I too had surgery in 2004--must have been a bad year.  About 5 years ago I began to have moments of tingling lips and tongue which I asked my doctors about.  They even ran a seizure test..could not figure out what I was referring to.  I asked my family doctor for Metformin to jump start some weight loss--since I was still 50 pounds from what I wanted to be.  She gave me a test set at the time also.  At that time my episode were about every 6 weeks.  Checked it one day for 'fun' when I was feeling my head thing.  My Blood reading was in the 50's...SURPRISE !!  And it has gone downhill since.  I now can get drops every day even watching the carb intake.  Last week I traveled to Indianapolis to see an endo DR who has many cases like this.  She ordered loads of blood work..waiting for results.  At least she was able to explain why this is happening--700 gut neuropeptides have been removed..which regulate tons of stuff--all now working aganist me.  I, unfortunately, am the only patient of my by-pass surgeon with this problem.  On restricted 15 gr of carb a meal (x 6).  Hoping it helps !!  She her again in 3 months.