Can lack of sleep and food & then taking prescribed pain medications cause a seizure?

My boyfriend just had a seizure today, but the doctor's at the hospital do not know why. He hadn't slept or eaten for a few days but was still taking his pain medicine for his back ( Tramadol & Percocet) . Could this be the cause? I mainly ask because I am scared to fall asleep leaving him helpless if it happens again in the middle of the night. If his own slip up was the cause, I would feel much better because I would know it wouldn't happen again because he has now eaten. I know I did not word this very well, but I hope you understand my question and can help me out. Thank you very much