Intermittent Hypoxia Elicits Prolonged Restoration of Motor Function in Human SCI
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries; Hypoxia
Study type: Interventional
Phase: Phase 1

Summary: 
      The goal of the study is to determine whether repeatedly breathing low oxygen levels for
      brief periods (termed intermittent hypoxia) will improve limb function after spinal cord
      injury. This idea stems from animal studies on respiration, in which investigators have shown
      that mild intermittent hypoxia improves breathing in spinally injured rats. These studies
      have shown that intermittent hypoxia induces spinal plasticity, strengthening neural
      connections and motor neuron function within the spinal cord. Exposure to mild intermittent
      hypoxia triggers a cascade of events, including increased production of key proteins and
      increased sensitivity of spinal cord circuitry necessary for improved breathing.

      The ultimate goal of this research is to assess the potential of mild intermittent hypoxia as
      a therapeutic approach to stimulate recovery of limb function in human patients.
    

Detailed description: 
      : The goal of the study is to determine whether repeatedly breathing low oxygen levels for
      brief periods (termed intermittent hypoxia) will improve limb function after spinal cord
      injury. This idea stems from animal studies on respiration, in which investigators have shown
      that mild intermittent hypoxia improves breathing in spinally injured rats. These studies
      have shown that intermittent hypoxia induces spinal plasticity, strengthening neural
      connections and motor neuron function within the spinal cord. Exposure to mild intermittent
      hypoxia triggers a cascade of events, including increased production of key proteins and
      increased sensitivity of spinal cord circuitry necessary for improved breathing.

      The investigators initially hypothesize that daily exposure to intermittent hypoxia for 7
      consecutive days will improve limb function in rats and in humans with chronic spinal
      injuries. First, the investigators will compare limb function in spinally-injured rats which
      receive mild intermittent hypoxia treatment with rats that did not. The investigators will
      measure grip strength and locomotor abilities in both groups before treatment and for several
      months after treatment. The investigators will also examine the spinal cords of these rats to
      look for the key proteins, which are indicators of spinal plasticity. The investigators will
      use this information to guide the treatment protocols when the investigators compare limb
      function in spinal-injured persons with and without intermittent hypoxia treatment.

      The second hypothesis is that combining intermittent hypoxia with locomotor training will
      further improve limb function after spinal injury. To test this idea, the investigators will
      compare limb function in spinally-injured rats which have received combined intermittent
      hypoxia and treadmill training with rats which only received intermittent hypoxia or
      locomotor training alone. The investigators will examine key proteins in the spinal cords of
      these rats to determine whether the combination of hypoxia and training further alters these
      indicators of plasticity. The investigators will also compare limb function in
      spinally-injured humans who receive both intermittent hypoxia and locomotor treadmill
      training with those who receive either treatment alone.

      The ultimate goal of this research is to assess the potential of mild intermittent hypoxia as
      a therapeutic approach to stimulate recovery of limb function in human patients.
    

Intervention name(s): Acute intermittent hypoxia; Room air
Intervention type(s): Other; Other
Intervention description(s): 30 minutes of intermittent breathing low oxygen followed by walking on a body-weight support treadmill; 30 minutes of breathing room air followed by walking on a body-weight support treadmill
Other intervention name(s): breathing low oxygen; breathing room air
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: spinal cord injury; walking; low oxygen; air; strength