Encephalitis is inflammation of the brain. The inflammation causes the brain to swell. This leads to changes in a child's nervous system that can include confusion, changes in alertness, and seizures. Meningitis often happens at the same time as encephalitis. Meningitis is inflammation of the membranes that surround the brain and spinal cord. Both conditions are serious and life-threatening and need to be looked at and treated right away.

Viruses are thought to be the main cause. Children are vaccinated against many viruses, such as measles, mumps, rubella, and chickenpox. This has greatly lowered the rate of encephalitis from these diseases. But other viruses can cause it. These include herpes simplex virus, West Nile virus, Zika, and rabies. Encephalitis may happen after a viral illness. This may be an upper respiratory infection or an illness that causes diarrhea, nausea, and vomiting.

Encephalitis can also happen after a bacterial infection, such as Lyme disease, tuberculosis, or syphilis. It can also happen after an infection caused by parasites, such as toxoplasmosis.

Another cause is an autoimmune reaction. This happens when the body's own immune system attacks the brain tissues. For example, an antibody made against a protein called an NMDA receptor or others may cause encephalitis. This may be set off by an infection or tumor.

A child is more at risk if they have any of these:

• Upper respiratory infection
• Illness that causes diarrhea, nausea, and vomiting
• Measles
• Mumps
• Rubella
• Chickenpox
• Herpes simplex virus
• West Nile virus
• Rabies
• Lyme disease
• Tuberculosis
• Syphilis
• An infection caused by parasites, such as toxoplasmosis
• An autoimmune reaction

Children who are not vaccinated against certain viruses are at greater risk for encephalitis. Very rarely, vaccines have been linked with encephalitis. But most vaccines are more likely to protect a child from encephalitis and other illnesses. If travel is planned, different vaccines may be needed.

Symptoms may occur a bit differently in each child. They can include:

• Fever.
• Headache.
• Bulging of the soft spots on a baby's head (fontanelles).
• Sensitivity to light.
• Neck stiffness.
• Sleepiness.
• Lack of energy (lethargy).
• Increased irritability.
• Seizures.
• Skin rash.
• Trouble talking and speech changes.
• Changes in alertness.
• Confusion or hallucinations.
• Loss of appetite.
• Unsteady walking.
• Nausea and vomiting.
• Loss of consciousness (coma).

The symptoms of encephalitis can be like other health conditions. Take your child to their doctor right away for a diagnosis.

The doctor will ask about your child's symptoms and health history. This includes questions about your child's vaccine history. Tell the doctor if your child has recently had a cold, other respiratory illness, or a digestive illness. Also let them know if your child has recently had a tick bite, been around pets or other animals, or has traveled.

Your child may also have tests, such as:

• MRI. This test uses large magnets, radio waves, and a computer to make images of the inside of the body. In some cases, a special dye is injected into a vein for the test. This dye helps show organs more clearly.
• CT scan. This test uses a series of X-rays and a computer to create images of the inside of the body. A CT scan shows more detail than a regular X-ray.
• Blood tests. These may include a test for the NMDA receptor antibody and other antibodies.
• Urine and stool tests. These are done to check for infection and other problems.
• Sputum culture. This test looks at mucus that is coughed up from the lungs. This test is done to find out if your child has a lung infection.
• Electroencephalogram. This test records the brain's electrical activity through sticky pads (electrodes) attached to the scalp.
• Spinal tap (lumbar puncture). This test uses a needle to help measure the pressure in the spinal canal and brain. The doctor can also remove a small amount of cerebrospinal fluid (CSF) to send for testing. CSF is the fluid that surrounds your child's brain and spinal cord. The fluid sample can help show if your child has an infection or other problems.
• Brain biopsy. In rare cases, your child may need a biopsy. A small sample of brain tissue is removed to test for diagnosis.

Encephalitis needs treatment right away. A child needs to stay in the hospital where they can be closely watched.

Treatment will depend on your child's symptoms, age, and general health. It will also depend on how bad the condition is.

The goal of treatment is to reduce the swelling in the head and to prevent problems (complications). Your child may need to take medicines to stop the infection and control seizures or fever. In severe cases, your child may need to use a breathing machine (ventilator).

As your child recovers, they may need physical, occupational, or speech therapy. This will help your child regain muscle strength and speech skills.

The health care team will tell you how to best care for your child at home. Your child will likely need regular checkups with the doctor after they get home from the hospital.

Talk with your child's doctors about the risks, benefits, and possible side effects of all treatments.

Most children recover fully. But in some cases, children may have ongoing nervous system problems. These may include trouble with learning, thinking, speech, or movement. Your child may need regular follow-up with the doctor. Your child may need speech, physical, or occupational therapy to recover.

Encephalitis is a serious and life-threatening condition that needs to be looked at and treated right away. If your child has symptoms, call your doctor right away.

After treatment for encephalitis, call the doctor if your child has:

• Symptoms that don't get better, or get worse.
• New symptoms.

• Encephalitis is inflammation of the brain. It causes the brain to swell. It is a serious and life-threatening condition that needs to be treated right away.
• Experts think that viruses are the main cause. It can also happen after a bacterial infection. Or it may happen after an infection caused by parasites, such as toxoplasmosis.
• Symptoms can include fever, headache, sleepiness, and changes in behavior.
• A child needs to stay in the hospital where they can be closely watched. Your child may need tests, such as an MRI scan, CT scan, or blood tests.
• The goal of treatment is to reduce the swelling in the head and to prevent complications. Your child may need to take medicines to stop the infection and control seizures or fever. In severe cases, your child may need to use a breathing machine (ventilator).
• As your child recovers, they may need physical, occupational, or speech therapy. This will help your child regain muscle strength or speech skills.

Tips to help you get the most from a visit to your child's doctor:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
• Ask if your child's condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child's doctor after office hours, and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.