Cranial computed tomography (CT) is of limited use in acute bacterial meningitis. It has been used mistakenly to exclude raised intracranial pressure.12 CT in cerebral oedema may show slit-like lateral ventricles, areas of low attenuation, and absence of basilar and suprachiasmatic cisterns. However, there is considerable variation in the size of normal lateral ventricles, which makes interpretation of the CT scan difficult. There are case reports of cerebral herniation following an LP with a normal CT scan.13 In a prospective Canadian study of 41 children, clinical management was not influenced by CT findings; those abnormalities detected were already suspected on neurological examination.14 The main indication for a CT scan in meningitis is when the diagnosis is uncertain and other possible causes of meningism are being considered, for example, posterior fossa tumours or if complications of meningitis are suspected, for example, cerebral abscess. Any decision to perform a CT should not delay the use of antibiotics.