Management of Encephalitis

Initial Assessment and Management

The American Academy of Neurology recommends that patients with suspected encephalitis should have urgent neurological specialist assessment and be managed in a setting where clinical neurological review can be obtained within 24 hours of referral 1
Patients with falling level of consciousness require urgent assessment by Intensive Care Unit staff for airway protection, ventilatory support, management of raised intracranial pressure, and optimization of cerebral perfusion pressure 1
The Infectious Diseases Society of America suggests that metabolic, toxic, autoimmune, and non-CNS sources of sepsis should be considered early in patients presenting with encephalopathy 2

The American Academy of Neurology recommends that access to neuroimaging (MRI and CT), under general anesthesia if needed, and neurophysiology (EEG) should be available, which may require transfer to a specialist neuroscience unit 1
Lumbar puncture is crucial with CSF examination for opening pressure, CSF and serum glucose, CSF protein, microbiology culture and sensitivity, virology PCR, and lactate, as recommended by the Infectious Diseases Society of America 2
The results of CSF PCR assays should be available within 24-48 hours of lumbar puncture, according to the American Academy of Neurology 1

The Centers for Disease Control and Prevention recommends that acyclovir should be initiated as soon as possible in all patients with suspected encephalitis, with a dose of 10 mg/kg IV every 8 hours for 14-21 days 3, 4
For Varicella Zoster Virus (VZV) encephalitis, the Infectious Diseases Society of America recommends intravenous acyclovir 10-15 mg/kg three times daily, with or without a short course of corticosteroids 1
The American Academy of Neurology suggests that for cytomegalovirus (CMV) encephalitis, combination therapy with ganciclovir and foscarnet for 3 weeks is recommended 3

The Infectious Diseases Society of America recommends continuing intravenous acyclovir for 14-21 days in confirmed HSV encephalitis 3
The American Academy of Neurology suggests considering repeating lumbar puncture at the end of treatment to confirm CSF is negative for HSV by PCR 3
Monitoring renal function throughout treatment is crucial, as acyclovir-induced nephropathy can affect up to 20% of patients, typically after 4 days of IV therapy, according to the American Academy of Neurology 3

The Infectious Diseases Society of America recommends that immunocompromised patients may require longer courses of therapy and closer monitoring 3
For patients with antibody-mediated encephalitis, different management approaches may be needed, according to the American Academy of Neurology 2

Delaying acyclovir treatment beyond 48 hours after hospital admission significantly worsens outcomes, as recommended by the Centers for Disease Control and Prevention 3
Inadequate hydration during acyclovir treatment increases risk of nephropathy, according to the American Academy of Neurology 3

The Infectious Diseases Society of America recommends Varicella Zoster Virus (VZV) encephalitis treatment with acyclovir 10-15 mg/kg IV every 8 hours for 7 days in adults and adolescents ≥12 years 5
The Infectious Diseases Society of America recommends Toxoplasma gondii treatment with pyrimethamine plus sulfadiazine OR clindamycin 5
The Infectious Diseases Society of America recommends Parasitic Encephalitis treatment with albendazole plus diethylcarbamazine for Baylisascaris procyonis, and albendazole OR ivermectin for Gnathostoma species 5
The Infectious Diseases Society of America recommends Acute Disseminated Encephalomyelitis (ADEM) treatment with high-dose corticosteroids as first-line, with alternatives being plasma exchange OR intravenous immunoglobulin 5, 6
The Infectious Diseases Society of America notes that missing bacterial meningitis can be a pitfall, and considers both diagnoses and adds appropriate antibacterial coverage if bacterial infection cannot be excluded 7