ABSTRACT
Laboratory diagnosis of viral infections is often made by examination of the cerebrospinal fluid and, less frequently, brain biopsy or other tissue specimens; adequate sampling is essential to increase the diagnostic yield. Commonly used diagnostic methods include nucleic acid tests (NATs), cytology, histology, viral culture, antigen detection, electron microscopy, and various serological techniques. In this chapter, the authors briefly describe the epidemiological context of viral CNS infections and typical clinical presentations, discuss the importance of sample collection and transport, present a general overview of current testing methods, and finally detail specific diagnostic modalities for established and emerging viral CNS pathogens. However, it is important to emphasize that CNS viral infections have serious clinical and, in some cases, public health implications; thus, an early, aggressive approach to specimen collection is warranted, guided by the patient's clinical presentation and risk factors.
