Paralysed man able to stand after stem cell injection

Injecting neural stem cells into patients with spinal cord injuries may help improve their motor function.

Around 20 million people worldwide live with spinal cord injuries, yet no effective treatment exists. Researchers from Keio University, Tokyo, Japan, conducted the first clinical study using stem cells to treat spinal cord injury paralysis. Induced pluripotent stem (iPS) cells, created by reverting mature cells to a juvenile state, were differentiated into neural stem cells, which can mature into neurons and glial cells. The team injected two million neural stem cells into the spinal cord of four paralysed patients. Two patients showed motor improvement: one patient can now stand, while the other can move their arms and legs.

Hideyuki Okano, a professor of physiology at Keio University who led the research, told Interesting Engineering: 'We were able to achieve results in the world's first spinal cord injury treatment using iPS cells.' He continued, 'There were difficult days when research using iPS cells did not produce results, but this research has produced results worthy of confirming safety and estimating efficacy.'

The results from this study were announced at a press conference and are yet to be peer-reviewed. By injecting neural stem cells at the injury site, the researchers aimed to regenerate the nerve connections lost due to injury. The main goal was to assess the safety of this approach. No serious adverse events were observed in the four adult male patients, who received the stem cell injections within 14–28 days of their initial injury.

When commenting on the safety of the treatment, Professor James St John, a translational neuroscientist at Griffith University, Australia, who was not associated with the study, said, 'That's a great positive outcome. It's very exciting for the field… Nothing's really worked so far.'

Although this study aimed to assess safety rather than efficacy, motor function improvement was measured using the American Spinal Injury Association Impairment Scale. All patients started the trial at level 'A', the highest classification, indicating no sensation or movement below the injury. After one year, two patients did not improve and remained at level 'A'. However, one patient progressed to level 'C', gaining independent arm and leg movement, while another patient reached level 'D', achieving independent standing. Normal function is classified as level 'E'.

When speaking about the patient capable of standing independently, Professor Okano said, 'That person is now training to walk. This is a dramatic recovery.' However, some patients with spinal cord injuries can improve over time. As Professor St John explained, 'Every spinal cord injury is different... Sometimes when people have spinal cord injury, they just naturally get recovery.'

In the future, the research team plans to publish their findings. Additionally, they are seeking approval to launch large-scale clinical trials. These large trials will be helpful in determining the efficacy of using neural stem cells in treating spinal cord injuries, and its potential for broader clinical use.