Spinal Cord Injury
Conditions
Keywords
auditory stimulation, peripheral stimulation, locomotion training, descending motor tracts
Brief summary
Locomotor recovery is one of the most important goals of individuals with spinal cord injury (SCI). Ambulatory deficits severely impact daily functions resulting in lower quality of life for people living with paralysis due to SCI. Although studies have shown that locomotor training improves locomotor function in people with chronic SCI, the benefits remain limited. Our overall hypothesis is that we can engage additional descending motor pathways, such as the reticulospinal tract (RST), to improve locomotor function in humans with chronic incomplete SCI. In this study we propose to test the effects of a novel intervention that uses repeated paired loud auditory and electrical stimulation of muscle afferents combined with locomotor training on walking speed and voluntary muscle strength.
Detailed description
Individuals with chronic incomplete SCI will be randomly assigned to a group that will receive 10 sessions of a startle stimulus (a very brief, loud sound) and electrical stimulation combined with locomotor training or 10 sessions of a non-startle stimulus (a very brief, soft sound) combined with locomotor training.
Interventions
This new intervention consists of locomotor training in combination with paired low-intensity electrical stimulation and stimulation of the reticulospinal tract through loud sounds. Participants will receive auditory stimulation (LAS, 110dB, 500Hz, 50ms) through headphones and electrical stimulation through a pair of electrodes with 2cm inter-electrode distance positioned on the motor point over the quadriceps and the tibialis anterior muscles bilaterally. The motor point will be identified as the position of the electrodes that elicits a small visible muscle twitch or muscle contraction upon palpation over the tendon with the minimum stimulation intensity. Stimuli will be delivered with a pulse duration of 200 microseconds and will be timed to arrive at the level of the brainstem \ 7ms before auditory signals.
BEHAVIORALLocomotor Training
Participants will walk on a treadmill with body-weight support (ZeroG, Aretech) in the range 0-70% as needed to prevent excessive knee flexion during stance phase or toe dragging during swing phase (Finch et al. 1991). Each session will last approximately 60-min and the duration of the treadmill training will be timed to be 30 min. Subjects will be encouraged to walk at a self-selected speed at or above 0.1m/s. Speed and body-weight support will be adjusted to achieve a perceived exertion score of 4-5 (Moderate) in the Borg scale (Borg 1982). Subjects will be allowed to rest as needed during the training sessions.
DEVICESham stimulation
Participants will receive brief low-intensity auditory clicks (80dB, 500Hz, 50ms) through headphones and electrical stimulation through a pair of electrodes with 2cm inter-electrode distance positioned on the motor point over the quadriceps and the tibialis anterior muscles bilaterally. The motor point will be identified as the position of the electrodes that elicits a small visible muscle twitch or muscle contraction upon palpation over the tendon with the minimum stimulation intensity. Stimuli will be delivered with a pulse duration of 200 microseconds and will be timed to arrive at the level of the brainstem \ 7ms before auditory signals.
Sponsors
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Shirley Ryan AbilityLab
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* History of traumatic or non-traumatic SCI ≥ 6 months * International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) level at and above T10. * American Spinal Injury Association AIS Grade C, or D * Weakness in ankle dorsiflexors (LEMS\<=3) with the ability to perform a small voluntary ankle dorsiflexion (as detected by presence of voluntary EMG activity in the tibialis anterior) with at least one leg. * Ability to tolerate standing position. * Ability to walk at a minimum speed of 0.1 mile/hour on a treadmill with less than 70% body weight support. * Requires use of assistive devices (KAFO, AFO, cane, walker) or body weight support for ambulation. * Ability to complete the 10-Meter Walk Test.
Exclusion criteria
* Preceding uncontrolled medical conditions including pulmonary, cardiovascular or orthopedic disease that interfere with physical performance. * Intolerance to physical activity. * Severe cognitive impairment that precludes the ability to participate in any of the study procedures or give verbal consent. * Any illness or condition that based on the research team's assessment, will compromise with the patient's ability to comply with the protocol, patient safety, or the validity of the data collected during the study. * History of stroke resulting in sensory motor deficits. * Pregnant women. * Participation in a high-intensity locomotor training program in the last 6 months. * Inability to detect somatosensory evoked potentials * Metal implant in the head * History of epilepsy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 10-meter walk test (10MWT) | baseline and day 12 | This standardized test assesses walking speed in meters per second over a short duration. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maximum Voluntary Contraction (MVC) | Baseline and day 12 | This will be measured on the electromyographic signal recorded during maximal isometric contractions. Participants will perform three maximal contractions against resistance into knee flexion and extension, dorsiflexion, and plantarflexion. Electromyographic activity will be monitored using surface electrodes placed on the belly of the quadriceps femoris, hamstrings, tibialis anterior, and soleus muscles bilaterally. The MVC will be quantified as the maximum value of the average over 1s of activity in each of the repetitions. |
| Maximal motor response (M-max) | Baseline and day 12 | M-max will be elicited in the quadriceps femoris, tibialis anterior, soleus and foot muscles by applying percutaneous electrical stimulation over the femoral, common peroneal and the tibial and the medial plantar nerve, respectively using 200μs rectangular electrical stimulus. The intensity of stimulation will be increased progressively until M-max is reached. |
| Motor Evoked Potentials conditioned with Startle (MEP-LAS) | Baseline and day 12 | Motor Evoked Potentials (MEPs) will be recorded from multiple leg muscles following transcranial magnetic stimulation over the leg representation of the primary motor cortex and electrical stimulation over the thoracic spine. Loud auditory Stimuli (LAS, 110dB, 500Hz, 50ms) will be delivered 50ms before magnetic stimulation to test for cortical effects of the intervention and 80ms before the electrical stimulation to test for subcortical effects of the intervention. Stimulation intensity will be adjusted to obtain unconditioned MEPs of \ 50% of the maximum MEP for each muscle. |
| Spasticity | Baseline and day 12 | We will use the Modified Ashworth scale (six-point ordinal scale, 0-4) to measure resistance encountered during manual passive muscle stretching. |
| SCI-QOL | Baseline and day 12 | Is a battery of questionnaires evaluating the quality of life. Will be used to measure the participant-related following aspects: (a) Ambulation: This questionnaire will ask the participant about their ability to do thing like walk, run and jump. (b) Basic Mobility: This questionnaire will ask the participant about their ability to perform their daily routine. (c) Fine Motor: This questionnaire will ask the participant about their ability to pick up small objects. (d) Manual and Power Wheelchair Mobility: This questionnaire ask the participant about their ability using a wheelchair. (e) Self-Care: This questionnaire will ask the participant about their ability to do activities of daily living such as getting dressed, bathing, and eating. |
| StartReact response | Baseline and day 12 | Participants will be asked to observe a light-emitting diode (LED) located \ 1 m in front of the participants' head and will be wearing headphones. When the LED will illuminate (20 ms), individuals will be asked to perform an isometric knee flexion/extension and/or ankle dorsi/plantarflexion as fast as possible. Reaction times will be evaluated following a visual cue either alone (20 trials) or paired with a non-startling (80dB, 500Hz, 50ms, 20 trials) or a startling (110dB, 500Hz, 50ms, 20 trials) auditory cue. Stimuli will be delivered every 5s in a randomized order. Target muscles will be quadriceps femoris, hamstrings, tibialis anterior, and soleus muscles of the weaker leg. The StartReact response will be computed as the difference between the reaction times during a non-startling and startling auditory cue |
Countries
United States
Contacts
Primary ContactDalia De Santis
Outcome results
None listed