This is an observational study to follow 12 paraplegics who received surgical transplantation of their donated stem cells. The study is a long-term follow-up of the participants in the Phase I/II Safety and Preliminary Efficacy Investigation of Intramedullary Spinal Cord Transplantation sponsored by Stem Cells Inc at the Uniklinik Balgrist in Zurich. The participants received the proprietary product HuCNS-SC® made from donated foetal tissue and will be monitored for complications and changes in their clinical condition for a further six years until March 2018.