Meningitis Flashcards
What is ‘meningism’
Headache
Neck stiffness (passive flexion) - key finding
Photophobia
Sometimes with vomiting
What are the common causes of meningitis? Including some non-infective causes?
Bacterial
- neisseria - ‘meningococcal’ - most common cause in children
- strep pneumoniae - ‘pneumococcal’ - most common cause in adults
- E. coli/group B strep - in neonates
Viral
- enteroviruses - echo/parecho/coxsackie
- Mumps (rare)
- HSV
Less common causes
- H flu type B
- Listeria
- Mycobacterium TB
- Leptospirosis, Borrelia, Mycoplasma
- HIV, Varicella-Zoster virus, EBV
Fungal
- Cryptococcus neoformans
Non-infective causes
- tumour cells in CSF = ‘aseptic’
How does meningitis present?
In addition to meningism (neck stiffness, photophobia, headache)
- vomiting
- fever
- reduced consciousness
- sometimes cranial nerve features
What are some risk factors for meningitis?
Recent skull trauma
Alcoholism
Diabetes Mellitus
Exposure to close contact with recent meningitis
What features may you look for on examination in someone with suspected meningitis?
Fever
GCS
Skin/conjunctival petechiae (purpuric - 60% of meningococcal, and other types)
Other rashes
BP in case of septic shock
Kernig’s sign
Neck flexion
What investigations may be performed in suspected meningitis?
LP - be aware of SOL - CT first if papilloedema/focal neuro signs
- Gram staining of CSF, cell counts, antigen detection, culture (bacterial and fungal), PCR, glucose + protein
Blood cultures
What will CSF findings be in meningitis - bacterial vs viral (and vs TB)
Bacterial
- turbid
- greatly increased cells
- neutrophils predominant
- reduced glucose
- greatly increased protein
Viral
- clear/turbid
- moderate increase
- lymphocytes predominant
- normal glucose
- moderately increased protein
TB
- very similar to viral
- except greatly increased protein, reduced glucose
How is bacterial meningitis treated?
Broad-spectrum until pathogen identified Antibiotic must penetrate into CSF - benzylpenicillin and ceftriaxone - try to take blood cultures first \+ supportive therapy
What is a similar, severe meningococcal illness to be aware of?
Fulminant meningococcal septicaemia
- startling sudden symptoms
- rapid deterioration of consciousness
- fever, septic shock, renal failure, disseminated intravascular coagulation
- purpuric rash characteristic
Sterile CSF - technically not meningitis - no increased white cells
50% die within first 24 hours
Rapid antibiotics
Who gets prophylaxis for meningococcal infection, and what is the prophylaxis?
Notifiable
Close contacts - family, roommates, school contacts
Rifampicin or ciprofloxacin to eradicate organism from nasopharynx
How is viral meningitis treated?
Enteroviruses and parechoviruses - symptomatic
- usually recovers within 72 hours
- IV Immunoglobulin if becomes chronic
HSV - aciclovir
Who is most at risk of fungal meningitis?
Those with HIV
Sometimes also seen in diabetes, lymphoma, and the immunosuppressed
How might fungal meningitis present?
Similar symptoms, but meningism less common at initial presentation
How is fungal meningitis treated?
Amphotericin
sometimes with flucytosine
