Infective agents in the central nervous system.

Almost all agents can cause infection within the central nervous system. The extent of infection ranges from diffuse involvement of the meninges, brain, or spinal cord to localized involvement presenting as a space-occupying lesion. Epidemiologic considerations, appreciation of the presenting clinical syndrome (acute bacterial meningitis, acute aseptic meningitis, chronic meningitis, or space-occupying lesion), and cerebrospinal fluid analysis facilitate arrival at a diagnosis.