Randy D. Trumbower, Emory University, Atlanta, USA

Repetitive exposure of intermittent hypoxia to enhance walking recovery in persons with chronic spinal cord injury

Funded in: 2014, 2015, 2016


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Problem: Neuronal Plasticity is impaired after spinal cord injury.

Target: Repeatedly breathing low oxygen levels for brief periods (‘intermittent hypoxia’) enhances plasticity via serotonin release.

Goal: Stimulation of the recovery of walking function in persons with chronic spinal cord injury.

Accumulating evidence suggests that repeatedly breathing low oxygen levels for brief periods (termed intermittent hypoxia) is a safe and effective treatment strategy to promote meaningful functional recovery in persons with chronic spinal cord injury. Repetitive exposure to mild hypoxia triggers a cascade of events in the spinal cord, including new protein synthesis and increased sensitivity in the circuitry necessary for breathing and walking. Recently the team demonstrated that daily intermittent hypoxia stimulated walking enhancement in persons with chronic spinal cord injury.

Despite these exciting findings, important clinical questions remain.
a)    Time and does relation of intermittent hypoxia: The hypothesis is that repetitive exposures (3 times per week for 4 weeks) to modest bouts of low oxygen will enhance and prolong walking recovery in persons with chronic spinal cord injury.
b)    Mechanisms:, Multiple experimental approaches, including muscle electromyography, measurements of walking dynamics and stretch reflexes will be used in the study to show that repetitive exposures to intermittent hypoxia will result in improved inhibition and subsequently enhance muscle coordination during walking.
c)    Safety: Finally, it is critical to confirm that repeat exposures to mild bouts of intermittent hypoxia is safe.

The ultimate goal of this research is to assess the potential of repetitive intermittent hypoxia as a therapeutic approach to stimulate recovery of walking function in persons with chronic spinal cord injury.