

No hyphal form - all yeast.

India ink.

Front 34

Aspergillosis

Back 34

Very grave. Ubiquitious in soil.

In immunosupp only.

Comes to CNS from BVs of lungs and causes emboli in CNS. As it is wedged in small BVs, it proliferates then the hyphae kill surrounding tissue and eat it as food.

Front 35

Histologically seen as hyphae branching at 45 degrees

Back 35

Think aspergillus.

Front 36

Mucormycosis

Back 36

Closely related to aspergillus. Their hyphae look similar.

Common in diabetics. No good tx.

Usually directly spreads from infected sinus to inferior surface of frontal lobe.

Front 37

Coccidioidomycosis

Back 37

Fungi/yeast

In dry arid areas (SW USA)

Seen in immunosupp. Can produce a nasty meningitis.

Found in soil. Parasitic cycle in resp tract.

Cold-like sx before progressing to meningitis.

Better seen with silver stain.

Front 38

Coccidioidomycosis - Meningitis presentation

Back 38

Entrapped BVs, fibrosis and vasomeningitis in meninges.

Hard to tx bc not dividing rapidly and their presence stimulates macrophages.

Chronic disease.

Front 39

Cysticercosis

Back 39

Infestation with larval form of a tape worm.

If humans eat undercooked pork and then get fecal-oral contamination, the cysticerci may move to brain or muscles.

Growing disease bc more population from central/south america.

Causes large cysts.

TYPICALLY DON'T CAUSE PROBLEMS UNTIL THE ORGANISM DIES BECAUSE THIS IS WHEN IMMUNE SYSTEM BEGINS TO ATTACK IT.

Tx - excise and surgery.