L11 - CNS finections

Question 1

What infections may occur in the brain?

Answer 1

meningitis
encephalitis
brain abscess

Question 2

What is meningitis?

Answer 2

infection of membranes surrounding the brain

Question 3

What 3 bacteria case >80% of bact meningitis?

Answer 3

H. influenzae

N. meningitidis

S. pneumoniae

Question 4

What is worse - viral or bacterial meningitis

Answer 4

bacterial

viral - self-limiting infection - complete recovery normally

Question 5

What are causes of neonatal meningitis?

Answer 5

Group B Strep

L. monocytogenes

Enterobacteriaceae

Question 6

Fatcs about S. pneumoniae meningitis?

Answer 6

gram-pos diplococcus

encapsulated

most COMMON cause of bacterial meningitis

occurs at any age

20-30% mortality

Question 7

Facts about N. menigitidis pneumonia?

Answer 7

gram-neg diplococcus

capnophilic

CAPSULE required for infection

most common in childred/young adults

Question 8

skin symptoms of N. meningitidis meningitis?

Answer 8

non-blanching rash

Question 9

What does the capsule prevent from?

Answer 9

opsonisation and complement-mediated lysis

Question 10

How does S.pneuomoniae bind and invade?

Answer 10

Ply overreacts the complement system

Adhesins PspA

PAFR - mediated uptake

Question 11

How does N. meningitidis bind and invade?

Answer 11

Type IV pilli

Cortical plaque production - open inter-endothelial junctions

Question 12

Facts about H. influenzae meningitis?

Answer 12

Gram-neg pleomorphic

capsule

Question 13

How are infants protected from H. influenzae?

Answer 13

mother’s antibodies, then they are vaccinated

not protected in between vaccinnation

Question 14

What is M. tuberculosis meningitis?

Answer 14

‘chronic’

difficult to diagnose = delay treatment

can’t gram stain, grows slowly in culture

Question 15

What are symptoms of meningitis?

Answer 15

fever
severe headache
Kernig’s sign (stiff neck)
Photophobia

Question 16

What is examined in the lab to detect meningitis?

Answer 16

CSF

Question 17

What can be done in the lab to diagnose meningitis?

Answer 17

macroscopic - blood (should NOT be in CSF)

microscopy - cell count, Gram/India ink stain

culture

Biochemistry

Molecular based detection

Question 18

How is real-time PCR used to identify causative agents of meningitis?

Answer 18

TaqMan probes

flourescence occurs when polymerase cleaves the probe, releasing the fluorophore and quencher

Question 19

What chemotherapy is used for menigits?

Answer 19

SO many

look at slides

Question 20

What is a brain abscess?

Answer 20

suppurative pus-filled lesions in brain parenchyma

Question 21

What are symptoms of a brain abscess?

Answer 21

fever
headache
seizures

Question 22

What bacteria cause brain abscess?

Answer 22

POLYMICROBIAL

Strep
S.aureus
Bacteroides
Gram-neg enteric

Question 23

How is a brain abscess diagnosed?

Answer 23

CT scan

NO lumbar puncture - OTHERWISE coning can occur - brain ‘sucked’ down spine

Question 24

What is a subdural empyema?

Answer 24

infection between outer 2 meningeal layers

POLYMICROBIAL

Question 25

What are the symptoms of subdural empyema?

Answer 25

fever
confusion
headache
seizure
coma

Question 26

What is a ventricular shunt infection?

Answer 26

shunt release high inter-cranial pressure causes in hydrocephalus

biofilm infection by CoNS

Question 27

How can a ventricular shunt infection occur?

Answer 27

surgical approach

seeding of organisms in the blood