Spinal neuronal dysfunction after deprivation of supraspinal input

2015 ◽  
pp. 67-75
Author(s):  
Michèle Hubli ◽  
Volker Dietz
Keyword(s):  
Spinal Cord ◽  
Spinal Reflexes ◽  
Emg Activity ◽  
Neuronal Dysfunction ◽  
Sensory Cues ◽  
Neuronal Function ◽  
Chronic Stage ◽  
Leg Muscles ◽  
Cord Injury ◽  
Locomotor Ability

The comprehension of basic spinal neuronal alterations after central nervous system lesions, such as spinal cord injury (SCI) or stroke, enables us to optimize rehabilitative approaches for affected subjects. Adverse changes in spinal neuronal function are best investigated by recordings of spinal reflexes (SR) and locomotor electromyography (EMG). In the first few weeks after an SCI, neither locomotor nor SR activity can be evoked. Once spinal shock has resolved, an early SR component can be re-evoked and locomotor EMG activity reappears in response to appropriate peripheral input. In a more chronic stage of SCI, however, alterations in SR components are accompanied by a decline of EMG amplitude in the leg muscles during assisted locomotion. It is assumed that not only the deprivation of supraspinal input but also of the lack of meaningful proprioceptive input to spinal neuronal networks account for such alterations in chronic immobilized individuals with SCI..A critical combination of sensory cues through appropriate training strategies seems to prevent the development of spinal neuronal dysfunction and to improve locomotor ability.

Spinal neuronal dysfunction after deprivation of supraspinal input

2020 ◽  
pp. 83-94
Author(s):  
Michèle Hubli ◽  
Volker Dietz
Keyword(s):  
Neural Plasticity ◽  
Neuronal Networks ◽  
Spinal Reflex ◽  
Emg Activity ◽  
Sensory Cues ◽  
Chronic Stage ◽  
Functional Changes ◽  
Leg Muscles ◽  
Proprioceptive Input ◽  
Cord Injury

A central nervous system lesion can lead to remote structural and functional changes which may limit functional recovery. For example, after a spinal cord injury (SCI) structural and functional alterations of spinal neuronal networks take place: in the first weeks after an SCI, neither locomotor nor spinal reflex (SR) activity can be evoked. Once spinal shock has resolved, an early SR component can be re-evoked and locomotor electromyography (EMG) activity re-appears when appropriate proprioceptive input is provided. In a more chronic stage of SCI alterations in SR components are accompanied by a decline of EMG amplitude in the leg muscles during assisted locomotion. According to rodent experiments it is assumed that the deprivation of supraspinal input and the lack of meaningful proprioceptive input to spinal neuronal networks account for such alterations. A critical combination of sensory cues through physiological training strategies might prevent the development of an undirected neural plasticity.

Influence of severity and level of injury on the occurrence of complications during the subacute and chronic stage of traumatic spinal cord injury: a systematic review

2021 ◽  
pp. 1-21
Author(s):  
Charlotte Y. Adegeest ◽  
Jort A. N. van Gent ◽  
Janneke M. Stolwijk-Swüste ◽  
Marcel W. M. Post ◽  
William P. Vandertop ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Injury ◽  
Chronic Phase ◽  
Autonomic Dysreflexia ◽  
Traumatic Spinal Cord Injury ◽  
Chronic Stage ◽  
Increased Risk ◽  
Cord Injury ◽  
Meta Analyses

OBJECTIVE Secondary health conditions (SHCs) are long-term complications that frequently occur due to traumatic spinal cord injury (tSCI) and can negatively affect quality of life in this patient population. This study provides an overview of the associations between the severity and level of injury and the occurrence of SHCs in tSCI. METHODS A systematic search was conducted in PubMed and Embase that retrieved 44 studies on the influence of severity and/or level of injury on the occurrence of SHCs in the subacute and chronic phase of tSCI (from 3 months after trauma). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. RESULTS In the majority of studies, patients with motor-complete tSCI (American Spinal Injury Association [ASIA] Impairment Scale [AIS] grade A or B) had a significantly increased occurrence of SHCs in comparison to patients with motor-incomplete tSCI (AIS grade C or D), such as respiratory and urogenital complications, musculoskeletal disorders, pressure ulcers, and autonomic dysreflexia. In contrast, an increased prevalence of pain was seen in patients with motor-incomplete injuries. In addition, higher rates of pulmonary infections, spasticity, and autonomic dysreflexia were observed in patients with tetraplegia. Patients with paraplegia more commonly suffered from hypertension, venous thromboembolism, and pain. CONCLUSIONS This review suggests that patients with a motor-complete tSCI have an increased risk of developing SHCs during the subacute and chronic stage of tSCI in comparison with patients with motor-incomplete tSCI. Future studies should examine whether systematic monitoring during rehabilitation and the subacute and chronic phase in patients with motor-complete tSCI could lead to early detection and potential prevention of SHCs in this population.

Time-dependent progression of neurogenic lower urinary tract dysfunction after spinal cord injury in the mouse model

2021 ◽  
Author(s):  
Tetsuichi Saito ◽  
Daisuke Gotoh ◽  
Naoki Wada ◽  
Pradeep Tyagi ◽  
Tomonori Minagawa ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Time Course ◽  
Time Dependent ◽  
Lower Urinary Tract Dysfunction ◽  
Emg Activity ◽  
Mrna Levels ◽  
Mechanosensitive Channels ◽  
Reduction Time ◽  
Cord Injury

This study evaluated the time-course changes in bladder and external urinary sphincter (EUS) activity as well as the expression of mechanosensitive channels in lumbosacral dorsal root ganglia (DRG) after spinal cord injury (SCI). Female C57BL/6N mice in the SCI group underwent transection of the Th8/9 spinal cord. Spinal intact mice and SCI mice at 2, 4 and 6 weeks post SCI were evaluated by single-filling cystometry and EUS-electromyography (EMG). In another set of mice, the bladder and L6-S1 DRG were harvested for protein and mRNA analyses. In SCI mice, non-voiding contractions was confirmed at 2 weeks post-SCI, and did not increase over time to 6 weeks. In 2-weeks SCI mice, EUS-EMG measurements revealed detrusor-sphincter dyssynergia (DSD), but periodic EMG reductions during bladder contraction were hardly observed. At 4 weeks, SCI mice showed increases of EMG activity reduction time with increased voiding efficiency (VE). At 6 weeks, SCI mice exhibited a further increase in EMG reduction time. RT-PCR of L6-S1 DRG showed increased mRNA levels of TRPV1 and ASIC1-3 in SCI mice with a decrease of ASIC2-3 at 6 weeks compared to 4 weeks whereas Piezo2 showed a slow increase at 6 weeks. Protein assay showed the SCI-induced overexpression of bladder BDNF with a time-dependent decrease post SCI. These results indicate that detrusor overactivity is established in the early phase whereas DSD is completed later at 4 weeks with an improvement at 6 weeks post SCI, and that mechanosensitive channels may be involved in the time-dependent changes.

scholarly journals Effects of a Contusive Spinal Cord Injury on Spinal Motor Neuron Activity and Conduction Time in Rats

2020 ◽  
Author(s):  
Jordan A. Borrell ◽  
Dora Krizsan-Agbas ◽  
Randolph J. Nudo ◽  
Shawn B. Frost
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spike Activity ◽  
Short Latency ◽  
Neuron Activity ◽  
Emg Activity ◽  
Conduction Time ◽  
Dorsal Midline ◽  
Cord Injury ◽  
Contusion Injury

AbstractObjectiveThe purpose of this study was to determine the effects of spinal cord injury (SCI) on spike activity evoked in the hindlimb spinal cord of the rat from cortical electrical stimulation.ApproachAdult, male, Sprague Dawley rats were randomly assigned to a Healthy or SCI group. SCI rats were given a 175 kDyn dorsal midline contusion injury at the level of the T8 vertebrae. At four weeks post-SCI, intracortical microstimulation (ICMS) was delivered at several sites in the hindlimb motor cortex of anesthetized rats, and evoked neural activity was recorded from corresponding sites throughout the dorsoventral depths of the spinal cord and EMG activity from hindlimb muscles.Main resultsIn healthy rats, post-ICMS spike histograms showed reliable, evoked spike activity during a short-latency epoch 10-12 ms after the initiation of the ICMS pulse train (short). Longer latency spikes occurred between ~20-60 ms, generally following a Gaussian distribution, rising above baseline at time LON, followed by a peak response (Lp), and then falling below baseline at time LOFF. EMG responses occurred between LON and Lp (25-27 ms). In SCI rats, short-latency responses were still present, long-latency responses were disrupted or eliminated, and EMG responses were never evoked. The retention of the short-latency responses indicates that spared descending spinal fibers, most likely via the cortico-reticulospinal pathway, can still depolarize spinal cord motor neurons after a dorsal midline contusion injury.SignificanceThis study provides novel insights into the role of alternate pathways for voluntary control of hindlimb movements after SCI that disrupts the corticospinal tract in the rat.

scholarly journals Effect of cervicolumbar coupling on spinal reflexes during cycling after incomplete spinal cord injury

2018 ◽  
Vol 120 (6) ◽  
pp. 3172-3186 ◽  
Author(s):  
R. Zhou ◽  
B. Parhizi ◽  
J. Assh ◽  
L. Alvarado ◽  
R. Ogilvie ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
H Reflex ◽  
Spinal Reflexes ◽  
Incomplete Spinal Cord Injury ◽  
Reflex Amplitude ◽  
Arm Cycling ◽  
Cord Injury ◽  
Leg Cycling ◽  
Cycling Training

Spinal networks in the cervical and lumbar cord are actively coupled during locomotion to coordinate arm and leg activity. The goals of this project were to investigate the intersegmental cervicolumbar connectivity during cycling after incomplete spinal cord injury (iSCI) and to assess the effect of rehabilitation training on improving reflex modulation mediated by cervicolumbar pathways. Two studies were conducted. In the first, 22 neurologically intact (NI) people and 10 people with chronic iSCI were recruited. The change in H-reflex amplitude in flexor carpi radialis (FCR) during leg cycling and H-reflex amplitude in soleus (SOL) during arm cycling were investigated. In the second study, two groups of participants with chronic iSCI underwent 12 wk of cycling training: one performed combined arm and leg cycling (A&L) and the other legs only cycling (Leg). The effect of training paradigm on the amplitude of the SOL H-reflex was assessed. Significant reduction in the amplitude of both FCR and SOL H-reflexes during dynamic cycling of the opposite limbs was found in NI participants but not in participants with iSCI. Nonetheless, there was a significant reduction in the SOL H-reflex during dynamic arm cycling in iSCI participants after training. Substantial improvements in SOL H-reflex properties were found in the A&L group after training. The results demonstrate that cervicolumbar modulation during rhythmic movements is disrupted in people with chronic iSCI; however, this modulation is restored after cycling training. Furthermore, involvement of the arms simultaneously with the legs during training may better regulate the leg spinal reflexes.NEW & NOTEWORTHY This work systematically demonstrates the disruptive effect of incomplete spinal cord injury on cervicolumbar coupling during rhythmic locomotor movements. It also shows that the impaired cervicolumbar coupling could be significantly restored after cycling training. Actively engaging the arms in rehabilitation paradigms for the improvement of walking substantially regulates the excitability of the lumbar spinal networks. The resulting regulation may be better than that obtained by interventions that focus on training of the legs only.

scholarly journals Limits of locomotor ability in subjects with a spinal cord injury

Spinal Cord ◽  
2005 ◽  
Vol 43 (10) ◽  
pp. 593-603 ◽  
Author(s):  
H J A van Hedel ◽  
B Wirth ◽  
V Dietz
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cord Injury ◽  
Locomotor Ability

scholarly journals Undirected compensatory plasticity contributes to neuronal dysfunction after severe spinal cord injury

Brain ◽  
2013 ◽  
Vol 136 (11) ◽  
pp. 3347-3361 ◽  
Author(s):  
Janine Beauparlant ◽  
Rubia van den Brand ◽  
Quentin Barraud ◽  
Lucia Friedli ◽  
Pavel Musienko ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuronal Dysfunction ◽  
Cord Injury ◽  
Compensatory Plasticity

scholarly journals Altered modulation of sensorimotor rhythms with chronic paralysis

2017 ◽  
Vol 118 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Stephen T. Foldes ◽  
Douglas J. Weber ◽  
Jennifer L. Collinger
Keyword(s):  
Spinal Cord ◽  
Motor Imagery ◽  
Muscle Activity ◽  
Cervical Spinal Cord ◽  
The Other ◽  
Emg Activity ◽  
Cortical Oscillations ◽  
Cord Injury ◽  
Intact Muscle ◽  
Sensorimotor Rhythms

After paralysis, the disconnection between the cortex and its peripheral targets leads to neuroplasticity throughout the nervous system. However, it is unclear how chronic paralysis specifically impacts cortical oscillations associated with attempted movement of impaired limbs. We hypothesized that μ- (8–13 Hz) and β- (15–30 Hz) event-related desynchronization (ERD) would be less modulated for individuals with hand paralysis due to cervical spinal cord injury (SCI). To test this, we compared the modulation of ERD from magnetoencephalography (MEG) during attempted and imagined grasping performed by participants with cervical SCI ( n = 12) and able-bodied controls ( n = 13). Seven participants with tetraplegia were able to generate some electromyography (EMG) activity during attempted grasping, whereas the other five were not. The peak and area of ERD were significantly decreased for individuals without volitional muscle activity when they attempted to grasp compared with able-bodied subjects and participants with SCI,with some residual EMG activity. However, no significant differences were found between subject groups during mentally simulated tasks (i.e., motor imagery) where no muscle activity or somatosensory consequences were expected. These findings suggest that individuals who are unable to produce muscle activity are capable of generating ERD when attempting to move, but the characteristics of this ERD are altered. However, for people who maintain volitional muscle activity after SCI, there are no significant differences in ERD characteristics compared with able-bodied controls. These results provide evidence that ERD is dependent on the level of intact muscle activity after SCI. NEW & NOTEWORTHY Source space MEG was used to investigate sensorimotor cortical oscillations in individuals with SCI. This study provides evidence that individuals with cervical SCI exhibit decreased ERD when they attempt to grasp if they are incapable of generating muscle activity. However, there were no significant differences in ERD between paralyzed and able-bodied participants during motor imagery. These results have important implications for the design and evaluation of new therapies, such as motor imagery and neurofeedback interventions.

scholarly journals Changes in Locomotor Muscle Activity After Treadmill Training in Subjects With Incomplete Spinal Cord Injury

2009 ◽  
Vol 101 (2) ◽  
pp. 969-979 ◽  
Author(s):  
Monica A. Gorassini ◽  
Jonathan A. Norton ◽  
Jennifer Nevett-Duchcherer ◽  
Francois D. Roy ◽  
Jaynie F. Yang
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Treadmill Training ◽  
Emg Activity ◽  
Incomplete Spinal Cord Injury ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Cord Injury

Intensive treadmill training after incomplete spinal cord injury can improve functional walking abilities. To determine the changes in muscle activation patterns that are associated with improvements in walking, we measured the electromyography (EMG) of leg muscles in 17 individuals with incomplete spinal cord injury during similar walking conditions both before and after training. Specific differences were observed between subjects that eventually gained functional improvements in overground walking (responders), compared with subjects where treadmill training was ineffective (nonresponders). Although both groups developed a more regular and less clonic EMG pattern on the treadmill, it was only the tibialis anterior and hamstring muscles in the responders that displayed increases in EMG activation. Likewise, only the responders demonstrated decreases in burst duration and cocontraction of proximal (hamstrings and quadriceps) muscle activity. Surprisingly, the proximal muscle activity in the responders, unlike nonresponders, was three- to fourfold greater than that in uninjured control subjects walking at similar speeds and level of body weight support, suggesting that the ability to modify muscle activation patterns after injury may predict the ability of subjects to further compensate in response to motor training. In summary, increases in the amount and decreases in the duration of EMG activity of specific muscles are associated with functional recovery of walking skills after treadmill training in subjects that are able to modify muscle activity patterns following incomplete spinal cord injury.

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