Hello,
Have you explored our other forums, or tried a forum search to find other posts mentioning Arachnoid cyst?
http://neurotalk.psychcentral.com/forum87.html

I moved your other post to our new members forum for more thoughts/ideas.
http://neurotalk.psychcentral.com/thread184843.html

I sent you a PM with similar info.

Are your drs doing other tests to rule in/out other conditions?