From the Guidelines
Viral encephalitis CSF results typically show a lymphocytic pleocytosis with 10-500 white blood cells per mm³, predominantly lymphocytes, and PCR testing is crucial for identifying specific viral pathogens, such as herpes simplex virus (HSV) 1.
Key CSF Findings
- Lymphocytic pleocytosis with 10-500 white blood cells per mm³, predominantly lymphocytes
- Protein levels usually mildly to moderately elevated (50-200 mg/dL)
- Glucose remains normal or slightly decreased
- Red blood cells may be present in hemorrhagic forms of encephalitis
- Opening pressure is often elevated
Diagnostic Approach
- PCR testing of CSF is essential for identifying specific viral pathogens, particularly HSV
- Acyclovir treatment should be started promptly if HSV encephalitis is suspected, without waiting for confirmation by PCR 1
- A negative initial CSF PCR result does not rule out HSV encephalitis, especially if taken early in the illness (<72 h after symptom onset) or late in the illness after virus has been cleared 1
Treatment and Management
- Acyclovir (10 mg/kg IV every 8 hours for 14-21 days) is the recommended treatment for HSV encephalitis 1
- The dose of aciclovir should be reduced in patients with pre-existing renal impairment 1
- Patients with suspected encephalitis due to infection should be notified to the appropriate Consultant in Communicable Disease Control 1
From the Research
Viral Encephalitis CSF Results
- The diagnosis of viral encephalitis is based on medical history, examination, and analysis of cerebrospinal fluid (CSF) for protein and glucose contents, cellular analysis, and identification of the pathogen by polymerase chain reaction (PCR) amplification 2 and serology 2.
- CSF examination is a crucial diagnostic tool for viral encephalitis, and it may show pleocytosis, which is an increase in the number of cells in the CSF 3.
- The CSF results may also show abnormal protein and glucose levels, which can help in diagnosing viral encephalitis 2.
- PCR amplification is a sensitive and specific method for detecting viral DNA in CSF, and it is recommended as a first-line diagnostic test for viral encephalitis 2.
- Serology, which involves testing for antibodies against specific viruses, can also be used to diagnose viral encephalitis, but it may not be as sensitive or specific as PCR amplification 2.
Diagnostic Approach
- The diagnostic approach to viral encephalitis involves a combination of medical history, physical examination, CSF analysis, and neuroimaging studies, such as magnetic resonance imaging (MRI) 2, 4.
- Lumbar puncture is an essential diagnostic procedure for viral encephalitis, and it should be performed as soon as possible after the diagnosis is suspected 2, 4.
- Neuroimaging studies, such as MRI, can help to identify abnormalities in the brain and to rule out other causes of encephalitis, such as stroke or tumor 2, 4.
Treatment and Management
- The treatment of viral encephalitis depends on the specific virus causing the infection, and it may involve antiviral medications, such as acyclovir, which is effective against herpes simplex virus (HSV) encephalitis 2, 5.
- Supportive care, such as management of cerebral edema and prevention of secondary neurological injury, is also an important aspect of treatment and management of viral encephalitis 3.
- Corticosteroids may be used as an adjunct treatment for viral encephalitis, but their use is controversial and not universally recommended 2, 5.