Low-oxygen sessions and noninvasive spinal stimulation to improve walking after spinal cord injury.
Breathing Low Oxygen to Enhance Spinal Stimulation Training and Functional Recovery for Aging Adults With Chronic SCI: The BO2ST-II Trial
This study tries short, repeated bouts of mild low oxygen together with noninvasive spinal cord stimulation and walking practice to help adults with chronic spinal cord injury walk better and build leg strength.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 60 (estimated) |
| Ages | 18 Years to 80 Years |
| Sex | All |
| Sponsor | Spaulding Rehabilitation Hospital Academic / other |
| Locations | 2 sites (Jacksonville, Florida and 1 other locations) |
| Trial ID | NCT06521723 on ClinicalTrials.gov |
What this trial studies
The trial combines acute intermittent hypoxia (brief, mild low-oxygen breathing), transcutaneous spinal cord stimulation (tSTIM), and supervised walking training to determine dosing that best enhances walking recovery. Participants receive AIH as a pretreatment to tSTIM during walking sessions, with outcomes such as walking speed (10-meter walk) and lower-limb strength measured over the course of the protocol. The design stratifies by age groups to identify whether older versus younger adults need different numbers of AIH sessions to maximize plasticity and functional gains. Safety screening excludes individuals with serious cardiovascular, pulmonary, or other medical issues that could increase risk during low-oxygen exposure or stimulation.
Who should consider this trial
Good fit: Adults 18–80 years old with chronic (>12 months), non‑progressive spinal cord injury between C1 and L2 who are ambulatory without another person's support, have some preserved motor or sensory function below the injury, and are medically cleared to participate.
Not a fit: People who are non‑ambulatory, have progressive neurological disease, severe medical comorbidities (e.g., uncontrolled cardiac or pulmonary disease), severe autonomic dysreflexia, significant cognitive impairment, or other exclusionary conditions are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, the combined approach could improve walking speed, leg strength, and everyday mobility, increasing independence and quality of life for people with chronic SCI.
How similar studies have performed: Preliminary studies indicate that combining AIH and tSTIM with walking training yields greater walking improvements than either intervention alone, but age- and sex-specific dosing has not been established.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 18 to 80 years of age * medically stable with medical clearance from study physician to participate * SCI at or below C1 and at or above L2 with at least some sensory or motor function preserved below the neurologic level * non-progressive etiology of spinal injury * American Spinal Injury Association (ASIA) scores of C-D at initial screen * ambulatory (able to complete the 10-meter walk test without support from another person) * chronic injury (define as \> 12 months post-injury) to avoid potential for spontaneous neurological plasticity and recovery Exclusion Criteria: * severe concurrent illness or pain, including unhealed decubiti, severe neuropathic or chronic pain syndrome, severe infection (e.g., urinary tract), hypertension, cardiovascular disease, pulmonary disease, severe osteoporosis, active heterotopic ossification in the lower extremities, severe systemic inflammation * \< 24 on Mini-Mental Exam * severe recurrent autonomic dysreflexia * history of severe cardiovascular/pulmonary complications including hypertension (systolic blood pressure \> 150 mmHg) * pregnancy because of unknown effects of AIH or tSTIM on a fetus (individuals of childbearing potential will not otherwise be excluded) * botulinum toxin injections in lower extremity muscles within the prior three months * history of tendon or nerve transfer surgery in the lower extremity * untreated severe sleep-disordered breathing characterized by uncontrolled hypoxia and sleep fractionation that may impact the outcome of this study. * active implanted devices (e.g., intrathecal baclofen pump) * receiving concurrent electrical stimulation * motor threshold evoked by transcutaneous spinal stimulation \>200 mA
Where this trial is running
Jacksonville, Florida and 1 other locations
- Brooks Rehabilitation Hospital — Jacksonville, Florida, United States (Recruiting)
- Spaulding Rehabilitation Hospital — Cambridge, Massachusetts, United States (Recruiting)
Study contacts
- Principal investigator: Randy Trumbower, PT, PhD — Harvard Medical School (HMS and HSDM)
- Study coordinator: Noah Piazza
- Email: npiazza2@mgb.org
- Phone: (617) 952-6953
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.