Cervical Spinal Cord Injury
Conditions
Keywords
SCI, diaphragm pacing, respiratory impairment, diaphragm stimulation
Brief summary
This project will evaluate the effects of intramuscular diaphragm stimulation (pacing) and test the hypothesis that diaphragm pacing enhances neuromuscular diaphragm activation and respiratory function in adults with cervical spinal cord injuries (C-SCIs). The investigators will test the hypothesis by recording activity of the diaphragm from intramuscular pacing electrodes and conduct respiratory assessments in adults with intramuscular diaphragm pacing electrodes following acute, traumatic C-SCIs.
Detailed description
Respiratory dysfunction is a leading cause of death in individuals with spinal cord injuries (SCIs). Nearly one-quarter of all SCI cases involve injury to the upper spinal cord segments which impairs neural activation of the diaphragm muscle and compromises breathing. Although mechanical ventilation can be life-saving after cervical SCI (C-SCI), it also triggers rapid and profound diaphragm muscle atrophy, thereby complicating (or even preventing) ventilator weaning. Intramuscular diaphragm stimulation, or diaphragm pacing, was developed to replace long-term ventilator support and is now used acutely post C-SCI (\<4 months following injury) to promote ventilator weaning. This study will assess the effects of diaphragm stimulation on respiratory neural drive and breathing function in individuals with acute, traumatic C-SCI. Recording from these surgically implanted electrodes allows comparisons of electromyogram (EMG) recordings, in association with respiratory assessments, before and after short periods of diaphragm pacing to isolate the unique contribution of diaphragm pacing on neuromuscular diaphragm activation.
Interventions
DEVICEDiaphragm Pacing
Intramuscular stimulation of the diaphragm, or diaphragm pacing' is achieved by laparoscopic placement of stimulation wires into each hemidiaphragm. Phrenic motor points on the diaphragm are mapped to optimize electrode placement. The electrodes are threaded into the diaphragm muscle and wire leads are externalized and attached to a stimulation controller.
Sponsors
National Institutes of Health (NIH)
University of Florida
Study design
Observational model
CASE_ONLY
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* Acute, traumatic cervical spinal cord injuries (C-SCIs), classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) as A-C * Scheduled to undergo implantation of a diaphragm pacer, or who have recently received (in past 5-days) implantation of intramuscular diaphragm pacing electrodes due to severe respiratory impairments and dependence on mechanical ventilation
Exclusion criteria
* Progressive neuromuscular diseases such as multiple sclerosis and myasthenia gravis * History of neurologic injuries such as stroke or prior SCI * Chest wall injuries or deformities likely to influence breathing * Pregnancy * Cognitive impairments limiting study participation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Electromyogram (EMG) | Baseline up to 24 hours | Neuromuscular activation of the diaphragm will be assessed by recording diaphragm EMGs from the surgically-implanted intramuscular stimulating electrodes. This approach will allow for comparisons of EMG recordings across time. EMGs will be recorded during non-stimulated respiration (diaphragm pacer turned off) and simultaneously with assessments of respiratory function. |
| Change in Maximal Inspiratory Pressure (MIP) | Baseline up to 24 hours | The Maximum Inspiratory Pressure (MIP) is measured by a device that applies an inspiratory load which provides a resistance. The MIP will be measured in cmH20 and assesses diaphragm strength. MIP will be recorded will be recorded during non-stimulated respiration (diaphragm pacer turned off). |
| Change in Tidal Volume | Baseline up to 24 hours | The measurement of Tidal Volume is performed through a simple spirometry and is measured in liters. Tidal Volume will be recorded during non-stimulated respiration (diaphragm pacer turned off). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Cervical SCI Participants with acute, traumatic cervical spinal cord injuries (C-SCIs), classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) as A-C (complete SCI (A); motor complete SCI (B); motor incomplete with minimal motor function (C)), affecting C1-C6 spinal cord segments, and who have been scheduled to undergo implantation of a diaphragm pacer, or who have recently received (in past 5-days) implantation of intramuscular diaphragm pacing electrodes due to severe respiratory impairments and dependence on mechanical ventilation.
Diaphragm Pacing: Intramuscular stimulation of the diaphragm, or diaphragm pacing' is achieved by laparoscopic placement of stimulation wires into each hemidiaphragm. Phrenic motor points on the diaphragm are mapped to optimize electrode placement. The electrodes are threaded into the diaphragm muscle and wire leads are externalized and attached to a stimulation controller. | 6 |
| Total | 6 |
Baseline characteristics
| Characteristic | Cervical SCI |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 2 Participants |
| Age, Categorical Between 18 and 65 years | 4 Participants |
| Age, Continuous | 48 years |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 5 Participants |
| Region of Enrollment United States | 6 participants |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 6 |
| other Total, other adverse events | 0 / 6 |
| serious Total, serious adverse events | 0 / 6 |
Outcome results
Primary
Change in Electromyogram (EMG)
Neuromuscular activation of the diaphragm will be assessed by recording diaphragm EMGs from the surgically-implanted intramuscular stimulating electrodes. This approach will allow for comparisons of EMG recordings across time. EMGs will be recorded during non-stimulated respiration (diaphragm pacer turned off) and simultaneously with assessments of respiratory function.
Time frame: Baseline up to 24 hours
Population: Data not obtained from 3 participants. Data recorded during quiet breathing from 3 of 6 participants, 24hrs after use of diaphragm pacing.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical SCI | Change in Electromyogram (EMG) | -.0031 mV | Standard Deviation 0.043 |
Primary
Change in Maximal Inspiratory Pressure (MIP)
The Maximum Inspiratory Pressure (MIP) is measured by a device that applies an inspiratory load which provides a resistance. The MIP will be measured in cmH20 and assesses diaphragm strength. MIP will be recorded will be recorded during non-stimulated respiration (diaphragm pacer turned off).
Time frame: Baseline up to 24 hours
Population: 3 of the 6 participants were unable to complete this outcome measure.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical SCI | Change in Maximal Inspiratory Pressure (MIP) | .27 cmH2O | Standard Deviation 3.2 |
Primary
Change in Tidal Volume
The measurement of Tidal Volume is performed through a simple spirometry and is measured in liters. Tidal Volume will be recorded during non-stimulated respiration (diaphragm pacer turned off).
Time frame: Baseline up to 24 hours
Population: data were not obtained from 1 participant
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical SCI | Change in Tidal Volume | .02 liters | Standard Deviation 0.15 |