When Your Child Has Encephalitis

Sick girl with a thermometer in her mouth.

Encephalitis is inflammation of the brain. It is a rare condition that is most often caused by a viral infection. A mild case may not be recognized, and may be diagnosed as a viral illness with a headache. But severe cases are serious and can be life-threatening. If you think your child has encephalitis, call the healthcare provider right away. Treatment can decrease your child’s chances of long-term complications, and help with recovery.

What causes encephalitis?

Bacteria can cause encephalitis, however the most common cause are viruses. These include viruses such as those that cause the stomach flu, chickenpox, fever blisters, or other childhood viral infections. In rare cases, encephalitis can also occur in children who have caught certain infections from an insect or animal bite or scratch. Mosquito- and tick-borne viruses can also cause encephalitis. These viruses can cause infections such as West Nile, La Crosse, St. Louis, western equine, and eastern equine encephalitis. Mosquitoes transfer the virus from animals, such as birds, chipmunks, or horses, to humans. Symptoms may appear from a few days to a couple of weeks after exposure. In people with weak immune system, there are many other causes for encephalitis including fungi and parasites.

In some cases, encephalitis may occur a few weeks after an infection. This happens because the immune system, while attacking the virus, also attacks the brain tissue by mistake.

Despite advances in medicine, often the cause is not known.

What are the symptoms of encephalitis?

In mild cases, symptoms are similar to the flu. These include:

  • Fever

  • Headache

  • Poor appetite

  • Achiness

  • Extreme tiredness (fatigue)

In moderate to severe cases, symptoms may include:

  • High fever

  • Headache

  • Muscle weakness, loss of sensation in some parts of the body

  • Trouble walking or using arms

  • Convulsions or seizures

  • Confusion, memory loss, personality changes

  • Trouble communicating

  • Speech, hearing, or vision problems

  • Nausea or vomiting

  • Trouble swallowing

  • Sleepiness

How is encephalitis diagnosed?

If the encephalitis is severe, your child will be admitted to the hospital and will likely see a pediatric neurologist for diagnosis and treatment. This is a doctor who specializes in neurologic problems in children. The neurologist examines your child. He or she also asks about your child’s health history and symptoms. The following may also be done:

  • Spinal tap (lumbar puncture). This test checks the health of the fluid around the brain and spinal cord. This fluid is called cerebrospinal fluid. During the test, the skin on the lower back is numbed with a local anesthetic. Then a needle is inserted into the spinal canal and a sample of the fluid is taken. The fluid is checked in a lab for signs of infection. The pressure of the fluid can also be measured.

  • MRI or CT scan. These are done to make detailed pictures of the brain and check for swelling. Both tests are painless. Fluid called contrast dye may be used to make the brain easier to see. MRI is the preferred test. But CT may be done if your child can't have an MRI, or if an MRI is not available right away. Medicine can be given to help your child stay calm and lie still during the tests.

  • Blood tests. These check for certain viruses.

  • EEG (electroencephalogram). This test measures the brain’s electrical activity.

How is encephalitis treated?

A child with severe encephalitis will need to be in the hospital. He or she will be given fluids and medicines (antibiotics and antiviral medicines) through an IV (intravenous) line. If your child is having seizures, they may be given medicines to prevent seizures (anticonvulsants). There are more unusual forms of encephalitis that may require treatment with IV steroids or immunoglobulin. Your child may be watched in the hospital until symptoms improve. Overall treatment time will vary for each child based on the severity and cause of the brain inflammation. The doctor will speak with you about other forms of treatment if they are needed.

What are the long-term concerns?

Children can recover completely, and most do. But in some cases, children may have ongoing (chronic) neurologic problems. This can include trouble with learning, reasoning, speech, or movement. Regular follow-up with the doctor may be recommended depending on your child’s condition. Supportive care may be prescribed to help your child if needed. This can include speech, physical, or occupational therapy.