Viral Encephalitis

By: Alan Gooden

What is Viral Encephalitis?

• Encephalitis literally means “inflammation of the brain” but it usually results from a viral infection.

• Encephalitis occurs in two forms — a primary form and a secondary form. Primary encephalitis involves direct viral infection of your brain and spinal cord. In secondary encephalitis, a viral infection first occurs somewhere in your body and then travels to your brain.

Causes

• Usually a result of viral infections passed between humans, or from contact with infected animals or insects.

• Viruses that cause this include the West Nile virus, herpes viruses, and rabies.

• It can develop 5 to 10 days after a childhood illness such as chickenpox, measles, mumps, polio, etc or, on rare occasions, occur weeks, months, or years after the initial viral infection.

Symptoms

• fever, headache, sensitivity to light, confusion, decreased level of consciousness

• Most people only have mild, often flu-like symptoms. In some cases, people might not have any symptoms.

• More serious infections can cause: hallucinations, personality changes, double vision, muscle weakness, and seizures.

• In infants, the bulging of the fontanels is the main symptom of viral encephalitis.

Area of Nervous System Affected

• It can arise in the brain and directly attack the brain and spinal cord.

• The virus can travel to the nervous system after beginning somewhere else in the body.

Who is affected?

• Older people and younger children are at a greater risk of serious disease and death from West Nile and St. Louis encephalitis.

• California encephalitis poses a greater danger to children under 15 years of age.

• Having a weakened immune system puts you at risk for many types of encephalitis.

Prognosis

• Episodes last about one to three weeks, with fever and symptoms that gradually or suddenly subside.

• However, it may take months for you to fully recover.

Treatment

• Encephalitis requires immediate emergency care so that diagnosis and treatment can begin as soon as possible.

• Plenty of rest, liquids, and Tylenol are used to treat mild cases.

• More serious cases call for the use of anti-viral and anti-inflammatory drugs.

Resources

• http://www.pdrhealth.com/disease/disease-m

ono.aspx?contentFileName=BHG01ID01.xml&contentName=Viral+Encephalitis&contentId=159&sectionMonograph=ht1

• http://www.mayoclinic.com/health/encephalitis/DS00226

Other Info

• The most common insect-borne encephalitis in the U.S. is St. Louis encephalitis.

• The St. Louis encephalitis virus is transmitted by mosquitoes which bite humans thus causing West Nile.

• The Herpes Virus is the main cause of many encephalitis cases.