brain abscesses and other infections of the central nervous system Flashcards Preview

Clinical Pathology > brain abscesses and other infections of the central nervous system > Flashcards

Flashcards in brain abscesses and other infections of the central nervous system Deck (29):
1

define brain abscess

focal suppurative process within the brain parenchyma

2

what are the main causes of brain abscess

bacterial
fungal
polymicrobial

3

what is the main bacterial pathogen which causes brain abscesses

streptococci (streptococcus milleri)

4

what 4 clinical settings do brain abcessess develop in.

direct spread- continuous supparative focus e.g. ear or sinus.
Haematogenous spread from a distant focus via bloodstream e.g. endocarditis (heart), bronchiectasis (lungs) (often multiple abscesses).
Trauma- post neurosurgery
Cryptogenic (no known cause)- no focus, commonly found in immunocompromised people as they have had the breakdown of the muscosal barrier and have access devices such as hickman lines.

5

clinical presentation of patient with brain abcesses

headache- most common
focal neurological deficit
confusion- generalised neurological deficit.
fever
nausea and vommitting
dizziness, seizures
neck stiffness
(papilloedema), coma- optic nerve swelling.

6

main treatment of choice for brain abscess

drainage

7

is the abscess in small drainage may not be used as treatment, what might be used ins tea

antibiotics

8

why is drainage the best option for treatment of brain abscess.

reduce ICP- can causes seizures and coms
confirm diagnosis- CT not 100%
obtain pus fro micobiological investigation.
to enhance efficacy of antibiotics
to avoid spread of infection to ventricles.

9

why are oral ampicillin, penicillin not used to treat brain abscesses.

they are not targeted to the right place. e.g. CSF and CNS

10

which antibiotics are used to treat brain abscesses.

cefuroxime (penetrate brain and CSF))
cefotaxime, ceftazidime (works against pseudomonal aspergilloma)
metronidazole achieve therapeutic concentrations in intracranial pus

11

unto how many weeks after surgery are antibiotics given to patients who had a brain abscess

4-6 weeks and then have a oral switch.

12

complications of a brain abscess

Raised intracranial pressure, mass effect.
Rupture (usually into ventricles) causing ventriculitis

13

what is the mortality rate if the brain abscess speeds to the ventricles

100%

14

define subdural empyema

Infection between dura and arachnoid mata-

15

most common pathogenic organisms to cause subdural empyema

often polymicrobial
anaerobes, streptococci, aerobic gram negative bacilli, streptococcus pneumoniae, haemophilius influenza and staphylococcus aureus (after surgery)

16

pathogenesis of subdural empyema

spread of primary infection from sinuses (most common) , middle ear and mastoid or distant site` and following surgery or trauma- but it does not enter the brain parenchyma it is stopped by the dura.

17

most common site of origin of infection of subdural empyema

sinuses

18

what is the clinical presentation of a patient with subdural empyema

headache, fever, focal neurological deficit, confusion, seizure, coma due to increased pressure.

19

how is subdural empyema treated

surgical drainage of pus
antimicrobial agents (guided by culture of pus results)

20

Is a Ventriculoperitoneal (VP) shunt permanent or temporary

permanent

21

what age groups present with Ventriculoperitoneal (VP) shunt

children

22

is a external ventricular drain (EVD) permanent of temporary

temporary.

23

in what conditions is a external ventricular drain (EVD) inserted to drain CSF

hydrocephalus.

24

how can Ventriculoperitoneal (VP) shunt and external ventricular drain (EVD) cause infection.

can become colonised with organisms that subsequently cause ventriculitis (often peritonitis)

25

2 main functions of external ventricular drain (EVD)

monitor ICP, and drain excess fluid.

26

how are Ventriculoperitoneal (VP) shunt and external ventricular drain (EVD) infections diagnosed

CSF microscopy and cultures

27

most common cause of Ventriculoperitoneal (VP) shunt and external ventricular drain (EVD) infections

coagulase negative staphylococci- common skin flora

28

treatment for Ventriculoperitoneal (VP) shunt and external ventricular drain (EVD)

device removal, intraventricular antibiotics

29

how doe we administer and antibiotics

start smart and then focus.