In Reply.—Drs Tobin and Jaffee address an important clinical point: at the bedside, large intracranial mass lesions, such as brain abscesses, subdural empyemas, and even brain tumors, may be indistinguishable from or (except in the last case) accompanied by bacterial meningitis. Although the diagnosis of bacterial meningitis should not be significantly delayed, LP may expose the patient to risk of severe neurological injury or death from temporal lobe or cerebellar herniation when such a mass is present. It is just such a mass that may make the patient's condition appear to be deteriorating. Whether to perform a neuroradiological procedure such as a CT scan before lumbar puncture is a matter to be judged for each clinical situation.
If lumbar puncture is followed by acute deterioration, which is often in the form of posturing or respiratory arrest, the appropriate measures to take would include intubation, hyperventilation, administration of intravenous mannitol