Maybe record / document it, so that you can show it in a future appointment?
His doctor is somewhat correct, an EEG test doesn't always confirm epilepsy or a seizure disorder unless he's having activity related to a seizure at the time of the test. All of his EEG's and MRI's may show no evidence of seizures, however, that doesn't mean ignore his seizures, he needs treatment. Sometimes a seizure will leave evidence of a stroke which may or may not show up on an MRI. It doesn't sound like your husband is having strokes. He may be having a TIA (minor stroke activity) and an MRI may not show a TIA because they heal quickly. Find him a good neurologist, board-certified, if possible, unless his current doctor treats his seizures properly.
Maybe try another Doctor? I tried several before I got the right dx and treatment.