Maybe this has already been posted somewhere, maybe not; sorry for potential cross-posting. I'm browsing green med info for the second day in a row now and found an anormous wealth of useful and high-quality information, like this one.
High homocysteine and low B12 levels are apparently able to cause motor neurons death
http://www.greenmedinfo.com/article/...ted-cell-death
Test your homocysteine levels.