To assess the clinical value for stem cell transplantation in patients with spinal cord injury (SCI), researchers in China, led by Zhao et al., reviewed the data of 22 trials. After completing a meta-analysis, they concluded that stem cell transplantation is a reliable treatment modality, particularly for patients in the intermediate and/or chronic phase of injury. With a low incidence of side effects, this type of minimally invasive treatment appears to be a valid option deserving of continued study. The full report of their findings appears in the May, 2019 issue of the European Spine Journal, and is entitled “Is Cell Transplantation a Reliable Therapeutic Strategy for Spinal Cord Injury in Clinical Practice? A Systematic Review and Meta-Analysis from 22 clinically controlled trials.”
Types of spinal cord injuries
Injuries to the spinal cord fall into two categories: complete and incomplete. For patients with a complete SCI, permanent damage is incurred—the type of severe functional limitation is dependent on which area of the spinal cord is damaged. In incomplete SCIs, damage is not as catastrophic. Depending on the patient’s health, some degree of sensation and mobility are preserved and/or responsive to treatment.
The spine is divided into four areas:
- cervical—damage here affects the head and neck, and is considered the most severe of SCI cases.
- thoracic—injuries here affect the chest, upper and mid-back, as well as the abdominal muscles; patients with complete thoracic SCIs are considered quadriplegic and typically need ventilator assistance to breathe.
- lumbar—the legs and hips are affected; patients are considered paraplegic and must use wheelchairs for mobility, and require toileting assistance.
- sacral—injuries to the lowest portion of the spine affect the hips, thighs, buttocks and pelvic organs.
Prevalence of SCIs and current treatment models
The National Spinal Cord Injury Association estimates that close to 450,000 people in the US have SCIs. Damage to the spinal cord usually results from some kind of trauma to the spinal column, although certain neurological disease processes can attack and injure the spinal cord, too. No matter the cause, SCI is a devastating condition—estimated by the CDC to cost approximately $9.7 billion dollars each year—with limited treatment options.
SCIs are graded by the American Spinal Injury Association (ASIA) on a scale from A (most severe) to E (normal). For younger patients, car accidents cause the highest number of SCIs, followed by acts of violence and recreational activities; for older adults, falls are the main mechanism of injury.
At the time of injury, every effort is made to stabilize the spine. This immobilization must be maintained even during imaging tests and/or emergency surgery. In the most severe cases, supporting the body’s autonomic functions—like breathing—are the top priority. Traction can be utilized to reduce pressure and improve alignment of the spine. When compression to the spinal cord is caused by vertebral injury or circulation impairment, surgery is needed to stabilize the spine. Once the acute phase of injury has passed, treatment then focuses on rehabilitative services that attempt to recover any degree of lost functionality.
For patients with incomplete SCIs, slow improvement can and does happen. Treatment goals include recovering enough mobility to walk, and/or control their bowel and bladder function. For patients with compete SCIs, however, damage is permanent. Deficits must be accepted and often a patient’s entire life is upended by this change. Treatment in these cases, therefore, focuses on preventing secondary issues that arise from the degree of paralysis incurred, like pneumonia, bed sores, and blood clots.
On the whole, it was concluded that “cell transplantation appears to be a safe therapeutic strategy possessing substantial beneficial effects in the patients with SCI in clinic.”
Future of stem cell therapy with SCIs
Ever since stem cell transplantation was successfully used to regenerate cardiac tissue in 2001, researchers have raced to discover new ways to apply this treatment model. Stem cells are valuable for three main reasons: their ability to differentiate, their anti-inflammatory effect on diseased tissue, and their secretion of growth factors that promote regeneration in damaged tissue. Investigative study into the use of stem cells has been conducted for the past four decades—it was the aim of Zhao et al. to review the safety and effectiveness of transplanting stem cells for SCI patients in particular.
With a total of 973 SCI patients included in their review, it was shown that ASIA scores improved significantly across the board following stem cell transplantation. What’s more, a target stem cell dosage, the best window for treatment following injury, and the superiority of using a minimally invasive technique were all determined from this review. On the whole, it was concluded that “cell transplantation appears to be a safe therapeutic strategy possessing substantial beneficial effects in the patients with SCI in clinic.”
For patients facing the dire diagnosis of SCI, traditional treatment options are limited. Therefore, this review by Zhao et al. offers hope about the safety and effectiveness for stem cell transplantation as a viable treatment modality, and has the potential to completely disrupt current treatment models.