Pronounced: En-sef-uh-light-iss
by Rosalyn Carson-DeWitt, MD
En Espaol (Spanish Version) Encephalitis is inflammation of the brain. The inflammation may involve the whole brain, or just parts of the brain.
2008 Nucleus Medical Art, Inc.
Viral infection of the central nervous system can be asymptomatic, present with mild symptoms, or cause meningitis and/or encephalitis. Most cases of encephalitis are caused by a viral infection. Encephalitis may be sporadic or epidemic. In the United States, the most common cause of sporadic encephalitis is the herpes simplex virus . Epidemic encephalitis are usually mosquito - or tick-borne, which may be dependant on the geography and season.
The most common viruses that cause encephalitis include:
A risk factor is something that increases your chance of getting a disease or condition.Risk factors for encephalitis include:
Living, working, or playing in an area where mosquito-borne viruses are common Not being immunized against diseases such as: MeaslesMumpsChickenpoxPolio Having cancerTaking immunosuppressive medications after organ transplant Having AIDS Newborns of mothers who have genital herpes simplex are at risk for herpes simplex encephalitis. Symptoms The symptoms may range from mild, such as fever and headache, to severe, such as seizures , loss of consciousness, and permanent neurological damage. Death may also result. Symptoms include: FeverWeakness, severe fatigueHeadacheSensitivity to lightStiff neck and backVomitingChanges in consciousnessMuscle achesRashPersonality changesConfusionIrritabilitySeizures Partial or complete paralysisProgressive drowsinessYawningTrouble walkingTrouble speakingTrouble swallowing DiagnosisThe doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include: Blood teststo look for signs of infectionSpinal tap to test spinal fluid for signs of infection CT and/or MRI scans of the head to look for abnormal areas of enhancement, hemorrhage, or edema in the brain Electroencephalogram (EEG) to look for abnormal electrical activity in the brain Brain biopsy removal of a small sample of brain tissue to test for signs of infection Treatment Treatment is mostly supportive. It may include:
Antiviral drugs (eg, intravenous acyclovir for herpes simplex encephalitis)to potentially help shorten the duration of the illnessSteroid medicationsto decrease brain swellingDiuretics such as mannitolto decrease elevated intracranial pressureIntubation with hyperventilationto decrease elevated intracranial pressureAnticonvulsant medicationsto prevent and/or treat seizures PreventionMake sure that you and your children are vaccinated against preventable viral illnesses. RESOURCES: Encephalitis Information Resourcehttp://www.encephalitis.info National Institute of Neurological Disorders and Strokehttp://www.ninds.nih.gov CANADIAN RESOURCES: BC Health Guidehttp://www.bchealthguide.org/ Health Canadahttp://www.hc-sc.gc.ca/index_e.html References: Cecil Textbook of Medicine . 21st ed. WB Saunders Company; 2000. Conn's Current Therapy 2001 . 53rd ed. WB Saunders Company; 2001. Emergency Medicine: Concepts and Clinical Practice . 4th ed. Mosby-Year Book; 1998. Herpes simplex encephalitis. EBSCO Publishing Dynamed website. Available at: http://www.ebscohost.com/dynamed . Updated December 2, 2007. Accessed Feb 23, 2008. Principles and Practice of Infectious Diseases . 6th ed. Churchill Livingstone; 2005.
Samuels MA, Feske SK. Office Practice of Neurology . Philadelphis, PA: Churchill Livingstone; 2003. Last reviewed February 2008 by J. Thomas Megerian, MD, PhD, FAAPPlease be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
