Aseptic Meningitis Management

Initial CSF Examination

The initial CSF examination is essential for diagnosis and includes CSF opening pressure measurement, CSF cell count and differential, CSF glucose with concurrent plasma glucose, CSF protein, CSF lactate, Gram stain and culture, and PCR testing for viral pathogens, according to the Journal of Infection guidelines 1, 2, 3, 4, 5
The initial CSF examination should include measurement of CSF opening pressure, unless performed in sitting position, as recommended by the Journal of Infection 1, 2

Normal to mildly elevated protein levels are typically found in aseptic meningitis, with normal glucose levels and a CSF:plasma glucose ratio >0.66, as reported by the Journal of Infection 1, 2

The UK Joint Specialist Societies guideline does not recommend routine follow-up CSF examination for aseptic meningitis with clinical improvement, as stated by the Journal of Infection 6, 3
Clinical improvement is a more reliable indicator for treatment decisions than serial CSF examinations, according to the Journal of Infection 6, 5
Once viral etiology is established through initial CSF PCR testing, repeat examination adds little diagnostic value, as reported by the Journal of Infection 5

Failure to clinically improve despite appropriate treatment may require repeat CSF examination, as recommended by the Journal of Infection 6
Concern for development of complications or unusual presentation may also necessitate repeat CSF examination, according to the Journal of Infection 5, 2

Antibiotics can be safely discontinued once viral etiology is confirmed, as stated by the Journal of Infection 3, 5

Continuing unnecessary antibiotics after viral etiology is confirmed should be avoided, as recommended by the Journal of Infection 3, 5
Delaying discharge in patients with confirmed viral meningitis who are clinically improving should also be avoided, according to the Journal of Infection 3, 5

Typical CSF findings in aseptic meningitis include lymphocytic pleocytosis, mildly elevated protein levels, normal or slightly decreased glucose levels, and a CSF:plasma glucose ratio >0.66, according to the Journal of Infection guidelines 7
CSF PCR can rapidly identify viral pathogens with high sensitivity (87-100%) and specificity (98-100%), especially valuable when antibiotics have been given prior to lumbar puncture, as reported in Clinical Microbiology and Infection 8

For most neurologic immune-related adverse events, including aseptic meningitis, initial diagnostic workup should include MRI of the brain and/or spine with and without contrast and CSF analysis, including cytology, to rule out leptomeningeal metastasis, as recommended by the Journal of Clinical Oncology 9, 10
CSF analysis is helpful in cases of clinical suspicion of encephalitis, aseptic meningitis, and sensorimotor neuropathy, often revealing lymphocytic pleocytosis and elevated protein, according to the Journal of Clinical Oncology 9, 11
In patients with suspected meningitis, it is essential to evaluate for new confusion, altered behavior, aphasia, seizure-like activity, or short-term memory loss, which might suggest encephalitis rather than aseptic meningitis, as noted in the Journal of Clinical Oncology 10