Spinal Cord Injury Treatment: What's on the Horizon?
Approximately 250,000 people in the United States live with spinal cord injury (SCI), and more than 12,000 new cases occur each year. Injury is associated with significant morbidity, quality of life issues, and long-term costs. The average lifetime cost of caring for a patient with quadriplegia is estimated at $US1.35 million. The most common causes of SCI include motor vehicle crashes, falls, assaults, and sports. SCI is three to four times more likely to occur in men than in women and has a bimodal age distribution. A myriad of novel studies and therapies are targeting different aspects of the pathophysiology of SCI (Figure 1). An extensive review of the literature, including clinicaltrials.gov, was conducted. The review was limited to 2010 to 2016 data. A summary of findings was organized by treatment type: (A) intervention at the injury (pharmacologic, neuroprotectant therapies); and (B) stimulation to bypass the site of injury (neuromodulation). Multiple uncontrolled and unregulated studies were initially identified; therefore, focus was on phase 2/3 registered trials only. Some novel therapies, such as SUN13837 (a basic fibroblast growth factor), had exciting results in animals, but this finding did not translate to humans. Others, such as minocycline, riluzole, Rho-antagonists, stem cells, and intramedullary scaffolds (INSPIRE), have shown promise. For example, two of three patients with cervical SCI receiving a specific dose of Rho-antagonist converted from ASIA A to ASIA C or D in a phase 1/2a study. Advances have also been made in neuromodulation. Functional electrical stimulation led to improvements in muscle strength and bone mineral density. Stimulation of the central pattern generator of the lumbar spine is also being actively evaluated. Direct epidural stimulation was shown to augment recovery in a 23-year-old man with C7–T1 ASIA B SCI. With active stimulation and physical therapy came improvement in the ability to stand and in bladder/sexual function. Progress has been made with brain machine interfaces. Participants have learned to control computer cursors, virtual reality environments, hand orthotics, and wheelchairs. In a patient with C5–6 ASIA A, direct cortical arrays that bypass the spinal cord led to functional improvement to C7–T1. Spinal cord injury is devastating, and ideal treatments are currently lacking. However, it is an exciting time for those who work in the SCI field, with numerous clinical trials exploring the topics of neuroprotection, neuroregeneration, and neuromodulation. A multimodal approach will soon lead to significant advances in SCI treatment.