Fact-sheet: Meningitis


Updated on 09/01/2021 at 11:48 AM

Note : 10/10 ( 1 note )

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Definition

Most common organisms:

- Neisseria meningitidis in young adults

- Streptococcus pneumoniae at all ages.

Most common portal of entry: airways.

Meningeal dissemination: via the hematogenous route.

Clinical features

- Meningeal syndrome: headaches, neck stiffness, Brudzinski and Kernig signs
- Infectious syndrome
- Signs of severity: purpura, shock, seizures, focal neurological signs, encephalopathy, signs of elevated ICP
Complications:
- hydrocephalus
- ventriculitis, ependymitis
- abcess of brain
- empyema
- vasculitis
- dural sinus thrombosis, most often by contiguity

Laboratory findings

Biological inflammatory syndrome

Lumbar puncture: to be performed before imaging UNLESS focal neurological signs or elevated ICP are present
- Hypercellular CSF (>10/mm3), predominantly neutrophilic if bacterial meningitis, with low glucose and elevated protein

MRI

Essential sequences: Diffusion, T2 FLAIR, T1 without and with gadolinium injection
- Diffusion hyperintensity of the cortical sulci
- T2 FLAIR hyperintensity of the subarachnoid spaces
- Meningeal enhancement after injection:
leptomeningeal: cortical sulci and basal cisterns;
pachymeningeal: linear rather than nodular dural enhancement

Management

Emergency empirical antibiotic therapy after lumbar puncture without waiting for results
UNLESS purpura fulminans is present: immediate antibiotic therapy with an adequate dose of third-generation cephalosporin