Encephalitis: Symptoms & Signs

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Medically Reviewed on 3/14/2019

Encephalitis is the medical term that refers to inflammation of the brain tissue.

The main signs and symptoms associated with encephalitis include headache, fever, chills, nausea, vomiting, light sensitivity, mental confusion, malaise, muscle weakness, and stiff neck. Other possible associated symptoms can include problems with coordination, altered level of consciousness, delirium, seizures, disorientation, unsteady gait, dementia, memory loss, and hallucinations.

Cause of encephalitis

Bacterial or viral infections may cause encephalitis. Viral infections are the most common cause, and the herpes virus causes the most serious cases of viral encephalitis. Enterovirus infections and mosquito-borne viral infections are other causes of viral encephalitis. Sometimes conditions other than infections, such as systemic lupus erythematosus and Behcet's disease, can cause encephalitis.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.

Medically Reviewed by a Doctor on 3/14/2019

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