How do doctors tell the difference between migraines and simple partial seizures (seizures without memory loss)?

Simple partial: seizures are defined by lack of alteration of consciousness not by the absence of memory loss and they run the gamut. Migraine is an event triggered by activation of the trigeminal vascular system. There may or may not be a component of cephalgia. Now that I've given you some tasty tidbits of information we can talk about the overlap between migraine and seizures. Its a lengthy discussion.