coldhardknitter,
What has your doctor said about the seizures? Although there is a type of seizure triggered by Migraine aura, it's rare, and seizures aren't known to be part of Basilar-Type Migraine.
As for the days with BAM events but no headache, Migraines can do that; they can skip the headache phase. When that happens, they're described as "acephalgic" or "silent."
Here are some links to information for you...
• Basilar-Type Migraine: https://migraine.com/migraine-types/basilar-migraine/
• Acephalgic Migraine: https://migraine.com/migraine-types/acephalic-complicated-migraine/
With so many Migraine days, it would be best for you to be talking with your doctor about preventive treatments. Are you and your doctor looking for effective preventive treatments?
Please let us know how you're doing and what other information we can help you with?
Teri