Spinal Cord Stimulation for Respiratory Rehabilitation in Patients With Chronic Spinal Cord Injury

Official title

Neuromodulatory Rehabilitation for Respiratory Motor Function in Individuals With Chronic Spinal Cord Injury

Overview

Respiratory complications are among the leading causes of death in patients with chronic spinal cord injury (SCI). Our previous work showed that pulmonary function can be improved by using our original respiratory training method. However, the effectiveness of this intervention is limited due to the disruption of brain-spinal connections and consequently lowered spinal cord activity below the injury level. Our recent studies showed that electrical stimulation of the spinal cord below the level of injury leads to increased ventilation which indicates activation of the spinal cord structures related to respiration. These findings indicate that spinal cord stimulation can be a promising therapeutic additive to the treatment. The goal of this study is to justify the establishment of a new direction in rehabilitation for patients with SCI by using a non-invasive spinal cord stimulation in combination with respiratory training. Our aims are: 1) to evaluate the effects of such stimulation applied to the injured spinal cord on pulmonary function and respiratory muscle activity, and 2) to evaluate the effectiveness and therapeutic mechanisms of the spinal cord stimulation combined with respiratory training. Thirty-six individuals with chronic SCI will be recruited and assigned to three groups to receive respiratory training or spinal cord stimulation alone or a combination of them. All participants will be tested before and after cycles of experimental procedures with/or without stimulation. Our hypotheses will be confirmed if the respiratory training combined with spinal cord stimulation results in the most enhanced positive effects.

Detailed description

This is a respiratory rehabilitation-based clinical study consisting of physiologically and functionally relevant mapping of respiratory function that enhances our knowledge of neurophysiological modulation evoked by non-invasive spinal cord Transcutaneous Stimulation (scTS) and contributes to the development of the next generation of rehabilitative approaches. Following the screening process and recruiting, the research subjects will undergo the following procedures: Subjects (total n=36) will be randomly assigned to three groups and will undergo baseline assessments; evaluations before and after 80 sessions of specific intervention (Respiratory Training /RT/ alone, scTS alone, or RT in combination with scTS); and during 16 week-long follow up period.

Interventions

• Device Transcutaneous spinal cord stimulator
  Stimulation to the spinal cord will be administered using Neostim/Biostim (Cosyma Inc., Denver CO) device by applying up to five conductive electrodes placed on the skin at the midline over the thoracic levels as cathodes between T1 to T8, and up to four self-adhesive electrodes located symmetrically on the skin over the iliac crests and shoulders as anodes.
• Device Respiratory Training
  Standard threshold Positive Expiratory Pressure Device (PEP, Respironics Inc., Cedar Grove, NJ) and standard threshold Inspiratory Muscle Trainer (IMT, Respironics Inc., Cedar Grove, NJ) assembled together using a T-shaped connector with a flanged mouthpiece (Airlife 001504) will be used for the respiratory training intervention.

Primary outcome measures

• Maximum Expiratory Pressure (PEmax). [Time frame: Within 2 weeks during screening period; within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Maximum Inspiratory Pressure (PImax). [Time frame: Within 2 weeks during screening period; within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Surface electromyography (sEMG) Similarity Index (SI) [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]

Secondary outcome measures (7)

• Forced Vital Capacity (FVC). [Time frame: Within 2 weeks during screening period; within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Forced Expiratory Volume in 1 second (FEV1). [Time frame: Within 2 weeks during screening period; within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Baroreflex blood pressure sensitivity (BRS). [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Baroreflex heart rate sensitivity (BRS). [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Baroreflex blood pressure effectiveness index (BEI). [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Baroreflex heart rate effectiveness index (BEI). [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]
• Spinal Cord Independence Measure (SCIM, Version III). [Time frame: Within 4 weeks before an intervention period; within 2 weeks after intervention #40; within 2 weeks after intervention #80; within 2 weeks after 16-weeks and 32-weeks follow-up periods.]

Eligibility criteria

Inclusion criteria

• At least 18 years old;
• stable medical condition;
• no painful musculoskeletal dysfunction, unhealed fracture, contracture, pressure sore or urinary tract infection that might interfere with respiratory training or stimulation;
• no clinically significant depression, psychiatric disorders or ongoing drug abuse;
• non-progressive SCI (no negative change in the neurological level and motor-completeness assessed during screening when compared to the neurological status assessed at 6-mo period after injury or at least 6 months prior to the screening), non-ventilator dependence, motor-complete SCI according to the American Spinal Injury Association Impairment Scale (AIS) grade "A" or "B" above T5 spinal level;
• sustained SCI at least 12 months prior to entering the study;
• compared to the normative values for healthy population, at least 15%-deficit in pulmonary function outcomes (FVC and FEV1) as detected by screening spirometry.

Exclusion criteria

Participants will be excluded from the study if there is a presence of

• major pulmonary or cardiovascular disease,
• ventilator dependence,
• endocrine disorders,
• malignancy,
• marked obesity,
• deep vein thrombosis,
• HIV/AIDS-related illness,
• secondary hypotension (anemia, hypervolemia, endocrine and neurological diseases),
• major esophageal/gastrointestinal problem or other major medical illness contraindicated for respiratory training or testing.

During screening, the potential participant will be asked whether she is pregnant or planning to become pregnant during the study period. Pregnant women are excluded from this study, as the risk to the fetus is unknown. No pregnancy test or birth control regimen will be required.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

United States · 1 center

• Frazier Rehabilitation and Neuroscience Institute — Louisville

Identifiers

NCT: NCT06019949 · 23.0570 · 1R01HL168294

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗