Dorothy Gronwall et.al. of New Zealand reported similar findings in the 1970's. Nobody was willing to listen to her. She and her colleagues developed the PASAT (Paced Auditory Serial Addition Task) during that era. She was able to use the PASAT to predict the long term outcome of concussion victims.

Even though those subjects were injured long ago, we still need to consider that the brain does not do the "remodeling" that all of the other cells in the body do. The other cells routinely die and are replaced (remodeled) on a regular basis. When this does not happen, the tissues become weak. Stem cells are found throughout the other tissues ready to do this replacement process.

The brain cells are not known to do this "die and replacement" process. Thus, they need to heal from within. Even the stem cell research has found that the brain does not react well to stem cell implantation. One study found that implanted embryonic stems cells have a tendency to grow into differentiated cells, but not brain cells, within the brain.

The Spinal Injury Foundation web site has some interesting links about stems cells and nervous system issues. www.spinalinjuryfoundation.org