I'm sorry but I don't know. Several people have reported severe post-op occular migraines. My younger son possibly suffered with "complex partial seizure" following an acquired traumatic head injury years ago (the description of which reminds me a bit of what you are describing).
They don't suspect any kind of a TIA, do they?
Also, I was thinking of something I saw once, so I searched it out, and while this may be a wild stretch, I will post a link to some info that possibly you could research and ask about? I don't know if it will help. I hope he will be okay.
http://www.epilepsy.org.uk/info/ketogenic.html
Edited to add: If that diet information is too wild a stretch, please excuse me; I may have posted too hastily last evening when I first saw your thread.
Hoping Sammy is better today; best wishes
