Viral encephalitis medical therapy

Overview

Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. Sometimes, encephalitis can result from a bacterial infection, such as bacterial meningitis, or it may be a complication of other infectious diseases like rabies (viral) or syphilis (bacterial). Certain parasitic or protozoal infestations, such as toxoplasmosis, malaria, or primary amoebic meningoencephalitis, can also cause encephalitis in people with compromised immune systems. Treatment with acyclovir with or without steroids and antibiotics should be initiated as soon as possible. Antiviral agent like acyclovir has been useful in treatment of encephalitis due to herpes simplex virus and varicella zoster. Treatment for other causative agents of encephalitis is mostly supportive.

Reliably tested specific antiviral agents are available only for a few viral agents (e.g. acyclovir for herpes simplex virus and varicella-zoster encephalitis. Administer the first dose of acyclovir as soon as possible (in the emergency department itself). This helps in decrease in complications that may occur with delay in therapy. Acyclovir can be initiated with or without antibiotics or steroids.
Treatment for Toxoplasma gondii and cytomegalovirus encephalitis are available but are used with limited success.
Treatment is usually symptomatic. In patients who are very sick, supportive treatment, such as mechanical ventilation, is equally important.
Systemic complications like hypotension, shock, hypoxemia, electrolyte imbalances (hyponatremia, SIADH should be treated promptly.
Neuroimaging with MRI or CT scan should be done before lumbar puncture especially if raised intracranial pressure is suspected.
Lab tests like blood samples should be taken before initiation of therapy.

Adult & Pediatrics- Acyclovir, 10 mg/kg body weight, 8h, intravenously, for 2-3 weeks.
Neonatal HSV- Give acyclovir 10-15 mg/kg IV q8h for neonatal HSV
HIV positive - Foscarnet is generally the treatment of choice given the high incidence of acyclovir resistance in these patients.