90% of your body, wow.
I have to friends that have PWS from head to toe, on is 60%, and the other is 75%. Both of them have Sturge-Weber Syndrome. Do you have glacouma, or seizures?
If so, you might want to look into SWS.
I have SWS on the brain.
If you want more info on SWS let me know and I can get some for you.