My pre-surgery symptoms included numbess of the left arm, leg and sometimes the tongue.  I still sometimes have numbness in the arm and leg post surgery but not the tongue.  This has happened sporatically all of my conscious 53 years so I sorta just write it off as just another episode. Wish you the best.
Russ

Yes there are times I get numbness to my tongue, it often comes w/ numbness to my nose (one side) and my finger tips.  I had surgery 16 months ago... we checked to see if possible seizures but they ruled that out.  I am not on any medication for that... I do find when I get worked up or am doing too much and not drinking enough water that I am more prone to experiencing a minute or two episode of the feeling.  I keep aware of them and note when, where, and how long they last and what I was doing when they occurred.  Maybe if you haven't yet you might note the same things to see if there is a pattern.  I have personally counted them as part of my moya moya post surgery deal... however that is because I see a small pattern and I had it checked by having another costly Cscan and MRI!  I trust you can figure it out with your doctor and find a cure...!

My 9.5 y/o is 3+ years post-surgeries (pial synangiosis) & for the most part is doing great.  All her scans post-surgeries have shown adequate blood supply to both sides of her brain.  She has the occasional "migraine-like" headache when she is not well hydrated (for her at 65 lbs. this is at least 64 oz. of fluid per day). 

However, in the past 8 weeks, she has had two separate episodes of tongue numbness, combined with numbness on one side of her body &/or numbness in her thumb and fingers on one side of her body.  The first episode, which also included severe headache, nausea & vomiting, landed her in the hospital, where she received both a CT Scan in the ED and later an MRI.  Both tests indicated adequate blood flow and no evidence of new stroke or TIA. 

She had a follow-up EEG a couple of weeks later to rule out seizure. We see her pedi-neurosurgeon next week to get the results, but my guess is that the doc would have contacted me by now if the test had indicated seizure activity in her brain, since it's been quite a long time since the procedure (original appt was rescheduled due to doc having an emergent case the same day we were to see her in early Jan).

Because my daughter responded well to IV fluids during the 1st episode, meaning her symptoms abated, the general thought is that she was just dehydrated.  However, I have seen her dehydrated and I really don't think that's what caused the episode.  On the other hand, there seems to be no better explanation of the symptoms. 

The 2nd episode of tongue/digit/arm numbness was not accompanied by h/a, vomiting or nausea so we did not head to the ED.  After discussing the next day with the nurse practitioner who works with my daughter's neurosurgeon, we think it was possibly caused by the stress of going back to school after a longer winter break.  I'm curious to know if anyone else has experienced similar symptoms after a particular stressful time or incident.

I feel for all of you who face this or who experience it with your kids.