Download Aseptic Meningitis

Aseptic Meningitis
30/10/10
Uptodate
= meningeal inflammation with negative bacterial cultures.
CAUSES (great table in Uptodate)
- enteroviruses (most common)
- other infections (mycobacteria, fungi, spirochetes, viruses)
- parameningeal infections
- malignancy (lymphoma, leukaemia, metastatic disease)
- autoimmune (sarcoid, SLE, Bechets)
- medications (NSAIDs, co-trimoxazole, anti-CD3 monoclonal antibody, azathioprine) -> either (1)
delayed hypersensitivity or (2) direct meningeal irritation
HISTORY
- there may be much overlap between aseptic meningitis, encephalitis and aseptic meningitis on
presentation.
- in encephalitis brain function abnormal:
-> altered mental status (confused, agitated, obtunded)
-> motor and sensory deficits
-> altered behaviour
-> personality changes
-> speech disorders
-> movement disorders
-> seizures
-> hemiparesis
-> cranial nerve palsies
-> exaggerated deep tendon reflexes
- meningitis: headache, uncomfortable and lethargic (but normal brain function)
-
travel history
exposure to rodents (lymphocytic choriomeningitis virus), ticks(Lyme) and Tb
sexual activity (HSV 2, HIV, syphilis)
contacts with viral exanthems (enteroviruses)
drug history (NSAIDs, IV Ig, co-trimoxazole)
EXAMINATION
-
diffuse maculopapular exathem (enterovirus, HIV, syphilis)
parotitis (mumps)
vesicular and ulcerative genital lesions (HSV 2)
oropharyngeal thrush and cervical lymphadenopathy (HIV)
Jeremy Fernando (2011)
- asymmetric flaccid paralysis (West Nile virus)
INVESTIGATIONS
CSF
-
opening pressure
PCR for HSV
VDRL
HIV antibody
RNA testing
Lyme serology
fungal and mycobacterial culture
- bacterial meningitis: positive gram stain, WCC > 1000, glucose < 2.2
- viral meningitis: WCC < 500, >50% lymphocytes, low protein, normal glucose
Serum
-
VDRL
HIV antibody
RNA testing
Lyme serology
acute and convalescent serology (LCMV, mumps, measles)
CT head
MRI
MANAGEMENT
- ceftriaxone 50mg/kg IV OD
- acyclovir 10mg/kg Q8hrly
- consider repeat LP
Jeremy Fernando (2011)