Hemiplegic Migraines and Brain Damage?

For those of you who have suffered from a hemiplegic migraine, have any of your doctors ever mentioned any kind of permanent or long term damage?

Two years ago I had an incident. The best I could describe was that it felt like a stroke (at 25 years old). The doctor (an RN) ordered an MRI and there was no evidence of damage, but he said that it was a hemiplegic migraine. I've had a migraine since and as I type this, the same area of my head hurts that felt like someone had smacked me with a baseball bat two years ago.

I had mentioned once, in passing, this to my mother's doctor (an MD I admit, I trusted more than my RN). And she, on the way out, said something about the migraine could've caused brain damage. So I'm curious, has a doctor said anything like that to anyone here?