scholarly journals Progress towards regenerating the corticospinal tract after spinal cord injury

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Oswald Steward
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Corticospinal Tract ◽  
Cord Injury

A critical reappraisal of corticospinal tract somatotopy and its role in traumatic cervical spinal cord syndromes

2021 ◽  
pp. 1-7
Author(s):  
Allan D. Levi ◽  
Jan M. Schwab
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Upper Extremity ◽  
Corticospinal Tract ◽  
Cervical Spinal Cord ◽  
Hand Function ◽  
Cervical Spinal Cord Injury ◽  
Pathophysiological Mechanism ◽  
Cord Injury ◽  
Central Cord Syndrome

The corticospinal tract (CST) is the preeminent voluntary motor pathway that controls human movements. Consequently, long-standing interest has focused on CST location and function in order to understand both loss and recovery of neurological function after incomplete cervical spinal cord injury, such as traumatic central cord syndrome. The hallmark clinical finding is paresis of the hands and upper-extremity function with retention of lower-extremity movements, which has been attributed to injury and the sparing of specific CST fibers. In contrast to historical concepts that proposed somatotopic (laminar) CST organization, the current narrative summarizes the accumulated evidence that 1) there is no somatotopic organization of the corticospinal tract within the spinal cord in humans and 2) the CST is critically important for hand function. The evidence includes data from 1) tract-tracing studies of the central nervous system and in vivo MRI studies of both humans and nonhuman primates, 2) selective ablative studies of the CST in primates, 3) evolutionary assessments of the CST in mammals, and 4) neuropathological examinations of patients after incomplete cervical spinal cord injury involving the CST and prominent arm and hand dysfunction. Acute traumatic central cord syndrome is characterized by prominent upper-extremity dysfunction, which has been falsely predicated on pinpoint injury to an assumed CST layer that specifically innervates the hand muscles. Given the evidence surveyed herein, the pathophysiological mechanism is most likely related to diffuse injury to the CST that plays a critically important role in hand function.

Lack of adenylate cyclase 1 (AC1): Consequences on corticospinal tract development and on locomotor recovery after spinal cord injury

2014 ◽  
Vol 1549 ◽  
pp. 1-10 ◽  
Author(s):  
H. Nait Taleb Ali ◽  
M.P. Morel ◽  
M. Doulazmi ◽  
S. Scotto-Lomassese ◽  
P. Gaspar ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Adenylate Cyclase ◽  
Corticospinal Tract ◽  
Locomotor Recovery ◽  
Cord Injury

scholarly journals Segmental analysis in cervical spinal cord injury reveals the recovery potential of hand muscles with preserved corticospinal tract: Insights beyond impairment scales

2021 ◽  
Author(s):  
Gustavo Balbinot ◽  
Guijin Li ◽  
Sukhvinder Kalsi-Ryan ◽  
Rainer Abel ◽  
Doris Maier ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Muscle Strength ◽  
Evoked Potentials ◽  
Corticospinal Tract ◽  
Cervical Spinal Cord ◽  
Hand Muscles ◽  
Recovery Potential ◽  
Strength Recovery ◽  
Cord Injury

Cervical spinal cord injury (SCI) severely impacts widespread bodily functions with extensive impairments for individuals, who prioritize regaining hand function. Although prior work has focused on the recovery at the person-level, the factors determining the recovery potential of individual muscles are poorly understood. There is a need for changing this paradigm in the field by moving beyond person-level classification of residual strength and sacral sparing to a muscle-specific analysis with a focus on the role of corticospinal tract (CST) sparing. The most striking part of human evolution involved the development of dextrous hand use with a respective expansion of the sensorimotor cortex controlling hand movements, which, because of the extensive CST projections, may constitute a drawback after SCI. Here, we investigated the muscle-specific natural recovery after cervical SCI in 748 patients from the European Multicenter Study about SCI (EMSCI), one of the largest datasets analysed to date. All participants were assessed within the first 4 weeks after SCI and re-assessed at 12, 24, and 48 weeks. Subsets of individuals underwent electrophysiological multimodal evaluations to discern CST and lower motor neuron (LMN) integrity [motor evoked potentials (MEP): N = 203; somatosensory evoked potentials (SSEP): N = 313; nerve conduction studies (NCS): N = 280]. We show the first evidence of the importance of CST sparing for proportional recovery in SCI, which is known in stroke survivors to represent the biological limits of structural and functional plasticity. In AIS D, baseline strength is a good predictor of segmental muscle strength recovery, while the proportionality in relation to baseline strength is lower for AIS B/C and breaks for AIS A. More severely impaired individuals showed non-linear and more variable recovery profiles, especially for hand muscles, while measures of CST sparing (by means of MEP) improved the prediction of hand muscle strength recovery. Therefore, assessment strategies for muscle-specific motor recovery in acute SCI improve by accounting for CST sparing and complement gross person-level predictions. The latter is of paramount importance for clinical trial outcomes and to target neurorehabilitation of upper limb function, where any single muscle function impacts the outcome of independence in cervical SCI.

scholarly journals Reorganization of corticospinal tract fibers after spinal cord injury in adult macaques

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Hiroshi Nakagawa ◽  
Taihei Ninomiya ◽  
Toshihide Yamashita ◽  
Masahiko Takada
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Corticospinal Tract ◽  
Cord Injury

scholarly journals Pten Deletion Promotes Regrowth of Corticospinal Tract Axons 1 Year after Spinal Cord Injury

2015 ◽  
Vol 35 (26) ◽  
pp. 9754-9763 ◽  
Author(s):  
K. Du ◽  
S. Zheng ◽  
Q. Zhang ◽  
S. Li ◽  
X. Gao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Corticospinal Tract ◽  
Cord Injury ◽  
Pten Deletion

Increases in Corticospinal Tract Function by Treadmill Training After Incomplete Spinal Cord Injury

2005 ◽  
Vol 94 (4) ◽  
pp. 2844-2855 ◽  
Author(s):  
Sarah L. Thomas ◽  
Monica A. Gorassini
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Corticospinal Tract ◽  
Emg Activity ◽  
Percentage Increase ◽  
Sigmoid Function ◽  
Locomotor Recovery ◽  
Recruitment Curve ◽  
Intensive Training ◽  
Cord Injury

In this study, we examined if several months of intensive locomotor training increases the function of spared corticospinal tract pathways after chronic spinal cord injury (SCI) in association with the recovery of locomotor function. Transcranial magnetic stimulation (TMS) at incrementing levels of intensity was applied over the motor cortex supplying either the tibialis anterior or vastus lateralis muscles, and the resulting peak-to-peak amplitude of the motor-evoked potentials (MEPs) were measured to obtain a recruitment curve both before and after training. In the majority of subjects (7/8), 3–5 mo of daily intensive training increased the responses to TMS in at least one of the leg muscles tested (9/13). On average, across all muscles tested MEPmax, which was evoked at high stimulation intensities, increased by 46% and MEPh, which was evoked at intermediate stimulation intensities, increased by 45% (both significantly different from 0), indicating an increase in corticospinal tract connectivity from training. The slope of the sigmoid function fit to the recruitment curve increased by 24% after training (significantly different), indicating an expansion and/or increased excitability of corticospinal circuits supplying muscles to the lower leg. We also observed that the average duration of the silent period measured at MEPmax increased after training from 130 to 178 ms, suggesting that training had effects on cortical circuits thought to mediate this long-lasting inhibition. The percentage increase in MEPmax was positively and significantly correlated to the degree of locomotor recovery as assessed by the WISCI II score, the distance a subject could walk in 6 min, and the amplitude of the locomotor EMG activity, suggesting that the corticospinal tract, in part, mediated the functional locomotor recovery produced from training.

*Poster 43: Gait Deficits Due to Impairment of the Corticospinal Tract in Persons With Incomplete Spinal Cord Injury

2010 ◽  
Vol 91 (10) ◽  
pp. e18
Author(s):  
Dorothy Barthelemy ◽  
Maria Willerslev-Olsen ◽  
Henrik Lundell ◽  
Bernard Conway ◽  
Hanna Knudsen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Corticospinal Tract ◽  
Incomplete Spinal Cord Injury ◽  
Cord Injury
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