Micro 7 : CNS infections

Question 1

which virus can infect the cNS from the PNS?

Answer 1

Rabies

Question 2

most common route of entry of pathogens in to the brain?

Answer 2

Haematogenous

Question 3

main clinical difference between encephalitis and meningitis

Answer 3

in encephalitis you have severe disturbance of brain function

Question 4

3 subclassifications of meningitis

Answer 4

acute (hours to days)
chronic (days to weeks)
aseptic (caused by viruses so there is no pus)

Question 5

3 main causes of acute meningitis

Answer 5

Neisseria meningitiis, streptococcus pneumonia and haemophilus influenzae

Question 6

3 main causative organisms of meningitis in neonates

Answer 6

E coli
GBS
Listeria

Question 7

Main causes of meningitis in elderly

Answer 7

GBS + Listeria

Question 8

main cause of chronic meningitis

Answer 8

TB, cryptococcus neoformans (lower mortality than acute meningitis)

Question 9

what is the most common infection of the CNS?

Answer 9

Aseptic meningitis

Question 10

most common viruses causing meningitis

Answer 10

Coxsackie group B virus

echoviruses

Question 11

management of viral meningitis/aseptic

Answer 11

self-limiting, usually heals in 1-2 weeks

Question 12

viral causes of encephalitis - which most common in UK and which worldwide?

Answer 12

UK - HSV2
World-wide: arbovirus

MMR
VZV
West Nile

Question 13

viral causes of encephalitis - which most common in UK and which worldwide?

Answer 13

UK - HSV1
World-wide: arbovirus

MMR
VZV
West Nile

Question 14

1 organism which causes severe infection in the immunocompromised and can cause encephalitis?

Answer 14

Toxoplasmosis

Question 15

enhancing lesion on MRI

Answer 15

Brain abscess

Question 16

main causative organisms of brain abscesses

Answer 16

Strep > Staph > gram -ves > TB/fungi/parasites

Question 17

which imaging modality is best for visualising parenchymal abnormalities?

Answer 17

MRI

Question 18

india ink stain ?

Answer 18

Cryptococcus neoformans

Question 19

CSF results in TB meningitis

Answer 19

V high protein
Low glucose
Lymphocytes
-ve gram stain (Scanty AFB)

Question 20

CSF results in viral meningitis

Answer 20

High protein
Normal glucose
Lymphocytes
-ve gram stain (Aseptic)

Question 21

CSF results in bacterial meningitis

Answer 21

High protein
Low glucose
polymorphs
+ve gram stain

Question 22

gram +ve red causing meningitis in elderly

Answer 22

Listeria monocytogenes

Question 23

MSM
High opening pressure on LP
Which meningiits?

Answer 23

Cryptococcus neofromans

HOP pathognomic of cryptococcus

Question 24

MSM
High opening pressure on LP
Which meningiits?

Answer 24

Cryptococcus neofromans

HOP pathognomic of cryptococcus

Question 25

appearance of CSF in TB meningitis

Answer 25

fibrinous

Question 26

empirical antibiotics in an adult with suspected meningitis

Answer 26

IV ceftriaxone (+ ampicillin/amoxicillin if >50 or immunocompromised)

Question 27

When would you consider steroids?

Answer 27

Risk of cerebral oedema

Question 28

meningoencephalitis mx

Answer 28

IV acyclovir + ceftriaxone (+ampicillin >50)

Question 29

Gram +, alpha haemolytic diplococcus

Answer 29

streptococcus pneumonia