Migraine - Help Please

Hello,
My husband had his kidney stones removed two years ago, and he got sick with an infection. He was given a spinal tap, and then the migraines came back with a vengeance. Now he suffers from a balance disorder because of the migraines.
Difficulty maintaining upright orientation. Cannot walk without staggering, and cannot stand. He falls or near-falls. He walks with a cane.
A sensation of dizziness all the time.
Lightheadedness or feeling woozy.
Problems reading and difficulty seeing.
Disorientation.
Nausea and vomiting (sometimes)
Anxiety.
Depression
He received the vestibular testing, physical therapy, and all the exercises that are recommended.
Has anyone ever heard of this? We have seen lots of doctors and all of them are lost for words in regards to balancing. Any information will be greatly appreciated.
Thanks!

The only thing I'm familiar with that sounds similar is vertigo, but I've never known it to last so long and I'm sure his doctor would have considered that already...

Sorry, not much help but I didn't want to read and run....

Dear WitsEnd,
Thanks for your prompt reply. The first three months one doctor thought it was vertigo then shortly after four doctors ruled that out. We have seen doctors at Brighams and Women's, Mass Eye and Ear and HarvardVanguard, plus two private doctors.