CNS infections and meningitis

Question 1

List the 4 Four routes of entry in CNS infections

Answer 1

a) haematogenous spread
b) direct implantation
c) local extension
d) PNS into CNS

Question 2

which areas do the following affect:

Meningitis
Encephalitis
Myelitis
Neurotoxin

Answer 2

Meningitis - meninges
Encephalitis - brain
Myelitis - spinal cord
Neurotoxin - CNS and PNS

Question 3

Distinction between mengitis and encephalitis

Answer 3

Encephalitis - brain function disturbance:

confusion or disorientation
personality change
speech difficulty

Question 4

List organisms that can cause meningitis?

Answer 4

in order of pop:

Neisseria meningitidis 
Streptococcus pneumoniae 
Haemophilus influenzae 
Listeria M
GROUP B STREP!
E.coli

				               		                		Cryptococcus neoformans

a lot of still causes can causes meningitis btw

Question 5

List organisms that can cause Encephalitis?

Answer 5

RAAPT:

Rabies
Arboviruses
Ameoba
Prions
Trypanosoma

Toxoplasmosis

Bacterial encephalitis:
Listeria monocytogenes

Question 6

List organisms that can cause disturbance of nerve transmission - Myelitis?

Answer 6

polio

Question 7

List organisms that can cause

1. rigid paralysis
2. flaccid paralysis

Answer 7

1. clostridium tetani

2. clostridium botulinum

Question 8

what is Meningoencephalitis?

Answer 8

inflammation of meninges and brain parenchyma

Question 9

list the meninges from top to bottom in brain?

Answer 9

DAP

dura
arachnoid
pia

Question 10

In the UK, ~ 5% of _____ survivors have neurological sequelae, mainly sensorineural deafness??

Answer 10

meningitis

Question 11

neurologiical damage in meningitis is caused by?

Answer 11

Direct bacterial toxicity.

cytokine release and oedema.

Shock, seizures, and cerebral hypoperfusion.

Question 12

3 classes of meningitis and their causes?

Answer 12

a) Acute
usually bacterial meningitis

b) Chronic
	usually TB, spirochetes, cryptococcus

c) Aseptic

Question 13

how is Neiserria meningitides transmitted?

Answer 13

Transmission is person-to-person, from asymptomatic carriers.

Through nasopharyngeal mucosa in a susceptible individual.

Question 14

how long from exposure to infection in Neiserria meningitides?

Answer 14

Causes infections in less than 10 days

Question 15

characterise the rash in meningitis?

which is most popular?

Answer 15

A nonblanching rash (petechial or purpuric) develops in 80% of children.

A maculopapular rash remains in 13% of children,

No rash occurs in 7%.

Question 16

The clinical difference between septicemia and meningitis is important. why?

Answer 16

because patients who present with shock are treated

differently than patients who present primarily with increased intracranial pressure

Question 17

what are the processes underlying septicaemia?

Answer 17

4 processes:

Capillary leak;

Coagulopathy; bleeding and thrombosis.

Metabolic derangement; particularly acidosis

Myocardial failure….multi-organ failure.

Question 18

in which cause of meningitis is the following seen on CT:

enhancement in the basal cistern and
meninges, with dilatation
of the ventricles.

Answer 18

tuberculous meningitis

involves spinal cord too

Question 19

what is the most common infection of the CNS?

Answer 19

Aseptic meningitis

Question 20

which viruses are responsible for 80-90% cases in which a causative organism of aseptic meningitis is identified?

Answer 20

Coxsackievirus group B and echoviruses

Question 21

epidemiology of Aseptic meningitis?

Answer 21

children younger than 1 year

Question 22

Rx for aseptic meningitis?

Answer 22

is self-limited and resolves in 1-2 weeks

Question 23

the following cause CNS infections in which age group in particular?

Mumps
Measles
Varicella-zoster

Answer 23

kids/ infants

Question 24

how is Encephalitis transmitted?

Answer 24

person to person,

or through vectors:
Mosquitoes
Lice
Ticks

Question 25

all Encephalitis causes affects the young apart from?

Answer 25

St. Louis encephalitis | Rabies

Question 26

name a cause of Bacterial encephalitis?

Answer 26

Listeria monocytogenes

Question 27

name a cause of Amoebic encephalitis?

Answer 27

Naegleria fowleri

Question 28

toxoplasma is transmitted by which virus and routes?

Answer 28

Toxoplasma gondii Via the oral, transplacental route or organ transplantation.

Question 29

Brain abscess can come from which conditions?

Answer 29

otitis media/mastoiditis/paranasal sinuses | endocarditis/haematogenously

Question 30

top 4 causative organisms in brain abscess?

Answer 30

Strep Staph Gram-negative organisms. (particularly in neonates) Mycobacterium tuberculosis

Question 31

Name a common form of vertebral infection.

Answer 31

Pyogenic vertebral osteomyelitis

Question 32

name risk factors for spinal infections?

Answer 32

``` Advanced age Intravenous drug use Long-term systemic steroids Diabetes mellitus Organ transplantation Malnutrition Cancer ```

Question 33

In the detection of parenchymal abnormalities such as abscesses and infarctions, which imaging modalities are best

Answer 33

MRI is superior to CT

Question 34

India ink stain is used to identify which organism?

Answer 34

cryptococcus neoformans

Question 35

what are the bacterial meningitis results like on csf?

Answer 35

``` Turbid - purulent low glucose high cell count - polymorphs higher protein positive stain/antigen ```

Question 36

what are the viral meningitis results like on csf?

Answer 36

Clear or slightly turbid 15-500 lymphocytes Negative stain Normal glucose

Question 37

ddx for aseptic meningitis?

Answer 37

Viral meningitis, partially antibiotic treated bacterial meningitis, encephalitis, brain abscess, TB/fungal meningitis

Question 38

what are the tb meningitis results like on csf?

Answer 38

``` Clear or slightly turbid 30-500 lymphocytes or polymorphs Negative stain high protein low glucose ```

Question 39

how long do CSF analysis and CSF cultures take?

Answer 39

analysis 1-2 hours | culture At 24-48 hours

Question 40

treatment for meningitis ?

Answer 40

Ceftriaxone 2g iv bd If >50yrs or immunocompromised add: Amoxicillin 2g iv 4hourly

Question 41

treatment for meningo-encaphalitis?

Answer 41

Ceftriaxone 2g iv bd Aciclovir 10mg/kg iv tds If >50yrs or immunocompromised add: Amoxicillin 2g iv 4hourly

Question 42

treatment for meningo-encaphalitis?

Answer 42

Ceftriaxone 2g iv bd Aciclovir 10mg/kg iv tds If >50yrs or immunocompromised add: Amoxicillin 2g iv 4hourly

Question 43

in which causes of meningitis do we use Pen G 18-24 mu/d ?

Answer 43

Strep. pneumonia Group B strep Listeria (ampicillin 1st if possible)

Question 44

in which causes of meningitis do we use Cefotaxime?

Answer 44

H. influenza gram negs