Acute Intermittent Hypoxia Combined With Gait Training in Multiple Sclerosis (MINT)

Acute Intermittent Hypoxia (AIH) Primed Myoelectric Interface Neurorehabilitation Training (MINT) for Gait Recovery in Multiple Sclerosis

This interventional, randomized, sham-controlled study will examine whether Acute Intermittent Hypoxia (AIH) delivered immediately before Myoelectric Interface Neurorehabilitation Training (MINT)-based locomotor training improves gait in people with Multiple Sclerosis. The primary objectives are to evaluate changes in gait speed and endurance, with secondary objectives assessing spatiotemporal gait parameters, fatigue, and safety. Participants will receive AIH or sham priming followed by standardized treadmill and/or overground gait training, with outcome measures collected before and after the intervention across multiple sessions.

Study Overview

• Status: Not yet recruiting
• Conditions: Multiple Sclerosis; Multiple Sclerosis (MS) - Relapsing-remitting; Multiple Sclerosis (MS) Primary Progressive; Multiple Sclerosis (MS) Secondary Progressive
• Intervention / Treatment: Other: Acute Intermittent Hypoxia (AIH); Other: Myoelectric Interface Neurorehabilitation Training (MINT); Other: Sham Acute Intermittent Hypoxia (AIH)

Detailed Description

The study tests whether a brief breathing treatment, acute intermittent hypoxia (AIH), can make a computer-based muscle training program (MINT) more effective for people with MS who have difficulty walking. AIH involves breathing short alternating periods of low-oxygen air (about 9% oxygen versus the roughly 21% in room air) and normal room air. The premise, drawn from work in other neurological conditions like spinal cord injury, is that AIH delivered before movement training may improve strength and walking. Whether this benefits people with MS is not yet known, which is the gap the study addresses.

MINT itself uses surface EMG sensors on the leg muscles to capture muscle activity, which then controls game-like tasks on a screen. Participants practice activating the correct muscles for walking while suppressing unwanted activity.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rachel A Kalvakota, OTD, OTR/L; Phone Number: 1-312-238-3947; Email: rkalvakota@sralab.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of clinically definite multiple sclerosis
• Patient-Determined Disease Steps (PDDS) score between 3 and 6
• Relapse-free for at least 6 months prior to enrollment
• Age ≥ 18 years and ≤ 75 years
• Resting oxygen saturation (SpO₂) ≥ 95% on room air
• Systolic blood pressure between 85-140 mmHg and diastolic blood pressure between 55-90 mmHg
• Modified Ashworth Scale (MAS) score ≤ 3 at the ankle and knee
• Mini-Mental State Examination (MMSE) score ≥ 24
• Ability to walk at least 10 meters with or without an assistive device
• Ability to perform active ankle dorsiflexion and plantarflexion

Exclusion Criteria:

• Uncontrolled hypertension or hypotension outside the required ranges
• History of epilepsy or seizures
• Uncontrolled pulmonary, cardiovascular, or orthopedic disease
• Premorbid or ongoing major psychiatric illness (e.g., major depression, psychosis)
• Other neurological disease (e.g., stroke, traumatic brain injury, peripheral neuropathy)
• Illnesses with potential to cause brain injury
• Frequent or severe unexplained headaches
• Pregnancy
• Implanted medical devices (e.g., pacemakers, intrathecal pumps, brain stimulators)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: AIH + MINT	Other: Acute Intermittent Hypoxia (AIH); During AIH, the participant will be equipped with a non-rebreathing face mask, and provided with the AIH intervention. The AIH intervention involves alternating breathing cycles. One cycle involves breathing air with lower oxygen concentration (9-10% oxygen) for 30 and 90 seconds, followed by breathing normal room air (21% oxygen) for a similar duration. This cycle is repeated 15 times in one session. Blood oxygen and heart rate are monitored throughout.; Other: Myoelectric Interface Neurorehabilitation Training (MINT); MINT is a gamified rehabilitation paradigm that uses surface electromyography (sEMG) biofeedback to retrain lower-limb muscle activation patterns. The intervention is designed to reduce abnormal coactivation of agonist-antagonist muscle pairs and facilitate more efficient torque generation during functional movements. sEMG electrodes will be placed bilaterally over the tibialis anterior, gastrocnemius, and quadriceps muscles. EMG signals will be acquired in real time, processed, and used to control on-screen tasks within a custom Unity-based software environment. Participants will engage in interactive tasks where selective activation of target muscles allows them to move a virtual avatar, align a gauge, or achieve movement goals while minimizing antagonist activity. Each MINT session will last approximately 60 minutes and will be delivered immediately following AIH or sham exposure. Sessions will include calibration of EMG channels, a brief familiarization period, and four to five tra
Sham Comparator: SHAM AIH + MINT	Other: Myoelectric Interface Neurorehabilitation Training (MINT); MINT is a gamified rehabilitation paradigm that uses surface electromyography (sEMG) biofeedback to retrain lower-limb muscle activation patterns. The intervention is designed to reduce abnormal coactivation of agonist-antagonist muscle pairs and facilitate more efficient torque generation during functional movements. sEMG electrodes will be placed bilaterally over the tibialis anterior, gastrocnemius, and quadriceps muscles. EMG signals will be acquired in real time, processed, and used to control on-screen tasks within a custom Unity-based software environment. Participants will engage in interactive tasks where selective activation of target muscles allows them to move a virtual avatar, align a gauge, or achieve movement goals while minimizing antagonist activity. Each MINT session will last approximately 60 minutes and will be delivered immediately following AIH or sham exposure. Sessions will include calibration of EMG channels, a brief familiarization period, and four to five tra; Other: Sham Acute Intermittent Hypoxia (AIH); During Sham AIH, the participant will be equipped with a non-rebreathing face mask, and provided with the AIH intervention. The Sham AIH intervention involves alternating breathing cycles. One cycle involves breathing air closely resembling room air (~21% oxygen) for 30 and 90 seconds, followed by breathing normal room air (21% oxygen) for a similar duration. This cycle is repeated 15 times in one session. Blood oxygen and heart rate are monitored throughout.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Six-Minute Walk Test (6MWT)	Participants walk as far as they safely can in six minutes along a marked course, and total distance (meters) is recorded.	Change in distance (meters) from pre-training assessment (Day 1, before the first intervention) to Immediate Post (Day 5, after the final intervention), 1-week follow-up (Day 14-21), and 1-month follow-up (Day 36-41).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ten-Meter Walk Test (10MWT)	Measures gait speed over 10 meters at a self-selected comfortable pace, averaged across two trials.	Baseline/pre-training (Day 1) to immediately post-intervention (Day 5), with retention assessed at the 1-week (Day 14 to 21) and 1-month (Day 36 to 41)
Stair Climb Test (SCT)	Assesses functional mobility and lower-limb power. Participants ascend a standardized 12-step staircase (17 cm per step, 2.04 m total) as quickly and safely as possible across three trials, with ascent time recorded and handrail use documented.	Baseline/pre-training (Day 1) to immediately post-intervention (Day 5), then 1-week (Day 14 to 21) and 1-month (Day 36 to 41) follow-ups
Maximal Voluntary Contraction (MVC) Testing	Measures maximal strength of the trained leg on a Biodex dynamometer across ankle plantarflexion, dorsiflexion, knee flexion, and knee extension. Participants perform 3 to 5 maximal isometric contractions (10 seconds each) per movement while surface EMG quantifies agonist activation and antagonist coactivation.	Baseline/pre-training (Day 1) to immediately post-intervention (Day 5), then 1-week (Day 14 to 21) and 1-month (Day 36 to 41) follow-ups
Fatigability Testing	Quantifies muscle fatigue as the percent decline in torque across 20 consecutive maximal isometric plantarflexion contractions (5 to 10 seconds each) on the Biodex, with surface EMG monitoring changes in activation and coactivation through the series.	Baseline/pre-training (Day 1) to immediately post-intervention (Day 5), then 1-week (Day 14 to 21) and 1-month (Day 36 to 41) follow-ups
Ankle Proprioception Testing	Assesses joint sense on the trained leg via the Biodex while the participant is blindfolded with noise-cancelling headphones. It includes a movement detection threshold (trigger press when slow passive rotation is first felt, 5 to 6 trials) and joint position matching (reproducing a passively set target angle, 6 to 8 trials), with surface EMG confirming no compensatory activity.	aseline/pre-training (Day 1) to immediately post-intervention (Day 5), then 1-week (Day 14 to 21) and 1-month (Day 36 to 41) follow-ups

Collaborators and Investigators

• Sponsor: Shirley Ryan AbilityLab
• Investigators: Principal Investigator: Milap Sandhu, PT, PhD, Shirley Ryan AbilityLab

Study record dates

Study Major Dates

• Study Start (Estimated): June 15, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: gait; rehabilitation; recovery; neuroplasticity; walking; hypoxia; strength; walk; lower extremities; AIH
• Additional Relevant MeSH Terms: Nervous System Diseases; Pathologic Processes; Chronic Disease; Disease Attributes; Autoimmune Diseases; Immune System Diseases; Demyelinating Autoimmune Diseases, CNS; Autoimmune Diseases of the Nervous System; Demyelinating Diseases; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Multiple Sclerosis; Hypoxia; Multiple Sclerosis, Relapsing-Remitting; Multiple Sclerosis, Chronic Progressive
• Other Study ID Numbers: STU00225287

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: We do not currently have a plan to share IPD.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No