Exercise therapy research being conducted by the Pain and Sensory Dysfunction Research Group at the University of Newcastle is bringing hope of restored muscle function to those suffering paralysis from spinal damage.
Through laboratory modelling, neurophysiologist Dr Michelle Rank believes that exercise is more beneficial than any pharmacological or applied therapy currently available – even for patients with long-term injuries who have not previously had access to the intervention.
Dr Rank’s project, “The effect of exercise training on interneurons after incomplete spinal cord injury”, won a major NSW Office for Health and Medical Research postdoctoral award at the recent ASMR NSW Scientific Meeting. It is the first electrophysiological evidence of its kind.
“Two things happen, post injury,” Dr Rank explains. “Messages from the brain have difficulty getting to the muscles because the pathway is interrupted and, in addition, muscles tend to have atrophy because they’re not being used.
“We are addressing what’s happening in the spinal cord to see how we can make those messages pass more effectively to the command muscles. With exercise training we can determine whether individual neurons in the vicinity of a spinal cord lesion are faring better and forming new connections.
“Just as the brain has plasticity after injury it appears that nerve fibres are sprouting to create new pathways that ‘bridge’ or ‘detour’ around the injury.
“We’ve seen some profound improvements, with limbs that were originally paralysed getting a better range of motion and more normal movement. Even the use of arm exercises can improve recovery in lower limbs, so there’s a systemic effect.”
Working with University of Newcastle exercise physiologist Professor Robin Callister and University of Melbourne physiotherapist Professor Mary Galea, Dr Rank is aiming to define the optimum types and durations of exercise as well as determining the best time to initiate exercise training.
“Early intervention appears best but it’s never too late. Our results so far have demonstrated that just three weeks of treadmill training selectively strengthens the neural connections around the spinal cord injury site,” Dr Rank adds.
“I’m now examining the effect of exercise dose, and this work suggests that both six and nine weeks of treadmill work further enhance neuron-to-neuron communication and electrical signalling.
“Our work in the laboratory constantly informs the patient-based studies that Professor Galea is running and is important for designing rehabilitation programs and future drug therapies for patients.”