Lumbar puncture in the presence of increased intracranial pressure: the real danger.

Examination of cerebrospinal fluid remains a mainstay of the diagnosis of many acute central nervous system illnesses, including meningitis, encephalitis, and polyneuropathies such as Guillain-Barré syndrome. Although generally considered innocuous, there may be considerable danger when lumbar puncture is performed in the presence of increased intracranial pressure, especially when a mass lesion is present. We review the literature surrounding the danger of lumbar puncture when intracranial pressure is increased and discuss our approach to the problem in lieu of the advent of computerized tomographic scanning.