recently i have been having episodes where first my tongue feels tingling (like when your hand falls asleep), then a flush feeling up the back of my neck, followed by dizziness and reduced vision. It started 4 months ago, however, infrequent. Now I have these episodes almost on a daily basis; sometimes lasting 15 - 30 seconds, to other times 45 minutes. I have had blood work done and nothing shows up there. Any suggestions? I am 56 and 114#.