Recent scientific advances are giving hope to spinal cord injury patients
Scientific advances give fresh hope to sufferers of spinal cord injuries, writes David Tan
Can those suffering paralysis ever walk again? It may not be as instantaneous as in the Bible - "Get up! Pick up your mat and walk" - but advances in science in the past decade are giving sufferers of spinal cord injury hope for a treatment.
Recently, in findings reported in the medical journal Brain, four young men in the US who had been paralysed for years were able to voluntarily move their legs as a result of epidural electrical stimulation of the spinal cord.
Closer to home, the China Spinal Cord Injury Network (ChinaSCINet) recently conducted phase-two clinical trials in Hong Kong and Kunming, where umbilical cord blood cells were transplanted together with lithium into people with chronic complete spinal cord injury.
In the Kunming trial, the 20 study subjects, who averaged seven years after complete spinal cord injury, also received intensive walking training for three to six months. After six to 12 months, 15 of the subjects could walk in a rolling device with minimal assistance. Another two subjects could walk without any assistance using a four-point walker.
"A cure for spinal cord injury, while it is not yet available, is conceivable. 'Possible' is a big word," says Dr Gilberto Leung, a doctor in the department of surgery at University of Hong Kong's Li Ka Shing Faculty of Medicine and one of the researchers with ChinaSCINet.
"It very much depends on how you define 'cure'. Partial restoration of body functions after spinal cord injury is possible. It is also important to help patients adapt to disability from the injury. We need to distinguish between 'cure', treatment, management, restoration and rehabilitation."
Spinal cord injury is commonly caused in traffic accidents, falls and sports injuries. The sudden trauma to the vertebral column compresses and damages the spinal cord, disconnecting the communication channel between the brain and the body, causing functional problems like sensory loss, neuropathic pain and lifetime paralysis.
Every year about 78,000 people in China suffer from spinal cord injury. In Hong Kong, there are about 400 people with severe chronic spinal cord injuries that are under care in rehabilitation centres, according to Dr Wise Young, CEO of ChinaSCINet.
Young notes that these numbers may not fully reflect the number of spinal cord injury patients because there may be others who have recovered and are no longer receiving care.
Considered an irreversible condition, tests on animals show that the transplantation of cells from umbilical cord blood, known as mononuclear cells, into the spinal cord could improve the function of spinally injured animals.
"These cells appear to stimulate regeneration of long tracts in the spinal cord, probably by releasing factors that stimulate regeneration or stimulating other cells in the spinal cord to release the factors," says Young.
Addition of the drug methylprednisolone could increase the survival of transplanted cells, while addition of lithium stimulates the cells to produce growth factors that prompt regeneration in the spinal cord.
A recent phase-two clinical trial of the treatment, conducted in Hong Kong by Leung and Professor Poon Wai-sang of Chinese University's department of surgery, involved eight people who have been living with severe spinal cord injury for an average of 13 years.
A key feature of the two-year study was to assess the safety of the transplantation procedure. "Previous treatments for other diseases involved intravenous delivery of cells - meaning into the blood - or into the cerebral spinal fluid via a lumbar puncture," says Leung.
Leung says the experimental treatment is an open operative procedure, involving opening up the back and removing bone to expose the spinal cord. The cord blood cells are then injected directly into the spinal cord.
"This could give rise to two issues. First, the open procedure of injecting into an injured region could do more damage. For example, there is a risk that any residual body function could be lost.
"Second, although cord blood cells are safe when delivered into the blood, very little is known about how these cells behave in the context of the spinal cord tissue," he says.
In the Kunming trial, Dr Hui Zhu and colleagues at the Kunming Army General Hospital found that surgery to expose the spinal cord could improve walking in people with chronic spinal cord injury.
Over the past decade, they have surgically exposed and removed adhesions between the spinal cord and surrounding tissues of 50 such patients. According to ChinaSCINet, many of the patients improved after such "untethering" surgery and intensive walking training.
The results of these clinical trials are being prepared for publication soon, says Young. "Based on these results, we are now planning to initiate phase III clinical trials in China, India, Norway and the USA."
ChinaSCINet plans to test 120 subjects with chronic complete spinal cord injury and to test different combinations of therapies. All patients would undergo three to six months of intensive locomotor training and be assessed for two years.
As for the four young men in the US reported in Brain, researchers implanted an epidural stimulator that delivers a continuous electrical current to the lower spinal cord, which mimics signals the brain normally transmits to initiate movement. It is revolutionary that three out of the four men could execute voluntary movements immediately following the implantation and activation of the stimulator.
"Because of epidural stimulation, they can now voluntarily move their hips, ankles and toes. This is groundbreaking for the entire field and offers a new outlook that the spinal cord, even after a severe injury, has great potential for functional recovery," says the study's lead author Dr Claudia Angeli of the University of Louisville, which co-developed the therapy with the University of California Los Angeles and the Pavlov Institute of Physiology.
Coupled with rehabilitative therapy, the impact of epidural stimulation intensified. Over the course of the study, the four men were able to activate movements with less stimulation, showing the ability of the spinal network to learn and improve nerve functions.
"We have uncovered a fundamentally new intervention strategy that can dramatically affect recovery of voluntary movement in individuals with complete paralysis, even years after injury," says Professor Susan Harkema of University of Louisville. "The belief that no recovery is possible and complete paralysis is permanent has been challenged."
Ben Kende is a young Hong Kong-born Australian who in 2010 was injured in an under-20s rugby tournament representing Hong Kong. The accident left Kende a quadriplegic with limited use of his arms and no use of his legs.
Today, he is studying in Australia and attends a private rehabilitation centre for spinal injury called Walk On, a franchise from Project Walk in the US. "His upper body has got stronger all the time with constant therapy," says Ben's mother Jennifer.
Jennifer is keen to highlight the need for post-injury protocols and early treatments to avoid compounding the injury. "It is important to be prepared for worst-case scenarios. For example, before a group of hang-gliders take the plunge, they need a plan of action, right down to which hospitals have the best practices. If the correct treatment is given within 24 hours, patients with spinal cord injuries could walk away."
The Ben Kende Foundation was established in 2011, and holds an annual ball to raise funds for spinal cord injury-related endeavours. Last year it bought spinal boards for injured players in Fiji.
"Spinal research is about 30 years behind that of AIDS and cancer research," says Jennifer. "It needs a lot of resources and funding. It would be good to see some of the tycoons in Hong Kong supporting these initiatives."