I have empathy for your husband and hope he's feeling better. But since you mentioned hallucination, I'm sharing the following. I have been on Keppra for over 10 years and it's worked well. I don't know if Keppra had anything to do with the following, but here it is.
1) I remember: walking on the treadmill and getting off
2) I don't remember: walking up the stairs and talking to my wife about my sister with whom I haven't spoken to in almost 10 years
3) Then I remember: walking back downstairs and getting back on the treadmill and finished my walk.
I had no typical partial complex seizure. Never experienced such a thing ever in my life. I welcome any comments. Could this have been some form of seizure? Has anyone experienced such a thing? Is this a hallucination?