Meningitis Flashcards Preview

Year 3 Human Disease > Meningitis > Flashcards

Flashcards in Meningitis Deck (30):
1

what drug caused big decrease in mortality of meningitis

penecillin

2

what is the mortality rate of meningitis

10-100%

3

5 disabilities caused by meningitis

-deafness
-paralysis
-speech problems
-epilepsy
-neuro-psychiatric problems

4

where is csf produced

choroid plexus in the ventricles

5

order of meninges out-in

DAP
Dura
arachnoid
pia

6

define meningitis

inflammation of lepto-meningeal membranes

7

4 infectious causes of meningitis and examples

virus (enterovirus, mumps (zosterovirus), herpes)
bacteria (meningococci, pneumococci, h influenzae)
fungus (cryptococcus neoformans, coccidiodomycosis)
parasitic (naegleria fowleri, acanthamoeba)

8

3 routes by which organisms reach the cns

-bacteraemia/ viraemia/ parasitaemia: in the blood, esp through choroid plexus
-direct spread: chronic infections in cranial bones, ears, sinuses, oral cavity or upper resp tract
-neuronal spread: infection of peripheral neurones, axonal transport, replication and cell-cell spread of infection to connecting neurones on CNS

9

flowchart of meningitis pathogenesis 9 (see lecture)

mucosal colonisation -->
intravascular survival -->
meningeal invasion -->
survival in subarachnoid space -->
inflammatory response, inc BBB permeability, cerebral vasculitis -->
oedema, CSF flow disturbances -->
inc intracranial pressure, dec cerebral blood flow -->
loss of cerebro-vascular autoregulation -->
coma, death

10

4 factors influencing cause of bacterial meningitis

-age ( BBB not fully formed. >75, BBB weakens)
-geography (overcrowding, high temp --> epidemics)
-immunity (chemo/ transplants/ steroids)
-trauma/ post-neurosurgical (esp base of skull, as oropharyngeal trauma enter skull)

11

why do neonates have different bacterial causes of bacterial meningitis to other age groups?

due to mothers bacteria during birth

12

what are the common bacterial causes of bacterial meningitis in >50s, immunocomp, basilar skull fracture 2

s pneumoniae
n meningitidis

13

additional bacteria in
a. >50/immunocompromised
b. basilar skull fracture

a. >50/immunocompromised: listeria, gram - bacilli, pseudomonas aeruginosa (immunocomp)
b. basilar skull fracture: group A beta-hemolytic strep

14

4 bacterial causes of head injury/ post neurosurgery meningitis and why these are different to most

-s aureus
-s epidermis
-aerobic gram - bacilli
-p aeruginosa
oropharyngeal/ skin flora

15

5 symptoms of meningitis

-fever
-neck stiffness
-altered mental state
-headache
-photophobia

16

3 signs of meningitis

-neck rigidity
-kernigs sign
-brudzinski's sign

17

problems with
A. signs
b. symptoms of meningitis

a. signs: common to many illnesses, normally not all present in meningitis
b. symptoms: only 5% sensitivity

18

what is the gold standard test in CNS infection diagnosis

lumbar puncture

19

normal csf:
a. colour
b. opening pressure
c.lymphocyte count
d. protein
e. glucose
f. gram stain
g. culture

a. colour: clear
b. opening pressure: 5-20cm
c.lymphocyte count: 60% of blood glucose
f. gram stain: NOS
g. culture: sterile

20

csf findings in meningitis *TABLE*
when is a CT/ MRI scan needed before lumbar puncture 3
and WHY

-fitting
-focal neurological disorder
-dec on coma scale
--> may be something else where lumbar puncture contraindcated, eg cerebral tumour, subarachnoid haemorrhage, frontal sinusitis

21

6 indications of neuro-imaging in meningitis

- history of unconsciousness
-history of seizures
-focal neurology
-low gcs

22

4 main complications of bacterial meningitis and explain each

-seizures (scar epilepsy): scarring of brain tissue are foci of epileptic activity
-hydrocephalus: thickened CSF/ fibrinoid accumulations --> CSF builds up in brain --> pressure on brainstem --> cardiorespiratory arrest
-infarcts:vascular pressure/ vasculitis --> failed blood supply --> tissue dies --> haemoplegia, palsy
-transtentorial herniation: inc intracranial pressure --> pressure on brainstem (resp and motor centres) --> coma, death

23

management of meningitis 5

-supportive care
-specific antimicrobial therapy
-steroids
-surgical intervention
-prophylaxis

24

6 aspects of supportive care of meningitis

-airway
-breathing
-circulation
-nutrition
-physiotherapy
-rehabilitation

25

6 considerations of specific antimicrobial therapy for meningitis

-pathogen
-sensitivities/ resistance of pathogen
-csf penetration
-allergy, renal function etc
-route (IV, IT, IM, PO)
-duration of therapy

26

name antibiotics with good penetration 4

-penicillin
-ceftriaxone
-meropenem
-chloramphenicol

27

name antibiotics with poor penetration 2

vancomycin
gentamycin

28

when to use steroids to treat meningitis

BEFORE anything else (antibiotics, lumbar puncture etc)

29

2 roles of neurosurgery in meningitis management

-definitive (eg must drain csf in hydrocephalus)
-supportive: for IT antibiotics, external ventricular drain (EVD)

30

2 prophylaxis methods of meningitis

antibiotics
vaccines