[Spinal puncture in suspected purulent meningitis].

Today, CT scan of the brain is performed as a routine a the first diagnostic procedure in cases of suspected acute subarachnoid haemorrhage. Subarachnoid blood is demonstrated in a high percent of these cases provided that the scan is carried out within the first few days after the bleeding. Furthermore, the scan may also disclose localised intracranial haematoma or other expansive lesions with brain shift. In such cases, lumbar puncture may be dangerous, due to the risk of herniation. In cases of suspected acute bacterial meningitis or other infectious disease of the central nervous system, performance of a CT scan before lumbar puncture is not a well established procedure. Two case histories are described. Both patients had brain abscesses and deteriorated dramatically after lumbar puncture. The role of brain CT scanning in the management of such patients is discussed.