sparklep,
Welcome to NeuroTalk. Sorry to hear about your nephew. I can't imagine what you and your family are going through. I know how my family struggled when I was injured at 10 and I was just talking in a slurred voice.
There are substances that help the myelin sheath heal. He likely needs help to heal his nerve fibers and myelin. Myelin is the coating around the nerve fibers. It insulates the nerve fibers so the signal does not short circuit. Here is a link to help you understand myelin. It is the focus of some MS research.
http://www.myelinrepair.org/
Here are some other links:
http://www.google.com/url?sa=t&rct=j...3bQ2zUeFW7mnTg
http://www.google.com/url?sa=t&rct=j...jyEFHQiNUL8tfw
There is also a post in NT at
http://www.google.com/url?sa=t&rct=j...eIDxcoeLlFW5IQ
My best to you.