Mild (Aseptic meningitis)


Headache, fever and meningeal symptoms


  • Brain MRI to exclude brain metastasis and leptomeningeal involvement
  • Lumbar puncture after brain imaging: CSF
    • white blood cell analysis (ideally including flowcytometry analysis)
    • protein level
    • glucose level
    • presence for cancer cells
    • infectious workup (incl. viral serologies and (myco)bacterial analysis in CSF and blood according to local practice)
    • lactate
  • Open pressure measurement (done during lumbar puncture)


  • Suspend ICPi untill clear diagnosis
  • Exclude infectious cause before start of steroids
  • Prednisone according to local practice: symptoms should disappear within 1 week if not: treat as severe aseptic meningitis
  • Symptomatic treatment (paracetamol and NSAID)
  • Restart of ICPi can be discussed in a multidisciplinary team if symptomatology was mild and steroids are stopped for some time
  • Evacuating lumbar punctures to lower elevated ICP, consider other measures to lower elevated ICP


CSF: Cerebrospinal fluid
ICP: Intracranial pressure
ICPi: Immune Checkpoint Blockade Inhibition
ICU: Intensive Care Unit
MRI: Magnetic Resonance Imaging
NSAID: Non Steroidal Anti-Inflammatory Drugs