From what I read, you can have both at the same time. Not a lot of info on that but I did read that having the two at the same time is possible. It's possible to have seizures from Lupus also. Be best to talk to your Doctor and get tested to be sure.
Seizures, Epilepsy, Lupus and Chronic Illness
itwaslupus.tumblr.com/post/.../seizures-epilepsy-lupus-and-chronic-illnes