Effects of Breathing and Walking Treatments on Recovery Post-Spinal Cord Injury

Not Applicable

Completed

Brief Summary: Change to Reflect What Was Done and reason Changes Were Made.

The purpose of this study is to determine (1) if a specific breathing treatment (intermittent hypoxia) can promote changes in breathing function and (2) if pairing breathing treatments (hypoxia) with locomotor training can enhance the benefits of walking recovery observed with locomotor training alone (without breathing treatments).

Detailed Description: Spinal cord injury (SCI) is a very disabling health problem. Paralysis and paresis of limb and trunk muscles are major consequences of SCI and result in the inability to walk or difficulty walking. The most commonly stated goal by individuals with SCI during rehabilitation is the desire to walk again. Locomotor training (LT) that uses a body-weight support system and treadmill (BWST) is a task-specific rehabilitation intervention that allows practice of walking at normal speeds while loading the lower extremities, facilitating upright posture, and hip extension. Substantial improvement in ambulation can occur following locomotor training (LT) in individuals with motor incomplete spinal cord injury (iSCI). Despite these advances in activity-dependent rehabilitation, a need exists for defining complementary strategies that further amplify endogenous neuroplasticity. The proposed study will assess the therapeutic potential of (1) a respiratory training intervention (acute intermittent hypoxia, or AIH) on breathing function and (2) a combined locomotor (LT) and respiratory (AIH) training intervention for enhancing walking recovery.

Recruitment & Eligibility

Inclusion Criteria

Adults at least 18 years of age
At least 12 months post-incomplete spinal cord injury (I-SCI), including but not limited to the following syndromes: Brown Sequard and Central Cord Syndromes
Upper motor neuron lesion (with upper motor neuron signs (i.e. presence of clonus, spasms, and/or hyperreflexia))
A diagnosis of first time SCI including etiology from trauma, vascular, or orthopedic pathology
Resting oxygen saturation (SpO2) levels of 95-99%
Individuals who ambulate independently, with an assistive device, or who can walk when provided manual assistance
Persons using anti-spasticity medication must maintain stable medication dosage during the study
Able to give informed consent.
Medical approval by individual's physician

Exclusion Criteria

Current participation in a rehabilitation program/research protocol that could interfere or influence the outcome measures of the current study
History of congenital SCI (e.g. myelomeningocele, intraspinal neoplasm, Frederich's ataxia) or other degenerative spinal disorders (e.g. spinocerebellar degeneration, syringomyelia) that may complicate the protocol
Inappropriate or unsafe fit of the harness due to the participant's body size and/or joint contractures or severe spasticity that would prohibit the safe provision of either training modality.
Severe spasticity that would prohibit the safe provision of training.
Pregnancy - all women of childbearing age will be required to undergo pregnancy testing prior to enrollment
Unstable medical condition that could interfere with safety during participation in study (i.e. symptomatic cardiopulmonary complication, osteoporosis, contractures or other significant medical complications that would prohibit or interfere with testing of walking function and training or alter compliance with a training protocol)

Arm && Interventions

Group	Intervention	Description
Phase 1 Arm (Pilot)	Locomotor Training	Individuals were exposed to intermittent hypoxia and locomotor training to establish our interventions (set up lab, train personnel, develop study protocols/interventions, etc)
Phase 1 Arm (Pilot)	Intermittent Hypoxia	Individuals were exposed to intermittent hypoxia and locomotor training to establish our interventions (set up lab, train personnel, develop study protocols/interventions, etc)
Phase 3 Arm (Ventilatory Loading)	Intermittent Hypoxia	Individuals were exposed to 10 days of intermittent hypoxia to determine changes in ventilatory loading.
Phase 2 Arm (LTF)	Intermittent Hypoxia	Individuals were exposed to 10 days of intermittent hypoxia to determine the effect of this intervention on ventilatory long-term facilitation, as measured by minute ventilation

Primary Outcome Measures

Name	Time	Method
Minute Ventilation - Phase 2	Pre- versus Post-treatment	Minute ventilation (Ve) is the volume of gas inhaled or exhaled from a person's lungs per minute. Minute ventilation during the end-recovery (ER) period at initial (i.e., Days 1 and 2, initial ER period) and final (i.e., Days 9 and 10, final ER period) days of the IH protocol were normalized to values from baseline with elevated carbon dioxide (B2) within each individual session to characterize daily effects of exposure to IH at the beginning and end of treatment. Values from baseline with elevated carbon dioxide and the ER period during the final days of the protocol (final B2 and final ER period, respectively) also were normalized to elevated carbon dioxide baseline during initial days of the protocol (initial B2) to describe the cumulative effects of repeated exposure to IH. Outcomes are reported as % increases in minute ventilation during initial and final treatment sessions for daily/acute effects and cumulative/chronic effects.

Secondary Outcome Measures

Name	Time	Method
Ventilatory Loading - Phase 3	Pre- versus Post-treatment	Ventilatory load compensation was assessed in two ways. Mean slopes for (1) pressure vs. resistance (P vs R) and (2) airflow vs. resistance (AF vs R) were calculated for pre- and post-IH treatment.

Locations (1): North Florida/South Georgia Veterans Health System
🇺🇸
Gainesville, Florida, United States