Addressing Possible Life-Threatening Complications
Patients with very severe encephalitis are at risk for systemic complications including shock, low oxygen, low blood pressure, and low sodium levels. Any potentially life threatening complication should be addressed immediately with the appropriate treatments.

Treating Possible Causes
Since it is difficult to determine the cause of encephalitis, and since rapid treatment is essential, it is common to medicate the patient for the causes that respond to medication without waiting to determine the cause of the illness:

• Some experts advise immediately administering acyclovir, the standard treatment for herpes simplex encephalitis, to all patients whose symptoms indicate encephalitis.
• Corticosteroids, which reduce inflammation, may also be administered immediately.

Antibiotics are used in case the cause of the symptoms is bacterial meningitis.

Supportive Treatments
For any form of encephalitis, treatments are aimed at reducing symptoms:

• Seizures may be prevented using fosphenytoin (Cerebyx) and treated with intravenous lorazepam (Ativan).
• Sedatives may be prescribed for irritability or restlessness.
• Simple pain relievers may be used for fever and headache.
• In patients who are otherwise stable, the only other treatment measures are to keep the head elevated and monitor the patient's status.

Anti-Viral Agents
Acyclovir. Intravenous acyclovir is the treatment of choice for encephalitis caused by herpes simplex virus or varicella-zoster virus. It should be started immediately and administered for at least 10 days. Although at this time treatment is nearly always administered in the hospital, some centers are finding that some patients can be safely treated with intravenous medications at home after the first few days, although close monitoring by a health professional is essential. Some experts advocate use of acyclovir in any patient with herpesvirus who has fever and any other early symptoms of encephalitis, since the drug is relatively safe and delay may have significantly negative effects on outcome.

Other Antiviral Agents. Other antiviral agents have been investigated, but to date acyclovir has proven superior.

• Foscarnet (Foscavir) is another powerful anti-viral agent known as a pyrophosphate analogue, which may be useful for herpes simplex viral strains that have become resistant to acyclovir.
• Foscarnet or ganciclovir, another antiviral drug, may have some benefits for patients with encephalitis from cytomegalovirus.
• Ribavirin (Virazole) is under evaluation for LaCross virus.

Relapse Rate. Of concern is a relapse rate of about 25% in patients who have been successfully treated for herpes encephalitis. It is not clear whether all of such relapses are a reactivation of the herpes virus or whether they are caused by a different virus.

Treatment for Acute Disseminated Encephalomyelitis (ADEM)
ADEM is usually treated with high-dose intravenous methylprednisolone, a corticosteroid. This agent is a powerful anti-inflammatory drug. Intravenous immunoglobulin (IVIG) is also showing promise in certain patients.

Last Updated: August 8, 2001
Source: Well-Connected