Symptoms and Signs of Encephalitis

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 9/10/2021

Doctor's Notes on Encephalitis

Encephalitis is inflammation of the brain. Encephalitis is not the same as meningitis, which is inflammation of the membranes covering the brain. Both of the diseases may be present at the same time, and both conditions share many of the same symptoms so they may be difficult to distinguish. Causes of encephalitis include viruses, bacteria, parasites, chemicals, and even autoimmune reactions. 

Symptoms of encephalitis may last for two to three weeks, are flu-like, and may include

  • fever,
  • fatigue,
  • muscle weakness,
  • rhythmic muscle contractions,
  • muscle pain,
  • sore throat,
  • stiff neck and back,
  • loss of appetite,
  • nausea,
  • vomiting,
  • headache,
  • confusion,
  • irritability,
  • unsteady gait,
  • weakness,
  • problems with coordination,
  • drowsiness, and
  • visual sensitivity to light.

Symptoms of encephalitis in infants may also include

  • poor feeding,
  • irritability,
  • vomiting,
  • bulging fontanel, and
  • body stiffness.

Symptoms of severe cases of encephalitis may include

  • seizures,
  • muscle weakness,
  • paralysis,
  • memory loss,
  • impaired judgment,
  • delirium and/or hallucinations,
  • disorientation,
  • poor responsiveness, or
  • altered level of consciousness

What Is the Treatment for Encephalitis?

Encephalitis can cause a wide range of symptoms that gradually worsen. Many patients with encephalitis are significantly ill and require hospitalization for treatment. Some are severely or gravely ill and require treatment in an intensive care unit (ICU). Encephalitis treatment depends on the cause.

Possible treatments for encephalitis include:

  • Antiviral medications
  • Antibiotic medications
  • Antifungal medications
  • Immunoglobulin therapy   

Occasionally, surgery to remove a small piece of the skull may be needed if the pressure inside increases and medications are not helping.

Supportive care for severely ill patients is also a key component of encephalitis care. Supportive care for encephalitis consists of:

  • Intravenous fluids (IV) to prevent dehydration
  • Corticosteroids for swelling or inflammation of the brain tissue
  • Pain medications
  • Fever reducers
  • Muscle relaxers
  • Tranquilizers
  • Anti-seizure medications
  • Oxygen or a ventilator if the patient is unresponsive or needs heavy sedation

The prognosis for encephalitis can range from rapid improvement in just a few days to death. Patients hospitalized with encephalitis often spend several days to weeks in the hospital recovering. Long term neurologic problems often persist after recovery from encephalitis.

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