Neuro- Infection

Question 1

How is neurological infection classified?

Two ways

Answer 1

2 basic types

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

Also classified by:
- Viral or Bacterial

Question 2

Describe 4 primary ports of entry for microbes?

Answer 2

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

Question 3

What bacteria can cause Bacterial Meningitis?

Answer 3

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)

Question 4

What might predispose you to Bacterial meningitis?

Answer 4

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

Question 5

Pathology of Bacterial Meningitis?

Answer 5

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

Question 6

MNFTS of BM?

Answer 6

• 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

Question 7

Brudzinski’s test?

Answer 7

Meningeal irritation test

flex of neck leading to flexion of knee

Question 8

Kernigs test?

Answer 8

Meningeal irritation test

pain and resistance to extension of knee at hip

Question 9

Dx of BM?

Answer 9

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

Question 10

TX of BM?

Answer 10

TX
• ABX
• Steroids (Serious INFLM)

Question 11

Describe Viral Meningitis and how it compares to BM?

Answer 11

• 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

Question 12

What might you find in CSF during Viral Meningitis?

Answer 12

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

Question 13

TX for VM

Answer 13

o Symptomatic Tx

• No need for anti virals if it is self limiting

Question 14

What is Encephalitis?

Answer 14

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

Question 15

Why would encephalitis normal be viral and not bacterial?

Answer 15

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

Question 16

What are the two virus commonly associated with encephalitis?

Answer 16

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

Question 17

Patho of Encephalitis

Answer 17

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

Question 18

MNFTS of Encephalitis

Answer 18

• 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