An interventional study of Acute Intermittent Hypoxia (AIH) in Spinal Cord Injuries (SCI), sponsored by Zev Rymer. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-13.
Sponsored by Zev Rymer · Not applicable, Interventional, and Diagnostic
This study aims to observe the effects of administration of a breathing intervention (Acute Intermittent Hypoxia (AIH)) on spasticity (tightness) in individuals with incomplete Spinal Cord Injury. It is hypothesized that hypoxia will decrease the reflex threshold of the biceps brachii, indicating an increase in spasticity following the AIH.
In the case of incomplete traumatic spinal cord injury, it is know now that muscular strength improves quickly after AIH administration, and this Increase in voluntary strength lasts from three to six hours. The Increase in strength, coupled with demonstrated improvements in spinal cord neural plasticity, makes AIH administration a potentially valuable new therapeutic intervention. AIH initially acts by releasing serotonin in the central nervous system, enhancing persistent sodium uptake (via the motor neuron soma) and activating voltage-gated calcium channels in motor neuron dendrites. There are also other effects of serotonin on motor neuron excitable channels. One potential complication of hypoxia is linked to the changes in motor neuron excitability in humans with SCI.
These issues may be relevant to our potential work on the Therapeutic efficacy of AIH in persons with incomplete spinal cord injury. In other words, if individuals are highly spastic, it may indicate that their neuronal receptor sites are inaccessible, and increasing spinal cord serotonin levels may not be beneficial.
1,948 studies on the registry are indexed under Spinal Cord Injuries; 505 are open to participants now.
This study's planned enrollment of 10 is below the median of 24 across 1,566 interventional studies indexed under Spinal Cord Injuries.
Browse Spinal Cord Injuries studies →This is the only study on the registry with Zev Rymer as lead sponsor.
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Exclusion Criteria:
In this Arm, participants will receive the Acute Intermittent Hypoxia Intervention. In this AIH, participants will breath alternating bouts of lowered oxygen and room air (approximately 60 seconds of each) for around 30 minutes.
Device: Acute Intermittent Hypoxia (AIH)
This intervention involves breathing lowered levels of oxygen for 60 seconds, alternating with 60 seconds of room air breathing. Participants will be monitored and observed during the entire session for any changes in vital signs
Change in reflex indentation threshold
Similar to a tendon tap that a doctor may perform, this study uses an automated tendon tapper to measure the level of indentation needed to elicit a reflex in the bicep muscle. The aim is to observe any changes in reflex threshold following the AIH intervention
Time frame: Day 1 of Intervention
Change in Modified Ashworth Scale - Elbow
The modified Ashworth scale is a measure of Spasticity, performed by a trained administrator. This test involves rapidly rotating the participant's arm and feeling the spastic muscle response. This assessment is scored from 0 to 4, with 0 indicating no spasticity, and 4 indicating a fully contracted limb
Time frame: Day 1 of intervention
Grip Strength
Using a handheld dynamometer, maximum grip strength of participants will be measured
Time frame: Day 1 of intervention
Plan to share: Yes — Upon request, we will provide de-identified study data to researchers. The ICF and Protocol will be uploaded upon completion of study procedures
Supporting information: Study protocol, Icf
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