Encephalitis is the abnormal swelling or inflammation of the brain. People with encephalitis usually experience mild symptoms, if any. However, encephalitis can be severe or even fatal in some circumstances. Children are among the populations most often affected by encephalitis.

Encephalitis is acquired by either direct introduction to the brain and spinal cord (primary encephalitis) or as a secondary effect of a separate virus or condition (secondary or post-infectious encephalitis) already present in the body. Although less common than secondary encephalitis, primary encephalitis tends to be more dangerous.

There are a number of causes, including viruses (e.g., herpes simplex virus type 1), or bites from infected mosquitoes or ticks (arthropod-borne encephalitis), bacteria, fungi, parasites and others.

Pain and discomfort (e.g., headache, neck or back stiffness) are common symptoms of encephalitis. However, the type and severity of symptoms can vary greatly among children. Symptoms of encephalitis can be much more difficult to detect in infants. However, there are some symptoms typically associated with encephalitis in younger children, including a stiff body, full or bulging “soft spot” (fontanel) on the head and continuous crying.

Methods for diagnosing encephalitis include blood testing, brain imaging, spinal tap (puncturing of the lumbar to remove fluid) and others. Depending on the severity of the disease in the child, treatment options may involve rest, physical therapy, speech therapy, antibiotics and anticonvulsant (seizure) medications.