KEPPRA PRESCRIPTION

I had brain aneurysm surgery in April 2007 - I was given some Keppra medicine after the surgery, did fine a
few months later. The aneurysm surgery was done before any blood veins collapsed.
Due to other illnesses i.e. hypoglycemia, thyoid etc I was still weak during 2008.  In February of 2009
I fainted while driving only approx. 3 minutes from my house. I was taken by ambulance to a hospital were
they kept me for one week trying all kinds of test to find out while I fainted. There was no positive result so
they thought I might have had a seizure and then prescribed me the Keppra pills.
Since then I have taken 500 mg in the morning and 500 mg at night and felt terrible since that time.
Super fatigue, mucsle cramps that I could hardly stand or walk when it happened, nausea, great weakness.
I kept asking the doctors why and most of them just mentioned my age, my imitation etc.
Last week I saw the neurologist again and said I need to find out for sure that I shoud be taken Keppra
as this is known to give problems like I have. I only weigh 106 lbs which might also be a factor of how
much Keppra to take.
The Neurologist suggested I take 1000 mg once at night - this is a RX pill, which also means Medicare of
Blue Cross will not pay, so it will cost me $ 275.00 a month.
I still want to try it if my body can take it.
My main question is - how can a doctor prescribe Keppra if there is no proof of having had seizures and
also how can one give it up to see if my physical health will get better.
I am having another Brain MRI and an EEG next week - and if nothing shows up - can anyone tell me
how and when to give up Keppra?
Thank you for any help. Christl