is a brain disorder characterized by recurrent seizures,
which are uncontrolled, excessive electric discharge by the
neurons in the
brain. The prevalence of seizures is very common; about 1
person in 20 will experience at least one seizure during a
lifetime. However, the prevalence of epilepsy -- defined by
multiple seizures -- is much smaller: about 1 person in 200.
Epilepsy does run in families, although it is unlikely that
a single gene accounts for the seizures.
One feature of epilepsy is the individual
variation; for example, the interval between seizures may
vary from minutes to weeks to even years. Many individuals
with epilepsy experience an aura
or warning of impending seizure (which may take the form of
a sensation such as smell, or may simply be a "feeling" that
a seizure is about to occur).
In many cases, epileptic seizures arise from a particular
site or "focus" in
the brain. When there is such a focus, it is often the medial
temporal lobe. Repeated severe seizures can damage the underlying
brain tissue. Thus, many individuals who suffer severe epilepsy
show cognitive deficits, particularly memory deficits due
to damage to the medial temporal lobe.
In many cases, epileptic seizures can be
controlled or eliminated by the use of drugs,
drugs or antiepileptic drugs. In cases where drugs are
ineffective and seizures are so severe as to be life-threatening,
surgery may be conducted to remove the part of the brain where
the seizures arise. The surgery is only done on one side of
the brain, leaving the other side intact. The surgery is often
very effective, and patients may experience little or no impairments
resulting from the lost tissue. (In fact, in some cases, patients
appear to show cognitive improvement following surgery - possibly
because relief from near-continual seizures allows them to
Article : "STORM
IN THE BRAIN"
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain