Non-infectious fever in a post neurosurgical patient

Fever is common in the post operative period and often poses a diagnostic dilemma. Clinical signs, cerebrospinal fluid (CSF) findings in the post neurosurgical patient are not always useful to distinguish bacterial meningitis from a nonbacterial meningeal syndrome (NBMS). Therefore, CSF lactate > 4.2 mmol/L has been proposed to be positive discriminative factor for bacterial meningitis. We report a case of posterior fossa syndrome in which an elevated CSF lactate was not useful in making this distinction as it could have been raised due to the fact that the CSF was xanthochromic.

It is very important to differentiate NBMS from bacterial meningitis in the post neurosurgical period. We also emphasize on the fact that empirical antibiotics before CSF examination should be avoided to maximize the chances of a positive culture. If NBMS is found, further unnecessary investigations and unnecessary use of antibiotics can be avoided which is an important aspect of antibiotic stewardship.