Stem cells hold potential for treating spinal cord injuries. Based on the findings from a large number of animal studies, scientists are working on the ways that stem cells may contribute to spinal cord repair:

• stem cells may be used to replace the nerve cells that have died as a result of the injury;
• stem cells may be used to generate new supporting cells that will re-form the insulating nerve sheath (myelin) and stimulate re-growth of damaged nerves;
• when introduced into the spinal cord shortly after injury, stem cells cells may protect the cells at the injury site from further damage, by releasing protective factors.

Stem cell clinical trials for spinal cord injury

In December 2010 the Swiss regulatory agency for therapeutic products gave the go-ahead for a Phase I/II clinical trial on chronic spinal cord injury at the Balgrist University Hospital in Zurich, Switzerland.  The trial uses a type of stem cell developed by the company Stem Cells Inc. The cells are known as human central nervous system stem cells, or HuCNS-SC, and are derived from human brain tissue. HuCNS-SC cells can make any of the three major kinds of neural cells found in the central nervous system. In the trial, HuCNS-SC cells will be transplanted into the spinal cord of patients at least six weeks after injury.

Phase and objective: This is a phase I/II trial to evaluate the safety of transplanting HuCNS-SC cells into the spine of patients with chronic spinal injury.
Dates: March 2011–March 2016.
Enrollment status: Recruiting. Aims to enroll 12 patients.
More information on this study

California-based biotech company Geron also had a widely-reported clinical trial under way for a human embryonic stem cell-based therapy. In November 2011 Geron announced it was halting this trial to focus on other areas of research.

Nasal cavity stem cells

Other studies have shown that cells in the lining of the nasal cavity help regenerate spinal injuries when transplanted into the spinal cords of injured rats. Researchers would like to transfer this approach to patients with a specific type of spinal cord injury, called brachial plexus avulsion. In this type of injury, which occurs most commonly in motorcycle accidents, the nerves of the arm are separated from the spinal cord, resulting in paralysis of the arm.

Relevant links:
Professor Geoffrey Raisman's research page - using cells in the lining of the nasal cavity for spinal cord regeneration
The National Institute of Neurological Disorders and Stroke
European Spinal Cord Injury Federation