Last reviewed: 1 Feb 2021
Last updated: 17 Dec 2019
Summary
Definition
History and exam
Key diagnostic factors
- headache
- nausea and vomiting
- photophobia
- neck stiffness
- fever
Risk factors
- infants and young children
- young adults
- older people
- summer and autumn
- exposure to mosquito or tick vector
- unvaccinated for mumps
- use of swimming pools and ponds
- immunosuppression
- exposure to rodents
Diagnostic investigations
1st investigations to order
- CSF microscopy
- CSF Gram stain
- CSF bacterial culture
- CSF protein
- CSF glucose
- CT/MRI head
Investigations to consider
- EEG
- CSF viral culture
- PCR for enteroviruses
- PCR for herpes viruses
- HIV serology/HIV reverse transcriptase (RT)-PCR
Treatment algorithm
Contributors
Authors

Consultant
The James Cook University Hospital
Middlesbrough
UK
Disclosures
JW declares that he has no competing interests.
Dr John Williams would like to gratefully acknowledge Dr David Chadwick, a previous contributor to this monograph. DC is an author of a reference cited in this monograph.
Peer reviewers
John and Nancy Nelson Professor of Neurology
Indiana University School of Medicine
Indianapolis
IN
Disclosures
KR declares that she has no competing interests.
Professor of Pediatrics
University of Athens
Aghia Sophia Children's Hospital
Athens
Greece
Disclosures
VS declares that she has no competing interests.
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