The EEG is just looking at electrical activity in the brain.  The only way
old brain problems like seizures could appear on the EEG is if they have
altered the brain in some way to create an abnormal reading now.

Here is a quote from http://www.epub.org.br/cm/n03/tecnologia/eeg.htm
describing some of the potential uses of the EEG.

"Its main indication is
to determine the presence of tumors and focal disease of the brain
(including epilepsy, arteriovenous
mal-formations and stroke). It is also appropriate when disturbances in
consciousness and vigilance are present,
such as narcolepsy (the abrupt onset of sleep), coma, etc.. In addition,
EEG brain topography is being increasingly
used to monitor the effects of withdrawal of psychoactive drugs, and in
infectious diseases of the braim, such as
meningites, as well as to follow up patients who where subjected to brain
operations. In psychiatry, EEG brain
topography has been of value in identifying disorders of biological
origin, such as schizophrenia, dementias,
hyperactivity and depression, brain atrophy and attention deficit
disorders in children."

Karen, the EEG will not be able to record what is happening deep inside
the brain.  For many people the EEG is normal.  The only time they've been
able to record abnormal brain waves for me is when I was actually having
seizures (I wore a portable monitor).

Barb

Howdy!

My EEGs have always been abnormal too. (In spite of everything that I say
about normal tests proving nothing.)

Hi Karen,

If you have an absence seizure during the test that will certainly be
detected.  Our daughter presented with generalised tonic/clonic seizures and
for that reason had an EEG.  When we saw the specialist later she quizzed us
closely about whether our daughter had ever had absence seizures.  We have
never detected them either before or since, but apparently she had
half-a-dozen in the course of the EEG.

We are not unobservant parents, so we can only imagine that our daughter is
one of those people who can make some sort of automatic response during an
absence seizure.  Or alternatively that as the EEG was done only a couple of
days after she had a generalised tonic/clonic seizure there was a lot of
residual electrical activity floating around in her brain which has
subsequently (thankfully) declined.

Good luck with your test.  Hopefully it will give the neurologist some ideas
for a treatment strategy.

Regards,

Peter Beach