The BOOST Trial: Breathing low oxygen to enhance spinal neuromodulation training in persons with SCI

Research Objectives: To investigate the safety and efficacy of breathing low oxygen (acute intermittent hypoxia, AIH) as a pretreatment to enhance the functional benefits of transcutaneous spinal neuromodulation (TSN) on walking training (WALK+TSN) in people with chronic, motor-incomplete spinal cord injury (iSCI).

Design: Double-blind, placebo-controlled multisite randomized clinical trial

Setting: Spaulding Rehabilitation Hospital; Boston, MA and Shirley Ryan AbilityLab; Chicago, IL

Participants: We plan to enroll 60 adults (18-70 yrs.) with chronic (>1 yr. post injury) iSCI who are ambulatory.

Interventions: All participants will receive two weeks of high intensity (8, 60min sessions) walking practice (WALK) before randomly receiving either two weeks (8 sessions) of AIH (15 episodes; 90s at 10% O2, 60s intervals of room air) pretreatment to WALK+TSN, SHAM (15 episodes; 90s at 21% O2, with 60s intervals of room air) pretreatment to WALK+TSN, or AIH pretreatment to WALK+NoTSN.

Main Outcome Measures: The primary outcome of this study is walking speed which we will quantify using the change in 10-meter walk test time relative to baseline as the primary endpoint. The timed up-and-go test, six-minute walk test, as well as measures of pain, spasticity, autonomic dysreflexia, cognition, and bladder and bowel function will be secondary outcomes. We will record these measures at baseline, after WALK, and after the combinatorial treatments, and at 1-week, 4-weeks, and 8-weeks follow-up.

Results: We hypothesize that AIH pretreatment to WALK+TSN safely increases potency and efficacy of training-related walking improvements in people with chronic iSCI more than either alone. We also predict dose-dependent associations between a single day of AIH pretreatment and the long-term effects of daily AIH pretreatment.

Conclusions: Functional walking remains a significant goal for many persons with iSCI. Prior studies show daily AIH promotes rapid spinal plasticity and augments the benefits of other therapies that enhance walking ability in individuals with chronic iSCI. The outcomes from this study will offer new insight into the potential enduring benefits of AIH pretreatment for TSN training to boost walking recovery in people with chronic iSCI.

Author(s) Disclosures: Gad & Edgerton: SpineX