(CBS News) For most people who are paralyzed, there is no treatment available to help them regain full function of their limbs.
But, promising new research from a phase 1 study conducted at the University of Zurich sponsored by StemCells, Inc. shows that six months after the implantation of neural stem cells, two out of three complete injury patients - meaning they had no neurological function below the point of injury - were able to gain some sensory function.
"We haven't made progress in how to address injury after they occur, but using neural stem cells in a transplant lets us, for the first time, think we can repair this," Dr. Stephen Huhn, a neurosurgeon and the vice president and head of the CNS program at StemCells, Inc. said to HealthPop.
The phase 1 study was intended to see if the implantation treatment had any unwanted side effects. For the procedure, 20 million neural stem cells were implanted directly into the spinal cord, something that has never been done before. Then, any reactions were monitored including complex examinations of sensory function - for example light touch, sensitivity to temperature and sensitivity to subtle electronic stimulation - as well as electrostimulation of the spinal cord itself.
What researchers were surprised to find was that the neural stem cell implantation was able to return some sensation to these paralyzed patients, who were all injured at the thoracic or chest level.
Hugh explained that if you think of the spinal cord and its 31 segments as a building with a series of floors, these patients could not access the floor below the point of the initial trauma. However, after the implantation, one patient was able to access three to four floors (or spinal cord segments below the paralysis point) and the other was able to reach five or six floors.
"These patients have had such an injury to their spinal cord that to see this kind of effect is amazing. They contain the worst of the worst injuries," he explained.
While the other patient did not regain sensation, none of the patients had any negative side effects. Huhn believes this means that the treatment may be able to work even better for people who have limited function after a traumatic injury. Since the treatment has been deemed to be safe, the next phase is to test the implantation on nine other people who have incomplete injuries or some limited sensation or function after an injury.
Huhn recognizes that the field of stem cell research is controversial. The world's only other trial using stem cells to treat spinal injury - which used embryonic stem cells - was ended in 2011 for financial reasons, according to the New Scientist. But, Huhn feels that the unique properties of neural stem cells and potential benefits warrant their use in medical treatment. Neural stem cells have the unique ability to divide and replicate themselves though cell culture. This means that for this trial, the team was able to use only one donated brain source to supply all the material needed for the study.
"This is a very delicate area, and we appreciate that neural stem cells are one of the first discoveries that we've had in which we can think about biologically repairing the nervous system," "Now we have a tool, a technology - something we can think about repairing the central nervous system with."
The information was presented at the International Spinal Cord Society's (ISCoS) annual meeting in London on Sept. 3.