Hi sharman_uk,
Perhaps the best thing to do would be to write to the CAA, give them all the details of your condition and ask them yourself! I did this with a medical worry I had prior to going for my Class One and they sent a detailed letter back- fortunately it was no problem but it was good to know this before I forked out £400 for the full check up, and also gave me one less thing to worry about on the day! Make sure you given them as much information as possible, otherwise they'll just end up writing to you asking for more details.
I think there's an e-mail address on their website, but make sure you include your postal address if you send them an e-mail because they won't e-mail you back, they need to post your reply. Also it might take a while, my advice took about a month to arrive.
Eurotraveller