EncephalitisSymptoms, Doctors, Treatments, Advances & More
Learn About Encephalitis
Encephalitis is irritation and swelling (inflammation) of the brain, most often due to infections.
Encephalitis is a rare condition. It occurs more often in the first year of life and decreases with age. The very young and older adults are more likely to have a severe case.
Encephalitis is most often caused by a virus. Many types of viruses may cause it. Exposure can occur through:
- Breathing in droplets from the nose, mouth, or throat from an infected person
- Contaminated food or drink
- Mosquito, tick, and other insect bites
- Skin contact
Different viruses occur in different geographic locations. Many cases occur during a certain season.
Encephalitis caused by the herpes simplex virus is the leading cause of more severe cases in all ages, including newborns.
Routine vaccination has greatly reduced encephalitis due to some viruses, including:
- Measles
- Mumps
- Polio
- Rabies
- Rubella
- Varicella (chickenpox)
Other viruses that cause encephalitis include:
- Adenovirus
- Coxsackievirus
- Cytomegalovirus
- Eastern equine encephalitis virus
- Echovirus
- Japanese encephalitis, which occurs in Asia
- West Nile virus
After the virus enters the body, the brain tissue swells. This swelling may destroy nerve cells, and cause bleeding in the brain and brain damage.
Other causes of encephalitis may include:
- An allergic reaction to vaccinations
- Autoimmune disease
- Bacterial infections such as Lyme disease, syphilis, and tuberculosis
- Parasites such as roundworms, cysticercosis, and toxoplasmosis in people with HIV/AIDS and other people who have a weakened immune system
- The effects of cancer
Some people may have symptoms of a cold or stomach infection before encephalitis symptoms begin.
When this infection is not very severe, the symptoms may be similar to those of other illnesses:
- Fever that is not very high
- Mild headache
- Low energy and a poor appetite
Other symptoms include:
- Clumsiness, unsteady gait
- Confusion, disorientation
- Drowsiness
- Irritability or poor temper control
- Light sensitivity
- Stiff neck and back (sometimes)
- Vomiting
Symptoms in newborns and younger infants may not be as easy to recognize:
- Body stiffness
- Irritability and crying more often (these symptoms may get worse when the baby is picked up)
- Poor feeding
- Soft spot on the top of the head may bulge out more
- Vomiting
Emergency symptoms:
- Loss of consciousness, poor responsiveness, stupor, coma
- Muscle weakness or paralysis
- Seizures
- Severe headache
- Sudden change in mental functions, such as flat mood, impaired judgment, memory loss, or a lack of interest in daily activities
The goals of treatment are to provide supportive care (rest, nutrition, fluids) to help the body fight the infection, and to relieve symptoms.
Medicines may include:
- Antiviral medicines, if a virus caused the infection
- Antibiotics, if bacteria are the cause
- Antiseizure medicines to prevent seizures
- Steroids to reduce brain swelling
- Sedatives for irritability or restlessness
- Acetaminophen for fever and headache
If brain function is severely affected, physical therapy and speech therapy may be needed after the infection is controlled.
Cleveland Clinic Main Campus
Amy Kunchok is a Neurologist practicing medicine in Cleveland, Ohio. She has been practicing medicine for over 23 years. Dr. Kunchok is rated as an Elite provider by MediFind in the treatment of Encephalitis. She is also highly rated in 14 other conditions, according to our data. Her clinical expertise encompasses Encephalitis, Multiple Sclerosis (MS), Anti-NMDA Receptor Encephalitis, Optic Neuritis, and Thymectomy.
Regenstein Center For Neurological Care - Lavin Family Pavilion
Igor Koralnik is a Neurologist practicing medicine in Chicago, Illinois. Dr. Koralnik is rated as an Elite provider by MediFind in the treatment of Encephalitis. He is also highly rated in 17 other conditions, according to our data. His clinical expertise encompasses Progressive Multifocal Leukoencephalopathy, CACH Syndrome, Encephalitis, Thrombectomy, and Endovascular Embolization. Dr. Koralnik is board certified in American Board Of Psychiatry And Neurology - Neurology (Certified). Dr. Koralnik is currently accepting new patients.
UPMC Neurological Institute - Magee
Jenny Linnoila, MD, PhD, specializes in neurology and is board-certified in neurology by the American Osteopathic Board of Neurology & Psychiatry. She practices at University of Pittsburgh Physicians, Department of Neurology and is affiliated with UPMC Magee-Womens Hospital and UPMC Shadyside. Dr. Linnoila completed her medical education at University of Pittsburgh School of Medicine, residency at Massachusetts General Hospital - Harvard Medical School, and fellowship at Mayo Clinic School of Graduate Medical Education. Dr. Linnoila is rated as an Elite provider by MediFind in the treatment of Encephalitis. She is also highly rated in 4 other conditions, according to our data. Her clinical expertise encompasses Encephalitis, Anti-NMDA Receptor Encephalitis, Rasmussen Encephalitis, and Herpes Simplex Encephalitis. Dr. Linnoila is board certified in American Board Of Psychiatry And Neurology. Dr. Linnoila is currently accepting new patients.
The outcome varies. Some cases are mild and short, and the person fully recovers. Other cases are severe, and permanent problems or death is possible.
The acute phase normally lasts for 1 to 2 weeks. Fever and symptoms gradually or suddenly disappear. Some people may take several months to fully recover.
Permanent brain damage may occur in severe cases of encephalitis. It can affect:
- Hearing
- Memory
- Muscle control
- Sensation
- Speech
- Vision
Go to the emergency room or call 911 or the local emergency number if you have:
- Sudden fever
- Other symptoms of encephalitis
Children and adults should avoid contact with anyone who has encephalitis.
Controlling mosquitoes (a mosquito bite can transmit some viruses) may reduce the chance of some infections that can lead to encephalitis.
- Apply an insect repellant containing the chemical DEET when you go outside (but do not use DEET products on infants younger than 2 months).
- Remove any sources of standing water (such as old tires, cans, gutters, and wading pools).
- Wear long-sleeved shirts and pants when outside, especially at dusk.
Children and adults should get routine vaccinations for viruses that can cause encephalitis. People should receive specific vaccines if they are traveling to places such as parts of Asia, where Japanese encephalitis is found.
Vaccinate animals to prevent encephalitis caused by the rabies virus.
Summary: Alzheimer's Disease and related dementias (ADRD) affect about 6 million people in the U.S. and are the fifth leading cause of death for adults over 65. Recent research is investigating how chronic liver diseases like Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), which affects one-third of the U.S. population, might influence ADRD through the liver-brain axis. MASLD shares risk ...
Background: \- Progressive multifocal leukoencephalopathy (PML) is a severe viral infection of the brain. It is caused by JC virus. Many people have this virus in their bodies all their life, but it is usually kept in check by their immune system. If the immune system does not work right because of a disease or medication, the virus becomes active and can damage cells in the brain. Not much is known about PML...
Published Date: July 16, 2024
Published By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Beckham JD, Tyler KL. Encephalitis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 89.
Bronstein DE, Glaser CA. Encephalitis and meningoencephalitis. In: Cherry JD, Harrison GJ, Kaplan SL, Steinbach WJ, Hotez PJ, eds. Feigin and Cherry's Textbook of Pediatric Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 36.