Meningitis is a rare complication following neurosurgical procedures and is associated with high morbidity and mortality. The aim of this study is to describe the clinical characteristics and microbiological characteristics in patients who develope meningitis following neurosurgical operations, and investigate the useful tips for the differential diagnosis of postneurosurgical meningitis.

Besides description of characteristics of patients with postneurosurgical patients, we also will investigate the usefulness of prolonged cerebrospinal fluid (CSF) culture, and profiles of blood and CSF inflammatory markers for the differential diagnosis of meningitis. CSF culture will be extended upto 2 weeks. Serum procalcitonin and C-reactive protein, CSF adenosine deaminase levels will be monitored and analyzed for the differential diagnosis of meningitis.

Inclusion Criteria:

• Cerebrospinal fluid corrected WBC >6/mm^3 and/or fever (> 38℃) and/or neck stiffness

Exclusion Criteria:

• Patients already treated more than 48 hours for meningitis before cerebrospinal fluid examination

All patient who develop meningitis after neurosurgical operation