The promise and uncertainty of ‘breakthroughs’
Each case is unique in people with spinal cord injury: the level of paralysis, and loss of sensation and function relate to the type of injury and its location. Injuries as a result of stab wounds or infection may result in different outcomes from those incurred as a result of trauma from a car accident or serious fall. The previous health of those injured, the care received at the time of injury, and the type of rehabilitation they access can all impact on subsequent health and mobility.
Such variability means caution needs to accompany claims of “man walking again” – particularly when reports relate to a single individual.
In the case that was linked to the Australian of the Year award, the actual 2013 study focused on whether it was safe to take the patient’s own nerves and other cells from the nose and place these into the damaged region of the spine. While the researchers themselves recommended caution in interpreting the results, accompanying media reports focused on the outcome from just one of the six participants.
While the outcome was significant for the gentleman involved, we simply do not know whether recovery may have occurred for this individual even without stem cells, given the type of injury (stab wounds), the level of injury, the accompanying rehabilitation that he received or a combination of these factors. It cannot be assumed a similar outcome would be the case for all people with spinal injury.
We are not there yet – but there is hope
Finding a way to alleviate the suffering of those with spinal cord injury, and many other conditions, drives the work of thousands of researchers and doctors around the globe. But stem cells are not a “silver bullet” and should not be immune from careful evaluation in clinical trials.
Failure to proceed with caution could actually cause harm. For example, a paraplegic woman who was also treated with nasal stem cells showed no clinical improvement, and developed a large mucus-secreting tumour in her spine. This case highlights the need for further refinement and assessment in properly conducted clinical trials before nasal stem cells can become part of mainstream medicine.
It’s also worth noting that for spinal cord injury, trials for recovery of function are not limited to the use of stem cells but include approaches focused on promoting health of surviving nerves (neuroprotection), surgery following injury, nerve transfers, electrical stimulation, external physical supports known as exoskeletons, nanotechnology and brain-machine interfaces.
Ultimately, determining which of these approaches will improve the lives of people with spinal injury can only be done through rigorous, ethical research.
Megan Munsie, Head of Education, Ethics, Law & Community Awareness Unit, Stem Cells Australia, University of Melbourne; Andrew Nunn, Adjunct Research Associate , Monash University, and Claire Tanner, Postdoctoral research fellow, University of Melbourne