Meningitis Flashcards
What is Meningitis?
inflammation of the leptomeningeal (pia + arachnoid mater) coverings of the brain
What is meningitis usually due to?
Infection
Describe the aetiology of meningitis
Viral
Bacterial
Aseptic
Non-infective (cancer, AI, drugs)
What is Meningococcal meningitis? What sign is indicative of this?
Neisseria meningitidis meningitis
Non-blanching rash/ cutanoues petechiae
What is Pneumococcal meningitis?
Streptococcus pneumoniae meningitis
What are the 3 most common causes of bacterial meningitis?
Neisseria meningitis
Haemophilus influenzae type B
Streptococcus pneumoniae (most common in adults)
What is the classic triad of meningitis?
Fever
Meningismus: headache, neck stiffness, photophobia
Altered mental state
List 4 symptoms of meningitis
Classic triad
N+V
Drowsiness
Seizures
List 3 signs of meningitis
Neck stiffness
Kernig’s Sign
Brudzinski’s Sign
What is Kernig’s sign?
Hips flexed, pain/ resistance on passive knee extension
What is Brudzinski’s sign?
flexion of hips when neck is flexed
List 3 risk factors for meningitis
Immunosuppression
Crowding (homes, students)
Close contact with infected person
List 4 signs suggestive of meningoencephalitis
Focal neurological signs (e.g., paresis, extrapyramidal Sx, aphasia)
Seizures (focal-onset or generalized)
Behavioral changes, psychosis
Altered consciousness
Describe immediate management of suspected meningitis in the community
Blue light to hospital
IM Benzylpenicillin
What dose IM benzylpenicillin should be used in suspected meningitis?
<1y: 300 mg
1–9y: 600 mg
Adults + >10s: 1.2 g
Describe immediate management of suspected meningitis in the hospital
A-E
Dexamethasone 10mg IV
Ceftriaxone or Cefotaxime 2g IV (empiric)
What investigations are used in meningitis?
FBC
Blood cultures x 2
Blood glucose
U+Es
LFTs
Serum Pneumococcal + Meningococcal PCR
LP + CSF analysis
When is imaging performed in suspected meningitis? What modality?
CT head
Before LP if raised ICP is suspected
What would a lumbar puncture of bacterial meningitis show?
Cloudy CSF
High neutrophils/ polymorphs
High protein
High opening pressure
High lactate
Low glucose (<1/2 plasma glucose)
What may be found on gram stain of CSF in bacterial meningitis?
Meningococci: -ve diplococci
Pneumococci: +ve diplococci
Haemophilus influenzae: -ve coccobacilli
Listeria: +ve rods
What would a lumbar puncture of viral meningitis show?
Cloudy/ clear
High lymphocytes
N/ High protein
N/ High opening pressure
Variable lactate
Normal glucose
What would a lumbar puncture of TB meningitis show?
CSF slightly cloudy, fibrin web
High lymphocytes + WCC
High protein
High opening pressure
High lactate
Low glucose
Describe management of confirmed bacterial meningitis
Targeted Abx
+/- Dexamethasone 10mg IV
In which patients with meningitis is dexamethasone indicated? Why?
Meningitis due to S. pneumoniae or H. influenzae
Reduces local + systemic inflammation
What are 5 neurological complications of meningitis?
Sensorineural hearing loss (most common)
Seizures
Focal neurological deficit
Infective: sepsis, intracerebral abscess
Pressure: Herniation, Hydrocephalus
Name a complication specific to meningococcal meningitis
Waterhouse-Friderichsen Syndrome
Adrenal failure secondary to adrenal haemorrhage
Give 3 prognostic facts about meningitis
Bacterial: fatal if untreated
Mortality risk very low for other causes.
Viral: resolves spontaneously in most
