What is encephalitis?

Encephalitis is a term used to describe inflammation of the membranes that surround the brain and spinal cord. This condition causes problems with the brain and spinal cord function. The inflammation causes the brain to swell, which leads to changes in the child's neurological condition, including mental confusion and seizures.

What causes encephalitis?

The cause of encephalitis varies depending on the season, the area of the country, and the exposure of the child. Viruses are 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).

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:

• Fever
• Headache (or bulging of the fontanelles, the soft spots on a baby's head)
• Sensitivity to light
• Neck stiffness
• Sleepiness or lethargy
• Increased irritability
• Seizures
• Skin rashes
• Difficulty talking and speech changes
• Changes in alertness, confusion, or hallucinations
• Loss of energy
• Loss of appetite
• Unsteady gait
• 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 performed to confirm the diagnosis of encephalitis may include the following:

• X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
• Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
• 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
• Urine and stool tests
• Sputum culture. A diagnostic test performed on the material that is coughed up from the lungs and into the mouth. A sputum culture is often performed to determine if an infection is present.
• 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, into the spinal canal. This is the area around the spinal cord. 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

Specific treatment for encephalitis will be determined by your child's doctor based on:

• Your child's age, overall health, and medical history
• The extent of the condition
• Your child's tolerance for specific medications, procedures, or therapies
• Expectations for the course of the condition
• 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.

The extent of the problem is dependent on the severity of the encephalitis and the presence of other organ system problems that could affect the child. In severe cases, a breathing machine may be required to help the child breathe easier.

As the child recovers, physical, occupational, or speech therapy may be necessary 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 clinical problems that require immediate medical attention by his or her doctor. A child with encephalitis requires frequent medical evaluations following hospitalization.