How exactly can stem cells treat neurological disorders?

Investigational. Stem cell therapy is still experimental in most cases. There are clinical studies looking at autologous cord blood stem cells for the treatment of cerebral palsy. For other forms of neurological disorders, little is known.
In clinical trials. Use of adult mesenchymal stem-stromal cells (mscs) are currently in clinical trial in us/internationally. Trend is toward use of fat derived mscs, havested by liposuction, isolated and concentrated in tissue culture. Early reports suggest significant improvement in neurological, autoimmune and organ functions. Many more mscs in fat than bone marrow making ad-msc the center of most research now.
Unknown. Use of adult mesenchymal stem/stromal cells are being reported to improve neurological function and regeneration. In clinical trials now in us/interntl. Trend is to isolate from fat tissue (which have the highest conc of mscs in the body. Harvested by lipoaspiration, isolation/conc of mscs can be cultured and used in some specific instances with good early reporting.