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Rejc E, Bowersock C, Pisolkar T, Omofuma I, Luna T, Khan M, Santamaria V, Ugiliweneza B, Angeli CA, Forrest GF, Stein J, Agrawal S, Harkema SJ. Robotic Postural Training With Epidural Stimulation for the Recovery of Upright Postural Control in Individuals With Motor Complete Spinal Cord Injury: A Pilot Study. Neurotrauma Rep 2024; 5:277-292. [PMID: 38515546 PMCID: PMC10956531 DOI: 10.1089/neur.2024.0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024] Open
Abstract
Activity-based training and lumbosacral spinal cord epidural stimulation (scES) have the potential to restore standing and walking with self-balance assistance after motor complete spinal cord injury (SCI). However, improvements in upright postural control have not previously been addressed in this population. Here, we implemented a novel robotic postural training with scES, performed with free hands, to restore upright postural control in individuals with chronic, cervical (n = 5) or high-thoracic (n = 1) motor complete SCI, who had previously undergone stand training with scES using a walker or a standing frame for self-balance assistance. Robotic postural training re-enabled and/or largely improved the participants' ability to control steady standing, self-initiated trunk movements and upper limb reaching movements while standing with free hands, receiving only external assistance for pelvic control. These improvements were associated with neuromuscular activation pattern adaptations above and below the lesion. These findings suggest that the human spinal cord below the level of injury can generate meaningful postural responses when its excitability is modulated by scES, and can learn to improve these responses. Upright postural control improvements can enhance functional motor recovery promoted by scES after severe SCI.
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Affiliation(s)
- Enrico Rejc
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
- Department of Medicine, University of Udine, Udine, Italy
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Collin Bowersock
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Mechanical Engineering, Northern Arizona University, Flagstaff, Arizona, USA
| | - Tanvi Pisolkar
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Isirame Omofuma
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Tatiana Luna
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Moiz Khan
- Department of Radiology at BWH, Harvard Medical School, Boston, Massachusetts, USA
| | - Victor Santamaria
- Department of Physical Therapy, New York Medical College, Valhalla, New York, USA
| | - Beatrice Ugiliweneza
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
| | - Claudia A Angeli
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
| | - Gail F Forrest
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Joel Stein
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Sunil Agrawal
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Susan J Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
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Bowersock CD, Pisolkar T, Omofuma I, Luna T, Khan M, Santamaria V, Stein J, Agrawal S, Harkema SJ, Rejc E. Robotic upright stand trainer (RobUST) and postural control in individuals with spinal cord injury. J Spinal Cord Med 2023; 46:889-899. [PMID: 35532324 PMCID: PMC10653750 DOI: 10.1080/10790268.2022.2069532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
CONTEXT/OBJECTIVE Assessed feasibility and potential effectiveness of using a novel robotic upright stand trainer (RobUST) to deliver postural perturbations or provide assistance-as-needed at the trunk while individuals with spinal cord injury (SCI) performed stable standing and self-initiated trunk movements. These tasks were assessed with research participants' hands on handlebars for self-balance assistance (hands on) and with hands off (free hands). DESIGN Proof of concept study. PARTICIPANTS Four individuals with motor complete (n = 3) or incomplete (n = 1) SCI who were not able to achieve independent standing and presented a neurological lesion level ranging from cervical 4 to thoracic 2. OUTCOME MEASURES Ground reaction forces, trunk displacement, and electromyography activity of trunk and lower limb muscles. RESULTS Research participants received continuous pelvic assistance via RobUST, and manual trainer assistance at the knees to maintain standing. Participants were able to attempt all tasks. Free hands trunk perturbations resulted in greater load bearing-related sensory information (73% ipsilateral vertical loading), trunk displacement (57%), and muscle activation compared to hands on. Similarly, free hands stable standing with RobUST assistance-as-needed resulted in 8.5% larger bodyweight bearing, 112% larger trunk movement velocity, and higher trunk muscles activation compared to standing with hands on. Self-initiated trunk movements controlled by hands on showed 116% greater trunk displacement, 10% greater vertical ground reaction force, and greater ankle muscle activation compared to free hands. CONCLUSION RobUST established a safe and challenging standing environment for individuals with SCI and has the potential to improve training paradigms and assessments of standing postural control.
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Affiliation(s)
- Collin D. Bowersock
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Tanvi Pisolkar
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Isirame Omofuma
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Tatiana Luna
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Moiz Khan
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Victor Santamaria
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Joel Stein
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Sunil Agrawal
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Susan J. Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
- Frazier Rehabilitation Institute, University of Louisville Health, Louisville, Kentucky, USA
- Department of Bioengineering, University of Louisville, Louisville, Kentucky, USA
| | - Enrico Rejc
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
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Dougherty JB, Disse GD, Bridges NR, Moxon KA. Effect of spinal cord injury on neural encoding of spontaneous postural perturbations in the hindlimb sensorimotor cortex. J Neurophysiol 2021; 126:1555-1567. [PMID: 34379540 PMCID: PMC8782649 DOI: 10.1152/jn.00727.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 07/02/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022] Open
Abstract
Supraspinal signals play a significant role in compensatory responses to postural perturbations. Although the cortex is not necessary for basic postural tasks in intact animals, its role in responding to unexpected postural perturbations after spinal cord injury (SCI) has not been studied. To better understand how SCI impacts cortical encoding of postural perturbations, the activity of single neurons in the hindlimb sensorimotor cortex (HLSMC) was recorded in the rat during unexpected tilts before and after a complete midthoracic spinal transection. In a subset of animals, limb ground reaction forces were also collected. HLSMC activity was strongly modulated in response to different tilt profiles. As the velocity of the tilt increased, more information was conveyed by the HLSMC neurons about the perturbation due to increases in both the number of recruited neurons and the magnitude of their responses. SCI led to attenuated and delayed hindlimb ground reaction forces. However, HLSMC neurons remained responsive to tilts after injury but with increased latencies and decreased tuning to slower tilts. Information conveyed by cortical neurons about the tilts was therefore reduced after SCI, requiring more cells to convey the same amount of information as before the transection. Given that reorganization of the hindlimb sensorimotor cortex in response to therapy after complete midthoracic SCI is necessary for behavioral recovery, this sustained encoding of information after SCI could be a substrate for the reorganization that uses sensory information from above the lesion to control trunk muscles that permit weight-supported stepping and postural control.NEW & NOTEWORTHY The role of cortical circuits in the encoding of posture and balance is of interest for developing therapies for spinal cord injury. This work demonstrated that unexpected postural perturbations are encoded in the hindlimb sensorimotor cortex even in the absence of hindlimb sensory feedback. In fact, the hindlimb sensorimotor cortex continues to encode for postural perturbations after complete spinal transection.
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Affiliation(s)
- Jaimie B Dougherty
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania
| | - Gregory D Disse
- Department of Biomedical Engineering, University of California at Davis, Davis, California
| | - Nathaniel R Bridges
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio
| | - Karen A Moxon
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania
- Department of Biomedical Engineering, University of California at Davis, Davis, California
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Kajtaz E, Montgomery LR, McMurtry S, Howland DR, Nichols TR. Non-uniform upregulation of the autogenic stretch reflex among hindlimb extensors following lateral spinal lesion in the cat. Exp Brain Res 2021; 239:2679-2691. [PMID: 34218298 PMCID: PMC9805805 DOI: 10.1007/s00221-020-06016-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 12/09/2020] [Indexed: 01/04/2023]
Abstract
Successful propagation throughout the step cycle is contingent on adequate regulation of whole-limb stiffness by proprioceptive feedback. Following spinal cord injury (SCI), there are changes in the strength and organization of proprioceptive feedback that can result in altered joint stiffness. In this study, we measured changes in autogenic feedback of five hindlimb extensor muscles following chronic low thoracic lateral hemisection (LSH) in decerebrate cats. We present three features of the autogenic stretch reflex obtained using a mechanographic method. Stiffness was a measure of the resistance to stretch during the length change. The dynamic index documented the extent of adaptation or increase of the force response during the hold phase, and the impulse measured the integral of the response from initiation of a stretch to the return to the initial length. The changes took the form of variable and transient increases in the stiffness of vastus (VASTI) group, soleus (SOL), and flexor hallucis longus (FHL), and either increased (VASTI) or decreased adaptation (GAS and PLANT). The stiffness of the gastrocnemius group (GAS) was also variable over time but remained elevated at the final time point. An unexpected finding was that these effects were observed bilaterally. Potential reasons for this finding and possible sources of increased excitability to this muscle group are discussed.
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Affiliation(s)
- E Kajtaz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30318, USA
| | - L R Montgomery
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, The University of Louisville, Louisville, KY, USA
- Research Service, Robley Rex VA Medical Center, Louisville, KY, USA
| | - S McMurtry
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30318, USA
| | - D R Howland
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, The University of Louisville, Louisville, KY, USA
- Research Service, Robley Rex VA Medical Center, Louisville, KY, USA
| | - T Richard Nichols
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30318, USA.
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Zelenin PV, Lyalka VF, Orlovsky GN, Deliagina TG. Changes in Activity of Spinal Postural Networks at Different Time Points After Spinalization. Front Cell Neurosci 2019; 13:387. [PMID: 31496938 PMCID: PMC6712497 DOI: 10.3389/fncel.2019.00387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/06/2019] [Indexed: 11/25/2022] Open
Abstract
Postural limb reflexes (PLRs) are an essential component of postural corrections. Spinalization leads to disappearance of postural functions (including PLRs). After spinalization, spastic, incorrectly phased motor responses to postural perturbations containing oscillatory EMG bursting gradually develop, suggesting plastic changes in the spinal postural networks. Here, to reveal these plastic changes, rabbits at 3, 7, and 30 days after spinalization at T12 were decerebrated, and responses of spinal interneurons from L5 along with hindlimb muscles EMG responses to postural sensory stimuli, causing PLRs in subjects with intact spinal cord (control), were characterized. Like in control and after acute spinalization, at each of three studied time points after spinalization, neurons responding to postural sensory stimuli were found. Proportion of such neurons during 1st month after spinalization did not reach the control level, and was similar to that observed after acute spinalization. In contrast, their activity (which was significantly decreased after acute spinalization) reached the control value at 3 days after spinalization and remained close to this level during the following month. However, the processing of postural sensory signals, which was severely distorted after acute spinalization, did not recover by 30 days after injury. In addition, we found a significant enhancement of the oscillatory activity in a proportion of the examined neurons, which could contribute to generation of oscillatory EMG bursting. Motor responses to postural stimuli (which were almost absent after acute spinalization) re-appeared at 3 days after spinalization, although they were very weak, irregular, and a half of them was incorrectly phased in relation to postural stimuli. Proportion of correct and incorrect motor responses remained almost the same during the following month, but their amplitude gradually increased. Thus, spinalization triggers two processes of plastic changes in the spinal postural networks: rapid (taking days) restoration of normal activity level in spinal interneurons, and slow (taking months) recovery of motoneuronal excitability. Most likely, recovery of interneuronal activity underlies re-appearance of motor responses to postural stimuli. However, absence of recovery of normal processing of postural sensory signals and enhancement of oscillatory activity of neurons result in abnormal PLRs and loss of postural functions.
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Khan M, Luna T, Santamaria V, Omofuma I, Martelli D, Rejc E, Stein J, Harkema S, Agrawal S. Stand Trainer With Applied Forces at the Pelvis and Trunk: Response to Perturbations and Assist-As-Needed Support. IEEE Trans Neural Syst Rehabil Eng 2019; 27:1855-1864. [PMID: 31395551 DOI: 10.1109/tnsre.2019.2933381] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Functional rehabilitation of patients with spinal cord injury remains a current challenge. Training these patients to successfully stand is the first step towards restoring advanced skills such as walking. To address this need, we have developed a novel robotic stand trainer that can apply controlled forces on the trunk and the pelvis of a user, while controlling the knee angle. The stand trainer utilizes cables to apply assistive, resistive, or perturbation forces at the trunk, pelvis, and the knees, simultaneously. We have conducted a human study to validate the system. In this study, we applied multi-direction perturbation forces either at the pelvis or the trunk while assist-as-needed forces were applied to the other segment to keep balance. This study characterizes the human kinematics and measures of balance under the perturbations and assistive forces on the human body. Results shows that the level of force-field assistance (trunk or pelvis) directly affects the motion of the trunk, pelvis, and center of pressure. This provides a quantitative framework to restore balance in patients while providing assistance only when needed. This stand trainer can potentially free up therapists to attend to higher level rehabilitation goals and objectively assist patients to engage in interventions that challenge both their musculoskeletal and sensorimotor impairments.
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Wilson S, Nagel SJ, Frizon LA, Fredericks DC, DeVries-Watson NA, Gillies GT, Howard MA. The Hemisection Approach in Large Animal Models of Spinal Cord Injury: Overview of Methods and Applications. J INVEST SURG 2018; 33:240-251. [PMID: 30380340 DOI: 10.1080/08941939.2018.1492048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Introduction: Translating basic science research into a safe and effective therapy for spinal cord injury (SCI) requires suitable large animal models for testing both implantable devices and biologic approaches to better approximate human anatomy and function. Hemisection lesions, routinely used for investigational purposes in small animals, are less frequently described in large animals that might be appropriate for translational studies. Size constraints of small animals (mice and rats) limits the predictability of the findings when scaled up. Our goal is to review the status of hemisection SCI in large animals across species and time to prepare for the testing of a novel intradural spinal cord stimulation device for control of spasticity in an ovine model. Methods and Results: We surveyed the literature on hemisection in quadrupeds and nonhuman primates, and catalogued the species, protocols and outcomes of the experimental work in this field. Feline, lapine, canine, simian, porcine, ovine and bovine models were the primary focal points. There is a consistent body of literature reporting use of the hemisection approach in large animals, but with differences in surgical technique depending on the goals and nature of the individual studies. While the injuries are not always consistent, the experimental variability is generally lower than that of the contusion-based approach. In general, as the body size of the animal increases, animal care requirements and the associated costs follow. In most cases, this is inversely correlated with the number of animals used in hemisection models. Conclusions: The hemisection approach to modeling SCI is straightforward compared with other methods such as the contusive impact and enables the transection of isolated ascending and descending tracts and segment specific cell bodies. This has certain advantages in models investigating post-injury axonal regrowth. However, this approach is not generally in line with the patho-physiologies encountered in SCI patients. Even so, the ability to achieve more control over the level of injury makes it a useful adjunct to contusive and ischemic approaches, and suggests a useful role in future translational studies.
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Affiliation(s)
- S Wilson
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - S J Nagel
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, OH, USA
| | - L A Frizon
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, OH, USA
| | - D C Fredericks
- Department of Orthopedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - N A DeVries-Watson
- Department of Orthopedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - G T Gillies
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA
| | - M A Howard
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
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Zelenin PV, Lyalka VF, Hsu LJ, Orlovsky GN, Deliagina TG. Effects of acute spinalization on neurons of postural networks. Sci Rep 2016; 6:27372. [PMID: 27302149 PMCID: PMC4908393 DOI: 10.1038/srep27372] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/18/2016] [Indexed: 11/15/2022] Open
Abstract
Postural limb reflexes (PLRs) represent a substantial component of postural corrections. Spinalization results in loss of postural functions, including disappearance of PLRs. The aim of the present study was to characterize the effects of acute spinalization on two populations of spinal neurons (F and E) mediating PLRs, which we characterized previously. For this purpose, in decerebrate rabbits spinalized at T12, responses of interneurons from L5 to stimulation causing PLRs before spinalization, were recorded. The results were compared to control data obtained in our previous study. We found that spinalization affected the distribution of F- and E-neurons across the spinal grey matter, caused a significant decrease in their activity, as well as disturbances in processing of posture-related sensory inputs. A two-fold decrease in the proportion of F-neurons in the intermediate grey matter was observed. Location of populations of F- and E-neurons exhibiting significant decrease in their activity was determined. A dramatic decrease of the efficacy of sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to E-neurons was found. These changes in operation of postural networks underlie the loss of postural control after spinalization, and represent a starting point for the development of spasticity.
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Affiliation(s)
- Pavel V. Zelenin
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - Vladimir F. Lyalka
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - Li-Ju Hsu
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - Grigori N. Orlovsky
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
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Deliagina TG, Beloozerova IN, Orlovsky GN, Zelenin PV. Contribution of supraspinal systems to generation of automatic postural responses. Front Integr Neurosci 2014; 8:76. [PMID: 25324741 PMCID: PMC4181245 DOI: 10.3389/fnint.2014.00076] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/14/2014] [Indexed: 11/13/2022] Open
Abstract
Different species maintain a particular body orientation in space due to activity of the closed-loop postural control system. In this review we discuss the role of neurons of descending pathways in operation of this system as revealed in animal models of differing complexity: lower vertebrate (lamprey) and higher vertebrates (rabbit and cat). In the lamprey and quadruped mammals, the role of spinal and supraspinal mechanisms in the control of posture is different. In the lamprey, the system contains one closed-loop mechanism consisting of supraspino-spinal networks. Reticulospinal (RS) neurons play a key role in generation of postural corrections. Due to vestibular input, any deviation from the stabilized body orientation leads to activation of a specific population of RS neurons. Each of the neurons activates a specific motor synergy. Collectively, these neurons evoke the motor output necessary for the postural correction. In contrast to lampreys, postural corrections in quadrupeds are primarily based not on the vestibular input but on the somatosensory input from limb mechanoreceptors. The system contains two closed-loop mechanisms - spinal and spino-supraspinal networks, which supplement each other. Spinal networks receive somatosensory input from the limb signaling postural perturbations, and generate spinal postural limb reflexes. These reflexes are relatively weak, but in intact animals they are enhanced due to both tonic supraspinal drive and phasic supraspinal commands. Recent studies of these supraspinal influences are considered in this review. A hypothesis suggesting common principles of operation of the postural systems stabilizing body orientation in a particular plane in the lamprey and quadrupeds, that is interaction of antagonistic postural reflexes, is discussed.
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Affiliation(s)
| | | | | | - Pavel V. Zelenin
- Department of Neuroscience, Karolinska InstituteStockholm, Sweden
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Pertici V, Pin-Barre C, Felix MS, Laurin J, Brisswalter J, Decherchi P. A new method to assess weight-bearing distribution after central nervous system lesions in rats. Behav Brain Res 2014; 259:78-84. [DOI: 10.1016/j.bbr.2013.10.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/23/2013] [Accepted: 10/26/2013] [Indexed: 12/24/2022]
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Abstract
Postural limb reflexes (PLRs) represent a substantial component of the postural system responsible for stabilization of dorsal-side-up trunk orientation in quadrupeds. Spinalization causes spinal shock, that is a dramatic reduction of extensor tone and spinal reflexes, including PLRs. The goal of our study was to determine changes in activity of spinal interneurons, in particular those mediating PLRs, that is caused by spinalization. For this purpose, in decerebrate rabbits, activity of individual interneurons from L5 was recorded during stimulation causing PLRs under two conditions: (1) when neurons received supraspinal influences and (2) when these influences were temporarily abolished by a cold block of spike propagation in spinal pathways at T12 ("reversible spinalization"; RS). The effect of RS, that is a dramatic reduction of PLRs, was similar to the effect of surgical spinalization. In the examined population of interneurons (n = 199), activity of 84% of them correlated with PLRs, suggesting that they contribute to PLR generation. RS affected differently individual neurons: the mean frequency decreased in 67% of neurons, increased in 15%, and did not change in 18%. Neurons with different RS effects were differently distributed across the spinal cord: 80% of inactivated neurons were located in the intermediate area and ventral horn, whereas 50% of nonaffected neurons were located in the dorsal horn. We found a group of neurons that were coactivated with extensors during PLRs before RS and exhibited a dramatic (>80%) decrease in their activity during RS. We suggest that these neurons are responsible for reduction of extensor tone and postural reflexes during spinal shock.
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12
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Arunakul M, Tochigi Y, Goetz JE, Diestelmeier BW, Heiner AD, Rudert MJ, Fredericks DC, Brown TD, McKinley TO. Replication of chronic abnormal cartilage loading by medial meniscus destabilization for modeling osteoarthritis in the rabbit knee in vivo. J Orthop Res 2013; 31:1555-60. [PMID: 23843150 PMCID: PMC5113956 DOI: 10.1002/jor.22393] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 04/29/2013] [Indexed: 02/04/2023]
Abstract
Medial meniscus destabilization (MMD) is a surgical insult technique for modeling osteoarthritis (OA) by replicating chronic abnormal cartilage loading in animal joints in vivo. The present study aimed to characterize the immediate biomechanical effects (ex vivo) and short-term histological consequences (in vivo) of MMD in the rabbit knee. In a compressive loading test, contact stress distribution in the medial compartment was measured in eight cadaver rabbit knees, initially with all major joint structures uninjured (Baseline), after MMD, and finally after total medial meniscectomy (TMM). Similarly, the effects on sagittal joint stability were determined in an anterior-posterior drawer test. These biomechanical (ex vivo) data indicated that both MMD and TMM caused significant (p < 0.001), distinct (>1.5-fold) elevation of peak local contact stress in the medial compartment, while leaving whole-joint stability nearly unchanged. Histological consequences in vivo were assessed in a short-term (8-week) survival series of MMD or TMM (five animals for each group), and both caused moderate cartilage degeneration in the medial compartment. The MMD insult, which is feasible through posterior arthrotomy alone, is as effective as TMM for modeling injurious-level chronic abnormal cartilage loading in the rabbit knee medial compartment in vivo, while minimizing potential confounding effects from whole-joint instability.
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Affiliation(s)
- Marut Arunakul
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA, Department of Orthopaedic Surgery, Thammasat University, Pathumthani, Thailand
| | - Yuki Tochigi
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA
| | - Jessica E. Goetz
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA, Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - Bryce W. Diestelmeier
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA, Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - Anneliese D. Heiner
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA, Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - M. James Rudert
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA
| | - Douglas C. Fredericks
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA
| | - Thomas D. Brown
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA, Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - Todd O. McKinley
- Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA
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Chvatal SA, Macpherson JM, Torres-Oviedo G, Ting LH. Absence of postural muscle synergies for balance after spinal cord transection. J Neurophysiol 2013; 110:1301-10. [PMID: 23803327 DOI: 10.1152/jn.00038.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Although cats that have been spinalized can also be trained to stand and step with full weight support, directionally appropriate long-latency responses to perturbations are impaired, suggesting that these behaviors are mediated by distinct neural mechanisms. However, it remains unclear whether these responses reflect an attenuated postural response using the appropriate muscular coordination patterns for balance or are due to fundamentally different neural mechanisms such as increased muscular cocontraction or short-latency stretch responses. Here we used muscle synergy analysis on previously collected data to identify whether there are changes in the spatial organization of muscle activity for balance within an animal after spinalization. We hypothesized that the modular organization of muscle activity for balance control is disrupted by spinal cord transection. In each of four animals, muscle synergies were extracted from postural muscle activity both before and after spinalization with nonnegative matrix factorization. Muscle synergy number was reduced after spinalization in three animals and increased in one animal. However, muscle synergy structure was greatly altered after spinalization with reduced direction tuning, suggesting little consistent organization of muscle activity. Furthermore, muscle synergy recruitment was correlated to subsequent force production in the intact but not spinalized condition. Our results demonstrate that the modular structure of sensorimotor feedback responses for balance control is severely disrupted after spinalization, suggesting that the muscle synergies for balance control are not accessible by spinal circuits alone. Moreover, we demonstrate that spinal mechanisms underlying weight support are distinct from brain stem mechanisms underlying directional balance control.
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Affiliation(s)
- Stacie A Chvatal
- The Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Atlanta, Georgia; and
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Chvatal SA, Ting LH. Common muscle synergies for balance and walking. Front Comput Neurosci 2013; 7:48. [PMID: 23653605 PMCID: PMC3641709 DOI: 10.3389/fncom.2013.00048] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/08/2013] [Indexed: 01/08/2023] Open
Abstract
Little is known about the integration of neural mechanisms for balance and locomotion. Muscle synergies have been studied independently in standing balance and walking, but not compared. Here, we hypothesized that reactive balance and walking are mediated by a common set of lower-limb muscle synergies. In humans, we examined muscle activity during multidirectional support-surface perturbations during standing and walking, as well as unperturbed walking at two speeds. We show that most muscle synergies used in perturbations responses during standing were also used in perturbation responses during walking, suggesting common neural mechanisms for reactive balance across different contexts. We also show that most muscle synergies using in reactive balance were also used during unperturbed walking, suggesting that neural circuits mediating locomotion and reactive balance recruit a common set of muscle synergies to achieve task-level goals. Differences in muscle synergies across conditions reflected differences in the biomechanical demands of the tasks. For example, muscle synergies specific to walking perturbations may reflect biomechanical challenges associated with single limb stance, and muscle synergies used during sagittal balance recovery in standing but not walking were consistent with maintaining the different desired center of mass motions in standing vs. walking. Thus, muscle synergies specifying spatial organization of muscle activation patterns may define a repertoire of biomechanical subtasks available to different neural circuits governing walking and reactive balance and may be recruited based on task-level goals. Muscle synergy analysis may aid in dissociating deficits in spatial vs. temporal organization of muscle activity in motor deficits. Muscle synergy analysis may also provide a more generalizable assessment of motor function by identifying whether common modular mechanisms are impaired across the performance of multiple motor tasks.
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Affiliation(s)
- Stacie A Chvatal
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University Atlanta, GA, USA
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Lyalka VF, Hsu LJ, Karayannidou A, Zelenin PV, Orlovsky GN, Deliagina TG. Facilitation of postural limb reflexes in spinal rabbits by serotonergic agonist administration, epidural electrical stimulation, and postural training. J Neurophysiol 2011; 106:1341-54. [DOI: 10.1152/jn.00115.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In quadrupeds, spinalization in the thoracic region severely impairs postural control in the hindquarters. The goal of this study was to improve postural functions in chronic spinal rabbits by regular application of different factors: intrathecal injection of the 5-HT2 agonist (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), epidural electrical spinal cord stimulation (EES), and specific postural training (SPT). The factors were used either alone (SPT group) or in combination (DOI+SPT, EES+SPT, and DOI+EES+SPT groups) or not used (control group). It was found that in none of these groups did normal postural corrective movements in response to lateral tilts of the supporting platform reappear within the month of treatment. In control group, reduced irregular electromyographic (EMG) responses, either correctly or incorrectly phased in relation to tilts, were observed. By contrast, in DOI+SPT and EES+SPT groups, a gradual threefold increase in the proportion of correctly phased EMG responses (compared with control) was observed. The increase was smaller in DOI+EES+SPT and SPT groups. Dissimilarly to these long-term effects, short-term effects of DOI and EES were weak or absent. In addition, gradual development of oscillatory EMG activity in the responses to tilts, characteristic for the control group, was retarded in DOI+SPT, EES+SPT, DOI+EES+SPT, and SPT groups. Thus regular application of the three tested factors and their combinations caused progressive, long-lasting plastic changes in the isolated spinal networks, resulting in the facilitation of spinal postural reflexes and in the retardation of the development of oscillatory EMG activity. The facilitated reflexes, however, were insufficient for normal postural functions.
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Affiliation(s)
- V. F. Lyalka
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - L.-J. Hsu
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - A. Karayannidou
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - P. V. Zelenin
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - G. N. Orlovsky
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - T. G. Deliagina
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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Musienko PE, Zelenin PV, Orlovsky GN, Deliagina TG. Facilitation of postural limb reflexes with epidural stimulation in spinal rabbits. J Neurophysiol 2010; 103:1080-92. [PMID: 20018835 PMCID: PMC2822695 DOI: 10.1152/jn.00575.2009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 12/16/2009] [Indexed: 11/22/2022] Open
Abstract
It is known that after spinalization animals lose their ability to maintain lateral stability when standing or walking. A likely reason for this is a reduction of the postural limb reflexes (PLRs) driven by stretch and load receptors of the limbs. The aim of this study was to clarify whether spinal networks contribute to the generation of PLRs. For this purpose, first, PLRs were recorded in decerebrated rabbits before and after spinalization at T12. Second, the effects of epidural electrical stimulation (EES) at L7 on the limb reflexes were studied after spinalization. To evoke PLRs, the vertebrate column of the rabbit was fixed, whereas the hindlimbs were positioned on the platform. Periodic lateral tilts of the platform caused antiphase flexion-extension limbs movements, similar to those observed in intact animals keeping balance on the tilting platform. Before spinalization, these movements evoked PLRs: augmentation of extensor EMGs and increase of contact force during limb flexion, suggesting their stabilizing postural effects. Spinalization resulted in almost complete disappearance of PLRs. After EES, however, the PLRs reappeared and persisted for up to several minutes, although their values were reduced. The post-EES effects could be magnified by intrathecal application of quipazine (5-HT agonist) at L4-L6. Results of this study suggest that the spinal cord contains the neuronal networks underlying PLRs; they can contribute to the maintenance of lateral stability in intact subjects. In acute spinal animals, these networks can be activated by EES, suggesting that they are normally activated by a tonic supraspinal drive.
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Affiliation(s)
- P. E. Musienko
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
- Pavlov Institute of Physiology, St. Petersburg, Russia
| | - P. V. Zelenin
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
| | - G. N. Orlovsky
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
| | - T. G. Deliagina
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
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Boulenguez P, Vinay L. Strategies to restore motor functions after spinal cord injury. Curr Opin Neurobiol 2009; 19:587-600. [PMID: 19896827 DOI: 10.1016/j.conb.2009.10.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 09/23/2009] [Accepted: 10/12/2009] [Indexed: 12/20/2022]
Abstract
This review presents recent advances in the development of strategies to restore posture and locomotion after spinal cord injury (SCI). A set of strategies focusing on the lesion site includes prevention of secondary damages, promotion of axonal sprouting/regeneration, and replacement of lost cells. Other strategies focus on spinal central pattern generators (CPGs). Training promotes functional recovery by enhancing the plasticity of CPGs and these sublesional networks can be reactivated by means of pharmacological or electrical stimulation. It is now clear that substantial functional recovery will require a combination of strategies adapted to each phase following SCI. Finally, improvements in the understanding of the mechanisms underlying spasticity may lead to new treatments of this disabling complication affecting patients with SCI.
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Affiliation(s)
- Pascale Boulenguez
- Laboratoire Plasticité et Physio-Pathologie de Motricité (UMR6196), Centre National de Recherche Scientifique (CNRS) & Aix-Marseille Université, CNRS, 31 chemin Joseph Aiguier, F-13402 Marseille cx 20, France
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