Correlation 9: Meningitis

Note the yellow-tan cloudiness that obscures the sulci of the cerebral cortex, as seen at the vertex of the brain.

An infection that involves the meninges produces meningitis. (Infection leads to inflammation, and the suffix for any inflammatory process is "-itis") Infectious organisms, typically bacteria, can be introduced via trauma with injury to the skull, but more commonly infection spreads to the meninges via the bloodstream from another site, such as the lungs. Patients with meningitis can present with sudden onset of a severe headache. Irritation of the nerve roots exiting the lower brain stem and cord can lead to a stiff neck. The diagnosis can be made by doing a lumbar puncture to obtain cerebrospinal fluid (CSF). The CSF will have increased numbers of white blood cells in a case of meningitis. It may be possible to identify the infectious organisms in the CSF by microscopy or by culture.