It would seem that epilepsy would be easy to prove and to get disability. It isn't; the claimant has to show that (s)he has epilepsy (which isn't so easy to prove since it doesn't always show up in tests) and that drugs won't control it.
I had to try an epilepsy case last year where the doctors' reports were conflicting as to what type of seizures the claimant was having, and how severe they were. The judge, to his credit, required very little testimony about the extent of the seizures from the claimant's mother, because we showed him the seven prescriptions that hadn't worked and the claimant was obviously very disabled (a seizure occurred about an hour before the hearing, in my office).