Management of Seizures in Encephalitis

Initial Management of Seizures

The Infectious Diseases Society of America recommends immediate treatment with acyclovir for patients with suspected encephalitis presenting with seizures, along with appropriate antiepileptic medications, with a dosage of 10 mg/kg intravenously every 8 hours in adults and children with normal renal function, and 20 mg/kg intravenously every 8 hours in neonates 1, 2, 3
Patients with seizures in encephalitis require urgent assessment by neurological specialists and should be managed in a setting where clinical neurological review can be obtained within 24 hours of referral, according to the Journal of Infection 4
Patients with falling level of consciousness require immediate ICU assessment for airway protection, ventilatory support, and management of raised intracranial pressure, as recommended by the Journal of Infection 4
Access to neuroimaging, such as MRI, and neurophysiology, such as EEG, is essential for proper diagnosis and management of seizures in encephalitis, according to the Journal of Infection 4

For herpes simplex virus encephalitis, the Infectious Diseases Society of America recommends acyclovir 10 mg/kg IV every 8 hours for 14-21 days in adults and children, and higher-dose acyclovir (20 mg/kg IV every 8 hours for 21 days) in neonates, which has shown decreased mortality to 5% 1, 2, 3
For varicella-zoster virus encephalitis, the Journal of Infection recommends acyclovir 10-15 mg/kg IV three times daily, with or without a short course of corticosteroids, and considers a stronger case for using corticosteroids if a vasculitic component is present 4
For cytomegalovirus encephalitis, the Infectious Diseases Society of America recommends a combination of ganciclovir (5 mg/kg IV every 12 hours) and foscarnet (60 mg/kg IV every 8 hours or 90 mg/kg IV every 12 hours) for 3 weeks 3

Adjunctive corticosteroids in herpes simplex encephalitis remain controversial, but one retrospective study showed better outcomes in patients treated with corticosteroids, according to the Infectious Diseases Society of America 3
For refractory status epilepticus, the Journal of Infection recommends consideration of continuous EEG monitoring and escalation to anesthetic agents under ICU care 5

All patients should have access to assessment for rehabilitation, as sequelae of encephalitis may not be immediately apparent at discharge, according to the Journal of Infection 6
Monitor for drug interactions between antimicrobials and antiepileptic medications, as recommended by the Journal of Infection 5

IV valproate at 20-30 mg/kg loading dose is highly effective for refractory seizures in encephalitis, with 88% seizure cessation within 20 minutes, and no associated hypotension, as recommended by the American Academy of Neurology 7
Levetiracetam 30-60 mg/kg/day is equally effective to valproate for refractory seizures, with a demonstrated 73% seizure cessation rate in refractory status epilepticus, according to the American Epilepsy Society 7
Phenytoin 18-20 mg/kg IV or fosphenytoin equivalent can be used, though efficacy is only 56% when following benzodiazepines, and is associated with hypotension in 12% of cases, as reported by the Neurocritical Care Society 7

Consider antibody-mediated encephalitis in all patients with intractable seizures, particularly with subacute presentation, orofacial dyskinesia, choreoathetosis, or hyponatraemia, and consider immunosuppression with high-dose steroids, IVIg, or plasma exchange, as recommended by the Infectious Diseases Society of America 8, 9
For VGKC-complex or NMDA receptor antibody-associated encephalitis, early immune suppression and tumor removal (if present) results in improved outcomes, according to the American Academy of Neurology 8, 9
Screen for neoplasm in all patients with VGKC complex or NMDA receptor antibody-associated encephalitis, as recommended by the National Comprehensive Cancer Network 8, 9