Within the brain and the
outer spinal cord, millions of nerve cells lie close to one another.
Even though they have almost no insulation separating them, they
usually function perfectly, relaying
messages and forming memory connections. Like a perfectly functioning
computer chip, each electrical impulse maintains its distinct path.
But not every electrical
signal follows its programmed path. Imagine a single uncontrolled
burst of impulses, sweeping across the brain like a static shock.
As these wild signals spread, unpredictable reactions occur. You
can see the difference between normal brain waves and erratic ones
in the graphic below. During a seizure the victim may become disoriented
for a second, or lose consciousness for even longer ...
sometimes the muscles receive nonsense messages and contract violently
in a reaction called a convulsion.
loss and convulsions can be a symptom of a condition called epilepsy.
It can be the result of head injury, infection, high temperature,
tumors, stroke, or drug abuse, or it can occur without any of these
causes. Between brainstorms, the person with epilepsy is completely
normal; the condition is not directly related to any other disability
or mental condition.
In many cases epileptic
seizures can be controlled by drug therapy. In a few serious cases,
surgery has been used to isolate the source of the erratic messages.