Micro Test 2 Lect 1

Front 1

4 ways to access CNS
which route is most common for microbes

Back 1

1. blood stream across choroid plexus or capillary endothelium
2. axonal transport by neuron from peripheral site
3. Entry from upper resp tract across olfactory epithelium
4. Direct invasion across anatomical barriers due to surgery or trauma.

Microbes usually use the hematogenous route

Front 2

tendencies and types of viruses that infect the CNS

Back 2

they tend to be small, or grow in lymphatics or vascular endothelium where viremia can be sustained

the common ones are enteroviruses, togaviruses, flaviviruses

Front 3

pachymeningitis

Back 3

meningitis of the epidural or subdural empyemas(collection of pus) and occurs less frequently than leptomeningitis

Front 4

Leptomeningitis

Back 4

meningitis confined by the pia or arachnoid mater. can be localized as meningocerebritis, or can be diffuse as meningoencephalitis

Front 5

acute leptomeningitis
describe its initial inflammatory response

Back 5

is an infection of the pia and arachnoid that has been present for hours to days.
initial inflammatory respose for most of these microbes consist of neutrophils that accumulate in sub arachnoid space (SAS)

Front 6

Chronic leptomeningitis
describe its inflammatory process

Back 6

infection of pia and arachnoid mater for weeks to months
its inflammatory process characterized by lymphocytes and macrophages.

Front 7

TNF alpha in CSF -->

Back 7

damaged capillary integrity and probably BBB damage in meningitis.
can also damage axons and myelin

Front 8

IL-1 is from what cells and-->

Back 8

IL-1 is from macrophage and induces fever

Front 9

TNF alpha and IL-1 together induce

Back 9

together they synergistically induce astrogliosis and new vessel outgrowth

Front 10

What are the symptoms of meningitis?

Back 10

fever, headache, nausea, vomiting, confusion, lethargy, and irritability and are in part due to release of TNF alpha

experimental administration of TNF alpha reproduces same symptoms

Front 11

antibiotic treatment of meningitis can lead to

Back 11

can lead to relase of bacterial produces that can induce a bolus of TNF alpha production that can be detrimental

Front 12

what is used to interupt effects of TNF alpha

Back 12

steroids and cyclo-oxygenase inhibitors. steroids are often used as adjunctive therapy in meningitis.

Front 13

microglia and MHC antigens

Back 13

microglia do not normally express MHC they express them when they become activated

Front 14

cranial nerve deficits are common in what kinds of infections?

Back 14

chronic infections like mycobacterium, tuberculosis and cryptococcus neoformans

Front 15

what are the most commonly affected CN's, and what do they lead to

Back 15

7 and 8
7. paralysis of muscles of facial expression --> abolition of both voluntary and reflex movents of facial muscles (Bell's palsy). cant whistle or blink, can lose taste, and sensitive to sound
8. hearing and equilibrium and orientation affected.

Front 16

what is predominant predisposing factor for subdural empyemas in children and adults
for infants

Back 16

adults and children- paranasal sinusitus- in adult, their arachnoid is highly impermeable to bacterial infection
in infants leptomeningitis is main predisposing condition for subdural empyema

Front 17

etiology and abscess locations are influenced by route of inoculation. the 4 main routes are

Back 17

1. metastatic cerebral abscess from infected thromboemboli
2. direct extension cerebral abscesses from adjacent infected foci such as ear, mastoid, or paranasal sinus
3. trauma related cerebral abscess
4. idiopathic or cryptogenic cerebral abscess where originating infectious focus is undetermined.

Front 18

causes of meningitis in
Newborns
Infants--> age 4
age 4-40
above 40
Immunocompromised

Back 18

Newborns- Group B strep, E. coli K1, Listeria monocytogenes
Infants-->4 Haemophilis influenzae type B, Neiseria meningitidis, Strep pneumoniae. (Enterovirus in children above 4)
Age 4-40 Neiseria meningitidis, and Strep pneumoniae
immunocompromised- age specific bugs plus cryptococcus, listeria and mycobacteria

Front 19

changes in CSF in meningitis
bacterial
viral
fungal
mycobacterial

Back 19

bacterial- huge increase in WBC mostly neutrophils, huge increase in protein, huge decrease in glucose
viral- increase in WBC mostly mononuclear cells increase in protein, glucose is normal
Fungal and mycobacterial meningitis is often in immunocompromised
small rise in WBC mostly mononuclear cells, small rise in protein and small decrease in glucose.

Front 20

What are the 4 clinical types of tetanus

Back 20

1. generalized
2. localized
3. cephalic
4. neonatal

Front 21

Generalized tetanus

Back 21

most common
begins with trismus (lockjaw) and risus (increase tone of eyes grimace face)
spasms resemble decorticate posturing with flex arms and extended legs
pt conscious with severe pain
upper airway may be obstructed or diaphragm maybe contracted in spasm
Major cause of death with resp support due to autonomic dysfunction
severity may be decreaed by partial immunity
recovery takes months

Front 22

Localized tetanus

Back 22

rigidity of muscles associatedwith site of spore inoculation
often resolves spontaneously
--> generalized tetanus if enough toxin gains access to CNS

Front 23

Cephalic tetanus

Back 23

special form of localized disease affecting cranial nerve musculature
associated with wounds to the head and neck

Front 24

Neonatal tetanus

Back 24

follows infection of umbilical stump
commonly due to lapse in aseptic technique where mother is inadequately immunized
presents as generalized weakness, and failure to nurse rigidity and spasms occur later
90% mortality rate