Do I have chronic silent migraine?

I used to get classic migraine until about 8 years ago when they switched to painless occular and more recently alternating with vestibular as well. I was never formally diagnosed and treated and just saw it as something I had to take painkillers for and ride out hopefully avoiding a trip to emergency.

I have been very unwell for about the last 8 years after a stroke like episode that was never diagnosed as anything left me with chronic pain, extreme exhaustion, nausea, vision problems, abdo pain, neuropathy, leg pain and dysfunction amongst other mystery symptoms I rarely got a break from. I've been so disabled by it I was worked up for stroke and MS and I had to stop working. Fast forward 8 years to now and numerous tests and drs later with no answers I had an upswing in mystery symptoms followed by a weekend of classic migraine for the first time since the stoke like episode and my dr put me on a preventive for the first time in my life (Sandomigran). Prior I've been trialed on a long list of meds for pain, depression, neuropathy etc that were useless and have had physio, natural therapies etc, the works at the pain clinic without much luck but with the migraine specific drug my response has been incredible. All the prior interventions got me maybe a point or two less on the pain scale, the migraine drug not only got my pain down from about a chronic 6-7 to about a 1-2 it got rid of a whole lot of other symptoms as well including a lot of the vestibular, occular ones and the crushing fatigue.

My question is if I'm responding so well to a migraine preventative with a history of migraine is it possible I have had a some form of chronic silent migraine for the past 8 years and it's just such an unusual presentation no one has picked up on it?