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Flashcards in Neuro- Infection Deck (18):
1

How is neurological infection classified?

Two ways

2 basic types
1. Within the Brain tissue
2. Within the meninges and Spinal Cord

Also classified by:
- Viral or Bacterial

2

Describe 4 primary ports of entry for microbes?

1) microbe entry by compromised Blood Brain Barrier
2) fracture in the skull
3) direct spread from adjoining area eg/middle ear, buckle cavity
4) along an axon that goes into the brain

3

What bacteria can cause Bacterial Meningitis?

Any bacterium able to enter and infect meningies Some bacteria are more likely to cause:
1) streptoccus pneumonia usually cause in Adults
2) neisseria meningitides causes meningococcal meningitis is Youth
3) Haemophilus Influenzae (under 5)

4

What might predispose you to Bacterial meningitis?

• Predisposition
o Head trauma
o Neuro Sx
o Congruent Infect (eg sinusitis)
o Lowered in Immunity

5

Pathology of Bacterial Meningitis?

Bacteria get in, microbial proliferation and lysis in the CSF
- inflm →purulent exudate into CSF
- pus accumulates around: meningies, subarachnoid
space, ventricles and blood vessels all affected
- exudate needs space, pus on brain surface and CSF

6

MNFTS of BM?

- inc pressure in cranium can be life threatening
- bacterial infection: develop fever, nausea, headache,
vomiting, back pain
- nuchal rigidity nape/back of neck stiff/rigid

7

Brudzinski’s test?

Meningeal irritation test
(flex of neck leading to flexion of knee)

8

Kernigs test?

Meningeal irritation test
(pain and resistance to extension of knee at hip)

9

Dx of BM?

• Hx and Px (physical)
• C & S (CSF)
o Analyze CSF
• INC proteins and neutrophils, pus, Dec Glucose (why?)
 Inlfm

10

TX of BM?

TX
• ABX
• Steroids (Serious INFLM)

11

Describe Viral Meningitis and how it compares to BM?

• Less severe then bacterial (intracranial pressure is serious however)
• Aseptic meningitis
• Usually self limiting
• d/t several virus (just require a portal of entry)
• similar MNFTS (but less severe)
o serous exudate not purulent

12

What might you find in CSF during Viral Meningitis?

o Lymphocytes (to fight viral infct)
o Moderate increase in protein content
o ***Elevated immunoglobulins***
o Glucose normal (viruses don’t utilize glucose)

13

TX for VM

o Symptomatic Tx
• No need for anti virals if it is self limiting

14

What is Encephalitis?

(encephalon is brain)
• Inflm of Parenchyma (pararhyme is functional tissue of any organ – neurons of brain or spinal cord in this case)
• Usually viral

15

Why would encephalitis normal be viral and not bacterial?

NOT SURE, something to do with

o Mode of action of bacteria and virus very different
o Virus hijack host cell and replicate DNA inside cell then cause lysis
o Bacteria does not need to get inside the cell

16

What are the two virus commonly associated with encephalitis?

• Herpes simplex Type 1 = cause cold sores
o Other types (Herpes simplex Type 2 = genital herpes)
• Arbovirus (carried by arthropods …like a tick)

17

Patho of Encephalitis

• Localized necrosis & hemorrhage -> becomes generalized -> edema
• Cell body degeneration
• Unpredictable course (progression is not uniform)

18

MNFTS of Encephalitis

• Neuro disturbances (eg lethargy, seizures, coma)
• Fever, Headache, Nuchal Rigidity
• Usually subside in ~2 weeks if arbovirus
• Herpes simplex more serious
oTreat more aggressively (acyclovic antivirals)
• Severe neurological impairment possible
• ~30% mortality rate