I really feel for you. Timber suffers from seizures, and I have to medicate him twice a day. He has seen an avian vet and was tested for everything. Sometimes, as with Timber, birds have seizures for unknown reason, like human epilepsy. It must be very frightening not to have access to an avian vet. He has not had a seizure for two years now, since we got the meds adjusted.
I'll share some of the things the vet had me do until we had his seizures under control. When Timber's started, he would have one every few weeks. I hope and pray that your bird never has another, but you might want to take some precautions in the meantime.
1. Lower his available perches. If he seizes he will fall, and that can injure him as much as the seizure.
2. Make sure there is a towel or some type of padding under him so that if he does fall it is cushioned.
3. I actually put Timber in a hospital cage (very small cage) until we had the seizures under control. His old cage was large and if he had fallen from the top of the cage (he would climb all over it even if there wasn't a perch) to the bottom, bouncing off perches and toys on the way down, he could have hurt himself. The small cage was easier to cover with toweling and kept him from falling much of a distance before hitting the towel.