At the Corners of Migraines and Magnesium

I've been told by a nutritionist to take magnesium (which I knew) in the form of magnesium aspartate (which I had thought was not so good).  So before I began actually taking the supplements I purchased I did a bit of extra research.  Turns out I was right.  Aspartate is an excitotoxin.  Excitotoxins are substances which stimulate neurotransmitters.  High levels can cause over-stimulation leading to damage and death of nerve cells.  In the long term it can lead to stroke, brain damage and even Alzheimer's, Parkinson's and Huntington's disease.  I guess it's possible that the amount of aspartate I would gain from taking magnesium aspartate isn't great enough to cause damage but I'm not yet convinced.  So now I venture to find a better magnesium supplement, one that won't damage my brain, if anyone out there has any information it would be great to have some help.