Encephalitis in Children
What is encephalitis?
Encephalitis is a term used to describe inflammation of the brain. The inflammation
causes the brain to swell, which leads to changes in the child's neurological condition,
including mental confusion, changes in mental status (sometimes even coma), and seizures.
Meningitis, which is inflammation of the membranes that surround the brain and spinal
cord, often accompanies encephalitis. Meningitis can also occur without encephalitis.
What causes encephalitis?
The cause of encephalitis varies depending on the season, the area of the country,
and the exposure of the child. Viruses have been thought to be the leading cause of
encephalitis. Although vaccines for many viruses, including measles, mumps, rubella,
and chickenpox have greatly lowered the rate of encephalitis from these diseases,
other viruses can cause encephalitis. These include herpes simplex virus, West Nile
virus (carried by mosquitoes) and rabies (carried by a number of different animals).
Encephalitis can also occur following a bacterial infection, such as Lyme disease
(carried by ticks), tuberculosis and syphilis, and by parasites, such as toxoplasmosis
(carried by cats).
Another cause of encephalitis is an autoimmune reaction, when the body's own immune
system attacks the brain tissues. For example, an antibody (a protein generated by
the body) against the NMDA receptor (a protein found on certain cells) may cause encephalitis.
This may sometimes be triggered by a tumor.
What are the symptoms of encephalitis?
Encephalitis often is preceded by a viral illness, such as an upper respiratory infection,
or a gastrointestinal problem, such as diarrhea, nausea, or vomiting. The following
are the most common symptoms of encephalitis. However, each child may experience symptoms
differently. Symptoms may include:
Headache (or bulging of the fontanelles, the soft spots on a baby's head)
Sensitivity to light
Sleepiness or lethargy
Difficulty talking and speech changes
Changes in alertness, confusion, or hallucinations
Loss of energy
Loss of appetite
Nausea and vomiting
The symptoms of encephalitis may resemble other problems or medical conditions. Always
consult your child's doctor for a diagnosis.
How is encephalitis diagnosed?
The diagnosis of encephalitis is made after the sudden or gradual onset of specific
symptoms and after diagnostic testing. During the examination, your child's doctor
obtains a complete medical history of your child, including his or her immunization
history. Your child's doctor may also ask if your child has recently had a cold or
other respiratory illness, or a gastrointestinal illness, and if the child has recently
had a tick bite, has been around pets or other animals, or has traveled to certain
areas of the country.
Diagnostic tests that may be done to confirm the diagnosis of encephalitis may include
Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies,
and a computer to produce detailed images of the brain, spinal cord, and other body
structures and organs..
Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology
to produce horizontal, or axial, images (often called slices) of the body. A CT scan
shows detailed images of any part of the body, including the bones, muscles, fat,
and organs. CT scans are more detailed than general X-rays.
Blood tests. These may include an assay for the NMDA receptor antibody and other antibodies.
Urine and stool tests.
Sputum culture. A diagnostic test performed on the material that is coughed up from the lungs and
into the mouth.
Electroencephalogram (EEG). A procedure that records the brain's continuous, electrical activity by means of electrodes
attached to the scalp.
Lumbar puncture (spinal tap). A special needle is placed into the lower back below the level where the spinal cord
has come to an end. The pressure in the spinal canal and brain can then be measured.
A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing
to determine if there is an infection or other problems. CSF is the fluid that bathes
your child's brain and spinal cord.
Brain biopsy. In rare cases, a biopsy of affected brain tissue may be removed for diagnosis.
Treatment for encephalitis
Your child’s health care provider will figure out the best treatment based on:
How old your child is
His or her overall health and medical history
How sick he or she is
How well your child can handle specific medications, procedures, or therapies
How long the condition is expected to last
Your opinion or preference
The key to treating encephalitis is early detection and treatment. A child with encephalitis
requires immediate hospitalization and close monitoring. Sometimes, depending on what
doctors think the specific cause of the encephalitis is, certain medications can be
used to fight infections that may cause it.
The goal of treatment is to reduce the swelling in the head and to prevent other related
complications. Medications to control the infection, seizures, fever, or other conditions
may be used. In severe cases, a breathing machine may be required to help the child
As the child recovers, physical, occupational, or speech therapy may be needed to
help the child regain muscle strength and/or speech skills.
The health care team educates the family after hospitalization on how to best care
for their child at home and outlines specific problems that require immediate medical
attention by his or her doctor. A child with encephalitis requires frequent medical
evaluations following hospitalization.