Encephalitis: A-to-Z Guide from Diagnosis to Treatment to Prevention

Little girl portrait smiling closeup face looking camera. Could she have Encephalitis?Introduction to encephalitis:

West Nile virus frightens many parents because it can cause a type of infection called encephalitis.

What is encephalitis?

Meningitis is primarily an inflammation of the lining of the brain and spinal cord, and sometimes of the brain itself. Encephalitis is primarily an inflammation of the brain.

Most of the time, the inflammation is caused by viral infections. West Nile virus rapidly spread across the United States at the turn of the 21st century as a cause of encephalitis, but enteroviruses are far and away the most common cause. Arboviruses and herpes are also common. West Nile virus is an arbovirus.

Measles, mumps, chickenpox, rubella, CMV, EBV, and rabies are other noteworthy causes. For example, before vaccination, mumps encephalitis was a common cause of deafness.

Most children with viral encephalitis recover completely with no complications, but sometimes the results are devastating. Some viruses, such as herpes, tend to cause more severe illness than others.

Who gets it?

Anyone can get encephalitis. It tends to be more common in the summer and fall. Some types are found in those who are bitten by infected mosquitoes or other insects. Some types are found in those who get infected stool particles in their mouths. Some types are found in those who just spend time in the same room as someone infected with the virus.

What are the symptoms?

The symptoms can vary quite a bit, from those of a very mild illness to coma or sudden death. A severe headache is usually the central symptom. Often there is sensitivity to light. There may be a fever, vomiting, fatigue, and/or irritability. With some viruses there is a characteristic rash. Neck pain, back pain, and leg pain are common.

In some, there are severe seizures, hallucinations, and loss of bowel or bladder control. Even these children may recover completely with no lasting problems.

Is it contagious?

Some types of encephalitis, such as that caused by West Nile virus, do not spread easily from person to person, although they can be spread by transfusion or organ transplant. Other encephalitis viruses, such as measles, spread very easily among unvaccinated people.

How long does it last?

These infections may be brief or prolonged. Children may recover completely or suffer lifelong consequences.

How is it diagnosed?

The diagnosis is suspected based on the history and physical examination. Lab tests of the spinal fluid or blood may be helpful. EEGs or imaging studies of the brain may help in making the diagnosis and evaluating the severity of the disease. Sometimes specific viral studies are helpful.

How is it treated?

Encephalitis may be so mild as to require only rest, fluids, and something for the headache — or it may require intensive care and full life-support.

Some types, such as that caused by herpes, require specific antiviral therapy.

How can it be prevented?

Measles, mumps, rubella, chickenpox, and even rabies encephalitis may be prevented by appropriately timed vaccines. Other types of encephalitis may be prevented by avoiding mosquito bites.

Fecal-oral transmission precautions are the best way to prevent enteroviral infections, the most common cause of encephalitis in places where vaccines are commonly used. Careful hand washing before eating and after toileting or diaper changes is essential. This is an important hygiene lesson to teach our children.

Related concepts:

Meningoencephalitis, Viral encephalitis, West Nile encephalitis.

Dr. Alan Greene

As a father of four himself, Dr. Greene has devoted himself to freely giving real answers to parents' real questions -- from questions about those all too common childhood conditions to those that address the most recent and rare pediatric illnesses. His answers combine cutting edge science, practical wisdom, warm empathy, and a deep respect for parents, children, and the environment. He is also an electrifying public speaker, and has personally touched many during his talks in North America, Europe, Asia, and the Middle East.

Dr. Greene is a graduate of Princeton University and the University of California at San Francisco. Upon completion of his pediatric residency program at Children's Hospital Medical Center of Northern California he served as Chief Resident. He entered primary care pediatrics in January 1993.

Dr. Greene is the Past President of The Organic Center and on the Board of Directors of Healthy Child Healthy World. He is a founding partner of the Collaborative on Health and the Environment. He also consults for the Environmental Working Group.

In 1995, he launched DrGreene.com, cited by the AMA as “the pioneer physician Web site” on the Internet. His award-winning site has received over 80 million Unique Users from parents, concerned family members, students, and healthcare professionals. In addition to being the founder of DrGreene.com, he is the Medical Director for HealthTap.

In 2010 Dr. Greene founded the WhiteOut Movement to change how babies in the United States are fed. In 2012 he founded TICC TOCC - Transitioning Immediate Cord Clamping To Optimal Cord Clamping. He is also the founder of KidGlyphs, a free iPhone app that provides a tool for young children to express themselves beyond their verbal skills while teaching them important language skills.

Dr. Greene is the Founding President of the Society for Participatory Medicine and has served as both President and Board Chair of Hi-Ethics (Health Internet Ethics. He is on the Board of Directors for Healthy Child Healthy World, The Lunchbox Project, and The Society for Participatory Medicine. He has also served as an advisor to URAC for both their inaugural and their updated health web site accreditation program. He is a founding member of the e-Patient Scholars Working Group, and a founding board member of the Center for Information Therapy.

Dr. Greene is a regular columnist for Parenting Magazine. He is also the Pediatric Expert for The People’s Pharmacy (as heard on NPR) and Healing Quest (seen on PBS stations). He was the original Pediatric Expert for both Yahoo! and iVillage.

Dr. Greene is the author of Feeding Baby Green (Wiley, 2009), Raising Baby Green (Wiley, 2007), From First Kicks to First Steps (McGraw-Hill, 2004), The Parent's Complete Guide to Ear Infections (People's Medical Society, 1997), and a co-author of The A.D.A.M. Illustrated Family Health Guide (A.D.A.M., Inc., 2004). He is the medical expert for three additional books, The Parent's Soup A-to-Z Guide to Your New Baby, (Contemporary Books, 1998) The Parent's Soup A-to-Z Guide to Your Toddler, (Contemporary Books, 1999), and The Mother of All Baby Books, (Hungry Minds, Inc., 2002).

Dr. Greene is a frequent keynote speaker at important events such as Health 2.0 2011 held in San Diego, CA, IFOAM 2008 (International Federation of Organic Agriculture Movements), held in Modena Italy, the first European Internet health conference, held in Maastricht, the first International eHealth Association Conference, held in Jeddah, and the largest e-Healthcare World Conference, held in Las Vegas, and the first Green Power Baby Shower, held in Hollywood. Dr. Greene also appears frequently on TV, radio, websites, and in newspapers and magazines around the world, including such venues as the TODAY Show, Good Morning America, Fox and Friends, The Dr. Oz Show, CNN, ABC, CBS, and NBC network news, NPR, The New York Times, The Wall Street Journal, USA Today, Time Magazine, Parade, Parenting, Child, Baby Talk, Working Mother, Better Home's & Gardens, and the Reader's Digest.

Dr. Greene loves to think about challenging ideas, he enjoys being where nothing manmade can be seen, and he wears green socks.

Get Dr. Greene's Wellness Recommendations

Sign up now for a delightful weekly email with insights for the whole family. Plus Dr. Greene's FREE Top 5 Wellness Tips For 2017.