Encephalitis is an inflammation (swelling and irritation) of the brain. In
most cases, a
causes this inflammation.
Encephalitis is also called acute viral encephalitis or aseptic encephalitis.
Who Gets Encephalitis?
Encephalitis (in-seh-fuh-LYE-tus) is a rare disease. Most cases happen in children,
the elderly, and people with a weakened immune
system (from HIV/AIDS,
cancer, etc.).
Several thousand cases of encephalitis are reported to the Centers for Disease
Control and Prevention (CDC) every year. But health experts think that many more cases
happen that aren't reported because symptoms vary and can be mild.
What Are the Signs & Symptoms of Encephalitis?
Symptoms in mild cases of encephalitis usually include:
It's harder to spot some of these symptoms in infants. Important signs to look
for include:
vomiting
a full or bulging soft spot (fontanel)
crying that doesn't stop or that seems worse when the baby is picked up or handled
body stiffness
Because encephalitis can happen during or after common viral illnesses, symptoms
of these illnesses can start before encephalitis happens. But often, it appears without
warning.
What Causes Encephalitis?
Three groups of viruses are common causes of encephalitis:
Herpes viruses, such as chickenpox,
EBV (Epstein-Barr virus, which causes mono),
and herpes simplex (which causes cold
sores).
Viruses that cause once-common childhood infections, such as measles,
mumps, and German
measles. Thanks to immunizations,
it's rare today for someone to develop encephalitis from these illnesses.
Less often, encephalitis can be:
caused by an infection from
, such as bacterial meningitis
a complication of other infectious diseases like syphilis
due to a parasite, like toxoplasmosis
(found in infected cat feces) in people with weakened immune systems
Is Encephalitis Contagious?
Brain inflammation itself is not contagious. But the viruses that
cause encephalitis can be. Of course, getting a virus does not mean
that someone will develop encephalitis.
How Is Encephalitis Diagnosed?
Doctors use several tests to diagnose encephalitis, including:
imaging tests, such as computed tomography (CT) scans or magnetic
resonance imaging (MRI), to check the brain for swelling, bleeding, or other problems
electroencephalogram (EEG),
which records the electrical signals in the brain, to check for unusual brain waves
blood tests to look
for bacteria or viruses in the blood. These also can show if the body is making antibodies
(specific proteins that fight infection) in response to a germ
lumbar puncture, or spinal tap, which checks cerebrospinal
fluid (the fluid that surrounds the brain and spinal cord) for signs of infection
How Is Encephalitis Treated?
Most kids with encephalitis need care in a hospital, usually in an intensive care
unit (ICU). Doctors will watch their blood pressure, heart rate, breathing, and body
fluids to prevent further swelling of the brain.
Medicines
Antiviral drugs can treat some forms of encephalitis, such as the type caused
by the herpes simplex virus.
Corticosteroids may be used to reduce brain swelling.
Anticonvulsants might be given to a child having seizures.
Over-the-counter (OTC) medicines, like acetaminophen,
can help with fever and headaches.
Antibiotics don't work against viruses, so aren't used to treat most forms of
encephalitis.
Many people with encephalitis make a full recovery. In some cases, brain swelling
can cause lasting problem like learning disabilities, speech problems, memory loss,
or lack of muscle control. Speech
therapy, physical
therapy, or occupational
therapy can help in these cases.
How Long Does Encephalitis Last?
Most of the time, the
phase of the illness (when symptoms are the most severe) lasts up to a
week. Full recovery can take longer, often several weeks or months.
Can Encephalitis Be Prevented?
Encephalitis can't be prevented, but you can avoid the illnesses that may lead
to it. Immunizations protect
kids from many common childhood illnesses. So follow the immunization
schedule recommended by your doctor. Kids should also avoid contact with anyone
who already has encephalitis.
It's also important for everyone in your family to wash
their hands well and often.
To avoid mosquito bites, kids should:
Avoid being outside at dawn and dusk, when mosquitoes are most active.
Wear protective clothing outside, like long sleeves and long pants.
Use insect repellent.
Drain standing water from around your home, including in buckets, birdbaths, flowerpots,
and tire swings. These are breeding grounds for mosquitoes.
Limit kids' contact with soil, leaves, and vegetation.
Have kids wear long-sleeved, light-colored shirts and long pants when outdoors.
Check your kids and your pets for ticks when they come inside.
When Should I Call the Doctor?
Call your doctor if your child has a high fever, especially if he or she also has
a childhood illness (like measles, mumps, or chickenpox) or is recovering from one.
Get medical care right away if your child has any of these symptoms:
a severe headache
convulsions (seizures)
stiff neck
can't look at bright lights
double vision
trouble walking
problems with speech or hearing
trouble moving an arm or leg
loss of sensation anywhere in the body
sudden personality changes
problems with memory
extreme drowsiness
loss of consciousness (passing out)
Get medical care right away if your baby has any of these symptoms:
high fever or any fever higher than 100.4°F (38°C) in infants younger
than 3 months old