Effects of transcutaneous spinal cord stimulation on voluntary locomotor activity in an incomplete spinal cord injured individual

Hofstoetter, Ursula S.; Höfer, Christian; Kern, Helmut; Danner, Simon M.; Mayr, Winfried; Mr, Dimitrijević; Minassian, Karen

doi:10.1515/bmt-2013-4014

Cited by 66 publications

(78 citation statements)

References 8 publications

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“…22 Computer modeling suggests that transcutaneous spinal cord stimulation, as well as epidural stimulation, can activate similar afferent neurons projecting to the locomotor circuitry within the spinal cord. 23 Therapeutic application of transcutaneous spinal cord stimulation has been used for modification of spasticity 24 and for facilitation of stepping-like movements in incomplete spinal cord injured subjects 25 . All of these observations suggest that transcutaneous electrical spinal cord stimulation can effectively neuromodulate the spinal locomotor circuitry after SCI.…”

Section: Discussionmentioning

confidence: 99%

Noninvasive Reactivation of Motor Descending Control after Paralysis

Gerasimenko

Modaber

et al. 2015

Journal of Neurotrauma

262

263

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The present prognosis for the recovery of voluntary control of movement in patients diagnosed as motor complete is generally poor. Herein we introduce a novel and noninvasive stimulation strategy of painless transcutaneous electrical enabling motor control and a pharmacological enabling motor control strategy to neuromodulate the physiological state of the spinal cord. This neuromodulation enabled the spinal locomotor networks of individuals with motor complete paralysis for 2-6 years American Spinal Cord Injury Association Impairment Scale (AIS) to be re-engaged and trained. We showed that locomotor-like stepping could be induced without voluntary effort within a single test session using electrical stimulation and training. We also observed significant facilitation of voluntary influence on the stepping movements in the presence of stimulation over a 4-week period in each subject. Using these strategies we transformed brain-spinal neuronal networks from a dormant to a functional state sufficiently to enable recovery of voluntary movement in five out of five subjects. Pharmacological intervention combined with stimulation and training resulted in further improvement in voluntary motor control of stepping-like movements in all subjects. We also observed on-command selective activation of the gastrocnemius and soleus muscles when attempting to plantarflex. At the end of 18 weeks of weekly interventions the mean changes in the amplitude of voluntarily controlled movement without stimulation was as high as occurred when combined with electrical stimulation. Additionally, spinally evoked motor potentials were readily modulated in the presence of voluntary effort, providing electrophysiological evidence of the re-establishment of functional connectivity among neural networks between the brain and the spinal cord.

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Section: Discussionmentioning

confidence: 99%

Noninvasive Reactivation of Motor Descending Control after Paralysis

Gerasimenko

Modaber

et al. 2015

Journal of Neurotrauma

262

263

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“…The interventions tested included a combination of non-invasive spinal cord stimulation, pharmacological activation via a monoaminergic agonist (Buspirone), and over-ground weight bearing stepping in an exoskeleton. It has been shown that activation of the lumbar enlargement via transcutaneous electrical stimulation facilitates passive locomotion and robust patterns of EMG activity in lower extremity muscles in SCI patients (Minassian et al, 2007; Hofstoetter et al, 2013, 2015). Recently we have shown that transcutaneous spinal cord neuromodulation (pcEmc) can be used to both initiate oscillatory movement and enable voluntary oscillatory movements in motor complete subjects.…”

Section: Discussionmentioning

confidence: 99%

Weight Bearing Over-ground Stepping in an Exoskeleton with Non-invasive Spinal Cord Neuromodulation after Motor Complete Paraplegia

et al. 2017

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We asked whether coordinated voluntary movement of the lower limbs could be regained in an individual having been completely paralyzed (>4 year) and completely absent of vision (>15 year) using two novel strategies—transcutaneous electrical spinal cord stimulation at selected sites over the spine as well as pharmacological neuromodulation by buspirone. We also asked whether these neuromodulatory strategies could facilitate stepping assisted by an exoskeleton (EKSO, EKSO Bionics, CA) that is designed so that the subject can voluntarily complement the work being performed by the exoskeleton. We found that spinal cord stimulation and drug enhanced the level of effort that the subject could generate while stepping in the exoskeleton. In addition, stimulation improved the coordination patterns of the lower limb muscles resulting in a more continuous, smooth stepping motion in the exoskeleton along with changes in autonomic functions including cardiovascular and thermoregulation. Based on these data from this case study it appears that there is considerable potential for positive synergistic effects after complete paralysis by combining the over-ground step training in an exoskeleton, combined with transcutaneous electrical spinal cord stimulation either without or with pharmacological modulation.

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“…Apparently, the bilateral, multisegmental activation as provided by SCS was essential to reveal this type of input processing and output generation by the human lumbosacral spinal circuitry. The recent renaissance of epidural lumbar SCS in SCI patients (Angeli et al 2014;Danner et al 2015;Harkema et al 2011) as well as novel neurophysiological studies employing transcutaneous SCS (Dy et al 2010;Hofstoetter et al 2013Hofstoetter et al , 2014Knikou 2014;Roy et al 2014) may provide means to further advance the current understanding of human spinal sensorimotor integration.…”

Section: Discussionmentioning

confidence: 99%

Periodic modulation of repetitively elicited monosynaptic reflexes of the human lumbosacral spinal cord

Hofstoetter

Danner

Freundl

et al. 2015

Journal of Neurophysiology

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Hofstoetter US, Danner SM, Freundl B, Binder H, Mayr W, Rattay F, Minassian K. Periodic modulation of repetitively elicited monosynaptic reflexes of the human lumbosacral spinal cord. J Neurophysiol 114: 400 -410, 2015. First published April 22, 2015 doi:10.1152/jn.00136.2015.-In individuals with motor-complete spinal cord injury, epidural stimulation of the lumbosacral spinal cord at 2 Hz evokes unmodulated reflexes in the lower limbs, while stimulation at 22-60 Hz can generate rhythmic burstlike activity. Here we elaborated on an output pattern emerging at transitional stimulation frequencies with consecutively elicited reflexes alternating between large and small. We analyzed responses concomitantly elicited in thigh and leg muscle groups bilaterally by epidural stimulation in eight motor-complete spinal cord-injured individuals. Periodic amplitude modulation of at least 20 successive responses occurred in 31.4% of all available data sets with stimulation frequency set at 5-26 Hz, with highest prevalence at 16 Hz. It could be evoked in a single muscle group only but was more strongly expressed and consistent when occurring in pairs of antagonists or in the same muscle group bilaterally. Latencies and waveforms of the modulated reflexes corresponded to those of the unmodulated, monosynaptic responses to 2-Hz stimulation. We suggest that the cyclical changes of reflex excitability resulted from the interaction of facilitatory and inhibitory mechanisms emerging after specific delays and with distinct durations, including postactivation depression, recurrent inhibition and facilitation, as well as reafferent feedback activation. The emergence of large responses within the patterns at a rate of 5.5/s or 8/s may further suggest the entrainment of spinal mechanisms as involved in clonus. The study demonstrates that the human lumbosacral spinal cord can organize a simple form of rhythmicity through the repetitive activation of spinal reflex circuits.

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Effects of transcutaneous spinal cord stimulation on voluntary locomotor activity in an incomplete spinal cord injured individual

Cited by 66 publications

References 8 publications

Noninvasive Reactivation of Motor Descending Control after Paralysis

Noninvasive Reactivation of Motor Descending Control after Paralysis

Weight Bearing Over-ground Stepping in an Exoskeleton with Non-invasive Spinal Cord Neuromodulation after Motor Complete Paraplegia

Periodic modulation of repetitively elicited monosynaptic reflexes of the human lumbosacral spinal cord

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