Diagnosis and treatment of viral encephalitis
- Correspondence to: Dr Abhijit Chaudhuri and Professor Peter G E Kennedy, University Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow G51 4TF, UK; P.G.
- Received 29 November 2001
- Accepted 22 July 2002
Acute encephalitis constitutes a medical emergency. In most cases, the presence of focal neurological signs and focal seizures will distinguish encephalitis from encephalopathy. Acute disseminated encephalomyelitis is a non-infective inflammatory encephalitis that may require to be treated with steroids. Acute infective encephalitis is usually viral. Herpes simplex encephalitis (HSE) is the commonest sporadic acute viral encephalitis in the Western world. Magnetic resonance imaging of brain is the investigation of choice in HSE and the diagnosis may be confirmed by the polymerase chain reaction test for the virus in the cerebrospinal fluid. In this article, we review the diagnosis, investigations, and management of acute encephalitis. With few exceptions (for example, aciclovir for HSE), no specific therapy is available for most forms of viral encephalitis. Mortality and morbidity may be high and long term sequelae are known among survivors. The emergence of unusual forms of zoonotic encephalitis has posed an important public health problem. Vaccination and vector control measures are useful preventive strategies in certain arboviral and zoonotic encephalitis. However, we need better antiviral therapy to meet the challenge of acute viral encephalitis more effectively.
- ADEM, acute disseminated encephalomyelitis
- AHLE, acute haemorrhagic leucoencephalitis
- EBV, Epstein-Barr virus
- EEG, electroencephalography
- HmPAO, 99mTc-hexamethylpropyleneamineoxime
- HSE, herpes simplex encephalitis
- HSV, herpes simplex virus
- NINAID-CASG, National Institutes of Allergy and Infectious Diseases Collaborative Antiviral Study Group
- SPECT, single photon emission computed tomography
- VZV, varicella zoster virus