Why does your brain get inflamed?

When you hear the word encephalitis, you probably think of mosquitoes or babies. However, it can impact anyone of any age, and the causes can vary widely. So, what exactly is it? How is treated? Can it be prevented?


Encephalitis is inflammation of the brain. The most common reason is a viral infection, but bacterial infections and noninfectious conditions can cause it. Some of the most common viral agents are herpes simplex virus 1 (HSV 1), herpes simplex virus 2 (HSV 2), Epstein-Barr virus (infectious mononucleosis), varicella-zoster virus (chickenpox & shingles), enteroviruses (poliovirus or coxsackievirus), mosquito-borne viruses (West Nile, La Crosse, St. Louis, western equine, and eastern equine), tick-borne viruses (Powassan), and rabies virus. Certain childhood infections (measles, mumps, and rubella) can also cause encephalitis.

There are two main types of encephalitis: primary and secondary. Primary is when the virus or other infectious agent directly infects the brain. It can be widespread or concentrated and may be a reactivation of a virus that had been inactive after a previous illness. Secondary comes from a faulty immune system response to an infection elsewhere in the body. Rather than attacking the cells causing the infection, the immune system attacks healthy cells of the brain. It typically occurs two to three weeks after an illness, which is why it’s also known as post-infection encephalitis.

The symptoms of encephalitis can range from mild to severe. Mild symptoms include headache, fever, aches in muscles/joints, and fatigue/weakness. More severe symptoms are confusion/agitation/hallucinations, seizures, muscle weakness, problems with speech/hearing, loss of sensation/paralysis of certain parts of the face/body, and loss of consciousness (coma). For infants and children, symptoms are bulging fontanels (soft spots of their skulls), nausea/vomiting, body stiffness, irritability, and poor feeding/not waking for feeding.

Complications depend on the person’s age, cause of infection, the severity of illness, and time from the start of the disease to treatment. Most people with mild illness recover within a few weeks without any long-term problems. One of the significant concerns with severe encephalitis is that inflammation leads to injury to the brain, making the chances of coma or death more likely. Other complications of severe illness can linger for months or are permanent and include persistent fatigue, weakness/lack of muscle coordination, personality changes, memory problems, hearing/vision defects, speech impairments, and paralysis.

TreatmentFast Facts - Encephalitis

For mild encephalitis, treatment is usually bed rest, plenty of fluids, anti-inflammatory drugs (acetaminophen, ibuprofen, and naproxen), and antivirals (acyclovir, ganciclovir, and foscarnet). It’s important to clarify that some viruses don’t respond to these treatments. However, most doctors will start a person on one of the antivirals because the type of virus isn’t identified right away. Individuals with severe symptoms may need to be hospitalized because they need breathing assistance, intravenous (IV) fluids, anti-inflammatory drugs (corticosteroids), and anticonvulsants (to prevent seizures).

If you have complications from encephalitis, you may need different therapies. Physical therapy will assist you in improving strength, flexibility, balance, motor coordination, and mobility. Speech therapy helps you to relearn muscle control and coordination to produce speech. Occupational therapy aids in developing everyday skills and learning how to use adaptive devices.


To prevent encephalitis, you should avoid exposure to viruses that cause it. One of the most important things is having good hygiene by washing your hands frequently and thoroughly, especially after going to the bathroom and before/after meals. It’s also a good idea not to share utensils or beverages. It’s vital to teach your children these habits, too. Another essential step is to keep your and your children’s vaccinations current, especially before traveling.

There are several things you can do when it comes to preventing the spread of mosquito and tick-borne viruses. The first should be to dress in long-sleeved shirts and long pants. Try to avoid being out during dawn and dusk when mosquitoes are most active. Also, stay away from wooded areas with tall grasses and shrubs since this is where ticks live. Another option is to use repellents that contain DEET on your skin and clothing. Do the same for children three months old and older (just don’t put it on their hands since these often end up in their mouths). When applying it to the face, spray your hands and then wipe it on your face (reduces the risk of inhaling the chemicals). If you’re going to use sunscreen as well, put that on first. (Note: Do not use products that contain both DEET and sunscreen on children since reapplication can expose the child to too much DEET.) For infants two-month-old and younger, cover their infant carrier or stroller with mosquito netting. An additional option for clothing and other outdoor gear is spraying it with the insecticide permethrin (do not apply this to your skin). Remove any sources of water around your house to prevent mosquitoes from laying their eggs in it. If you notice sick/dying birds or animals in your area, it could be a sign of a viral illness, and you should contact your local health department. Whenever you’re done outdoors, be sure to wash your body and clothing with soap and water to remove the bug spray.

Encephalitis can be mild or life-threatening. With the right treatment, you’ll be feeling better in no time. If you have any questions or concerns about encephalitis, please speak with your doctor. If you would like more information, please visit the Encephalitis Society at https://www.encephalitis.info/