3-3. ENCEPHALITIS

a. Definition of Encephalitis. This disease is defined as an inflammation of the brain due to a direct invasion by a virus. Lymphocytes (a white blood cell which has formed in lymphoid tissue) filter into the brain tissues and the leptomeninges (pia mater and arachnoid) and cause cerebral edema, degeneration of the brain's ganglion cells, and nerve cell destruction. Between World War I and the Depression, a type of encephalitis called lethargic encephalitis occurred from an unknown cause. The disease is rare today, but the term "sleeping sickness" still exists. You may find people who refer to all types of encephalitis by this term today.

b. Cause of Encephalitis. Encephalitis is caused by arthropod-borne viruses in rural areas. In cities, encephalitis can occur after mumps, influenza, chicken pox, or measles.

c. Signs/Symptoms of Encephalitis. There are some differences, but the several forms of encephalitis have similar signs and symptoms. The onset of the disease is usually sudden. Signs and symptoms include the following:

(1) Headaches.

(2) Fever.

(3) Lethargy or restlessness.

(4) Cranial nerve abnormality.

The signs and symptoms are similar to those of viral meningitis, but in this case are not bacterial. The patient has fewer chills, and his glucose level is normal.

d. Treatment of Encephalitis. Generally, give supportive treatment. That is, treat the symptoms of the disease.