scholarly journals A wireless spinal stimulation system for ventral activation of the rat cervical spinal cord

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthew K. Hogan ◽  
Sean M. Barber ◽  
Zhoulyu Rao ◽  
Bethany R. Kondiles ◽  
Meng Huang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Therapeutic Potential ◽  
Cervical Spinal Cord ◽  
Electrode Array ◽  
Novel Approach ◽  
Cord Injury ◽  
Motor Region ◽  
Muscle Groups ◽  
Stimulation System ◽  
Stimulation Of

AbstractElectrical stimulation of the cervical spinal cord is gaining traction as a therapy following spinal cord injury; however, it is difficult to target the cervical motor region in a rodent using a non-penetrating stimulus compared with direct placement of intraspinal wire electrodes. Penetrating wire electrodes have been explored in rodent and pig models and, while they have proven beneficial in the injured spinal cord, the negative aspects of spinal parenchymal penetration (e.g., gliosis, neural tissue damage, and obdurate inflammation) are of concern when considering therapeutic potential. We therefore designed a novel approach for epidural stimulation of the rat spinal cord using a wireless stimulation system and ventral electrode array. Our approach allowed for preservation of mobility following surgery and was suitable for long term stimulation strategies in awake, freely functioning animals. Further, electrophysiology mapping of the ventral spinal cord revealed the ventral approach was suitable to target muscle groups of the rat forelimb and, at a single electrode lead position, different stimulation protocols could be applied to achieve unique activation patterns of the muscles of the forelimb.

scholarly journals Electrical Stimulation Of The Cervical Dorsal Roots Enables Functional Arm And Hand Movements In Monkeys With Cervical Spinal Cord Injury

2020 ◽  
Author(s):  
B. Barra ◽  
S. Conti ◽  
M.G. Perich ◽  
K. Zhuang ◽  
G. Schiavone ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
Motor Control ◽  
Cervical Spinal Cord ◽  
Three Dimensional ◽  
Arm Movements ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury ◽  
Stimulation Of

SUMMARYRegaining arm motor control is a high priority for people with cervical spinal cord injury1. Unfortunately, no therapy can reverse upper limb paralysis. Promising neurotechnologies stimulating muscles to bypass the injury enabled grasping in humans with SCI2,3 but failed to sustain whole arm functional movements that are necessary for daily living activities. Here, we show that electrical stimulation of the cervical spinal cord enabled three monkeys with cervical SCI to execute functional, three-dimensional, arm movements. We designed a lateralized epidural interface that targeted motoneurons through the recruitment of sensory afferents within the dorsal roots and was adapted to the specific anatomy of each monkey. Simple stimulation bursts engaging single roots produced selective joint movements. We then triggered these bursts using movement-related intracortical signals, which enabled monkeys with arm motor deficits to perform an unconstrained, three-dimensional reach and grasp task. Our technology increased muscle activity, forces, task performance and quality of arm movements. Finally, analysis of intra-cortical neural data showed that a synergistic interaction between spared descending pathways and electrical stimulation enabled this restoration of voluntary motor control. Spinal cord stimulation is a mature clinical technology4–7, which suggests a realistic path for our approach to clinical applications.

scholarly journals Exercise Interventions Targeting Obesity in Persons With Spinal Cord Injury

2021 ◽  
Vol 27 (1) ◽  
pp. 109-120 ◽  
Author(s):  
David W. McMillan ◽  
Jennifer L. Maher ◽  
Kevin A. Jacobs ◽  
Mark S. Nash ◽  
David R. Gater
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Therapeutic Potential ◽  
Upper Body ◽  
Obesity Management ◽  
Common Component ◽  
Exercise Interventions ◽  
Cord Injury ◽  
Muscle Groups ◽  
Large Muscle

Spinal cord injury (SCI) results in an array of cardiometabolic complications, with obesity being the most common component risk of cardiometabolic disease (CMD) in this population. Recent Consortium for Spinal Cord Medicine Clinical Practice Guidelines for CMD in SCI recommend physical exercise as a primary treatment strategy for the management of CMD in SCI. However, the high prevalence of obesity in SCI and the pleiotropic nature of this body habitus warrant strategies for tailoring exercise to specifically target obesity. In general, exercise for obesity management should aim primarily to induce a negative energy balance and secondarily to increase the use of fat as a fuel source. In persons with SCI, reductions in the muscle mass that can be recruited during activity limit the capacity for exercise to induce a calorie deficit. Furthermore, the available musculature exhibits a decreased oxidative capacity, limiting the utilization of fat during exercise. These constraints must be considered when designing exercise interventions for obesity management in SCI. Certain forms of exercise have a greater therapeutic potential in this population partly due to impacts on metabolism during recovery from exercise and at rest. In this article, we propose that exercise for obesity in SCI should target large muscle groups and aim to induce hypertrophy to increase total energy expenditure response to training. Furthermore, although carbohydrate reliance will be high during activity, certain forms of exercise might induce meaningful postexercise shifts in the use of fat as a fuel. General activity in this population is important for many components of health, but low energy cost of daily activities and limitations in upper body volitional exercise mean that exercise interventions targeting utilization and hypertrophy of large muscle groups will likely be required for obesity management.

Recruitment of Upper-Limb Motoneurons with Epidural Electrical Stimulation of the Primate Cervical Spinal Cord

2020 ◽  
Author(s):  
Nathan Greiner ◽  
Beatrice Barra ◽  
Giuseppe Schiavone ◽  
Nicholas James ◽  
Florian Fallegger ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Motor Control ◽  
Upper Limb ◽  
Cervical Spinal Cord ◽  
Target Individual ◽  
Cord Injury ◽  
Hand Control ◽  
Cervical Stimulation ◽  
Stimulation Of

ABSTRACTEpidural electrical stimulation (EES) of lumbosacral sensorimotor circuits improves leg motor control in animals and humans with spinal cord injury (SCI). Upper-limb motor control involves similar circuits, located in the cervical spinal cord, suggesting that EES could also improve arm and hand movements after quadriplegia. However, the ability of cervical EES to selectively modulate specific upper-limb motor nuclei remains unclear. Here, we combined a realistic computational model of EES of the cervical spinal cord with experiments in macaque monkeys to explore the mechanisms of this modulation and characterize the recruitment selectivity of cervical stimulation interfaces. Our results indicate that interfaces with lateral electrodes can target individual posterior roots and achieve selective modulation of arm motoneurons via the direct recruitment of pre-synaptic pathways. Intraoperative recordings suggested similar properties in humans. These results provide a framework for the design of neuro-technologies to improve arm and hand control in humans with quadriplegia.

scholarly journals Recruitment of upper-limb motoneurons with epidural electrical stimulation of the cervical spinal cord

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathan Greiner ◽  
Beatrice Barra ◽  
Giuseppe Schiavone ◽  
Henri Lorach ◽  
Nicholas James ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Motor Control ◽  
Upper Limb ◽  
Cervical Spinal Cord ◽  
Sensory Afferents ◽  
Cord Injury ◽  
Hand Control ◽  
Muscle Responses ◽  
Stimulation Of

AbstractEpidural electrical stimulation (EES) of lumbosacral sensorimotor circuits improves leg motor control in animals and humans with spinal cord injury (SCI). Upper-limb motor control involves similar circuits, located in the cervical spinal cord, suggesting that EES could also improve arm and hand movements after quadriplegia. However, the ability of cervical EES to selectively modulate specific upper-limb motor nuclei remains unclear. Here, we combined a computational model of the cervical spinal cord with experiments in macaque monkeys to explore the mechanisms of upper-limb motoneuron recruitment with EES and characterize the selectivity of cervical interfaces. We show that lateral electrodes produce a segmental recruitment of arm motoneurons mediated by the direct activation of sensory afferents, and that muscle responses to EES are modulated during movement. Intraoperative recordings suggested similar properties in humans at rest. These modelling and experimental results can be applied for the development of neurotechnologies designed for the improvement of arm and hand control in humans with quadriplegia.

scholarly journals P.232 Motor Recovery after Early Surgical Decompression in Cervical ASIA A Spinal Cord Injury Patients

2021 ◽  
Vol 48 (s3) ◽  
pp. S87-S87
Author(s):  
A Moghaddamjou ◽  
JR Wilson ◽  
MG Fehlings
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Therapeutic Benefit ◽  
Surgical Decompression ◽  
Early Surgery ◽  
Significant Gain ◽  
Cervical Injury ◽  
Cord Injury ◽  
Muscle Groups

Background: Despite growing evidence for early surgical decompression for traumatic cervical spinal cord injury(tCSCI) patients, controversy surrounds the efficacy of early surgical decompression on patients with a complete (ASIA A) cervical injury. Methods: Patients with ASIA A cervical tCSCI were isolated from 4 prospective, multi-center datasets. Patients who had a Glasgow coma scale of less than 13, were over the age of 70 or under 16 were excluded. Significant gain was defined to include those that recovered more than two muscle groups (greater than 3/5 power) below their level of injury. Analysis of variance (ANOVA) was then done to compare significant gain over the 1 year follow-up period for patients with and without early decompressive surgery (<24hrs). Results: We identified 420 cervical ASIA A tCSCI patients. The mean number of muscle groups gained was 2.69 (SD 2.3.12) for those who had early surgery compared to 2.37 (SD 3.38) for those with late surgery. Of those patients who had early surgery 39.67% had a significant improvement vs. 28.76% of those who did not have early surgery (P = 0.030). Conclusions: For the first time, we have shown a clear therapeutic benefit of early surgical decompression within 24 hrs in ASIA A tCSCI patients.

scholarly journals Optogenetic surface stimulation of the rat cervical spinal cord

2018 ◽  
Vol 120 (2) ◽  
pp. 795-811 ◽  
Author(s):  
S. E. Mondello ◽  
M. D. Sunshine ◽  
A. E. Fischedick ◽  
S. J. Dreyer ◽  
G. D. Horwitz ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Muscle Activation ◽  
Cervical Spinal Cord ◽  
Dorsal Surface ◽  
Rat Spinal Cord ◽  
Intraspinal Microstimulation ◽  
Spinal Circuitry ◽  
Cord Injury ◽  
Specific Alternative ◽  
Stimulation Of

Electrical intraspinal microstimulation (ISMS) at various sites along the cervical spinal cord permits forelimb muscle activation, elicits complex limb movements and may enhance functional recovery after spinal cord injury. Here, we explore optogenetic spinal stimulation (OSS) as a less invasive and cell type-specific alternative to ISMS. To map forelimb muscle activation by OSS in rats, adeno-associated viruses (AAV) carrying the blue-light sensitive ion channels channelrhodopsin-2 (ChR2) and Chronos were injected into the cervical spinal cord at different depths and volumes. Following an AAV incubation period of several weeks, OSS-induced forelimb muscle activation and movements were assessed at 16 sites along the dorsal surface of the cervical spinal cord. Three distinct movement types were observed. We find that AAV injection volume and depth can be titrated to achieve OSS-based activation of several movements. Optical stimulation of the spinal cord is thus a promising method for dissecting the function of spinal circuitry and targeting therapies following injury. NEW & NOTEWORTHY Optogenetics in the spinal cord can be used both for therapeutic treatments and to uncover basic mechanisms of spinal cord physiology. For the first time, we describe the methodology and outcomes of optogenetic surface stimulation of the rat spinal cord. Specifically, we describe the evoked responses of forelimbs and address the effects of different adeno-associated virus injection paradigms. Additionally, we are the first to report on the limitations of light penetration through the rat spinal cord.

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