Diaphragm Pacing in Individuals With Spinal Cord Injuries

Sponsor

University of Florida (Other)

Overall Status

Recruiting

CT.gov ID

NCT04179799

Collaborator

National Institutes of Health (NIH) (NIH)

Enrollment

Location

30.7

Anticipated Duration (Months)

0.3

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Cervical Spinal Cord Injury	Device: Diaphragm Pacing

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.

Study Design

Study Type:

Observational

Anticipated Enrollment :

10 participants

Observational Model:

Case-Only

Time Perspective:

Prospective

Official Title:

Diaphragm Stimulation After Human Spinal Cord Injury: Effects on Respiratory Neural Drive and Function

Actual Study Start Date :

Jan 10, 2020

Anticipated Primary Completion Date :

Jul 31, 2022

Anticipated Study Completion Date :

Jul 31, 2022

Arms and Interventions

Arm	Intervention/Treatment
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.	Device: 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.

Arm

Intervention/Treatment

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.

Device: 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.

Outcome Measures

Primary Outcome Measures

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).

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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