Viral encephalitis is the inflammation (damage to cells) of brain tissue that may result from
infection with any of a number of viruses. Viruses are
extremely small infectious agents that are different from bacteria, cannot
live outside of cells, and cannot be treated with antibiotic drugs. Herpes simplex virus type 1 is the most common cause of
encephalitis in the United States. Other causative viruses include arboviruses (viruses including the West Nile virus that are transmitted
through the bites of mosquitoes, ticks, and sandflies), other herpes viruses,
and the rabies virus. In severe cases, encephalitis may result in persistent
neurological damage or death. The July 27, 2005, issue of JAMA includes an article that describes rabies encephalitis in the
recipients of organs transplanted from an infected donor.
In addition to obtaining a complete medical history and performing a
physical examination, including a detailed neurological examination, your
doctor may order blood tests to look for signs of infection. Your doctor may
order magnetic resonance imaging (MRI—the use of magnetic fields to obtain images of the body)
or computed tomography (CT—the
use of computerized x-rays to obtain images of the body) of your brain to
look for inflammation or other causes for your symptoms. Your doctor may also
perform a lumbar puncture (spinal tap) to obtain
some of the fluid that surrounds the brain and spinal cord in order to analyze
the spinal fluid for evidence of inflammation and for the presence of specific
viruses.
Hospitalization may be required to provide supportive care, including
adequate fluids and intravenous medication for pain control. Antiviral medications (medications designed to destroy certain viruses)
are given if the cause of encephalitis is determined and if an appropriate
antiviral medication is available. If there are persistent neurological deficits
your doctor may also refer you for physical and occupational therapies to
help you manage these impairments.
To find this and previous JAMA Patient Pages, go to the Patient Page
link on JAMA's Web site at http://www.jama.com. Many are available in English and Spanish. A Patient Page on rabies
was published in the August 23/30, 2000, issue; and one on West Nile virus
was published in the July 23/30, 2003, issue.
Source: National Institute of Neurological Disorders and Stroke
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate
in most instances, but they are not a substitute for medical diagnosis. For
specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied
noncommercially by physicians and other health care professionals to share
with patients. To purchase bulk reprints, call 718/946-7424.
TOPIC: NEUROLOGICAL DISEASE