Paralysis, Paraplegia, Spinal Cord Injury, Tetraplegia
Conditions
Keywords
Paraplegia, Tetraplegia, Spinal Cord Injury, FES
Brief summary
The purpose of this study is to improve the performance of neuroprosthesis for standing after SCI by developing and testing new advanced methods that use multiple contact peripheral nerve electrodes to slow the onset of fatigue and increase standing duration. The new advanced methods will take advantage of the ability of multiple-contact nerve cuff electrodes to selectively activate portions of a muscle that perform the same action. Alternating activation to multiple muscles (or parts of the same muscle) rather than continuously activation the entire muscle group constantly should allow them to rest and recover from fatiguing contractions. This should allow users to remain upright for longer periods of time to perform activities of daily living, reduce the risk of falls due to fatigue, and increase the potential of receiving the health benefits of standing.
Detailed description
Neuroprostheses for standing after SCI currently rely on continuous activation of the hip and knee extensor muscles, which results in rapid fatigue and ultimately compromises elapsed standing time. The primary objective of this study is to improve the performance of neuroprostheses for standing by developing and implementing advanced stimulation paradigms that use multi-contact peripheral nerve electrodes to delay fatigue onset and prolong standing duration. The new stimulation paradigms will take advantage of the ability of multi-contact nerve cuff electrodes to selectively activate independent portions of a muscle, or independent muscles that perform the same action. Such a capability will allow one or more muscles (or parts of the same muscle) to rest while the others continue to contract to keep the knee extended and the user upright. Stimulation waveforms that alternate activation to multiple muscles performing the same function, rather than continuously activate the entire muscle group constantly, should allow muscles to rest and recover from fatiguing contractions. In addition to these important clinical benefits, the project is also of high impact and significance because the methods to be developed will not be specific to any single electrode technology or stimulation system. Any clinical or therapeutic application that requires a sustained muscular contraction or the production of constant joint torques for prolonged periods of time will benefit from the successful completion of this project.
Interventions
DEVICEIST-16 (16-Channel implanted stimulator-telemeter
Surgical implantation of IST-16 stimulator and electrodes to stimulate paralyzed muscles. Subjects will receive exercise and physical therapy with the implanted device. Functional training and laboratory assessments of clinical and technical performance will be conducted.
Sponsors
National Institutes of Health (NIH)
VA Office of Research and Development
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DEVICE_FEASIBILITY
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Skeletal maturity (age 21 and above), and ability to sign informed consent * Paralysis resulting from neurological disorder such as low cervical/thoracic spinal cord injuries (C6-T12) * Time post injury greater than six months to assure neurological and emotional stability * Innervated and excitable lower extremity and lumbar trunk musculature * Absence of acute or chronic psychological problems or chemical dependency * Range of motion within normal limits, (full extension at the hip and knee, and ability to attain a neutral ankle position) * Controlled spasticity and absence of hip flexion and adduction spasms * Appropriate body habitus (BMI within normal range) * Adequate social support and stability * Willingness to comply with follow-up procedures. * Full coverage of the acetabulum and minimal knee and ankle laxity
Exclusion criteria
* History of vestibular dysfunction, balance problems or spontaneous falls. * Acute orthopaedic problems: severe scoliosis or joint dislocation, severe osteoporosis. * Acute medical complication: cardiac abnormalities, skin breakdowns, uncontrolled seizures, or immunological, pulmonary/ renal/ circulatory compromise, auto-immune deficiencies, sepsis, active infection, dental caries. * Diabetes * Non-English speaking subjects * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Average Standing Performance in Terms of Elapsed Standing Time for All Subjects. | 12 months post-rehabilitation | The investigators will assess standing performance in terms of elapsed standing time. The investigators will also collect data related to subjective impression of stability. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Body Weight Distribution on the Legs While Standing With Stimulation. | 12 months post-rehabilitation | Determine the amount of weight on both legs during standing with stimulation. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Neuroprosthesis Eligible subjects will receive an implanted device (IRS-8 or IST-16) and surgically implanted electrodes to excite muscles that move paralyzed muscles. These electrodes are connected to the implanted stimulator that delivers electrical pulses to the nerves. These pulses cause the muscles to contract to perform functional movements or to exercise. | 6 |
| Total | 6 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Neuroprosthesis |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 6 Participants |
| Age, Continuous | 35 years STANDARD_DEVIATION 10.3 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 1 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
Average Standing Performance in Terms of Elapsed Standing Time for All Subjects.
The investigators will assess standing performance in terms of elapsed standing time. The investigators will also collect data related to subjective impression of stability.
Time frame: 12 months post-rehabilitation
Population: 5 participants with spinal cord injury with an implanted IST-16
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Neuroprosthesis | Average Standing Performance in Terms of Elapsed Standing Time for All Subjects. | 32.6 Minutes | Standard Deviation 23.3 |
Secondary
Percentage of Body Weight Distribution on the Legs While Standing With Stimulation.
Determine the amount of weight on both legs during standing with stimulation.
Time frame: 12 months post-rehabilitation
Population: 5 participants with spinal cord injury with an implanted IST-16
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Neuroprosthesis | Percentage of Body Weight Distribution on the Legs While Standing With Stimulation. | 92.7 % of body weight on lower extremity | Standard Deviation 0.05 |