by Kimberly Allen RN
Encephalitis is the term used for inflammation of brain tissue. It is most commonly caused by a viral infection. Encephalitis is frequently referred to as “the rare complication of common illnesses”. Approximately 200,000 people are affected by encephalitis in the US every year. Many experts feel the number is actually higher as many people suffer from mild encephalitis but don’t recognize it and report it. Those most susceptible to encephalitis are children and the elderly as well as people with a weakened immune system.
Though the cause of encephalitis frequently is unknown the most frequently diagnosed cause is some type of viral infection. Viral infections may be the most common known cause of encephalitis however it can also be caused by bacteria, fungi or parasites.
Encephalitis is categorized into 2 categories, primary encephalitis and secondary encephalitis. Primary encephalitis developes when there is an infection in the brain itself whether it’s viral or some other agent causing the infection. This type of infection can develop because of a re- activation of a virus that has been lying dormant in your body after a previous illness. Secondary encephalitis also called post infectious encephalitis develops because the immune system malfunctions when responding to an infection somewhere else in your body. Usually what happens is the disease fighting proteins that have been sent to fight an infection instead they attack the brain cells by mistake. This type of encephalitis frequently develops 2-3 weeks after the original infection.
The most common viruses that cause encephalitis are those of the herpes family, including the herpes virus that causes cold sores and fever blisters as well as those that cause chicken pox and mononucleosis. Two other very common viruses that can lead to encephalitis are mosquito and tick borne viruses. Mosquito and tick borne viruses tend to be seasonal, the most recent being the West Nile Virus. Common childhood infections can also frequently lead to encephalitis including measles, mumps and rubella. Though these diseases have become rare due to childhood vaccinations they have been increasing in incidence as people are opting to not vaccinate their children.
The symptoms of encephalitis can vary significantly depending on the severity of the inflammation and infection. Some people may not have any symptoms at all while others may have severe symptoms. Someone with a mild case of encephalitis would usually experience flu like symptoms, a fever, and headache, weakness and fatigue as well as muscle aches and pains. However, in more severe cases you might have a high fever with a severe headache as well as other symptoms like seizures, confusion, personality changes and irritation. Some also experience hallucinations, double vision, difficulty with hearing or speech and loss of sensation, even paralysis and loss of consciousness. Infants and young children will demonstrate symptoms a little differently. They will usually have nausea and vomiting and will do poorly when feeding. They will usually cry constantly and can not be consoled, the crying also usually worsens when they are picked up. You may also notice some bulging in the “soft spots” in an infants skull.
If you or someone you know is experiencing symptoms associated with encephalitis and all infants and young children with any symptoms of encephalitis should seek immediate medical attention. Mild cases can be treated with bedrest and lots of fluids with NSAID’s to relieve the headache and fever. The more serious cases usually need aggressive treatment with antivirals like acyclovir or ganciclovir. However, insect borne viruses rarely respond to these medications.
Prevention is always better than treatment and the most effective way to prevent viral encephalitis is by avoiding exposure to viruses, especially those that can cause encephalitis. The easiest and most effective way to avoid infections is to practice good handwashing with soap and water, and by teaching your children the importance of good handwasing. Also, vaccinations are available for most viruses that can cause childhood illnesses that can lead to encephalitis. It’s very important to keep not only your childs vaccinations up to date but yours as well. Protecting yourself and your children from mosquitoes and tick bites is also very important especially during the fall.