Diaphragm Stimulation After Human Spinal Cord Injury: Effects on Respiratory Neural Drive and Function
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Cervical Spinal Cord Injury
- Sponsor
- University of Florida
- Enrollment
- 6
- Locations
- 1
- Primary Endpoint
- Change in Electromyogram (EMG)
- Status
- Completed
- Last Updated
- last year
Overview
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.
Investigators
Eligibility Criteria
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
Outcomes
Primary Outcomes
Change in Electromyogram (EMG)
Time Frame: 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)
Time Frame: 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
Time Frame: 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).