The Effect of Acute Intermittent Hypoxia on Motor Learning

NCT05341466 | Completed Results

• 2 other identifiers: 21-3980P2CHD086844
• Study Type: interventional
• Target: 56
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this study is to examine the effect of repetitive acute intermittent hypoxia on motor learning abilities in able-bodied individuals for subsequent study in individuals with incomplete spinal cord injury.

Conditions

Incomplete Spinal Cord Injury

Keywords

Spinal Cord Injury; Motor Adaptation; Acute Intermittent Hypoxia

Outcome Measures

Primary Outcomes (4)

• Change in Corticospinal Excitability

  Transcranial magnetic stimulation (TMS) can be applied over the primary motor cortex to examine changes in corticospinal excitability. The downstream muscle activation can be recorded with surface EMG as a motor-evoked potential (MEP). The peak-to-peak MEP amplitude (mV) is as an index of corticospinal excitability. A randomized sequence of TMS intensities can be applied over the primary motor cortex, ranging from 90-140% of the participants' resting motor threshold (RMT). The mean MEP amplitude will be plotted against the corresponding stimulation intensity to produce the recruitment curve. The area under the recruitment curve is an additional index of corticospinal excitability (mV/% RMT).

  We will measure TMS before the start of 5 consecutive days of AIH or SHAM treatment. We will measure TMS within 24 hours of the final treatment.

• Step Length Asymmetry

  Step length asymmetry will be quantified as the ratio of the normalized difference in step lengths between the fast and slow legs during split-belt motor adaptation: (Fast leg - Slow leg step length) / (Fast leg + Slow leg step length).

  We will compare asymmetry 15 minutes after the final AIH treatment to asymmetry following no treatment (control group).

• Step Time Asymmetry

  Step time asymmetry will be quantified as the ratio of the normalized difference in step times between the fast and slow legs during split-belt motor adaptation: (Fast leg - Slow leg step time) / (Fast leg + Slow leg step time).

  We will compare asymmetry 15 minutes after the final AIH treatment to asymmetry following no treatment (control group).

• Net Metabolic Power

  Using expired gas analyses, we will calculate net metabolic power by inputting steady-state values for V̇O₂ and V̇CO₂ into standard regression equations (W), subtracting resting values, and normalizing the result to each participant's body weight (kg).

  We will compare net metabolic power 15 minutes after the final AIH treatment to asymmetry following no treatment (control group).

Study Arms (3)

Repetitive Acute Intermittent Hypoxia

EXPERIMENTAL

5 consecutive days of 15, 1.5 min episodes at 9% O2 (AIH) alternating with 21% O2 at 1 min intervals

Other: Acute Intermittent Hypoxia

SHAM Acute Intermittent Hypoxia

SHAM COMPARATOR

5 consecutive days of 15, 1.5 min episodes at 21% O2 (SHAM AIH) alternating with 21% O2 at 1 min intervals

Other: SHAM Acute Intermittent Hypoxia

Control

NO INTERVENTION

The control group received no AIH exposure.

Interventions

Acute Intermittent Hypoxia OTHER

5 consecutive days of 15, 1.5 min episodes at 9% O2 (AIH) alternating with 21% O2 at 1 min intervals

Repetitive Acute Intermittent Hypoxia

SHAM Acute Intermittent Hypoxia OTHER

5 consecutive days of 15, 1.5 min episodes at 21% O2 (SHAM AIH) alternating with 21% O2 at 1 min intervals

SHAM Acute Intermittent Hypoxia

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• to 70 years old (the latter to reduce likelihood of heart disease);
• Medically stable with medical clearance from physician to participate;
• Motor-incomplete spinal cord injuries at or below C2 and at or above L5;
• AIS A-D at initial screen, or other non-traumatic spinal cord injury disorders (e.g. multiple sclerosis, ALS, tumors, acute transverse myelitis, etc.);
• More than 1 year since iSCI to minimize confounds of spontaneous neurological recovery;
• Ability to advance one step overground with or without assistive devices;

You may not qualify if:

• Severe concurrent illness or pain;
• Recurrent autonomic dysreflexia;
• History of cardiovascular/pulmonary complications;
• Concurrent physical therapy;
• Pregnant at time of enrollment or planning to become pregnant;
• Untreated painful musculoskeletal dysfunction, fracture or pressure sore;
• History of seizures or epilepsy;
• Recurring headaches;
• Concussion within the last six months;
• Depression or manic disorders
• Metal implants in the head, or pacemaker.

Sponsors & Collaborators

• University of Colorado, Boulder: lead
• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): collaborator
• University of Colorado, Denver: collaborator
• Medical University of South Carolina: collaborator

Study Sites (2)

University of Colorado, Anschutz Medical Campus

Aurora, Colorado, 80045, United States

Location

University of Colorado

Boulder, Colorado, 80309, United States

Location

Related Publications (2)

• Bogard AT, Hembree TG, Pollet AK, Smith AC, Ryder SC, Marzloff GE, Tan AQ. Intermittent hypoxia-induced enhancements in corticospinal excitability predict gains in motor learning and metabolic efficiency. Sci Rep. 2025 Feb 24;15(1):6614. doi: 10.1038/s41598-025-90890-8.

  PMID: 39994358 RESULT

• Bogard AT, Hemmerle MR, Smith AC, Tan AQ. Enhanced motor learning and motor savings after acute intermittent hypoxia are associated with a reduction in metabolic cost. J Physiol. 2024 Nov;602(21):5879-5899. doi: 10.1113/JP285425. Epub 2023 Nov 20.

  PMID: 37983629 RESULT

Related Links

• Related Info

MeSH Terms

Conditions

Spinal Cord Injuries

Condition Hierarchy (Ancestors)

Spinal Cord Diseases; Central Nervous System Diseases; Nervous System Diseases; Trauma, Nervous System; Wounds and Injuries

Results Point of Contact

• Title: Andrew Q. Tan
• Organization: University of Colorado, Boulder

andrew.tan@colorado.edu

303-735-0259

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: This study design is twofold. The first study examines the effects of AIH on motor learning using an AIH group and a control group (total N = 30). The second part of this study examines corticospinal indices of motor learning using an AIH group and a SHAM group (i.e., blinded normoxia; total N = 26).

Study Record Dates

• First Submitted: April 11, 2022
• First Posted: April 22, 2022
• Study Start: May 27, 2022
• Primary Completion: January 31, 2025
• Study Completion: February 24, 2025
• Last Updated: May 14, 2025
• Results First Posted: May 14, 2025

Record last verified: 2025-04

Locations

US (2)