[Detecting infectious agents in central nervous system inflammation by cerebrospinal fluid analysis].

Cerebrospinal fluid analysis is the method of choice in CNS infection and provides the basis for appropriate treatment. Due to the proximity of CSF and CNS, the infectious agent may be detected directly by microscopy or antigen or nucleic acid detection--the latter by polymerase chain reaction--in native CSF or after culture. Furthermore, intrathecal antibody synthesis against the infectious agent may identify the cause of infection. This indirect antigen detection method requires correction for a systemic antibody response and a blood-CSF barrier disturbance. The following text gives an overview of appropriate detection methods and their relevance to the most important CNS infections.