Intermittent Hypoxia to Enhance Motor Function After Spinal Cord Injury

Recent evidence has shown that acute intermittent hypoxia can strengthen motor pathways after
spinal cord injury, and enhance walking outcomes after walking rehabilitation compared to
walking rehabilitation alone. A single session of acute intermittent hypoxia has also been
shown to temporarily enhance breathing and limb strength in people with spinal cord injury.
Further evidence supports the hypothesis that acute intermittent hypoxia acts on all motor
pathways, and thus can enhance the strength of most muscles in the body.

Spinal cord injury affects the trunk muscles that control respiration and posture. Decreased
respiratory muscle function can lead to diseases of the respiratory system, which are the
primary cause of death and significant cause of re-hospitalization after spinal cord injury.
Deficits in postural muscle function affect one's ability to balance, safely maintain a
seated position, or ambulate after spinal cord injury, severely impacting daily activities
such as self-care and feeding skills.

This study will test the hypothesis that a single session of acute intermittent hypoxia will
increase strength and activation of the trunk muscles that control respiration and posture,
leading to improved scores on functional assessments in individuals with chronic spinal cord
injury. Our long term goal is to better understand the therapeutic potential of acute
intermittent hypoxia combined with physical rehabilitation for individuals with chronic
spinal cord injury.

Inclusion criteria:

1. Male or female, ages 18-65

2. Greater than 6 months post-spinal cord injury

3. Spinal cord injury affecting segments between C4-T12

4. No other known neurological disorders

5. Able to provide informed consent

6. no severe musculoskeletal impairments, open wounds, or skin lesions that would limit
participation in functional assessments.

Exclusion criteria:

1. Presence of a self-reported uncontrolled medical condition including, but not limited
to: cardiovascular disease; sleep apnea; obstructive lung disease; severe neuropathic
or chronic pain; severe recurrent autonomic dysreflexia

2. Severe, untreated bladder or urinary tract infection

3. Presence of severe musculoskeletal impairments, open wounds, or skin lesions that
would limit participation in functional assessments

4. Women who report being pregnant or test positive on a pregnancy test