Should anti-epileptics (antiepileptic drugs) be given to all patients with viral encephalitis?

Antiepileptic Drugs in Viral Encephalitis

Routine prophylactic antiepileptic drugs should not be given to all patients with viral encephalitis, as there is insufficient evidence to support this practice. 1

Current Evidence on Seizure Management in Viral Encephalitis

• There are no randomized controlled trials evaluating the efficacy of antiepileptic drugs for primary or secondary prevention of seizures in viral encephalitis 1
• The Cochrane systematic review found insufficient evidence to support or refute the routine use of antiepileptic drugs for prophylaxis in viral encephalitis 1
• Clinical guidelines from the Infectious Diseases Society of America and the Association of British Neurologists do not recommend routine prophylactic antiepileptic therapy for all patients with viral encephalitis 2

Risk Stratification Approach

Antiepileptic therapy should be guided by specific risk factors:

• High-risk patients who should receive antiepileptic drugs include those with:

  • More than one seizure during the acute illness 3
  • Temporal lobe involvement on imaging 3
  • Status epilepticus 3
  • Epileptiform discharges on EEG 3

• Low-risk patients (single seizure and no temporal lobe involvement) may not require antiepileptic drugs, as the risk of seizure relapse is similar between treated and untreated patients 3

Management Recommendations

For Patients Who Have Already Experienced Seizures:

• Initiate antiepileptic therapy promptly after the first seizure if risk factors are present 3
• The first three months after the acute phase is the peak time for seizure relapse, suggesting that antiepileptic coverage during this period is particularly important 3
• Both sodium valproate and levetiracetam are reasonable first-line options with similar efficacy 3
• For anti-LGI1 encephalitis specifically, carbamazepine may be more effective than levetiracetam 4

Important Considerations:

• Immunotherapy is crucial for treating the underlying cause of seizures in autoimmune encephalitis, with seizure freedom achieved faster and more frequently after immunotherapy than with antiepileptic drugs alone 4
• EEG monitoring is essential for all patients with encephalitis to identify non-convulsive seizure activity in confused, obtunded, or comatose patients 2
• Be vigilant about potential drug interactions between antiepileptic drugs and antimicrobials used to treat the underlying infection 5

Specific Viral Etiologies

Herpes Simplex Virus (HSV) Encephalitis:

• Acyclovir is the recommended antiviral treatment 2
• Adjunctive dexamethasone may be considered but has not been shown to significantly improve overall outcomes 6

Varicella Zoster Virus (VZV) Encephalitis:

• Intravenous aciclovir (10-15 mg/kg three times daily) is recommended 2
• Corticosteroids may be beneficial, particularly if there is a vasculitic component 2
• No specific antiepileptic treatment is needed for VZV cerebellitis 2

Long-term Outcomes

• Epilepsy after resolved viral encephalitis is relatively rare in patients who receive appropriate immunotherapy 4
• Continued antiepileptic therapy beyond the acute phase should be individualized based on EEG findings, clinical course, and presence of structural brain abnormalities 3

Conclusion

The decision to use antiepileptic drugs in viral encephalitis should be based on risk stratification rather than routine prophylaxis for all patients. Patients with multiple seizures, temporal lobe involvement, status epilepticus, or epileptiform discharges on EEG should receive antiepileptic therapy, while those with a single seizure and no temporal lobe involvement may not require it.