My Niece Has Complex Migraines That Mimic Stroke. She Has

My niece has complex migraines that mimic stroke. She has had a series of occurrences unlike any other over the past week. The episodes start with blank stare, aura, numbness, then irrational behavior, facial twitching, and she remembers nothing when it's over. She's been to the ER 4 times and in the hospital for several days. She's had MRI's (found a grouping of blood vessels that looked abnormal only to redo the test and find nothing) CT's are clear..EEG ruled out seizure. Released her with a PTSD diagnosis.. There is something they are missing.. What do we do? Now with that diagnosis, they won't treat her, they are sending her to psych. The migraine cycle hasn't been broken.. Any advice?