Cool it then move it; hypothermia and exercise to promote recovery after spinal cord injury.

Spinal cord injury is sudden, devastating and expensive both personally and for the health system with a price tag of ~$2bn pa in Australia. It affects approximately 1 person per day and approximately 10,000 people live with spinal cord injury. Paralysis is not just about nothing, but comes with serious medical sequelae as a result of the body being disconnected from the brain. Despite decades of research and increasing investment in clinical trials, all we have is improved medical management and rehabilitation. Here, Professor Dunlop uses hypothermia to acutely rescue tissue and then exercise drive long-term recovery.

Spinal cord injury is most often caused by trauma such as traffic accidents and falls. Fracture dislocation and burst fractures of the spinal column and intervertebral discs compress the spinal cord causing oedema, swelling and then rapid progressive waves of secondary biochemical degeneration that extend well beyond the initial trauma. The pattern of damage is very similar to stoke for which the gold standard of treatment with clot busting drugs is 4h and which has markedly improved long-term recovery, largely by preventing the toxic spread of secondary damage.

Professor Dunlop is therefore asking, if stroke can be treated within 4h, why not spinal cord injury? Recent evidence suggests that surgical or traction decompression of the cord provides some benefit if delivered within 24h of injury. However, even after low impact sporting injuries, closed reduction needs to be undertaken <4h to have any significant benefit. Organising emergency surgical decompression within this short time-frame is often impractical, particularly in a country such as Australia with injuries in rural and remote regions making access to specialised care challenging.

Hypothermia is emerging as an acute treatment that is safe, relatively simple to administer and has the capacity to reduce oedema and limit catastrophic secondary metabolic injury cascades. The team is therefore undertaking a major study called “ICED”, our hypothesis being that Immediate Cooling (<2h of injury) will buy time before Emergency Decompression (<18h of injury) and rescue as much tissue as possible in the minutes to hours following injury. ICED involves mapping access to care to identify, and then minimise delays, to decompression, validating a brief paramedic assessment of neurological function and confirming feasibility of intravenous cooling within <2h and decompression <18h in a subset of patients. The full trial will involve patients randomised to hypothermia or normothermia, both followed by emergency decompression.

Exercise has benefits after spinal cord injury both in terms of driving neurological recovery and by reducing many major secondary complications to look after the body and the mind. However, strong evidence to support the role of exercise after spinal cord injury is lacking. In Australia and New Zealand, the team is undertaking 3 randomized controlled trials, collectively termed SCIPA (Spinal Cord Injury and Physical Activity), to test novel interventions that move the paralysed limbs and determine whether they improve neurological recovery and overall health. After completion of the trials, the challenge will be to introduce new protocols to clinical practice.

Collaborator/s

  • Professor Mary Galea, Medicine, University of Melbourne
  • Dr Peter Batchelor, Austin Health & University of Melbourne
  • Dr Ruth Marshall, Dr Jillian Clark, Hampstead Rehabilitation Centre, Royal Adelaide Hospital
  • Professor Brain Freeman, Spinal Surgery, Royal Adelaide Hospital
  • Dr Tim Geraghty, Queensland Spinal Cord Injuries Service
  • Associate Professor Lisa Harvey, Medicine, University of Sydney