Jennifer, my son is autistic and had a problem with seizures when he became a teenager. His autism seems to effect his sleep, or lack of it. He was having 5–10 seizures (clonic-tonic) a year on awakening. We luckily were advised to put him on Keppra. He has not had a seizure since (3+yrs). Being able to get enough REM sleep is important and can cause seizures in just about anyone if deprived for too long. Keppra seems to allow him REM sleep. Not sure this would work for your husband, but you might try. Keppra has very few side effects other than being a bit expensive.
Just a thought.