Contraindications to performing lumbar puncture (LP):
- INR > 1.4 or other coagulopathy
- Platelets < 50
- Infection at desired puncture site
- Obstructive / non-communicating hydrocephalus
- Intracranial mass
- High intracranial pressure (ICP) / papilledema (relative contraindication depending on etiology; especially a concern with intracranial mass lesion secondary to the increased risk of transtentorial or cerebellar herniation)
- Focal neurological symptoms/signs, decreased level of consciousness
