Table 1 Diagnostic criteria for intracranial infection

Definitive diagnosis of an infection

Aetiological diagnosis: culture of pathogenic bacteria in CSF or positive immunological identification of pathogenic microorganisms in CSF

Diagnosis of a potential infection

(1) Fever (temperature ≥ 38 °C), headache, stiff neck, meningeal signs, cranial nerve signs, and/or irritability with no other recognized cause

(2) Examination of CSF released by lumbar puncture: cloudy, intracranial pressure > 200 mmH₂O, white blood cell count >  50 × 10⁶/L, glucose < 2.2 mmol/L or a CSF glucose/serum glucose ratio < 0.4, CSF protein > 0.45 g/L [9]

(3) CT or MRI findings: meningitis often indicates diffuse brain oedema; ventriculitis indicates ventricular dilatation or fluid level in the ventricle; circular enhancement can be seen in brain abscesses