Encephalitis Treatment & Management

Updated: Aug 07, 2018
  • Author: David S Howes, MD; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Approach Considerations

Prehospital care

In the prehospital setting, evaluate and treat for shock or hypotension. Administer crystalloid infusion in patients with evidence of circulatory compromise. Consider airway protection in patients with an altered mental status. Seizure precautions are indicated. Treat seizures according to usual protocols (ie, lorazepam 0.1 mg/kg given intravenously [IV]). All patients should receive oxygen and have intravenous access secured en route to the emergency department (ED). See the following for more information:


Emergency Department Care

With the important exceptions of HSE and varicella-zoster encephalitis, the viral encephalitides are not treatable beyond supportive care. Treatments for T gondii and cytomegalovirus (CMV) encephalitis are available but generally not initiated in the ED.

The goal of treatment for acutely ill patients is administration of the first dose or doses of acyclovir, with or without antibiotics or steroids, as quickly as possible. The standard for acute bacterial meningitis is the initiation of treatment within 30 minutes of arrival. Consider instituting an ED triage protocol to identify patients at risk for HSE.

Collect laboratory samples and blood cultures before the start of IV therapy. Even in uncomplicated cases of encephalitis, most authorities recommend a neuroimaging study (eg, magnetic resonance imaging [MRI] or, if that is not available, a contrast-enhanced head computed tomography [CT] scan) before lumbar puncture (LP).

Management of hydrocephalus and increased intracranial pressure

In patients with hydrocephalus and increased intracranial pressure (ICP), general measures include management of fever and pain, control of straining and coughing, and prevention of seizures and systemic hypotension.

In otherwise stable patients, elevating the head and monitoring neurologic status usually are sufficient. When more aggressive maneuvers are indicated, early use of diuresis (eg, furosemide 20 mg IV, mannitol 1 g/kg IV) may be helpful, provided that circulatory volume is protected. Dexamethasone 10 mg IV q6h helps in managing edema surrounding space-occupying lesions. Hyperventilation (arterial CO2 tension [PaCO2] 30 mm Hg) may cause a disproportional decrease in cerebral blood flow (CBF), but it is used to control increasing ICP on an emergency basis.

Intraventricular ICP monitoring is controversial. Some authorities believe that dangerous focal edema with a pressure gradient between the temporal lobe and the subtentorial space usually is not detected by the monitor and that this failure of detection can lead to a false sense of security. In fact, monitor placement may potentially aggravate a pressure gradient.

Treatment of systemic complications

Look for and treat systemic complications (eg, hypotension or shock, hypoxemia, hyponatremia, and exacerbation of chronic diseases), particularly in herpes simplex encephalitis (HSE), eastern equine encephalitis (EEE), Japanese virus encephalitis (JE).

Empiric treatment of HSV meningoencephalitis and VZV encephalitis

Empiric adult emergency treatment for herpes simplex virus (HSV) meningoencephalitis and varicella-zoster virus (VZV) encephalitis consists of acyclovir 10 mg/kg (infused over 1 h) q8h for 14-21 days. Give acyclovir 10-15 mg/kg IV q8h for neonatal HSV; for HSV encephalitis in the pediatric population, give acyclovir 10 mg/kg IV q8h.

In HIV-positive patients, consider foscarnet, given the increased incidence of acyclovir-resistant HSV and herpes zoster virus (HZV).