CNS infections and meningitis Flashcards
List the 4 Four routes of entry in CNS infections
a) haematogenous spread
b) direct implantation
c) local extension
d) PNS into CNS
which areas do the following affect:
Meningitis
Encephalitis
Myelitis
Neurotoxin
Meningitis - meninges
Encephalitis - brain
Myelitis - spinal cord
Neurotoxin - CNS and PNS
Distinction between mengitis and encephalitis
Encephalitis - brain function disturbance:
confusion or disorientation
personality change
speech difficulty
List organisms that can cause meningitis?
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
List organisms that can cause Encephalitis?
RAAPT:
Rabies Arboviruses Ameoba Prions Trypanosoma
Toxoplasmosis
Bacterial encephalitis:
Listeria monocytogenes
List organisms that can cause disturbance of nerve transmission - Myelitis?
polio
List organisms that can cause
- rigid paralysis
- flaccid paralysis
- clostridium tetani
2. clostridium botulinum
what is Meningoencephalitis?
inflammation of meninges and brain parenchyma
list the meninges from top to bottom in brain?
DAP
dura
arachnoid
pia
In the UK, ~ 5% of _____ survivors have neurological sequelae, mainly sensorineural deafness??
meningitis
neurologiical damage in meningitis is caused by?
Direct bacterial toxicity.
cytokine release and oedema.
Shock, seizures, and cerebral hypoperfusion.
3 classes of meningitis and their causes?
a) Acute
usually bacterial meningitis
b) Chronic usually TB, spirochetes, cryptococcus c) Aseptic
how is Neiserria meningitides transmitted?
Transmission is person-to-person, from asymptomatic carriers.
Through nasopharyngeal mucosa in a susceptible individual.
how long from exposure to infection in Neiserria meningitides?
Causes infections in less than 10 days
characterise the rash in meningitis?
which is most popular?
A nonblanching rash (petechial or purpuric) develops in 80% of children.
A maculopapular rash remains in 13% of children,
No rash occurs in 7%.
The clinical difference between septicemia and meningitis is important. why?
because patients who present with shock are treated
differently than patients who present primarily with increased intracranial pressure
what are the processes underlying septicaemia?
4 processes:
Capillary leak;
Coagulopathy; bleeding and thrombosis.
Metabolic derangement; particularly acidosis
Myocardial failure….multi-organ failure.