is the medical term for an inflammation of the brain, derived
from the Greek words enkephalos (brain) and itis (inflammation).
Inflammation causes swelling, and as brain tissues press against
their limited confines in the skull, those tissues can be
Encephalitis is often caused by a virus
spreading into the brain; the most common such cause is herpes
simplex encephalitis. Viruses such as influenza (flu),
measles, chickenpox, smallpox, and syphilis can all cause
encephalitis. Encephalitis can also be caused by a head wound
that penetrates to the brain and becomes infected, or by infection
elsewhere that gets into the bloodstream and is carried to
the brain. HIV- the virus leading to AIDS - can also weaken
the immune system, allowing various other infections to spread
into the brain.
Symptoms can range from cold-like headache,
fever and dizziness to more serious motor dysfunction, paralysis
and coma. If the underlying cause is treated promptly, outlook
for recovery is generally good; left untreated, encephalitis
can cause irreparable brain damage or even death.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain