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    Neurorestorative interventions involving bioelectronic implants after spinal cord injury Newton Cho1,2, Jordan W. Squair1,3,4, Jocelyne Bloch5,6 and Grégoire Courtine1,5,6*

    Abstract

    In the absence of approved treatments to repair damage to the central nervous system, the role of neurosurgeons after spinal cord injury (SCI) often remains confined to spinal cord decompression and vertebral fracture stabilization. However, recent advances in bioelectronic medicine are changing this landscape. Multiple neuromodulation therapies that target circuits located in the brain, midbrain, or spinal cord have been able to improve motor and autonomic functions. The spectrum of implantable brain-computer interface technologies is also expanding at a fast pace, and all these neurotechnologies are being progressively embedded within rehabilitation programs in order to augment plasticity of spared circuits and residual projections with training. Here, we summarize the impending arrival of bioelectronic medicine in the field of SCI. We also discuss the new role of functional neurosurgeons in neurorestorative interventional medicine, a new discipline at the intersection of neurosurgery, neuro-engineering, and neurorehabilitation.

    Keywords: Spinal cord injury, Neuromodulation, Brain-computer interface, Electrical stimulation, Neurosurgery

    Background A century of medical research and clinical practice has transformed the management of patients with spinal cord injury (SCI). The standards of good clinical practice for a traumatic SCI consist of stabilizing spine fractures, decompressing the spinal cord, and maintaining optimal hemodynamics to avoid hypotension and secondary spinal cord damage. As soon as possible, the patient is transferred to a specialized SCI center where expert clin- ical teams deploy intensive rehabilitation programs and educate patients in the management of their bladder, bowel, and general body condition. These surgical procedures, supportive measures, and

    rehabilitation programs have ameliorated neurological outcomes and decreased morbidity in patients with SCI (Fehlings et al. 2017). However, there is currently still no clinical trial that has reported robust efficacy of a spinal cord repair strategy for improving functional recovery after SCI. Due to the limited ability of the spinal cord for

    repair, many neurological deficits remain permanent, with devastating health consequences and substantial financial and social burdens for society. Until now, functional neuro- surgeons are remotely involved in SCI medicine and their role remains confined to the management of spasticity or neuropathic pain with spinal cord stimulation. Here, we summarize a series of preclinical and clinical

    advances in the development of neuromodulation ther- apies, brain-computer interfaces, and neurotechnology- supported neurorehabilitation programs that herald a new role of functional neurosurgeons in the restoration of neurological functions after SCI (Table 1).

    The era of restorative neurosurgery The brain broadcasts movement-related commands through parallel neuronal pathways that cascade from the cortex and brainstem to executive centers residing in the spinal cord (Arber and Costa 2018). An SCI scatters this exquisitely-organized communication system, which results in severe motor deficits and alters critical physio- logical functions. However, most SCIs spare bridges of intact neural tissue that contain fibers still connected to executive centers located below the injury. For unclear reasons, these anatomically intact neural projections

    © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

    * Correspondence: gregoire.courtine@epfl.ch 1École polytechnique fédérale de Lausanne (EPFL), Campus Biotech, Center for Neuroprosthetics and Brain Mind Institute, 1202 Genève, Switzerland 5Department of Neurosurgery, University Hospital of Lausanne (CHUV), Lausanne, Switzerland Full list of author information is available at the end of the article

    Bioelectronic MedicineCho et al. Bioelectronic Medicine (2019) 5:10 https://doi.org/10.1186/s42234-019-0027-x

    http://crossmark.crossref.org/dialog/?doi=10.1186/s42234-019-0027-x&domain=pdf http://orcid.org/0000-0002-5744-4142 http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ mailto:gregoire.courtine@epfl.ch

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